Coated substrate dunnage, self-caking coated substrate dunnage particles, and methods of making same

Abstract

A self-caking coated substrate dunnage composed of self-caking coated substrate dunnage particles, each particle being made of an inner substrate around which a particulate modified starch caking agent is agglomerated, forming an outer coating of the modified starch caking agent around the substrate. The coating has an inner self-adhering region adhering to the substrate and an outer region of the caking agent surrounding the inner region, the outer region defining an outer surface of each particle, the outer surface having absorption-enhanced microcracks and minute raised protrusions, including spikes, formed in and on the surface. The coating has a first single moisture activated moisture curing binder and a second moisture reactivated moisture recuring binder, both formed from starch that is modified during ultra-high pressure extrusion using a single screw extruder. In the process of preparation, a suitable agglomeration process comprises a substrate water wetting process in which substrate particulates are wetted with water, a powdered caking agent is applied, and the wetted mixture is tumbled until a circular low scatter agglomerated dunnage particle is obtained. Another suitable agglomerating method includes applying an agglomerating agent slurry onto substrate particulates while rolling until a circular low scatter agglomerated dunnage particle is obtained.

Description

Field of the Invention

[0001] The present invention generally relates to adsorbents, particularly animal litter, and more particularly to clumping animal litter or self-clumping animal litter that clumps when wetted. The present invention even further relates to self-clumping litter composed of litter particles formed from a substrate at least partially covered or coated with an adsorbent clumping material containing cold water-swellable water-absorbing starch and a cold water-soluble binder, which self-clump together when the litter particles are wetted, and to a method for its preparation. Background Art

[0002] In the past, others have made numerous attempts to develop low-cost cat litter using granular or pelleted materials that do not self-clump. The original non-clumping litters were products similar to a sandbox for play, as sand was cheap and readily available. Then came calcium-based bentonite litters, which absorb urine when a cat urinates but also do not clump. When a cat soils this non-clumping litter, the soiled litter is typically simply covered or covered with additional non-clumping litter. These types of non-clumping litters are not only inefficient but are actually more costly to use. This is because it is not uncommon for an entire box of litter to become contaminated, smelly, and unusable after just one day of use by a single cat, and sometimes even after just one use by the cat.

[0003] This led to the development of sodium-based bentonite clumping litters that absorb urine and liquid fecal matter. When soiled by a cat, the sodium-based bentonite litter has excellent clumping properties, which allows the soiled litter clumps to be easily removed from the non-soiled litter simply by using a perforated litter scoop with a handle. At the same time, due to its clumping ability, the improvement of the clumping litter has led to an increased clump retention rate. The sodium-based bentonite clumping litter has been the gold standard for years. The clump retention rate is a measure of the degree to which the litter clumps stay together after a predetermined height drop, typically from about 12 inches to 18 inches, in a drop test, and is used to measure the amount of the original clumps of soiled litter that stay together or are retained during removal from the non-contaminated litter in the litter box. A litter with a clump retention rate of over 90% is considered a good litter, meaning that at least 90% of the clumps stay together after the predetermined drop test height drop. A litter with a clump retention rate of at least 96% is considered a good litter. Additionally, the sodium-based bentonite litter has a clump retention rate of at least 99%, which is now the gold standard for all litter types.

[0004] Unfortunately, sodium bentonite is very dusty, and the amount of cleaning required in and around the litter box increases when using sodium bentonite litter. After mining, sodium bentonite used for clumping litter is usually minimally processed, except for being crushed into relatively small-sized particles to enhance clumping. Since sodium bentonite is a friable material with many impurities, which can include sand, limestone, sodium chloride, calcium chloride, magnesium chloride, potassium chloride, ammonium chloride, calcium carbonate, magnesium carbonate, calcium sulfate, sodium sulfate, sodium nitrate, ferrous sulfate, and other organic and inorganic contaminants, depending on its mining location, these litter particles are dusty. Due to its friability, the particles of sodium bentonite litter rub against each other during packaging, transportation to retailers, and handling by retailers, generating tiny powdery dust particles. When the litter is poured into the litter box and clumps are scooped out of the litter box, the dust spreads in the air, and consumers and cats are unfortunately exposed to the dust. The dust from sodium bentonite not only adheres to the litter box, floor, and surrounding walls, but also to the fur of the cats using the litter box, causing them to need to groom more frequently to remove the dust.

[0005] Sold sodium bentonite is also heavy, as its bulk density is typically 54 pounds per cubic foot to 72 pounds per cubic foot. Due to its weight, the cost of transporting sodium bentonite from the mine to the litter manufacturing plant is very high. Sodium bentonite is crushed into smaller-sized litter particles at the litter manufacturing plant and packaged in bags, cans, and other types of containers for consumer use. Its considerable weight also makes the cost of transporting sodium bentonite litter to stores and consumers' homes across the country very high. And due to its weight, it is difficult for consumers to lift the container of litter and take it home from the store and to lift and pour it into the litter box during actual use.

[0006] To reduce the weight and cost of the litter, litter manufacturers have introduced multi-component litter blends to the market, in which sodium bentonite litter particles are blended with one or more other types of litter particles that are lighter in weight, cheaper to transport, and also cheaper as a source of raw material. Examples of such mixed multi-component sodium bentonite litters include litters containing sodium bentonite with calcium bentonite particles, ground or crushed perlite particles, pellets or granules of compressed, crushed, milled, or ground organic materials that typically have a high cellulose content, and multi-component sodium bentonite litter blends containing sodium bentonite particles and particles, pellets, or granules of two or three other types of non-sodium bentonite litter components. However, almost all of these multi-component litters made with sodium bentonite not only have many, if not most, of the same drawbacks as litters made only with sodium bentonite, but they also generally fail to clump.

[0007] Newer, lighter products are now replacing sodium bentonite litter in the retail market. Natural litters derived from distillers dried grain are early products, but they even have difficulty meeting the 90% clumping retention standard. Although the applicant's new extruded grain litter even exceeds the best clumping sodium bentonite-based litters and has thus achieved considerable commercial success in the market, there is still a need to improve clumping litters.

[0008] For example, what is needed is a litter that supplements extruded grain litter and that also clumps when wetted and that not only outperforms many sodium bentonite litters and sodium bentonite multi-component litters still prevalent in the market, but also has and preferably even improves one or more desired properties and characteristics of the applicant's own commercially successful extruded grain litter.

[0009] Litter tracking is also a problem these days because not only is it desirable to prevent litter from flowing out of the litter box, but first and foremost it is desirable to prevent litter from sticking to and even accumulating on cat claws. Tracking depends on cat claw moisture and litter moisture in the litter box. The shape of the litter particles or pellets. Since cat claws have hair and sweat glands between the paw pads, litter particles or pellets can get stuck in the hair between the paw pads. When small particles invade between the paw pads, the hair pushes them back like a spring, often causing the small particles to be trapped by the hair. Especially when a cat sweats, small dust particles get tangled in the hair between the cat's paw pads. Sometimes, the litter particles accumulated in the hair between the paw pads of the cat's claws become so large and / or deep that it becomes painful or distressing when the cat walks, which may and often requires a veterinarian to remove the litter particles tangled in the hair between the paw pads.

[0010] There is also a need for a litter with low tracking characteristics that prevents litter from sticking to cat claws during litter box use. SUMMARY OF THE INVENTION

[0011] The present invention relates to a self-clumping adsorbent granular litter and a method for preparing a self-clumping adsorbent granular litter, the self-clumping adsorbent granular litter being composed of self-clumping adsorbent litter particles, the self-clumping adsorbent litter particles including integrally rounded self-clumping adsorbent-coated substrate litter particles. Each integrally rounded self-clumping adsorbent-coated substrate litter particle has a coating on the integrally rounded outer surface that at least partially and preferably substantially completely fills minute water-absorbing enhancing protrusions such as spikes that protrude from the outer surface of the particle during agglomeration. The outer surface of the coating of each integrally rounded self-clumping adsorbent-coated substrate litter particle is also configured with a large number of water-absorbing enhancing microcracks that are formed on the outer surface during curing after agglomeration and during drying after curing after agglomeration.

[0012] Each coated substrate litter particle is formed from an internal substrate in the form of a litter particle nucleating substrate particle and an external modified starch water-absorbing caking agent configured to absorb water or urine during litter use, agglomeration, and self-caking into a shovellable wet litter particle mass, the wet litter particle mass including at least multiple pairs of coated substrate litter particles, the litter particles being shovellable using a handled porous litter shovel and having a mass retention rate of at least 95%, preferably at least 97%, more preferably at least 99% when dried and a mass crush strength of at least 40 pounds per square inch (PSI), preferably at least 60 PSI, more preferably 80 PSI, even more preferably 100 PSI. In a preferred embodiment of the self-caking absorbent coated substrate litter particle of the present invention, each coated substrate litter particle of the present invention has an outer coating of a modified starch water-absorbing caking agent that adhesively self-adheres to the outer surface of the internal substrate particle through an internal self-adhesive region using the agglomeration method of the present invention discussed in more detail below.

[0013] In a preferred embodiment, at least 20%, preferably at least 30%, and more preferably at least a majority, i.e., at least 50%, of the litter weight of the self-caking litter according to the present invention is composed of the self-caking absorbent coated substrate litter particles of the present invention, forming a multi-component litter, the multi-component litter may have a remainder composed of one or more other types of particulate components, such as non-caking calcium-based bentonite particles and / or non-caking organic particles, and still form shovellable masses when wetted with water or urine, the masses having a mass retention rate of at least 95%, preferably at least 97%, more preferably at least 99% and a mass crush strength of at least 40 PSI, preferably 60 PSI, more preferably 80 PSI, even more preferably 100 PSI when dried. Such a self-caking absorbent particulate litter, which may be a multi-component litter, composed of 20% to 100% of the self-caking absorbent coated substrate litter particles of the present invention, advantageously improves one or more properties and / or characteristics of past and present sodium-based bentonite litters and sodium-based bentonite-based litters, is lighter in weight, cheaper to prepare and transport, easier to handle during transportation, easier for the user to lift, carry, and dump, generates less dust, preferably is dust-free or even dust-suppressing, and produces round coated substrate litter particles that are not easily caught by a cat's claws, thus also advantageously reducing spillage from the litter box.

[0014] During the preparation of coated substrate litter granules, a coating of a modified starch water absorbent agglomerant adheres to the outer surface of the substrate granules by agglomeration, preferably wet agglomeration, using some but not all of the modified starch water absorbent agglomerant that directly adheres to the outer surface of the substrate granules to form an internal self-adhesive region of the coating. The internal self-adhesive region of the coating adheres directly to the outer surface of the substrate granules by wetting at least one of the outer surface and the modified starch water absorbent agglomerant material applied to the outer surface. This allows the remaining modified starch water absorbent agglomerant in the outer region of the coating surrounding the internal self-adhesive region of the coating to be substantially unmodified and substantially unchanged and available for water absorption and promoting agglomeration when wetted by water or urine during litter or absorbent use. The internal adhesion region is self-adhesive because it is formed from the same modified starch water absorbent agglomerant as the outer region, but with some binder being activated to directly adhere the internal adhesion region to the outer surface of the substrate granules. In addition to at least one component of the modified starch water absorbent agglomerant for each coated substrate coating being a water absorbent, the modified starch water absorbent agglomerant has at least one other component for each coated substrate coating that is a water-activated binder, preferably a moisture-curing water-activated binder, which becomes activated by at least becoming tacky and preferably also becomes flowable, forming a flowable binder, and can also gel, i.e., thicken, during or after flow when wetted with an aqueous wetting liquid such as water or urine.

[0015] In a preferred embodiment, the modified starch water absorbent agglomerant has a first binder component and a second binder component, the first binder component being a once water-activated, once water-cured at least partially water-soluble binder, and the second binder component being a water-reactivated and water-re-cured at least partially water-soluble binder. The second binder component can preferably be water-reactivated and water-re-cured at least multiple times, preferably at least multiple pairs, i.e., at least three times. In a preferred embodiment, the first binder component is a starch that is at least physically modified during extrusion, i.e., a physically modified starch, and preferably a dextrinized starch, which can be or include dextrin, but not necessarily dextrin. In such a preferred embodiment, the second binder component is a starch pre-gel or pre-gelatinized starch having binder properties formed during extrusion.

[0016] The coating applied to the substrate granules or substrate microparticles contains both a first binder component and a second binder component. In a preferred embodiment, the coating applied to the substrate granules or substrate microparticles contains a first binder component, a second binder component, and a third water-absorbing component configured to absorb urine at room temperature or cat body temperature. In one embodiment, at least one of the first component, the second component, and the third component comprises or consists of cold-water-soluble starch, which can be an absorbent for water and urine and is at least partially soluble in urine at room temperature and cat body temperature. In another embodiment, at least both the first component and the second component consist of or include water-absorbing starch, the water-absorbing starch being an absorbent for water and urine and consisting of or including modified starch that is at least partially soluble in urine at room temperature and cat body temperature.

[0017] During the preparation of the coated substrate bedding granules, preferably by agglomeration, one or both of the outer surfaces of the modified starch water-absorbing agglomerant and the substrate granules are wetted with an aqueous wetting liquid, preferably water, ultimately causing at least some of the modified starch water-absorbing agglomerant to be wetted, activating the water-activated binder in some but not all of the modified starch water-absorbing agglomerant, and forming an internal self-adhesive region. In at least one preferred embodiment of the modified starch water-absorbing agglomerant, at least some of the binder activated by the aqueous wetting liquid becomes at least somewhat sticky, preferably sticky, causing at least some of the modified starch water-absorbing agglomerant to adhere to and stick to the outer surface of the external substrate granules. In at least another preferred embodiment of the modified starch water-absorbing agglomerant, at least some of the binder activated by the aqueous wetting liquid gel causes at least some of the modified starch water-absorbing agglomerant to adhere to and stick to the outer surface of the external substrate granules, forming an internal self-adhesive region. In at least a further preferred embodiment of the modified starch water-absorbing agglomerant, at least some of the binder activated by the aqueous wetting liquid becomes flowable, preferably forms a flowable binder, causing at least some of the modified starch water-absorbing agglomerant to adhere to and stick to the outer surface of the external substrate granules, forming an internal self-adhesive region. In at least one preferred embodiment of the modified starch water-absorbing agglomerant, at least some of the binder activated by wetting the modified starch water-absorbing agglomerant with an aqueous wetting liquid becomes sticky, at least some of the binder activated by wetting the modified starch water-absorbing agglomerant with an aqueous wetting liquid gels, and / or at least some of the binder activated by wetting the modified starch water-absorbing agglomerant with an aqueous wetting liquid forms a flowable water-activated binder, causing at least some of the modified starch water-absorbing agglomerant to adhere to and stick to the outer surface of the external substrate granules, forming an internal self-adhesive region.

[0018] This combination of tackiness and the tumbling action of using substrate particles during agglomeration, for example in a rotating drum to form the coated substrate litter particles of the present invention, results in the formation of an outer surface of the coated substrate litter particles that has a large number of raised protrusions, preferably including spikes, over substantially the entire outer surface of the coated substrate litter particles. These minute protrusions, including spikes, are minute in size and extend outwardly from the surface of the coated substrate litter particles by no more than 5 microns, preferably no more than 2 microns, and more preferably no more than about 1 micron (1 micron ± 0.25 microns). Preferably, these minute protrusions, including spikes, are on the nanoscale or nanometric in size and each extends outwardly from the outer surface by no more than 1 micron. This tumbling action, such as that carried out in a drum, also helps to produce the coated substrate litter particles of the present invention which are round and can be substantially round, minimizing spillage by minimizing the likelihood of being picked up by cat claws during litter use. Since these protrusions, including any spikes, are so minute in size, they advantageously enhance absorption by more rapidly transferring, via capillary action or wicking, the water or urine that wets the protrusions, including spikes, substantially along the entire outer surface of the coated substrate litter particles, while still maintaining the overall round configuration or shape of the coated substrate litter particles, which minimizes spillage.

[0019] Thereafter, upon curing the protrusions, including spikes, they become quite hard and form microcracks on the outer surface that enhance absorption. These microcracks continue to form and expand after curing, during drying, and even during storage of the coated substrate litter particles after packing and prior to use. The lengths of these microcracks can range from the nanoscale or nanometric size, i.e., less than 1 micron, to as long as the multi-micron thickness of the binder coating that at least partially covers the substrate microparticles or substrate particles that form the substrate-coated litter particles. In a preferred embodiment, these microcracks have a root thickness of no more than about 1 micron and a length of no more than about 50 microns (50 microns ± 5 microns) to a root thickness as small as about 5 nanometers (5 nanometers ± 3 nanometers) and a length as small as about 5 nanometers, e.g., a root thickness of about 5 nanometers to about 1 micron and a length of about 5 nanometers to about 50 microns. These microcracks further enhance absorption by opening the outer coating of a portion of the coated substrate litter particles upon wetting with water or urine via capillary action or wicking, thereby rapidly increasing the surface area available to absorb water or urine that is in contact with the water or urine. The protrusions, including spikes, work in concert with the microcracks to enhance absorption not only by accelerating absorption but also by accelerating the flow of the flowable binder from each wetted coated substrate particle, thereby also enhancing agglomeration.

[0020] In preferred methods and embodiments, at least some of the binders of the first binder component of the modified starch water-absorbing caking agent are activated and cured, thereby contributing to the adhesion of the self-adhesive region to the surface of the external substrate particles. At least some of the binders of the second binder component are also activated and cured, thereby also contributing to the adhesion of the self-adhesive region to the surface of the external substrate particles.

[0021] Preferred self-caking litter of the present invention comprises substrate litter particles coated with a self-caking absorbent, the particulate coating weight of each internal substrate microparticle of each particle being from about 5% to about 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the weight of the coated substrate litter particle of a modified starch water-absorbing caking agent, and which produces the self-caking coated substrate litter particles of the present invention, each particle absorbing at least twice, preferably at least three times, more preferably at least four times, most preferably at least six times its coating weight of water, such as preferably room temperature water at a temperature of 68 degrees Fahrenheit to 72 degrees Fahrenheit, and urine, such as urine at a temperature of about 100 degrees Fahrenheit to about 104 degrees Fahrenheit, the body temperature of a cat. The wetted coated substrate litter particles while doing so also agglomerate with adjacent water- or urine-wetted litter particles by self-caking to form a mass that is scoopable out of other non-wetted or non-contaminated litter particles using a handled porous litter scoop. The self-caking absorbent-coated substrate litter particles of the present invention absorb at least one time its coating weight of water, preferably room temperature water or urine, preferably urine at the body temperature of a cat, within one minute, i.e., sixty seconds, preferably within thirty seconds, more preferably within twenty seconds, after being wetted with water or urine, which occurs during agglomeration with other wetted litter particles into a mass consisting of at least multiple pairs of coated substrate litter particles. In such a preferred embodiment, each coated substrate particle consists of from about 5% to about 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the weight of the particle of the modified starch water-absorbing caking agent. In one such preferred embodiment and method of preparing the coated substrate litter particles of the present invention, the modified starch water-absorbing caking agent is applied to each substrate particle until a particulate coating weight of the modified starch water-absorbing caking agent on the substrate microparticles of 5% to 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the particle weight is obtained, such that each completed coated substrate litter particle contains from 5% to 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the weight of the particle of the modified starch water-absorbing caking agent.

[0022] Each self - caking absorbent - coated substrate litter particle of the present invention preferably has a particle coating weight of the external modified starch water - absorbing caking agent on the internal substrate particles that is about 5% to about 35%, preferably about 5% to 50%, more preferably about 5% to 85% of the particle weight, and this particle coating weight is sufficient to produce a coating on the self - caking coated substrate litter particles, and each particle absorbs at least one time the weight of water or urine of the coating weight of the coated substrate litter particles, and when absorbing water or urine, the volume swells by at least 25%, preferably at least 35%, more preferably at least 50%, most preferably at least 80% compared to the volume of the litter particles before wetting. In a preferred embodiment, each self - caking absorbent - coated substrate litter particle of the present invention has a particle coating weight of the external modified starch water - absorbing caking agent on the internal substrate particles that is about 5% to about 35%, preferably about 5% to 50%, more preferably about 5% to 85% of the particle weight, and this particle coating weight is sufficient to produce a coating on the self - caking coated substrate litter particles, and each particle absorbs at least two times the coating weight of the coated substrate litter particles of water or urine, and when absorbing water or urine, the volume swells by at least 25%, preferably at least 35%, more preferably at least 50%, most preferably at least 80% compared to the volume of the litter particles before wetting.

[0023] Each self - caking absorbent - coated substrate litter particle of the present invention, preferably a swellable and gellable self - caking absorbent - coated substrate litter particle, wherein the outer region of the outer coating of its modified starch water - absorbing caking agent swells upon absorption of water or urine, preferably room - temperature water or urine at cat body temperature, wets the particles and also substantially simultaneously forms a gel thereon, is viscous along and below the outer surface of the coated substrate litter particle, preferably when wetted, and may be, include or preferably contain a water - activated moisture - curable adhesive, which promotes caking with other contacting litter particles through its viscosity or tackiness, generating an adhesive force therebetween, and this adhesive force bonds the contacting particles into agglomerates through moisture - curing, which is achieved by the moisture evaporating from the agglomerates during drying. In one embodiment of the coated substrate litter particles of the present invention, the outer coating of the modified starch water - absorbing caking agent of each wetted coated substrate litter particle at least partially dissolves in water or urine, preferably room - temperature water or urine at cat body temperature, to form a flowable water - activated moisture - curable adhesive, whose viscosity remains low enough, preferably not greater than 15000 centipoise, more preferably not greater than 10000 centipoise, even more preferably not greater than about 5000 centipoise, for a sufficient length of time, preferably at least one second after wetting, more preferably at least 4 seconds after wetting, so that it flows along and between the contacting and adjacent particles from the water or urine wetted by the modified starch water - absorbing caking agent of the litter particles until the viscosity increases, and within 20 seconds after wetting, preferably within 10 seconds after wetting, more preferably within 5 seconds after wetting, reforming into a viscous semi - solid gel with a viscosity of at least about 30000 centipoise, preferably at least 50000 centipoise, more preferably at least 80000 centipoise. As the viscosity of the flowable adhesive increases, it gels (but at least remains slightly tacky) and hardens into a glassy material having a glassy material state at room temperature because moisture - curing forms during drying, thereby bonding the caked particles together. These bonds can include one of hydrogen bonds and covalent bonds, preferably covalent bonds. In any case, when the agglomerates are dried to a water content of about 12% (12% ± 1.5%) of the weight of the agglomerates, the formed agglomerates become hard enough to have an agglomerate retention rate of at least 95%, preferably at least 97%, more preferably at least 99% and an agglomerate crush strength of at least 40 PSI, preferably at least 60 PSI, more preferably 80 PSI, even more preferably at least 100 PSI.

[0024] Preferably, at least a portion of the modified starch water-absorbing caking agent of each litter particle of the present invention is at least partially dissolved in urine at room temperature or cat body temperature, and the wetting particles form a flowable binder by contacting the particles. The binder is preferably a flowable water-activated binder, which is also moisture-curing, and flows outwards from the wetting particles along the contacting particles and adjacent particles of the litter and between them. The flowable binder initially has a flowable viscosity greater than that of water, and its viscosity increases over time and cures into a binder gel. The binder gel initially adheres the contacting pellets to it and to each other, for example, by surface tension, capillary action, liquid adhesion, and / or intermolecular forces such as van der Waals forces. When it dries, it transforms into a more viscous binding gel with moisture curing, adhering the contacting pellets to it and to each other more strongly, for example, preferably at least by hydrogen bonds and / or preferably at least some covalent bonds. As the initially flowable binder transforms into a binder gel over time and then into a binding gel with further moisture curing, when it dries to a water content less than 15% by weight, preferably not more than 12%, it becomes a substantially fully cured solid binder, which is a vitreous material in a vitreous state, bonded to the litter particles of the litter at least by hydrogen bonds, i.e., hydrogen bonding, and / or preferably by covalent bonds, i.e., covalent bonding. Such a mass is formed by at least multiple pairs, i.e., at least three, of the litter particles of the present invention wetted by water or urine, and is bonded together by the solid binder formed from the initially flowable binder by a combination of hydrogen bonds, covalent bonds, or hydrogen bonds and covalent bonds, and becomes substantially fully moisture-cured into a rock-hard mass, which has a mass water content of about 12% of the mass weight, has a mass crushing strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even more preferably at least 100 PSI, and a mass retention rate of at least 95%, preferably at least 97%, more preferably at least about 99%.

[0025] In a preferred embodiment of the modified starch water-absorbing caking agent for each coated substrate litter particle of the present invention, the modified starch water-absorbing caking agent consists of the following components: (1) a water-swellable modified starch, preferably a cold-water-swellable modified starch, which is also water-absorbing and will swell when it absorbs water, absorbing at least 4.5 times, preferably at least six times the weight of the litter particle of room-temperature water or cat body-temperature urine, and (2) a water-soluble modified starch binder, preferably a cold-water-soluble modified starch binder, which is at least partially cold-water-soluble in room-temperature water and at least partially soluble in cat body-temperature urine, which becomes at least partially dissolved when forming a flowable mixture, flows out from the wetted litter particles, and the viscosity increases during the curing of the moisture into an adhesive gel, the adhesive gel being sticky and adhering the particles together by at least one of liquid adhesion, hydrogen bonding, and / or other intermolecular forces, and the viscosity further increases during the further curing of the moisture into a binding gel, adhering the particles together by at least one of hydrogen bonding and covalent bonding, and when substantially completely cured to a water content of less than 15% by weight, preferably not more than 12% by weight, the adhesive gel becomes a substantially solid adhesive, the adhesive being a vitreous material in a vitreous material state. The water-swellable modified starch, preferably the cold-water-swellable modified starch, of the modified starch water-absorbing caking agent in each litter particle is composed of natural starch, such as natural starch from one or more cereals, such as natural starch from or from one or more corn (corn) or maize, rice, wheat, rye, barley, millet, triticale, oats, fonio, and sorghum, and / or one or more leguminous crops, such as natural starch from or from one or more beans, soybeans, peas, chickpeas, peanuts, lentils, lupins, mesquite, carob, tamarind, alfalfa, and / or clover, which is modified, preferably physically modified, in order to use a starch modification method or process such as extruding and degrading starch granules and / or reducing the molecular weight of one or both of the amylose and / or amylopectin molecules of natural starch, wherein the natural starch is processed in a starch modification machine, such as an extruder, preferably a single-screw extruder, so that the natural starch is subjected to an ultra-high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, even more preferably at least 5000 PSI, at an extrusion temperature of at least 100 degrees Fahrenheit, and the natural starch is modified into a modified starch in the extruder, the modified starch being a water-swellable water-absorbing modified starch, preferably a cold-water-swellable cold-water-absorbing modified starch.At least a portion of the modified starch water absorbent caking agent of each bedding particle, a modified starch binder that is at least partially soluble, preferably at least partially cold water soluble, is also composed of natural starch, such as natural starch from one or more cereals, such as one or more corns or maize, rice, wheat, rye, barley, millet, triticale, oats, fonio, and sorghum, and / or one or more leguminous crops, such as one or more beans, soybeans, peas, chickpeas, peanuts, lentils, lupins, mesquite, carob, tamarind, alfalfa, and / or clover, which is modified, preferably physically modified, so as to degrade the starch granules and / or reduce the molecular weight of one or both of the amylose and / or amylopectin molecules of the starch using a starch modification method or process such as extrusion, wherein the natural starch is processed in a starch modification machine, such as an extruder, preferably a single screw extruder, to subject the natural starch to an ultra-high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, and even more preferably at least 5000 PSI, at an extrusion temperature of at least 100 degrees Fahrenheit to modify the natural starch into a modified starch in the extruder, the modified starch being at least partially water-soluble modified starch, preferably at least partially cold water-soluble modified starch, which is composed of a moisture-curing binder activated by water, the binder being activated by room temperature water and / or urine at cat body temperature into a flowable adhesive having the above properties and characteristics.

[0026] During the preparation of the coated substrate bedding particles of the present invention, a modified starch water absorbent caking agent in a crushed form, preferably a ground form, i.e., prepared by grinding, is used, which has a relatively small particle size, even smaller than the smallest size of the substrate microparticles, which preferably has a particle size within the range of flour or powder, e.g., passing through a 40-mesh sieve, preferably passing through a 60-mesh sieve, and even more preferably passing through a 40-mesh to 60-mesh sieve and remaining on a smaller sieve, such as an 80-mesh sieve. In doing so, the extruded pellets, such as pellets made using the extrusion method described above and / or methods disclosed elsewhere herein, are ground using a grinder into a powder or flour having the sieve mesh sizes disclosed in this paragraph.

[0027] In a preferred embodiment and in the practice of a method of preparing coated substrate litter particles, the extruded pellets prepared according to at least one modified starch water absorbent agglomerant extrusion method disclosed herein can be used as a modified starch water absorbent agglomerant for the agglomeration with substrate particles or fines to prepare the coated substrate litter according to the invention. In one such preferred embodiment and practice of the method, the extruded pellets can be mixed with water to form a slurry, which is applied to the substrate particles or substrate fines in a manner discussed in more detail below. In another such preferred embodiment and practice of the method, water can be applied to the substrate particles or substrate fines in a coalescer or coater, preferably in a rotary or tumbling granulator or coater, in a manner that will also be discussed in more detail below, before the extruded pellets can be mixed with water to agglomerate the substrate particles or substrate fines into the coated substrate particles of the invention.

[0028] In another preferred embodiment and practice of the method, a high-speed high-shear mixer, such as a batch, in-line or granulator high-speed high-shear mixer, is used to grind the extruded pellets into smaller modified starch water absorbent agglomerant fines. In one such preferred embodiment and practice of the method, the extruded pellets are ground with water in such a high-shear mixer to form a substantially homogeneous slurry of smaller-sized pellet fines of the modified starch water absorbent agglomerant, which is then applied to the substrate particles or substrate fines in slurry form and agitated, preferably tumbled, in a rotary granulator or coater in a manner discussed in more detail below.

[0029] In yet another preferred embodiment and practice of the method, the modified starch water absorbent agglomerant is formed by a combination of a powder or powdery material having the mesh size defined above and the extruded pellets prepared according to at least one modified starch water absorbent agglomerant extrusion method disclosed herein. In one such preferred embodiment and practice of the method, a high-speed high-shear mixer, such as in the manner described above, is used to homogenize the mixture of the powdered or powdery modified starch water absorbent agglomerant and the extruded pellets into an aqueous slurry.

[0030] If desired, the modified starch water-absorbing caking agent can be in the form of fine particles of a cereal-based bedding, which particles are classified as being too small to be used in one or more extruded beddings disclosed in one or more of co-owned U.S. Patent Nos. 9,491,926; 10,028,481; 10,098,317; 10,882,238; 11,013,211; and / or 11,083,168, the entire contents of which are incorporated herein by reference. If desired, the fine particles of the modified starch water-absorbing caking agent from waste particles of an extruded bedding prepared according to one or more methods can be further reduced in size, such as by grinding, such as hammer milling, using another particle size reduction machine, and / or using another particle size reduction or particle comminution method, such as the particle size reduction systems, devices, and methods disclosed in co-owned U.S. Patent No. 11,013,211, the entire contents of which are incorporated herein by reference.

[0031] As described in more detail herein, in the method of preparing self-caking absorbent bedding particles of a preferred bedding according to the present invention, these relatively small, powdery or powdered modified starch water-absorbing caking agent particles are wetted with a water-containing wettable liquid, such as water, thereby activating some but not all of at least some of the at least partially water-soluble binders in at least some but not all of the modified starch water-absorbing caking agent particles, resulting in at least some but not all of the modified starch water-absorbing caking agent particles adhering to the outer surface of each substrate particle when wetted and then becoming adhered to the outer surface of each substrate particle when substantially completely moisture-cured upon drying, forming an internal adhesion region between the internal substrate particles and the outer region of the modified starch water-absorbing caking agent in each bedding particle. Wetting of the modified starch water-absorbing caking agent of substantially all of the particles activates some but not all of at least some of the at least partially water-soluble binders of the remaining unadhered wetted particles of the modified starch water-absorbing caking agent, such that at least some but not all of the modified starch water-absorbing caking agent particles in contact with the internal adhesion region adhere to the internal adhesion region when wetted and then adhere to the internal adhesion region when substantially completely moisture-cured upon drying, forming one or more additional regions in which the modified starch water-absorbing caking agent adheres to each of the manufactured bedding particles.

[0032] In a preferred method of manufacturing bedding particles, the wetting of the modified starch water-absorbing caking agent particles is accomplished by mixing dry powder-sized or powdered-sized particles of the modified starch water-absorbing caking agent with an aqueous wetting liquid, preferably water, to form a slurry, and then applying it to the substrate particles, preferably while tumbling, stirring, or otherwise, such as by using a mixer, coater, blender, or another mixing device or apparatus, so that an internal adhesion region is formed thereon before an external region of the modified starch water-absorbing caking agent is formed on the outer surface of each substrate particle. In another preferred method of manufacturing bedding particles, the wetting of the modified starch water-absorbing caking agent particles is indirectly accomplished by wetting the substrate particles with an aqueous liquid, preferably water, before applying the dry powder-sized or powdered-sized particles of the modified starch water-absorbing caking agent to the wetted substrate particles, and preferably while doing so, flipping, stirring, or otherwise mixing the wetted substrate particles and the applied modified starch water-absorbing caking agent particles so that the water on the surface of the substrate particles wets the modified starch water-absorbing caking agent particles in contact therewith, thereby forming an internal adhesion region on the outer surface of each substrate particle. Preferably, one or more wetting cycles and application cycles are carried out, wherein during each rewetting cycle, additional aqueous wetting liquid is applied to at least partially coated substrate particles, substantially simultaneously with or substantially immediately following another application cycle, in which additional dry powder-sized or powdered-sized particles of the modified starch water-absorbing caking agent are applied to the wetted at least partially coated substrate particles, while tumbling, stirring, or otherwise mixing the wetted at least partially coated substrate particles until one or more additional external regions are added to the top of the internal adhesion region of each formed bedding particle.

[0033] Since an aqueous wettable liquid, preferably water, is applied at the beginning to the substrate particles and at least partially formed bedding particles until a coating of modified starch water-absorbing agglomerating agent particles of the desired thickness accumulates on each substrate particle, thereby forming the final bedding particles, the wetting of the modified starch water-absorbing agglomerating agent particles applied to each substrate particle causes the modified starch water-absorbing agglomerating agent particles in the outer region of each bedding particle surrounding its inner substrate particle to agglomerate into an amorphous region of substantially uniform modified starch water-absorbing agglomerating agent material, which amorphous region binds together when substantially completely water-cured to the inner substrate particles of the final bedding particles. Preferred self-agglomerating adsorbent particles of the present invention produced by the manufacturing method disclosed herein have an outer region of modified starch water-absorbing agglomerating agent with a thickness not greater than 1 mm, preferably not greater than 0.8 mm, and preferably not greater than about 0.5 mm, and even more preferably not greater than about 0.3 mm, and at least 50%, preferably at least 80%, more preferably at least 95%, and even more preferably substantially the entire outer surface of each substrate particle of each bedding particle is covered with modified starch water-absorbing agglomerating agent material. A preferred self-agglomerating absorbent particle of the present invention produced by the manufacturing method disclosed herein has an outer region of modified starch water-absorbing agglomerating agent with a thickness from 20 microns (i.e., 0.02 mm) to 1000 microns (i.e., 1 mm), preferably from 20 microns (i.e., 0.02 mm) to 800 microns (i.e., 0.8 mm), more preferably from 20 microns (i.e., 0.02 mm) to 500 microns (i.e., 0.5 mm), and even more preferably from 20 microns (i.e., 0.02 mm) to 300 microns (i.e., 0.3 mm), and at least 50%, preferably at least 80%, more preferably at least 95%, and even more preferably substantially the entire outer surface of each substrate particle of each bedding particle is covered with modified starch water-absorbing agglomerating agent material.

[0034] In a preferred embodiment, the coated round substrate litter particles advantageously have a size that minimizes litter spillage from the litter box during the use and operation of the coated substrate litter of the present invention. During the use of the litter box, the round shape of the coated substrate litter particles helps prevent the coated substrate litter particles from getting stuck in the cat's claws. In addition, the size of the coated substrate litter particles also helps prevent the litter from being carried away by the cat and spilled during the use of the litter box. In a preferred embodiment, the coated substrate particles need to have a size greater than a 25-mesh sieve, i.e., greater than a 25-mesh sieve but not greater than a 10-mesh sieve, i.e., not greater than a 10-mesh sieve. At least 80% of the coated substrate litter particles should have a size less than 10 mesh and greater than 25 mesh (10 / 25). For example, in one embodiment, 60% to 95%, and preferably at least about 80% (80% ± 15%) of the particles pass through a 12-mesh sieve and are greater than a 25-mesh sieve. The remainder of the coated substrate litter particles will be greater than 10 mesh. Round coated substrate litter particles with a particle size distribution of 12 mesh to 20 mesh (12 / 20) provide the best feel for the cat's claws.

[0035] Thus, in a preferred embodiment of the coated substrate cat litter, the coated substrate litter particles are generally round, have raised protrusions, including spikes, and have a particle size distribution of 12 mesh to 20 mesh (12 / 20) to produce a preferred embodiment of a low spillage litter according to the present invention that minimizes litter spillage caused by the cat from the litter box. In another preferred embodiment of the coated substrate cat litter, the coated substrate litter particles are generally round, have raised protrusions, including spikes, and have a particle size distribution of 10 mesh to 25 mesh (10 / 25) to produce another preferred embodiment of a low spillage litter according to the present invention that minimizes litter spillage caused by the cat from the litter box.

[0036] In the method of applying the modified starch water-absorbing caking agent to the substrate particles to produce the self-caking absorbent-coated substrate particles of the present invention, according to the type and size of the substrate particles, for a given amount, such as a given weight or mass, of the substrate particles, a certain amount of a slurry containing a predetermined amount, such as a predetermined weight or mass, of the modified starch water-absorbing caking agent particles is applied. The respective predetermined amounts of the modified starch water-absorbing caking agent forming a slurry in water are selected according to the size or size range and the given amount of the substrate particles to be coated and to become the self-caking absorbent particles of the present invention. In a preferred method of preparing the self-caking absorbent padding particles of the present invention using a slurry of water and modified starch water-absorbing caking agent particles, the slurry is applied to the substrate particles or substrate microparticles tumbling within the rotating barrel or drum of a drum mixer, cement mixer, drum coater, or similar device. This process uses one or more spaced-apart spray heads, nozzles, atomizers, or another type of slurry applicator or slurry dispenser that is configured or operated to controllably discharge the slurry onto the substrate microparticles in the rotating mixer or coater drum during the manufacture of the self-caking absorbent padding particles of the present invention. In another preferred method of applying the modified starch water-absorbing caking agent to the substrate particles or substrate microparticles to prepare the self-caking absorbent-coated substrate particles of the present invention, the substrate microparticles are wetted with a water-containing wettable liquid such as water, and dry particles of the modified starch water-absorbing caking agent are applied. At the same time, the substrate microparticles, the modified starch water-absorbing caking agent particles, and the water-containing wettable liquid, preferably water, are applied, with the substrate microparticles being applied first, and then the substrate microparticles, the modified starch water-absorbing caking agent particles, and the water-containing wetting liquid, preferably water, are tumbled or stirred, for example, preferably in the rotating barrel of a drum mixer, cement mixer, drum coater, etc., to mix all the substances together. One or more wetting cycles are carried out as needed by applying a water-containing wettable liquid, preferably water, to at least partially coated substrate particles, and then applying the modified starch water-absorbing caking agent particles until each substrate microparticle has the desired amount of particle coating weight such as coverage, and / or the external region thickness of the modified starch water-absorbing caking agent is obtained, thereby producing the final self-caking absorbent padding particles of the present invention. Thereafter, a moisture curing step is carried out on at least partially wet final self-caking absorbent padding particles. This step is preferably a moisture removal step, such as by convective drying of the padding particles using flowing air, preferably turbulent flowing air, drying using one or more types of radiant heat, hot air convection drying, or another type of heating drying method in a heating furnace until the moisture curing in each padding particle is completed or substantially completed, at which time each particle is dried to a water content not greater than 12%, preferably greater than 10%, and more preferably not greater than 8% of the weight of the padding particle.

[0037] When the slurry is used to prepare the substrate particles coated with the self - caking absorbent of the present invention, the slurry is a slurry of water and relatively small modified starch water - absorbing caking agent particles, preferably having the size of a powder or powdery substance. Thus, the modified starch water - absorbing caking agent particles are mixed with water until a substantially homogeneous mixture or slurry is formed. As previously described, mixing can be carried out using a high - speed high - shear mixer. In a preferred slurry, when water is used as the aqueous wetting liquid, the ratio of the amount of the modified starch water - absorbing caking agent to water is about 1:1 ± 10% by weight. The slurry is applied to the substrate particles or substrate microparticles by stirring, tumbling or otherwise, for example, by mixing the substrate microparticles in a rotating barrel, drum or bin of a mixer, coater or blender, so as to increase the area of the modified starch water - absorbing caking agent on each substrate microparticle until the desired area thickness or desired particle coating weight of the modified starch water - absorbing caking agent on the substrate microparticle is reached. Tumbling is preferably carried out in a rotating barrel or drum - type mixer or coater, as this also ensures that the resulting finally coated substrate bedding particles are rounded in the above - mentioned manner to minimize spillage from the bedding box. The water in the slurry activates at least some but not all of the water - soluble modified starch binders in the modified starch water - absorbing caking agent particles in the slurry, preferably cold - water - soluble modified starch binders, to produce a viscous gel and a flowable binder that adheres the modified starch water - absorbing caking agent particles to the substrate microparticles to which the slurry is applied. This viscosity helps to ensure the formation of raised protrusions including spikes on the outer surface of the coated substrate particles, thereby increasing the water absorption capacity and speed during the use of the bedding. Applying the slurry to the substrate microparticles while stirring, tumbling or mixing the substrate microparticles not only helps the modified starch water - absorbing caking agent particles to adhere more evenly to each substrate microparticle, but also helps to prevent at least some of the partially coated substrate microparticles from caking during the preparation of the slurry - based self - caking absorbent bedding particles. When the substrate microparticles are tumbled, stirred and / or mixed, the slurry is applied to the substrate microparticles until the modified starch water - absorbing caking agent particles on the substrate microparticles reach the desired thickness or particle coating weight. In a preferred method embodiment, the initial application of the slurry on the substrate microparticles causes each substrate microparticle to act as a bedding particle nucleating agent, and as a result, the modified starch water - absorbing caking agent in the slurry adheres to the outer surface of each substrate microparticle, forming an internal adhesion area, and the water - containing wetting promotes the adhesion of another outer area of the modified starch water - absorbing caking agent more quickly.

[0038] In a preferred method of applying the slurry, for a given amount, such as a given weight or mass of the substrate particles, depending on the type and size of the substrate particles, an amount of the slurry containing a predetermined amount, such as a predetermined weight or mass of the modified starch water-absorbing agglomerating agent particles, is applied, wherein the corresponding predetermined amount of the modified starch water-absorbing agglomerating agent forms a slurry in water, and the slurry is selected based on the size or size range and the given amount of the substrate particles to be coated and to become the self-agglomerating absorbent particles of the present invention. In a preferred method of preparing the self-agglomerating absorbent padding particles of the present invention using a slurry of water and modified starch water-absorbing agglomerating agent particles, the slurry is applied to the substrate particles or substrate microparticles tumbling within a rotating drum or cylinder of a drum mixer, a cement mixer, a drum coater, or a similar device, and the process uses one or more spaced-apart spray heads, nozzles, atomizers, or another type of slurry applicator or slurry dispenser configured or operated to controllably discharge the slurry onto the substrate microparticles in the rotating mixer or coater drum during the manufacture of the self-agglomerating absorbent padding particles of the present invention.

[0039] In an embodiment of the preferred method of applying the slurry, during the process of applying the slurry to the substrate microparticles, the amount and preferably the rate, such as the volumetric rate or metering, of the slurry applied to the substrate microparticles vary in real time so as to (a) control the weight coverage of the particle coating and / or the thickness of the modified starch water-absorbing agglomerating agent forming an outer region around each substrate microparticle, and (b) prevent agglomeration of at least some of the substrate microparticles covered by the modified starch water-absorbing agglomerating agent region during tumbling, stirring, or otherwise mixing. During the process of applying the slurry to the substrate microparticles, the ratio of the amount of the modified starch water-absorbing agglomerating agent to the amount of water can also be controllably adjusted or varied in real time by up to ±25%, such as from 1:1 up to +25% or from 1:1 down to -25%, to control (a) the water activation of at least partially soluble modified starch binder, (b) the particle coating weight coverage rate of the modified starch water-absorbing agglomerating agent adhering to and / or covering each substrate microparticle, (c) the particle coating weight coverage amount of the modified starch water-absorbing agglomerating agent adhering to and / or covering each substrate microparticle, (d) the thickness of the outer region of the modified starch water-absorbing agglomerating agent adhering to and / or covering each substrate microparticle during the preparation of the padding particles of the present invention, (e) the viscosity of the slurry, and / or (f) prevent agglomeration of partially coated or partially formed padding particles during tumbling, stirring, or otherwise mixing.

[0040] In a preferred method embodiment, the slurry formed can be and preferably is in the following form: (a) a suspension consisting of a water-wetting liquid, preferably water, and dry particles of a modified starch water-absorbing and caking agent mixed together, for example by using a high-shear mixer, another suitable type of mixer or another suitable type of mixer until a suspension is formed, or (b) an emulsion consisting of a water-wetting liquid, preferably water, and dry particles of a modified starch water-absorbing and caking agent mixed together, for example by using a high-shear mixer, another suitable type of stirrer or another suitable type of mixer until a suspension is formed. When using the slurry in this suspension form, the suspension can include one or more surfactants, which include one or more super surfactants, to facilitate the suspension of the dry powder-sized or powdery-sized particles of the modified starch water-absorbing and caking agent in the water-wetting liquid, preferably water, in the slurry suspension mixing step, in which all components of the suspension are mixed together. When using the slurry in this emulsion form, the emulsion can include (1) one or more surfactants, which include one or more super surfactants, and / or (2) one or more emulsifiers, to emulsify or facilitate all dry powder-sized or powdery-sized particles of the modified starch water-absorbing and caking agent in the water-wetting liquid, preferably water, in the slurry emulsion mixing step, in which all components of the emulsion are mixed together. During the application of the slurry to the substrate particles, at least one of the viscosity, the rate of increase in the thickness of the modified starch water-absorbing and caking agent coating, the amount of the thickness of the modified starch water-absorbing and caking agent coating, and / or the particle coating weight of the modified starch water-absorbing and caking agent on each substrate particle can be controlled by preferably controlling in real time the ratio of water to the modified starch water-absorbing and caking agent in the slurry suspension or emulsion during the application of the slurry suspension or emulsion to the substrate particles. This slurry suspension or emulsion, preferably a substantially uniform suspension or emulsion of modified starch water-absorbing and caking agent particles suspended or emulsified in water, is applied to the substrate particles while stirring, tumbling or otherwise mixing the substrate particles, so that the areas of the modified starch water-absorbing and caking agent accumulate on the outer surface of each substrate particle until the desired area thickness or desired particle coating weight of the modified starch water-absorbing and caking agent on the substrate particles is reached. The water in the slurry activates at least some but not all of the water-soluble modified starch binders, preferably cold-water-soluble modified starch binders, in the modified starch water-absorbing and caking agent particles in the slurry, producing one or more viscous gels and one or more flowable binders, which adhere the modified starch water-absorbing and caking agent in the suspension or emulsion to the substrate particles to which the slurry suspension or emulsion is applied.While stirring, tumbling, or mixing substrate particles, applying a slurry suspension or emulsion to the substrate particles not only facilitates more uniform adhesion of the modified starch water-absorbing caking agent to each substrate particle but also helps prevent agglomeration of at least partially coated substrate particles / partially completed bedding particles during the manufacture of slurry-based self-caking absorbent bedding particles while stirring, tumbling, or otherwise mixing during the application of the slurry suspension or emulsion.

[0041] While tumbling, stirring, and / or mixing substrate particles, applying a slurry, slurry suspension, or slurry emulsion to the substrate particles until the modified starch water-absorbing caking agent particles on the substrate particles reach the desired thickness or particle coating weight, thereby producing the self-caking absorbent bedding particles of the present invention. Thereafter, reducing the moisture content of the final bedding particles to moisture-cure at least partially soluble modified starch binder that is activated during slurry application and forms a flowable binder and gel that adheres one or more outer regions of the modified starch water-absorbing caking agent to each substrate particle. The water content of the final bedding particles is reduced to a water content of no greater than 12%, preferably no greater than 10%, and more preferably no greater than about 8% to substantially completely moisture-cure the water-activated at least partially soluble modified starch binder, the flowable binder, and the gel to form a vitreous solid binder that adhesively binds the outer regions of the modified starch water-absorbing caking agent to each inner substrate particle. In the outer regions of the modified starch water-absorbing caking agent of each completed self-caking absorbent bedding particle of the present invention, at least a portion of the at least partially soluble modified starch binder remains unactivated and / or uncured, and thus is readily wetted by water, such as room temperature water, or urine, such as urine at cat body temperature, and at least partially dissolves into the flowable binder, which flows out of the wetted bedding particle and flows along and between contacting bedding particles and adjacent bedding particles, increasing in viscosity during the initial moisture-curing process to become a binder or adhesive gel, which transforms into a bonding gel and ultimately into a vitreous starch-state solid binder as further moisture-curing occurs, the solid binder bonding the contacting bedding particles and adjacent bedding particles together into a mass that becomes substantially rock-hard when moisture-curing is completed due to moisture evaporation. The moisture-curing of the mass is preferably completed when the water content of the mass is no greater than about 12% of the mass weight, which is due to moisture evaporating from the mass during drying of the mass, such as air-drying the mass in a sand box, producing a substantially rock-hard mass that, when completely moisture-cured, has a mass retention of at least 95%, preferably at least 97%, more preferably at least 99% and / or a mass transverse strength of at least 40 PSI, preferably 60 PSI, more preferably 80 PSI, even more preferably 100 PSI.

[0042] The substrate particles or substrate microparticles can be organic, inorganic, smooth, rough, round, cylindrical, irregularly shaped, porous, non-porous, water-absorbent, water-impermeable, smooth and / or rough, and are preferably non-caking, i.e., composed of a material in which the microparticles do not agglomerate when the microparticles are wetted with water. Preferred substrate materials include nut shells or husks, wood, paper, sand, perlite, and bentonite, which are crushed, ground, milled, or otherwise comminuted into substrate microparticles of relatively small size, at least partially coated with a modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing caking promoting material, to form the self-caking bedding particles of the present invention, which have an outer region of the modified starch water-absorbing caking agent that at least partially covers and preferably substantially completely encapsulates each substrate particle. The modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing caking promoting material, is more preferably composed of a starch-modified, preferably extruded, more preferably ultra-high pressure extruded using a single-screw extruder, so as to rapidly swell and absorb water and gel while doing so, and preferably further contains at least some previously natural or unmodified starch that is modified into at least partially water-soluble binder, which at least partially dissolves and flows when wetted with water to form a flowable binder that adheres the swelling and gelling material to the substrate particles during the manufacture of the bedding particles. In a preferred form of the starch-based water-absorbing caking promoting material, the preferred modified starch water-absorbing caking agent is more preferably a starch-based adsorbent swelling biopolymer gelling agent, such as composed of a gelling biopolymer or a biopolymer that gels upon wetting, preferably forms a gel, and is composed of a cold-water soluble extruded modified starch binder and a cold-water swellable extruded modified adsorbent starch, the cold-water swellable extruded modified adsorbent starch preferably being or including a cold-water swellable extruded modified cold-water adsorbent starch, which is crushed or otherwise reduced in particle size to a powdery or powdered form that coats the substrate microparticles when wetted. If desired, the powder or powdered microparticles of such modified starch water-absorbing caking agent are pellets or microparticles of discarded or unused extruded cereal fines bedding, which are classified as too small to be used as one or more than one bedding disclosed in one or more of the co-owned U.S. Pat. Nos. 9,491,926, 10,028,481, 10,098,317, 10,882,238, 11,013,211, and / or 11,083,168, the contents of which are incorporated herein by reference in their entirety. The resulting bedding particles form the removable cakable bedding of the present invention because each particle has an outer self-caking water-absorbing region surrounding the internal substrate microparticles, whereby the outer region rapidly absorbs and swells upon contact with water, at least some of the outer region at least partially dissolves and forms a flowable binder that flows along and between the contacting and adjacent bedding particles, and gelation also occurs during the process of wetting the bedding particles to agglomerate into clumps that can be shoveled from the bedding.

[0043] In the process for preparing the self - caking coated substrate bedding particles of the present invention, one can (a)(1) while stirring, wet a desired or predetermined amount of substrate microparticles, the particle size of which falls within a desired particle size range or particle size distribution, (2) mix with a modified starch water - absorbing caking agent, which is preferably in the form of a starch - based water - absorbing caking agent promoting powder or powder, while continuing to stir, and while the water wets the outer surface of the substrate particles, resulting in (i) some but not all of the water - soluble binder at least partially dissolving and forming a flowable binder, causing the starch - based water - absorbing caking agent promoting powder or powder to adhere to the outer surface of the substrate particles, and (ii) some but not all, at least a plurality of, preferably at least a plurality of pairs, i.e., at least three different types of modified starch, thereby coalescing the wetted powder or powder particles together into an amorphous and substantially uniform starch - based water - absorbent caking - promoting material mass, which material mass surrounds each substrate microparticle and forms an outer region thereon, producing the final bedding particles of the present invention, which are then dried, for example, with turbulent air, hot air, and / or radiant heat directed at and / or towards the final bedding particles. Drying is carried out to reduce the water content of the still - moist final bedding particles until each bedding particle has a water content of less than 12%, preferably less than 10%, more preferably not more than 8% of the particle weight. The water reduction is carried out to water - cure the water - soluble binder into a solid binder, bond the starch - based water - absorbent caking - promoting material of the outer region to the outer surface of each inner substrate microparticle, and prevent the water activation and / or further water - curing of at least some of the at least partially soluble binder of each final bedding particle, preferably by preventing its retrogradation, such that at least some of the water - activatable and at least partially soluble binder in each particle is still available to cake the particles together when wetted by water or urine.

[0044] The water - removal step, preferably the drying step, can and preferably is carried out while the newly - completed still - moist particles continue to be mixed, such as stirred, to cure the binder, bond the outer self - caking water - absorbent region to the inner substrate microparticles, while preventing the water activation of the binder within the outer region of the starch - based water - absorbing caking - promoting material that does not adhere to the outer surface of each substrate microparticle. The water - removal step, preferably the drying step, can and preferably is carried out when the partially - coated bedding particles, such as the partially - completed bedding particles, are wetted and / or re - wetted, including during the simultaneous mixing of all substances, such as activation, for example, while mixing in the mixing vessel or drum, with the further application of the dried starch - based water - absorbing caking - promoting powder or powder material. Although the water - removal step, such as the drying step, can be carried out when the substrate microparticles are coated with a slurry of the starch - based water - absorbing caking - promoting powder or powder and water, including during the process of mixing all substances together, the water - removal step is preferably carried out after the slurry application step is completed.

[0045] In preferred embodiments of the coated substrate padding and coated substrate padding particles, the modified starch water-absorbing agglomerant is in the form of a starch-based water-absorbing agglomeration-promoting powdery substance or powder, which consists of at least multiple, preferably at least multiple pairs, namely at least three different types of modified starches, and the molecular weight of each different type of modified starch is different from, preferably less than, the unmodified or natural starch that forms the corresponding modified starch. Each different type of modified starch is formed from unmodified or natural starch, such as preferably unmodified amylose and amylopectin, in one or more cereals and / or legumes in a mixture containing cereals and / or legumes, wherein the unmodified or natural starch in the mixture is modified during extrusion using a single-screw extruder at an ultra-high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, and even more preferably at least 5000 PSI, which modifies the unmodified or natural starch to produce a modified starch water-absorbing agglomerant in the form of an extrudate of a starch-based water-absorbing agglomeration-promoting material, and the extrudate is used in the form of a powdery substance or powder to manufacture the self-agglomerating adsorbent padding particles of the present invention.

[0046] The method for wetting the substrate with water for preparing the coated substrate padding particles of the present invention involves wetting the substrate microparticles before applying the modified starch water-absorbing agglomerant, preferably in the form of a starch-based water-absorbing agglomeration-promoting powdery substance or powder, and the amount of water used is greater than the amount of the modified starch water-absorbing agglomerant powdery substance or powder, preferably the amount of the starch-based water-absorbing agglomeration-promoting powdery substance or powder used. Whether the agglomerant is in the form of a powder or powdery substance, in the form of extruded pellets, or in the form of extruded pellets crushed using, for example, a high-speed high-shear mixer, water is added before adding any modified starch water-absorbing agglomerant until the substrate particles or substrate microparticles start to agglomerate by themselves to achieve proper wetting.

[0047] In a method implementation, in the application step, water is used in a ratio of 6:1 to 10:1, preferably 7:1 to 9:1, more preferably about 8:1, with the modified starch water-absorbing caking agent powder or powder, preferably the starch-based water-absorbing caking-promoting powder or powder, to coat the substrate particles or substrate microparticles. When implementing the substrate water wetting method, multiple cycles of wetting the substrate are carried out. The dry modified starch water-absorbing caking agent powder or powder, preferably the dry starch-based water-absorbing caking-promoting powder or powder, is applied to each wetted substrate microparticle, and the mixture is wetted or re-wetted with additional water. More dry modified starch water-absorbing caking agent powder or powder, preferably the dry starch-based water-absorbing caking-promoting powder or powder, is applied to at least partially coated and wetted substrate particles or substrate microparticles, while the substrate particles or substrate microparticles and the modified starch water-absorbing caking agent powder or powder, preferably the starch-based water-absorbing caking-promoting powder or powder, are continuously mixed by tumbling, rolling or another form of stirring, preferably in a rotating barrel or drum of a drum coater, cement mixer, drum mixer, mixing blender, etc.

[0048] Compared with the amount of granular modified starch water-absorbing caking agent, the slurry method uses less water, preferably in the form of a powder or powder of a starch-based water-absorbing caking agent. Preferably, water and the granular modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing promoting powder or powder, are mixed together at a ratio of 0.5:1 to 2:1 and more preferably about 1:1 before the slurry is applied to the substrate microparticles, and preferably all substances are mixed together. The mixing is preferably carried out by tumbling in a mixer, such as a paddle mixer, a drum coater, a cement mixer, a blender such as a belt blender, or using another type of mixing or blending device. In a preferred method implementation, a continuous slurry process is adopted, in which water and the granular modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing promoting powder or powder, are mixed and stored in a tank, barrel or other container, and the slurry can be pumped from these containers substantially continuously into one or more sprayers, spray guns, nozzles, dispensers or other applicators, and when they are in a rotating drum, a tumbler, or a conveyor device, these applicators discharge the slurry onto the substrate microparticles, while during the continuous application process, preferably a continuous flow application process, the substrate microparticles pass under the sprayer, spray gun, nozzle, dispenser or applicator. In another preferred method implementation, the slurry can be applied, for example, using a sprayer, spray gun, nozzle, dispenser or other applicator to the substrate microparticles that are being stirred, tumbled or otherwise mixed together, such as in a drum coater, a drum mixer, a concrete mixer, a paddle mixer, a belt blender or other type of suitable blender or mixer, and the microparticles are more evenly coated with the granular modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing promoting powder or powder. Advantageously, the self-caking adsorbent litter particles of the present invention are generated in or from the slurry, which have an outer region of substantially uniform modified starch water-absorbing caking agent, preferably starch-based water-absorbing promoting material, and the outer region has substantially the same thickness from litter particle to litter particle, and substantially completely encapsulates each substrate microparticle. During the application process of the modified starch water-absorbing caking agent, preferably the application process of the starch-based water-absorbing promoting material, preferably in a rotating generally cylindrical or barrel or drum of a coater, mixer, etc., the particles are tumbled, rolled or otherwise agitated to form an outer region of the modified starch water-absorbing caking agent, preferably starch-based water-absorbing promoting material, which fills any pockets and voids on the outer surface of the substrate microparticles, and also smooths the irregularities on the surfaces of other substrate microparticles, advantageously generating litter particles with a substantially smooth and round outer surface, which will not hurt the paw pads of cats without claws and will not scatter, because the smooth and round particles are not easily picked up by cat claws and scattered onto the floor area outside the litter box outside the litter box.In the case where the substrate particles are generally circular, for example, in the case of using paper substrate particles, i.e., paper pellets, the self - caking absorbent litter particles of the present invention produced each have an outer region of a modified starch water - absorbing caking agent, preferably a substantially smooth starch - based water - absorbing caking - promoting material, which is circular, and preferably produces substantially circular and / or generally spherical litter particles, such as the self - caking absorbent litter particles balls of the present invention.

[0049] As previously mentioned, the circular coated substrate litter particles advantageously have a size that minimizes litter spillage from the litter box during the use and operation of the coated substrate litter of the present invention. During the use of the litter box, the circular shape of the coated substrate litter particles helps prevent the coated substrate litter particles from getting caught in a cat's claws. In addition, the size of the coated substrate litter particles also helps prevent litter from being scattered by the cat from the litter box during the use of the litter box. In a preferred embodiment, the coated substrate particles need to have a size greater than a 25 - mesh sieve, i.e., greater than 25 mesh but not greater than 10 mesh, i.e., not greater than 10 mesh. At least 80% of the coated substrate litter particles should have a size less than 10 mesh and greater than 25 mesh (10 / 25). For example, in one embodiment, 60% to 95%, and preferably at least about 80% (80% ± 15%) of the particles pass through a 12 - mesh sieve and are greater than 25 mesh. The remaining portion of the coated substrate litter particles will be greater than 10 mesh. Circular coated substrate litter particles having a particle size distribution of 12 mesh to 20 mesh (12 / 20) provide the best feel for a cat's claws.

[0050] Thus, in a preferred embodiment of the coated substrate cat litter, the coated substrate litter particles are generally circular, have raised protrusions, including spikes, and have a particle size distribution of 12 mesh to 20 mesh (12 / 20) to produce a preferred embodiment of the low - spill litter according to the present invention, which minimizes spillage caused by the cat from the litter box. In another preferred embodiment of the coated substrate cat litter, the coated substrate litter particles are generally circular, have raised protrusions, including spikes, and have a particle size distribution of 10 mesh to 25 mesh (10 / 25) to produce another preferred embodiment of the low - spill litter according to the present invention, which minimizes spillage caused by the cat from the litter box.

[0051] In the method for preparing a self-caking adsorbent bedding according to the present invention, during the manufacture of a batch of the bedding of the present invention composed of the self-caking bedding particles of the present invention, at least a plurality of different types, preferably at least a plurality of pairs, i.e., at least three different types of substrate microparticles are substantially simultaneously coated with an outer region of a modified starch water-absorbing caking agent, and the bedding has at least a plurality of different types of substrate microparticles, preferably at least a plurality of pairs, i.e., at least three different types of substrate microparticles. In one such method, at least one type of substrate microparticle is an organic substrate microparticle having a density lower than that of other types of inorganic substrate microparticles, preferably a functional substrate microparticle, wherein a slurry or an aqueous wetting liquid is used to wet and re-wet the method for manufacturing the bedding particles, and two types of substrate microparticles are substantially simultaneously coated or covered with a granular modified starch water-absorbing caking agent.

[0052] In a preferred embodiment, the modified starch water-absorbing caking agent is preferably a starch-based water-absorbing caking promoting material, which is extruded from an extruder at an ultra-high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, and even more preferably 5000 PSI, at a relatively low water content of not more than about 25% by weight, such as the above-mentioned mixture containing one or more grains and / or one or more legumes, thereby extruding a modified starch water-absorbing caking agent preferably in the form of a starch-based water-absorbing caking promoting material, which is more preferably or comprises a starch-based adsorbent swellable biopolymer gelling agent, the gelling agent comprising modified starch modified by ultra-high extrusion pressure in the extruder, the gelling agent swelling and gelling upon adsorption, including absorption of liquids such as aqueous liquids, such as water or aqueous solutions at room temperature, such as urine at cat body temperature, and is preferably composed of at least some starch in the ultra-high pressure extruded mixture modified into a cold water-soluble binder and at least some other starch in the ultra-high pressure extruded mixture modified into a cold water-swellable water-absorbing modified starch. In a preferred litter particle embodiment and a litter particle preparation method, the waste fines from the process of preparing an absorbent starch-based litter, such as the extruded cereal-based litter disclosed in one or more co-owned U.S. Pat. Nos. 9,491,926, 10,028,481, 10,098,317, 10,882,238, 11,013,211, and / or 11,083,168, the entire contents of which are incorporated herein by reference, can be used as a particulate modified starch water-absorbing caking agent, preferably a starch-based water-absorbing caking promoting granular material, which is applied directly or in the form of a slurry to the substrate microparticles, or is ground, milled, pulverized, or otherwise reduced in particle size to an even smaller powdery substance or powder-sized particles, having a mesh size and / or mesh size range according to those discussed elsewhere herein, which is applied to or in the form of a slurry to the substrate microparticles. When the particulate modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing caking promoting granular material, more preferably composed of a starch-based adsorbent swellable biopolymer gelling agent, is used in the form of powder-sized granules, the powder-sized microparticles preferably have a particle size of less than 1000 μm and are preferably composed of microparticles sized from 100 μm to 400 μm. When the particulate modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing caking promoting granular material, more preferably composed of a starch-based adsorbent swellable biopolymer gelling agent, is used in the form of granules of powdery substance size, the granules of powdery substance size preferably have a particle size passing through a 40-mesh sieve, preferably passing through a 60-mesh sieve, and even more preferably passing through a 40-mesh sieve to a 60-mesh sieve and remaining on an 80-mesh sieve. This extremely small particle size enables the water-soluble binder in some microparticles to be quickly wetted and activated, but not all of the water-soluble binder in the microparticles can come into contact with and be applied to the larger substrate microparticles.

[0053] The final result produces substantially instantaneously self - caking absorbent litter granules that are non - friable, which minimizes dust generation during storage, packaging, transportation, and actual litter use. It preferably reduces dust by attracting dust particles and making them adhere to it. It has a round granule shape to minimize litter granule spillage from the litter box by the cat. It has a smooth, round exterior that does not harm the paw pads of a clawless cat, and it forms clumps with a clump retention rate of at least 95%, preferably at least 97%, more preferably at least 99%. This means that when a clump formed from litter granules moistened with 10 ml of water or urine is dropped from a height of about ten inches onto a porous screen for testing, the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. In another preferred embodiment, when such a clump formed from litter granules moistened with 15 ml of water or urine and dried to a moisture content of about 12% is dropped from a height of about ten inches onto a screen for a drop test, the clump retention rate of each clump is at least 95%, preferably at least 97%, more preferably at least 99%, which means that the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. In another also preferred embodiment, when such a clump formed from litter granules moistened with 10 ml of water or urine and dried to a moisture content of about 12% is dropped from a height of about twelve inches onto a screen for a drop test, the clump retention rate of each clump is at least 95%, preferably at least 97%, more preferably at least 99%, which means that the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. In another even more preferred embodiment, when such a clump formed from litter granules moistened with 15 ml of water or urine and dried to a moisture content of about 12% is dropped from a height of about twelve inches onto a screen for a drop test, the clump retention rate of each clump is at least 95%, preferably at least 97%, more preferably at least 99%, which means that the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. Each such clump dried to a moisture content of about 12% also has a clump crush strength of at least 40 PSI, preferably at least 60 PSI, more preferably 80 PSI, and even more preferably 100 PSI.

[0054] In another preferred litter particle embodiment and method of manufacture, the outer region of each litter particle surrounding the internal substrate particle is composed of a modified starch water-absorbing agglomerant, the agglomerant being formed by ultra-high pressure extrusion as described elsewhere herein or during ultra-high pressure extrusion, the agglomerant being composed of at least one of the following: (a) at least partially water-soluble water-activated moisture-curing modified starch binder, which is or comprises a thermoplastic modified starch component, which can be repeatedly wetted and dried and still retain the properties of its water-soluble binder and / or water-activated moisture-curing binder, and (b) a disposable at least partially water-soluble water-activated moisture-curing modified starch binder, which is or comprises a binder of a thermoset modified starch component or a thermosetting modified starch component, such as a gel or a flowable binder, which forms a water-activated single and moisture-curing single when wetted by water or urine and, when dried, causes it to irreversibly moisture-cure, and when dried to a water content of not more than 15%, preferably about 12% by weight, preferably the weight of the agglomerate, the litter particles of the present invention are formed and dried. The native folding of one or more proteins in the starch-containing mixture is modified during ultra-high pressure extrusion, which is caused by the forces presented thereon due to the extrusion temperature, ultra-high pressure extrusion pressure and shear force presented thereon during the ultra-high pressure extrusion process, forming proteins whose folding is altered in a manner that results in cross-linking of some extruded modified starch, such as extruded modified amylopectin and / or extruded modified amylose, thereby forming at least partially water-soluble water-activated and moisture-curing thermoplastic binders, which are reversible, and the generation, gelation and moisture-curing by drying of rewetting, redissolving, flowable binders can be repeated, preferably infinitely repeated.

[0055] The end result also produces absorbent litter particles that are substantially instantaneously self - caking, which are non - friable, minimizing dust generation during storage, packaging, transportation, and actual litter use. It preferably reduces dust by attracting dust particles and making them adhere to it. It has a round particle shape to minimize litter particle spillage from the litter box by the cat. It has a smooth, round exterior that does not harm the paw pads of clawless cats, and it forms clumps with a clump retention rate of at least 95%, preferably at least 97%, more preferably at least 99%. This means that when a clump formed from litter particles wetted with 10 milliliters of water or urine is dropped from a height of about ten inches onto a porous screen for testing, the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. In another preferred embodiment, when such a clump formed from litter particles wetted with 15 milliliters of water or urine and dried to a moisture content of about 12% is dropped from a height of about ten inches onto a screen for a drop test, each clump has a clump retention rate of at least 95%, preferably at least 97%, more preferably at least 99%, meaning the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. In another also - preferred embodiment, when such a clump formed from litter particles wetted with 10 milliliters of water or urine and dried to a moisture content of about 12% is dropped from a height of about twelve inches onto a screen for a drop test, each clump has a clump retention rate of at least 95%, preferably at least 97%, more preferably at least 99%, meaning the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. In another even - more - preferred embodiment, when such a clump formed from litter particles wetted with 15 milliliters of water or urine and dried to a moisture content of about 12% is dropped from a height of about twelve inches onto a screen for a drop test, each clump has a clump retention rate of at least 95%, preferably at least 97%, more preferably at least 99%, meaning the clump retains at least 95%, preferably at least 97%, more preferably at least 99% of its weight or mass. Each such clump dried to a moisture content of about 12% also has a clump crush strength of at least 40 PSI, preferably at least 60 PSI, more preferably 80 PSI, and even more preferably 100 PSI.

[0056] The present invention also relates to a self - caking adsorbent granular bedding, which is composed of at least partially cold - water - soluble, water - activated, moisture - cured self - caking of the present invention containing a binder and cold - water - swellable, water - absorbent starch - containing adsorbent bedding granules. Each bedding granule is composed of an internal substrate, such as a non - caking material, preferably a coated nucleating substrate fine particle, which has an outer surface wetted with an aqueous liquid, preferably water, or is treated with a slurry of water and a granular modified starch water - absorbing caking agent, so that the substrate fine particle becomes a nucleating agent, and the outer region of the modified starch water - absorbing water - activated caking agent adheres to the nucleating agent. The modified starch water - absorbing water - activated caking agent is preferably a material containing self - caking modified starch, and more preferably composed of an extruded self - caking of at least partially cold - water - soluble water - activated moisture - cured binder and a cold - water - swellable material containing water - absorbent modified starch. Such granular material preferably has a particle size of a powdery substance or powder, is applied and adhered when wet, and during the moisture - curing process of the wet bedding granules completed by drying the bedding granules, adheres and bonds to the outer surface of the substrate granules, for example, through hydrogen bonds and / or preferably through covalent - bond adhesion bonds. The self - caking of at least partially cold - water - soluble water - activated moisture - cured binder and the granular material of cold - water - swellable water - absorbent modified starch are formed by extruding a starch - containing mixture using a single - screw extruder at an ultra - high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, even more preferably at least 5000 PSI. The starch - containing mixture contains a relatively low water content not greater than about 25% of the weight of the mixture to gelatinize at least a first amount of starch in the mixture in the extruder during the ultra - high - pressure extrusion process; a second amount of the mixture starch is subjected to ultra - high extrusion pressure in the extruder during the extrusion process to be modified, such as thermally modified and / or mechanically modified, to form at least 5% of the extrudate weight, preferably at least 7.5% of the extrudate weight, more preferably at least 10% of the extrudate weight of at least partially cold - water - soluble ultra - high - extrusion - pressure water - activated moisture - cured modified starch binder in the mixture extruded in the extruder; a third amount of the mixture starch is subjected to ultra - high extrusion pressure in the extruder during the extrusion process to be modified, such as thermally modified and / or mechanically modified, to form at least 5% of the extrudate weight, preferably at least 10% of the extrudate weight, more preferably at least 20% of the extrudate weight of cold - water - swellable ultra - high - extrusion - pressure modified water - absorbent starch in the mixture extruded in the extruder.

[0057] The present invention also relates to a method for preparing such self - caking adsorbent granular litter, said self - caking adsorbent granular litter being composed of water adsorbent litter particles, said water adsorbent litter particles self - caking together when wetted with water, said water adsorbent litter particles being composed of a particulate substrate having an exterior of adsorbent caking material, said adsorbent caking material being extruded from a starch - containing material under extrusion conditions to form a cold - water - swellable extruded modified water adsorbent starch, said starch preferably being or including, for example, a cold - water - swellable extruded modified water - absorbent starch and at least partially cold - water - soluble extruded modified water - activated moisture - curable starch binder. In a preferred self - caking granular litter of the present invention, each self - caking adsorbent litter particle is formed from smaller internal particles of the substrate, for example, a substrate made of a non - caking material, which may also be a non - absorbent material, even a non - adsorbent material, and even smaller extruded self - caking adsorbent material particles, such as powder of extruded self - caking adsorbent material, are applied and adhered thereto. The extruded self - caking adsorbent material of each litter particle covers or surrounds at least most of the outer surface of the internal substrate microparticles of each particle, preferably covers or surrounds at least 65% of the outer surface of the internal substrate microparticles of each particle, and more preferably covers or surrounds at least 75% of the outer surface of the internal substrate microparticles of each coated litter substrate particle. Each litter particle is composed of 2% to 30% by volume, preferably 3% to 27% by volume, more preferably 5% to 25% by volume of the extruded self - caking adsorbent material. Each litter particle of the present invention is composed of 2% to 30% by weight, preferably 3% to 27% by weight, more preferably 5% to 25% by weight of the extruded self - caking adsorbent material.

[0058] Each self - caking absorbent - coated substrate litter particle contains an extruded at least partially water - soluble water - activated moisture - curable modified starch binder. The self - caking absorbent - coated material contains a cold - water - swellable extruded modified superabsorbent starch, preferably a cold - water - swellable extruded modified superabsorbent starch, which absorbs at least twice its own weight of water, preferably at least three times its own weight of water, more preferably at least four times its own weight of water, even more preferably at least six times its own weight of water. Each self - caking adsorbent - coated substrate litter particle contains a self - caking adsorbent material with an extruded at least partially water - soluble water - activated moisture - curable modified starch binder and contains a cold - water - swellable extruded modified superabsorbent starch, preferably a cold - water - swellable extruded modified superabsorbent starch. The amount in each litter particle is sufficient to cause the coating on the substrate of each coated substrate litter particle to adsorb, preferably absorb at least multiple times, i.e., at least three times the weight of the substrate coating, of water, urine, or synthetic urine, preferably adsorb, preferably absorb at least four times the weight of the substrate coating of water, urine, or synthetic urine, more preferably adsorb, preferably absorb at least five times the weight of the substrate coating of water, urine, or synthetic urine, even more preferably adsorb, preferably absorb at least six times the weight of the substrate coating of water, urine, or synthetic urine. This includes during the process of actually using these litter particles in the self - caking litter of the present invention, and the litter particles are composed of at least 60%, preferably at least 75%, and more preferably at least 85% of the weight of the coated substrate litter particles of the present invention. In at least one preferred embodiment, the extruded self - caking adsorbent material of each coated substrate litter particle contains a cold - water - swellable extruded modified superabsorbent starch, preferably a cold - water - swellable extruded modified superabsorbent starch. The amount in each coated substrate litter particle is sufficient to cause the coating on the substrate of each coated substrate litter particle to adsorb, preferably absorb at least multiple times, i.e., at least three times the weight of the substrate coating, of water, urine, or synthetic urine. During the process of wetting the particles with water, urine, or synthetic urine, preferably adsorb, preferably absorb at least four times the weight of the coating of water, urine, or synthetic urine, more preferably absorb at least five times the weight of the coating of water, urine, or synthetic urine, even more preferably absorb at least six times the weight of the coating of water, urine, or synthetic urine.

[0059] The extruded self - caking adsorbent material of each coated substrate litter particle contains a cold - water - swellable extruded modified water - absorbent starch. Preferably, the amount of the cold - water - swellable extruded modified water - absorbent starch in each coated substrate litter particle is sufficient to cause the outer coating of each coated substrate litter particle to adsorb, preferably absorb, at least multiple pairs, i.e., at least three times the weight of the substrate coating, of water, urine, or synthetic urine. Preferably, it adsorbs, preferably absorbs, at least four times the weight of the litter coating of water, urine, or synthetic urine, more preferably adsorbs, preferably absorbs, at least five times the weight of the coating of water, urine, or synthetic urine, and even more preferably adsorbs, preferably absorbs, at least six times the weight of the coating of water, urine, or synthetic urine. And including during the actual use of the self - caking litter of the present invention, the litter is composed of at least 60%, preferably at least 75%, more preferably at least 85% of the coated substrate litter particles of the present invention by weight of the litter. In a preferred embodiment, the extruded self - caking adsorbent material of each coated substrate litter particle contains a cold - water - swellable extruded modified water - absorbent starch. Preferably, the amount of the cold - water - swellable extruded modified water - absorbent starch in each coated substrate litter particle is sufficient to cause the coating of each coated substrate litter particle to adsorb, preferably absorb, at least multiple pairs, i.e., at least three times the weight of the litter particle coating, of water, urine, or synthetic urine during the wetting process of the particle with water, urine, or synthetic urine. Preferably, it adsorbs, preferably absorbs, at least four times the weight of the substrate coating of water, urine, or synthetic urine, more preferably adsorbs, preferably absorbs, at least five times the weight of the coating of water, urine, or synthetic urine, and even more preferably adsorbs, preferably absorbs, at least six times the weight of the coating of water, urine, or synthetic urine. And including during the actual use of the self - caking litter of the present invention, the litter is composed of at least 60% and not more than 75%, i.e., 60% to 75%, preferably at least 75% and not more than 90%, i.e., 75% to 90%, more preferably at least 90% and up to 100%, i.e., 90% to 100% of the coated substrate litter particles of the present invention by weight of the total litter weight. The extruded self - caking adsorbent material of each coated substrate litter particle preferably consists of at least 5%, preferably at least 7.5%, more preferably at least 10%, even more preferably at least 15% of the cold - water - swellable extruded modified water - absorbent starch, which is preferably or includes at least some cold - water - swellable extruded modified water - absorbent starch, based on the weight of the extruded self - caking adsorbent material. In a preferred embodiment of the litter particle, the extruded self - caking coated substrate particle preferably consists of at least 5%, preferably at least 7.5%, more preferably at least 10%, even more preferably at least 15% of the cold - water - swellable extruded modified water - absorbent starch, based on the weight of the extruded self - caking adsorbent material of each coated substrate litter particle.

[0060] To prepare such a litter composed of litter particles of the self - caking adsorbent - coated substrate of the present invention, which is at least 60% and not more than 75% by weight of the litter, i.e., 60% to 75%, preferably at least 75% and not more than 90%, i.e., 75% to 90%, and more preferably at least 90% and up to 100%, i.e., 90% to 100%. This litter is also a self - caking litter that forms shovellable agglomerates of self - caking adsorbent - coated substrate litter particles when wetted with water, urine, or synthetic urine. The extruded self - caking adsorbent material of each substrate litter particle coated with the self - caking adsorbent contains a sufficient amount of at least partially cold - water - soluble extruded modified water - activated moisture - curable starch binder such that at least some of the water - activated moisture - curable at least partially cold - water - soluble extruded modified starch binder in the extruded self - caking adsorbent material of each substrate litter particle coated with the self - caking adsorbent at least partially or even completely dissolves when the self - caking adsorbent - coated substrate litter particles are wetted with water, urine, or synthetic urine and forms a flowable binder. This binder flows along at least a plurality of contacting litter particles and / or at least a plurality of adjacent litter particles and between them, preferably which have also been wetted with water, urine, or synthetic urine, to form an agglomerate that can be shoveled out of the litter using a hand - held litter shovel. In one such preferred self - caking litter embodiment, the extruded self - caking adsorbent material of each self - caking adsorbent - coated substrate litter particle contains at least 3%, preferably at least 5%, and more preferably at least 7.5% by weight of the extruded self - caking adsorbent material of at least partially cold - water - soluble water - activated moisture - curable extruded modified starch binder per particle. This is a sufficient amount of cold - water - soluble extruded modified starch binder in each coated substrate litter particle that at least partially dissolves and forms a flowable binder which, when wetted with water, urine, or synthetic urine, flows from the particles along at least a plurality of contacting wetted particles and at least a plurality of adjacent wetted particles and between them, self - caking them together into an agglomerate that can be shoveled out of the litter with one hand using a conventional - handled litter shovel such as a perforated litter shovel within thirty seconds after being wetted with water, urine, or synthetic urine.

[0061] The litter of the present invention is composed of less than 100% of the self-caking adsorbent coated substrate litter particles of the present invention, and still self-caking when wetted with water, urine or synthetic urine to form a mass of litter particles that can be scooped up with a conventional porous litter shovel with a handle. Such a litter of the present invention may be composed of no more than 75% of the granular and / or particulate material of the self-caking adsorbent coated substrate litter particles of the present invention, and preferably is composed of 60% to 75% of the granular and / or particulate material of the self-caking adsorbent coated substrate litter particles of the present invention, and may also be a self-caking litter that forms a mass that can be scooped up with a conventional porous litter shovel with a handle when the litter is wetted with water, urine or synthetic urine. In another preferred embodiment of the self-agglomerated litter of the present invention, the litter may be composed of no more than 85% of the granular and / or particulate matter of the self-agglomerated adsorbent-coated substrate litter particles of the present invention, and preferably composed of 70% to 85% of the granular and / or particulate matter of the self-agglomerated adsorbent-coated substrate litter particles of the present invention, and may also be a self-agglomerated litter that forms clumps that can be scooped out using a conventional handled porous litter shovel when the litter is wetted with water, urine or synthetic urine. In another still preferred embodiment of the self-agglomerated litter of the present invention, the litter may be composed of no more than 90% of the granular and / or particulate matter of the self-agglomerated adsorbent-coated substrate litter particles of the present invention, and preferably composed of 75% to 90% of the granular and / or particulate matter of the self-agglomerated adsorbent-coated substrate litter particles of the present invention, and may also be a self-agglomerated litter that forms clumps that can be scooped out using a conventional handled porous litter shovel when the litter is wetted with water, urine or synthetic urine.

[0062] When the litter of the present invention comprises less than 100% of the self-agglomerated adsorbent coated substrate litter particles of the present invention, the remainder of the litter may be made up of one or more types of particles or pellets that do not contain any extruded self-agglomerated adsorbent material, which may be or include non-absorbent and / or non-agglomerated particles or pellets, which may be or include particles or pellets of filler material, and / or which may be or include particles or pellets that are functional and provide or consist of one or more flavors, fragrances, deodorants, urea inhibitors, preservatives, desiccants, wetting agents, Activated carbon and / or activated carbon, carbon black, odor masking agents, fragrance masking agents, odor blockers or odor blockers, fragrance blockers or fragrance blockers, urine odor masking agents or urine odor masking agents, urine odor blockers or blockers or urine odor blockers or blockers, feces odor masking agents or feces odor masking agents, dyes such as urine-reactive dyes or feces-reactive dyes, reagents such as urine-reactive reagents or feces-reactive reagents, catalysts such as urine-reactive or responsive catalysts and / or feces-reactive or responsive catalysts, or it is composed of another type of functional chemical, molecule and / or component.

[0063] The extruded adsorbent caking material on the outside of each self-caking bedding particle of the present invention contains a cold water-swellable extruded modified water-absorbing starch. Preferably, the amount of the cold water-swellable extruded modified water-absorbing starch in each bedding particle is sufficient to enable each bedding particle to adsorb, preferably absorb, at least multiple pairs, i.e., at least three times the weight of the bedding particle, of water, urine or synthetic urine. Preferably, it adsorbs, preferably absorbs, at least four times the weight of the bedding particle of water, urine or synthetic urine. More preferably, it adsorbs, preferably absorbs, at least five times the weight of the bedding particle of water, urine or synthetic urine. Even more preferably, it adsorbs, preferably absorbs, at least six times the weight of the bedding particle of water, urine or synthetic urine. And even more preferably, it adsorbs, preferably absorbs, at least six times the weight of water, urine or synthetic urine. For example, during the actual use of the self-caking bedding of the present invention, the bedding is composed of at least 60%, preferably at least 75%, and more preferably at least 85% of the bedding particles of the present invention.

[0064] In a preferred bedding particle embodiment, the extruded adsorbent caking material forming at least a majority, preferably at least 65%, more preferably at least 75% of the outer surface surrounding the outer surface of each internal substrate particle forming each bedding particle is composed of at least 10%, preferably at least 15%, more preferably at least 20% of the cold water-swellable extruded modified water-absorbing starch, based on the weight of the extruded adsorbent caking material in each bedding particle. In a particularly preferred bedding particle embodiment, the extruded adsorbent caking material outside each bedding particle is composed of at least 10%, preferably at least 15%, and more preferably at least 20% of the cold water-swellable extruded modified water-absorbing starch based on the weight of the extruded adsorbent caking material of each bedding particle.

[0065] The extruded self-caking adsorbent material of each bedding particle contains a cold water-swellable extruded modified water-absorbing starch. Preferably, the amount of the cold water-swellable extruded modified water-absorbing starch in each bedding particle is sufficient to enable each bedding particle to adsorb, preferably absorb, at least multiple pairs, i.e., at least three times the weight of the bedding particle, of water, urine or synthetic urine. Preferably, it adsorbs, preferably absorbs, at least four times the weight of the bedding particle of water, urine or synthetic urine. More preferably, it adsorbs, preferably absorbs, at least five times the weight of the bedding particle of water, urine or synthetic urine. Even more preferably, it adsorbs, preferably absorbs, at least six times the weight of the bedding particle of water, urine or synthetic urine. This includes during the actual use of the self-caking bedding of the present invention, the bedding is composed of at least 60%, preferably at least 75%, and more preferably at least 85% of the bedding particles of the present invention.

[0066] In a preferred embodiment, each extruded self - caking adsorbent material of the coated substrate litter particle contains a cold - water - swellable extruded modified water - absorbent starch. Preferably, the amount of the cold - water - swellable extruded modified water - absorbent starch in each litter particle is sufficient to cause the coating of each coated substrate litter particle to adsorb, preferably absorb, at least multiple pairs, i.e., at least three times the weight of the litter particle, of water, urine, or synthetic urine. Preferably, it adsorbs, preferably absorbs at least four times the weight of the particle of water, urine, or synthetic urine, more preferably adsorbs, preferably absorbs at least five times the weight of the particle of water, urine, or synthetic urine, even more preferably adsorbs, preferably absorbs at least six times the weight of the particle of water, urine, or synthetic urine. This includes during the actual use of the self - caking litter of the present invention, the litter is composed of at least 60% and not more than 75%, i.e., 60% to 75%, preferably at least 75% and not more than 90%, i.e., 75% to 90%, and more preferably at least 90% to up to 100%, i.e., 90% to 100% of the litter particles of the present invention. The extruded self - caking adsorbent material of each litter particle preferably consists of at least 5%, preferably at least 7.5%, more preferably at least 10%, and even more preferably at least 15% of the cold - water - swellable extruded modified water - absorbent starch by weight of the extruded self - caking adsorbent material, which is preferably or includes at least some cold - water - swellable extruded modified water - absorbent starch. In a preferred embodiment of the litter particle, the extruded self - caking particle preferably consists of at least 5%, preferably at least 7.5%, more preferably at least 10%, even more preferably at least 15% of the cold - water - swellable extruded modified water - absorbent starch by weight of each extruded self - caking adsorbent material pellet.

[0067] The at least partially soluble cold - water - soluble extruded modified starch water - activated moisture - cured binder also contains in the extruded caking material outside each litter particle, which is at least partially soluble when wetted with water, urine, or synthetic urine, such that at least some of the at least partially dissolved binder forms a flowable adhesive that flows out from between and around at least multiple contacting litter particles and at least multiple adjacent litter particles, self - caking them together into a mass composed of at least multiple pairs, i.e., at least three, preferably at least five, more preferably at least ten, and even more preferably at least twenty litter particles. When the mass is air - dried at room temperature to a water content of about 12% of the weight of the mass, such a mass has a mass retention rate of at least 95%, preferably at least 97%, and more preferably at least 99%, and a mass crush strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and most preferably at least 100 PSI. This makes the litter of the present invention have a higher caking efficiency than the litter composed of substantially completely, e.g., 95% ± 5% of sodium - based bentonite.

[0068] In the preparation process of implementing the method for preparing bedding according to the present invention, the fine particles of the desired base material, which are composed of materials that do not agglomerate when wetted with water, urine, or even synthetic urine, can and preferably are classified in a particle size grading step, for example, by screening, sieving, etc., to remove the undesired over-sized particles and the undesired under-sized particles. In a preferred particle size grading step, the first or initial amount of ungraded fine particles of the base material is particle size graded using a plurality of sieves or screens of different sizes, the mesh number or sieve aperture size of which is selected to obtain a second and desired amount of particle size graded fine particles, the particle size graded fine particles having at least multiple pairs, i.e., at least three different particle size ranges falling within the desired upper and lower limits, i.e., within the desired base material particle size distribution range of the fine particles, which are respectively defined by passing through at least one sieve or screen having a first mesh number, mesh, or sieve aperture size, which is configured to define the upper limit or the large particle size cut-off value, and by passing through at least one other sieve having a second mesh number, mesh, or sieve aperture size, which is configured to define the lower limit or the small particle size cut-off value.

[0069] In a preferred particle size grading step of the base material fine particles, a plurality of size grading sieves are selected to particle size grade the first or initial amount of ungraded base material fine particles to obtain a second and desired amount of particle size graded base material fine particles, wherein at least 80%, preferably at least 90%, and more preferably at least about 95% of the base material fine particles have particle sizes falling within a particle size distribution range such as (a) 0.0165 inches or 0.42 mm (40 mesh sieve / screen or 35 mesh sieve) to 0.0937 inches or 2.38 mm (8 mesh sieve / screen or 8 mesh), (b) preferably 0.0234 inches or 0.595 mm (30 mesh sieve / screen or 28 mesh) to 0.0787 inches or 2.00 mm (10 mesh sieve / screen or 9 mesh), (c) more preferably between 0.0278 inches or 0.707 mm (25 mesh sieve / screen or 24 mesh) to 0.0661 inches or 1.68 mm (12 mesh sieve / screen or 10 mesh), and (d) even more preferably 0.0331 inches or 0.841 mm (20 mesh sieve / screen or 20 mesh) to 0.0661 inches or 1.68 mm (12 mesh sieve / screen or 10 mesh).

[0070] In a preferred embodiment of the bedding particles of the present invention and an embodiment of the method for preparing such particles, a preferred type of the substrate microparticles used as a nucleating agent for the bedding particles to prepare the bedding particles is an inorganic granular substrate material that is generally incompressible or crush-resistant, such as perlite, which is also non-caking and preferably also porous, for example, having micropores, preferably at least slightly water-absorbent and crushed, ground or otherwise comminuted to have a particle size in the range of (a) 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh), and / or (b) 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh). In another preferred embodiment of the bedding particles of the present invention and an embodiment of the method for preparing such particles, a preferred type of the substrate microparticles used as a nucleating agent for the bedding particles to prepare the bedding particles is a crush-resistant inorganic particulate substrate material, preferably of sand particles, such as non-porous and non-water-absorbent silica sand, size-graded to provide substrate microparticles, i.e., having a particle size or fine particle size in the range of (a) 0.0165 inches or 0.42 mm (No. 40 sieve / mesh or 35 mesh) to 0.0937 inches or 2.38 mm (No. 8 sieve / mesh or 8 mesh), and / or (b) 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh).

[0071] In another also preferred embodiment of the litter particles of the present invention and an embodiment of the method for preparing such particles, a preferred type of the substrate particles serving as a nucleating agent for the litter particles is a water-absorbing granular montmorillonite clay, such as preferably bentonite or bentonite clay, which is relatively soft so as to be crushable and / or friable, and may be porous and preferably is porous, which is at least partially composed of montmorillonite, and which preferably has a particle size distribution range from 0.0331 inches or 0.841 mm (No. 20 sieve / screen or 20 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh), but which may have a particle size distribution range from 0.0278 inches or 0.707 mm (No. 25 sieve / screen or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh). In one such preferred granular substrate material, each of the substrate particles is composed of a relatively soft non-caking water-absorbing montmorillonite clay, which is preferably a calcium-based bentonite having a particle size distribution range from 0.0331 inches or 0.841 mm (No. 20 sieve / screen or 20 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh) or from 0.0278 inches or 0.707 mm (No. 25 sieve / screen or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh). In another such preferred granular substrate material, which has a particle size distribution range similar to or substantially the same as one of the particle size distribution ranges described above in this paragraph, each of the substrate particles is composed of another type of montmorillonite, such as attapulgite, fuller's earth, sepiolite, and / or kaolinite.

[0072] The self - caking adsorption bedding of the present invention can also be made from self - caking adsorbent bedding particles, which are made from a mixture or blend of multiple or even multiple pairs of different types of montmorillonite clay nucleating agents according to the bedding particle preparation method of the present invention. It includes multiple or multiple pairs of combinations of calcium - based bentonite substrate microparticles, sodium - based bentonite substrate microparticles, and / or one or more palygorskite substrate microparticles, bleaching earth substrate microparticles, sepiolite substrate microparticles, and / or kaolinite substrate microparticles. All different types of substrate microparticles are mixed or blended together in a mixing step, which can be carried out during the wetting step, but is preferably carried out before adding the extruded self - caking adsorbent material microparticles. In a mixture of such different types of substrate microparticles, the combined substrate microparticle mixture can have a particle size distribution range of (a) from 0.0278 inches or 0.707 mm (No. 25 sieve / screen or 24 mesh sieve) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh sieve) and (b) from 0.0331 inches or 0.841 mm (No. 20 sieve / screen or 20 mesh sieve) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh sieve).

[0073] In another preferred embodiment of the self - caking adsorption bedding particles of the present invention and the method for preparing self - caking adsorption bedding particles, another preferred type of substrate material used as a bedding particle nucleating agent in granular form to prepare bedding particles is composed of organic materials, which can be substantially completely organic and in the form of substrate microparticles composed essentially entirely of paper, wood fibers such as wood or wood pellets, wood shavings, bark, etc., and has a particle size distribution range of (a) between 0.0331 inches or 0.841 mm (No. 20 sieve / screen or 20 mesh sieve) and 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh sieve), and / or (b) between 0.0278 inches or 0.707 mm (No. 25 sieve / screen or 24 mesh sieve) and 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh sieve). In a preferred embodiment of paper substrate microparticles, the paper substrate microparticles are preferably generally round and preferably substantially round or substantially spherical, and have a particle size range of (a) from 0.0331 inches or 0.841 mm (No. 20 sieve / screen or 20 mesh sieve) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh sieve), and / or (b) from 0.0278 inches or 0.707 mm (No. 25 sieve / screen or 24 mesh sieve) to 0.0661 inches or 1.68 mm (No. 12 sieve / screen or 10 mesh sieve).

[0074] In the further preferably self - caking adsorbent bedding particles and the method for preparing the same of the present invention, another preferably type of organic base material used in the form of granules as a bedding particle nucleating agent to prepare the bedding particles of the present invention is granular nut shell material, preferably in the form of porous, such as microporous. The water - absorbent walnut shell is crushed, ground or otherwise comminuted into relatively small base material microparticles, which have a size range of 0.0331 inches or 0.841 mm (No. 20 sieve / mesh or 20 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh), but it can be sized - classified to have a size range of 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh). In the further more preferably self - caking adsorbent bedding particles and the method for preparing the same of the present invention, another preferably type of organic nut shell base material used in the form of granules as a bedding particle nucleating agent to prepare the bedding particles of the present invention is granular hazelnut shell material, preferably in the form of porous, such as microporous. The water - absorbent hazelnut shell is crushed, ground or otherwise comminuted into relatively small base material microparticles, which have (a) a size range of 0.0331 inches or 0.841 mm (No. 20 sieve / mesh or 20 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh), and / or (b) a size range of 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh). In another preferably self - caking adsorbent bedding particles and the method for preparing the same of the present invention, another preferably type of organic nut shell base material used in the form of granules as a bedding particle nucleating agent to prepare the bedding particles of the present invention is granular cashew nut shell material, preferably in the form of porous, such as microporous. The water - absorbent cashew nut shell is crushed, ground or comminuted into relatively small base material microparticles, which have (a) a size range of 0.0331 inches or 0.841 mm (No. 20 sieve / mesh or 20 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh), and / or (b) a size range of 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh).In yet another even more preferred self - caking adsorbent bedding granule and method of making the self - caking adsorbent bedding granule of the present invention, another preferred type of organic nut shell base material used as a bedding granule nucleating agent in granular form to make the bedding granules of the present invention is granular almond shell material, preferably in a porous such as microporous form. The water - absorbent almond shells are crushed, ground or pulverized into relatively small base material microparticles having (a) a particle size range of 0.0331 inches or 0.841 mm (20 - mesh sieve / screen or 20 US mesh) to 0.0661 inches or 1.68 mm (12 - mesh sieve / screen or 10 US mesh), and / or (b) a particle size range of 0.0278 inches or 0.707 mm (25 - mesh sieve / screen or 24 US mesh) to 0.0661 inches or 1.68 mm (12 - mesh sieve / screen or 10 US mesh). Other types of nut shells, including the husks or shells from macadamia nuts such as macadamia nut shells, the husks or shells from peanuts such as peanut husks or peanut shells, the husks or shells from Brazil nuts such as Brazil nut shells, the shells or husks from pine nuts such as pine nut shells, and the husks or shells from pecans such as pecan shells, can also be found or pulverized into microparticles and used as bedding granule nucleating agents in the preparation of the bedding granules of the present invention, wherein the crushed or pulverized shell base material microparticles have (a) a particle size range of 0.0331 inches or 0.841 mm (20 - mesh sieve / screen or 20 US mesh) to 0.0661 inches or 1.68 mm (12 - mesh sieve / screen or 10 US mesh) and / or (b) a particle size range of 0.0278 inches or 0.707 mm (25 - mesh sieve / screen or 24 US mesh) to 0.0661 inches or 1.68 mm (12 - mesh or 10 US mesh).

[0075] Other types of materials are also contemplated, which include plastics, rubbers such as waste tires, glass, wood pellets, wood chip pellets, wood shavings, bark, and other types of non-agglomerated materials that can be ground, crushed, or pulverized into fine particles, which are screened, sieved, or otherwise size-graded to have a particle size range or particle size distribution range that falls within at least one preferred particle size range: (a) 0.0331 inches or 0.841 mm (No. 20 sieve / mesh or 20 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh), and / or (b) 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh). In a preferred embodiment of the paper substrate fine particles, the paper substrate fine particles are preferably generally round and preferably substantially round or substantially spherical, and have a particle size range of (a) 0.0331 inches or 0.841 mm (No. 20 sieve / mesh or 20 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh), and / or (b) 0.0278 inches or 0.707 mm (No. 25 sieve / mesh or 24 mesh) to 0.0661 inches or 1.68 mm (No. 12 sieve / mesh or 10 mesh).

[0076] It should be noted that the present invention contemplates a self-agglomerating adsorbent padding composed of self-agglomerating adsorbent padding particles, which are made of at least multiple pairs and preferably at least multiple pairs, i.e., at least three different types of substrate fine particles, which includes mixing or blending different types of substrate fine particles together before or during the wetting step, applying an aqueous liquid, preferably water, to wet the substrate fine particles in the wetting step, and in the activation step and / or the nucleation step (and any one or more drying steps), the wet substrate fine particles each act as a nucleating agent, and the extruded self-agglomerating adsorbent material fine particles adhere to the nucleating agent, and since some but not all of the water-soluble binders in the adhered extruded self-agglomerating adsorbent material fine particles are activated by the water on the wet contacting substrate fine particles and become sticky, at least partially dissolve some of the binders. In a preferred embodiment of the method for preparing the padding and padding particles, at least multiple and preferably at least multiple pairs, i.e., at least three different types of crushed nut shell fine particles, such as multiple, preferably at least multiple pairs of walnut shell fine particles, hazelnut shell fine particles, cashew nut shell fine particles, pecan shell fine particles, peanut shell fine particles, macadamia nut shell fine particles, pine nut shell fine particles, almond shell fine particles, and / or Brazil nut shell fine particles, can be blended together and wetted together, and smaller extruded self-agglomerating adsorbent material fine particles are added to the wetted nut shell fine particle mixture or blend, so that the activation step, the nucleation step, and any one or more drying steps are carried out together.

[0077] In a preferred embodiment of the method for preparing bedding and bedding particles, in the combined base material particle mixing step, at least one type of base material, such as base material particles of one or more types of the above-mentioned nut shells, is admixed or mixed with at least one other type of base material, such as base material particles of one or more types of montmorillonite clay, perlite, paper, pellets, or other types of base materials suitable for use as nucleating base material particles of the extrudable self-agglomerating adsorbent material. This step can be carried out before or during the application of the extrudable self-agglomerating adsorbent material particles in the application and / or nucleation step, and before or during the wetting of the mixture or admixture of each different type of base material particles. In another preferred embodiment of the method for preparing bedding and bedding particles, in the combined base material particle mixing step, base material particles of at least one type of bentonite clay, preferably calcium-based bentonite, are admixed or mixed with base material particles of an organic base material such as paper and / or nut shells (preferably walnut shells), wherein the different types of base material particles are mixed or admixed together, preferably substantially simultaneously. This step can be carried out before or during the application of the extrudable self-agglomerating adsorbent material particles, and before or during the wetting of the mixture or admixture of the calcium-based bentonite base material particles, paper base material particles, and / or nut shell base material particles (preferably walnut shell base particles). In another still preferred embodiment of the method for preparing bedding and bedding particles, in this combined base material particle mixing step, base material particles of at least one type of bentonite clay, preferably calcium-based bentonite, are admixed or mixed with base material particles of another base material, preferably perlite. In the preferred implementation of the bedding preparation method of the present invention, this step can be carried out before or during the application of the extrudable self-agglomerating adsorbent material particles, and before or during the wetting of the mixture or admixture of the calcium-based bentonite and perlite base material particles. In another still preferred embodiment of the method for preparing bedding and bedding particles, in this combined base material particle mixing step, base material particles of at least one type of bentonite clay, preferably calcium-based bentonite, are admixed or mixed with base material particles of another base material, preferably sand. In the implementation of the bedding preparation method of the present invention, this step can be carried out before or during the application of the extrudable self-agglomerating adsorbent material particles, and before or during the wetting of the mixture or admixture of the calcium-based bentonite and sand base material particles. In a further preferred embodiment of the method for preparing bedding and bedding particles, in the combined base material particle mixing step, base material particles of at least one type of organic material such as paper, wood pellets, wood shavings, bark, or another type of organic material are admixed or mixed with base material particles of another type of base material such as sand. In the preparation of the self-agglomerating bedding particles of the present invention, this step can be carried out before or during the application of the extrudable self-agglomerating adsorbent material particles, and before or during the wetting of the mixture or admixture of at least one type of organic material and sand base material particles.In a further preferred embodiment of the method for preparing litter and litter particles, in this combined substrate particle mixing step, substrate particles of at least one type of organic material such as paper, wood pellets, wood shavings, bark or another type of organic material are admixed or mixed with substrate particles of another type of substrate material such as perlite. This step can be carried out before or during the application of the extruded self-agglomerating adsorbent material particles, and before or during the wetting of the mixture or admixture of the substrate particles of at least one type of organic material and perlite. In a still further preferred embodiment of the method for preparing litter and litter particles, in the combined substrate particle mixing step, substrate particles of at least one type of organic material such as paper, wood pellets, wood shavings, bark or another type of organic material are admixed or mixed with substrate particles of another type of organic substrate material such as nut shells, e.g., walnut shells. In a preferred implementation of the method for preparing litter according to the present invention, this step can be carried out before or during the application of the extruded self-agglomerating adsorbent material particles, and before or during the wetting of the mixture or admixture of the substrate particles of at least one type of organic material and the substrate particles of another type of organic material.

[0078] In an agglomerated sandy litter composed of self-agglomerating adsorbent litter particles, the litter particles are made of fine sand particles of a substrate coated with a modified starch absorbent agglomerating material or reagent of the present invention. Only 10% by weight of the litter is composed of the fine powder / powdery substance / powder of the extruded modified starch absorbent agglomerating material or reagent, and the remaining 90% is composed of fine sand particles, which agglomerate to form dry lumps. When dried to a water content of about 12% of the lump weight, the lumps have a lump retention rate of at least 95% and a lump crushing strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even more preferably 100 PSI.

[0079] If the sand is a non-agglomerating substrate, the coating thickness is less than 0.5 mm - with a thickness of 0.25 mm to 0.5 mm, and the coating consists of: (a) a water-soluble binder, which consists of (i) a water-soluble binder portion that does not undergo retrogradation, and (ii) a redissolved water-soluble binder portion; (b) granular non-agglomerating substrate, where no more than 35% of the weight of the agglomerated litter is composed of the water-soluble binder and the extruded fine powder and powder, and the fine powder and powder are composed of the extruded modified starch absorbent agglomerating agent or material.

[0080] In an embodiment of a preferred method for preparing litter and litter particles, in the combined base material particle mixing step, base material particles of at least one type of montmorillonite clay, preferably calcium-based bentonite, are admixed or mixed with base material particles of at least one other type of montmorillonite clay, preferably sodium-based bentonite. In a preferred implementation of the method for preparing litter according to the present invention, this step can be carried out before or during the application of the extruded self-agglomerating adsorbent material particles, and before or during the wetting of the mixture or admixture of the calcium-based bentonite and sodium-based bentonite base material particles. In another embodiment of a preferred method for preparing litter and litter particles, a batch of the self-agglomerating litter particles of the present invention is prepared using fine particles of a first type of montmorillonite clay, preferably calcium-based bentonite or Ca-montmorillonite, as the base material particles, which are also nucleating agents, to which smaller particles of the extruded self-agglomerating adsorbent material adhere when wetted. Another batch of the self-agglomerating litter particles of the present invention is prepared using fine particles of a second type of montmorillonite clay, preferably sodium-based bentonite or Na-montmorillonite, as the base material particles, which are also nucleating agents, to which smaller particles of the extruded self-agglomerating adsorbent material adhere when wetted, and the resulting two batches of the self-agglomerating adsorbent litter particles of the present invention are combined together, for example, by mixing or admixing them in a drum mixer or a rotary drum mixer, a paddle mixer or another type of commercially available mixer or blender.

[0081] In an embodiment of a preferred method for preparing litter and litter particles, at least multiple and preferably at least multiple pairs, i.e., at least three different types of ground nut shell particles, such as multiple, preferably at least multiple pairs of walnut shell particles, hazelnut shell particles, cashew nut shell particles, pecan shell particles, peanut shell particles, macadamia nut shell particles, pine nut shell particles, almond shell particles, and / or brazil nut shell particles, can be admixed together, wetted together, and smaller particles of the extruded self-agglomerating base material are added to the wetted nut shell particle mixture or admixture such that the activation step, the nucleation step, and any one or more drying steps are carried out together.

[0082] The resulting self-agglomerating adsorbent bedding particles prepared using substrate microparticles having one of the preferred particle size ranges disclosed above have a similar particle size range or particle size distribution range, but are 1% to 8% larger in particle size than the substrate microparticles due to the thickness of the extruded self-agglomerating adsorbent material applied thereto when implementing one of the self-agglomerating bedding particle methods disclosed above. For example, when using substrate microparticles having a particle size range or particle size distribution range of 0.0165 inches or 0.40 mm (40 mesh / sieve or 35 mesh) to 0.0937 inches or 2.38 mm (8 mesh / sieve or 8 mesh), the resulting self-agglomerating bedding particles formed from substrate microparticles within this size range will be slightly larger than the resulting self-agglomerating bedding particles formed from substrate microparticles having a particle size range of approximately 0.018 inches or approximately 0.45 mm to approximately 0.0985 inches or approximately 2.5 mm. For example, when using substrate microparticles having a particle size range or particle size distribution range of 0.0234 inches or 0.595 mm (30 mesh / sieve or 28 mesh) to 0.0787 inches or 2.00 mm (10 mesh / sieve or 9 mesh), the resulting self-agglomerating bedding particles formed from substrate microparticles within this size range will be slightly larger than the resulting self-agglomerating bedding particles formed from substrate microparticles having a particle size range of approximately 0.025 inches or approximately 0.635 mm to approximately 0.085 inches or approximately 2.16 mm. When using substrate microparticles having a particle size range or particle size distribution range of 0.0278 inches or 0.707 mm (25 mesh / sieve or 24 mesh) to 0.0661 inches or 1.68 mm (12 mesh / sieve or 10 mesh), the resulting self-agglomerating bedding particles formed from substrate microparticles within this size range will be slightly larger than the resulting self-agglomerating bedding particles formed from substrate microparticles having a particle size range of approximately 0.0290 inches or approximately 0.736 mm to approximately 0.075 inches or approximately 1.90 mm. Finally, when using substrate microparticles having a particle size range or particle size distribution of 0.0331 inches or 0.841 mm (20 mesh / sieve or 20 mesh) to 0.0661 inches or 1.68 mm (12 mesh / sieve or 10 mesh), the resulting self-agglomerating bedding particles formed from substrate microparticles within this size range will be slightly larger than the resulting self-agglomerating bedding particles formed from substrate microparticles having a particle size range of approximately 0.0365 inches or approximately 0.927 mm to approximately 0.075 inches or approximately 1.90 mm.Accordingly, the above-preferred substrate particle size range advantageously results in a self-agglomerating adsorbent bedding according to the present invention, wherein after applying the required amount, such as the required mass, required weight, or required volume of extruded self-agglomerating adsorbent material particles to the required amount of one or more than one of the above types of substrate fine particles having a particle size, particle size range, or particle size distribution within one of the particle size ranges disclosed above, the resulting self-agglomerating adsorbent bedding particles of the present invention produce self-agglomerating adsorbent bedding particles of the present invention having a particle size falling within a similar particle size range of the substrate fine particles used to manufacture the bedding particles, but having a particle size 1% to 5% larger than the particle size of the substrate fine particles used to prepare the bedding particles.

[0083] During the application of the outer region of the extruded self-agglomerating adsorbent material, the resulting self-agglomerating bedding particles of the present invention prepared using the substrate fine particles as bedding particle nucleating agents produce the resulting bedding particles, wherein the coating weight of the extruded self-agglomerating adsorbent material particles on each substrate fine particle is 5% to 45% of the weight of the bedding particles, preferably the coating weight of the extruded self-agglomerating adsorbent material particles on each substrate particle is 10% to 40% of the weight of the extruded self-agglomerating adsorbent material bedding particles, and more preferably the extruded self-agglomerating adsorbent material on each substrate particle is 15% to 35% of the weight of the extruded self-agglomerating adsorbent material bedding particles. In the case of preparing self-agglomerating adsorbent bedding particles using sand as the substrate fine particles and particle nucleating agents, the application rate of the extruded self-agglomerating adsorbent material on each fine sand particle is 5% to 20% of the weight of the bedding particles, preferably 10% to 20% of the weight of the bedding particles, and more preferably 5% to 15% of the weight of the bedding particles. In the case of preparing self-agglomerating adsorbent bedding particles using calcium-based bentonite as the substrate fine particles and particle nucleating agents, the application rate of the extruded self-agglomerating adsorbent material on each calcium-based bentonite particle is 10% to 40% of the weight of the bedding particles, preferably 15% to 30% of the weight of the bedding particles, and more preferably 20% to 25% of the weight of the bedding particles.

[0084] It has been found that the larger the substrate particles, the greater the weight of the modified starch water-absorbing caking agent, preferably the particle coating of the extruded self-caking absorbent material, which needs to be applied to each substrate particle during the preparation of the litter particles to ensure that each final litter particle contains sufficient modified starch water-absorbing caking agent, preferably the extruded self-caking absorbent material, which constitutes the outer region of each litter particle to ensure good caking when the litter made of the litter particles is wetted with water or urine. In other words, it has been found that the larger the size of the substrate particles used to prepare the litter particles, the greater the coating weight of the granular modified starch water-absorbing caking agent, preferably the extruded self-caking absorbent material, which needs to adhere to the substrate particles of each litter particle to ensure that each final litter particle contains sufficient extruded self-caking absorbent material, which constitutes the outer water-absorbing water-soluble binder release region to ensure that when the litter made of the litter particles is wetted with water or urine, a quickly removable and shovelable mass is formed, which has a mass retention rate of at least 97%, preferably at least 99%.

[0085] The self-caking absorbent litter particles of the present invention made according to the method for preparing the litter particles of the present invention, the particles of which are formed by substrate particles, each substrate particle being at least partially covered or encapsulated by an extruded absorbent caking material, wherein the modified starch water-absorbing caking agent is preferably formed in an amount of 2% to 40%, preferably 5% to 35%, more preferably 5% to 25% of the weight of each particle in the form of the extruded absorbent caking material, which absorbs at least multiple pairs, i.e., at least three times the weight of the particles, of water or urine, preferably absorbs at least four times the weight of the particles of water or urine, more preferably absorbs at least five times the weight of the particles of water or urine, and even more preferably absorbs at least six times the weight of the particles of water or urine, and when the water or urine wets the particles, they self-cake into a mass having a mass retention rate of at least 95%, preferably at least 97% and more preferably at least 99% and a mass crushing strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI and even more preferably at least 100 PSI when the mass is dried at room temperature to a water content of about 12% of the mass weight.

[0086] In a preferred embodiment of the method for preparing the self - caking adsorbent litter particles of the present invention, in the wetting step, the substrate microparticles are wetted with an aqueous liquid, for example preferably only with water, to prepare substrate microparticles for the application of even smaller microparticles of a modified starch water - absorbing caking agent, preferably an extruded adsorbent caking material, while the substrate microparticles can be and preferably are non - caking, for example composed of non - caking material, and can also be non - adsorbent, for example composed of non - water - absorbing material. In this step, the substrate microparticles are wetted with an aqueous liquid, preferably water, by wetting their outer surfaces to prepare the microparticles such that even smaller microparticles of a modified starch water - absorbing caking agent, preferably an extruded adsorbent caking material, can be applied thereon and adhere thereto during the implementation of subsequent steps of the litter preparation method of the present invention, ultimately generating the self - caking adsorbent litter particles of the present invention. Wetting the substrate microparticles with an aqueous liquid, for example preferably water, ensures that at least some water, preferably sufficient water, is available on the outer surface of the substrate microparticles to at least partially dissolve some but not all of the cold - water - soluble extruded modified starch binder of the smaller particles of the modified starch water - absorbing caking agent, preferably the extruded adsorbent caking material in contact with the surface of the wetted substrate microparticles. When these smaller - sized microparticles of the modified starch water - absorbing caking agent, preferably the extruded adsorbent caking material, come into contact with the outer surface of the water - wetted substrate microparticles, at least some but not all of the cold - water - soluble extruded modified starch binder of the smaller microparticles of the modified starch water - absorbing caking agent, preferably the extruded adsorbent caking material, forms at least some flowable binder, which initially facilitates or further facilitates adhesion to the outer surface of the substrate microparticles before adhering and fixing substantially immovably to the outer surface of the substrate microparticles, since the flowable binder cures and hardens as it dries. In the process, at least partially dissolved water - soluble binder from the wetted microparticles of the extruded adsorbent caking material forms a flowable binder, which initially adheres to a portion of the outer surface of a corresponding wetted substrate microparticle by intermolecular attraction, but subsequently becomes substantially immovably adhered or fixed to the same portion of the outer surface of a corresponding wetted substrate microparticle by intramolecular attraction as the flowable binder cures and solidifies into a hard solid glassy material in a glassy material state. This occurs when the finally formed self - caking litter particles are dried, preferably dried to a water content not greater than 12% by weight, preferably not greater than 10% by weight, more preferably not greater than about 8% by weight, to ensure proper moisture curing, hardening, and adhesion of the outer region to each substrate microparticle of each final litter particle.

[0087] In a preferred embodiment of the method for manufacturing bedding particles, during the application step and / or the nucleation step, at least some but not all of the cold water-soluble extruded modified starch water-activated moisture-curing binder is at least partially dissolved, such that at least 5% and not more than 65%, i.e., 5% to 65%, preferably at least 10% and not more than 50%, i.e., 10% to 50%, more preferably at least 15% and not more than 45%, i.e., 15% to 45% by weight of the cold water-soluble extruded modified starch water-activated moisture-curing binder in the wetted smaller particles of the extruded self-caking adsorbent material is at least partially dissolved. In another method embodiment, in the 5% to 65%, preferably 10% to 50%, more preferably 15% to 45% by weight of the cold water-soluble extruded modified starch moisture-curing binder that is at least partially dissolved in one or more wetting and / or application steps and / or nucleation sub-steps, at least some but not all of the cold water-soluble extruded modified water-activated moisture-curing starch binder of the granular modified starch water-absorbing caking agent applied to the substrate particles during the wetting step, application step, and / or nucleation sub-step is substantially completely dissolved in or dissolved by the water in the aqueous wetting liquid that provides wetting of the substrate particles.

[0088] In a further still preferred method implementation, during the wetting step, application step, and nucleation sub-step, at least some but not all of the cold water-soluble extruded modified starch water-activated moisture-curing binder of the modified starch water-absorbing caking agent is at least partially dissolved, such that at least 5% and not more than 65%, i.e., 5% to 65%, preferably at least 10% and not more than 50%, i.e., 10% to 50%, more preferably at least 15% and not more than 45%, i.e., 15% to 45% by weight of the cold water-soluble extruded modified starch binder in the wetted smaller particles of the extruded self-caking adsorbent material is dissolved, preferably substantially completely water-dissolved. In a still further preferred method implementation, in the 5 wt% to 65 wt%, preferably 10 wt% to 50 wt%, and more preferably 15 wt% to 45 wt% of the cold water-soluble extruded modified starch binder that is at least partially dissolved during one or more wetting and / or application steps and / or nucleation sub-steps, during the wetting step, application step, and / or nucleation sub-step, at least some of the at least partially dissolved cold water-soluble extruded modified starch binder is substantially completely dissolved or dissolved by the water that provides wetting.

[0089] In yet another preferred method implementation, during the application step and / or the nucleating step, at least some but not all of the cold water-soluble extruded modified starch water-activated moisture-curing binder is dissolved, preferably substantially completely dissolved in water or provided with wetted water dissolution, such that at least 5% and not more than 65%, i.e., 5% to 65%, preferably at least 10% and not more than 50%, i.e., 10% to 50%, and more preferably at least 15% and not more than 45%, i.e., 15% to 45% by weight of the cold water-soluble extruded modified starch binder in the wetted smaller particles of the extruded self-caking adsorbent material is partially dissolved, preferably substantially completely water-dissolved. In a still further preferred method implementation, during the wetting step, application step, and nucleating step, at least some but not all of the cold water-soluble extruded modified starch binder is dissolved, preferably substantially completely water-dissolved, such that at least 5% and not more than 65%, i.e., 5% to 65%, preferably at least 10% and not more than 50%, i.e., 10% to 50%, more preferably at least 15% and not more than 45%, i.e., 15% to 45% by weight of the cold water-soluble extruded modified starch binder in the wetted smaller particles of the extruded self-caking adsorbent material is at least partially, preferably substantially completely water-dissolved.

[0090] During this time, at least partial dissolution of the cold water-soluble binder and any cold water-soluble starch of the extruded self-caking adsorbent material particles that have adhered to the corresponding outer wetted surfaces of the bedding particle nucleating substrate particles not only forms a flowable binder that causes the wetted extruded self-caking adsorbent material to flow, but also causes the cold water-soluble binder and other cold water-soluble starch of each adhered extruded self-caking adsorbent material particle to flow together, thereby causing the adhered extruded self-caking adsorbent material particles to coalesce into a substantially uniform and consistent outer region of the extruded self-caking adsorbent material, which outer region at least partially and preferably substantially completely surrounds or encapsulates the wetted outer substrate particle surface, and the flowable binder dries, retrogrades, and adhesively binds the substantially uniformly coalesced outer region of the extruded self-caking adsorbent material.

[0091] Because at least during the activation step, adhesion step, and / or nucleating step (as well as the wetting step, where the extruded self-caking adsorbent particle material is added while the wetting step is being carried out), only some but not all of the cold water-soluble extruded modified starch water-activated moisture-curing binder of at least partially wetted extruded adsorbent particles is partially or completely dissolved, and at least some of the other cold water-soluble extruded modified starch binders of at least partially wetted extruded adsorbent mass material particles are not partially or completely dissolved, the resulting self-caking adsorbent bedding particles thus formed can still be at least partially or completely dissolved when wetted with water, urine, or synthetic urine.

[0092] In at least one preferred embodiment of the method of preparing self - caking adsorbent bedding particles from any of the foregoing substrate particles, the drying step can and preferably is carried out during or after the application step, after the adhesion step and / or the nucleation step have been completed, in order to (a) remove excess moisture from each newly - formed bedding particle, which is formed from an extruded self - caking adsorbent material that at least partially and preferably substantially completely encapsulates the outer surface region of the corresponding substrate particle forming the particle nucleus, and (b) solidify, cure or at least promote solidification, or promote the curing of a water - soluble water - activated moisture - curable binder from at least partial dissolution of the microparticles of the extruded self - caking adsorbent material, thereby adhesively fixing or bonding the extruded self - caking adsorbent material region to the substrate microparticles forming the particle nucleus. In a preferred drying step, a turbulent hot - air stream having a temperature of at least 100°F, preferably at least 125°F, and more preferably at least 150°F is introduced into the drum, flows within the drum, and impinges on the newly - formed bedding particles, thereby drying each bedding particle by reducing the water content of the outer region of the extruded self - caking adsorbent material of each particle. When the outer region of the extruded self - caking adsorbent material of each bedding particle is dried with hot air, the hot air rapidly retrogrades, cures and moisture - cures or solidifies the flowable binder formed from the water - soluble binder, which was previously at least partially dissolved into the flowable binder by wetting the substrate microparticles with water, and the outer region of the extruded self - caking adsorbent material is now firmly bonded to the substrate microparticles. In one such preferred drying step, hot air at a high enough flow rate is introduced into the drum, turbulently flowing through and impinging on the newly - formed bedding particles by the hot air, while the drum preferably continues to rotate to continue agitating the bedding particles to accelerate retrogradation and drying. In such a preferred drying step, the temperature of the flowing hot air is heated to a high enough temperature to cause rapid retrogradation of the previously water - soluble starch in the flowable binder within at least 3 to 5 minutes, preferably within one to three minutes, and more preferably within 30 seconds to one minute after the start of the drying step. This rapid retrogradation of the starch, which is expected to cause at least partial dissolution of the water - soluble water - activated moisture - curable binder, forms a flowable binder when the outer surface of the final self - caking adsorbent bedding particles of the present invention that contacts the substrate microparticles is wetted with water, while the drum rotates to substantially simultaneously agitate the self - caking adsorbent bedding particles of the present invention during drying to help ensure that any adjacent self - caking adsorbent bedding particles that contact each other within the drum do not agglomerate into lumps within the drum. In addition, the rapid retrogradation caused by this drying step also helps to quickly eliminate any tackiness on the outer surface of the final self - caking adsorbent particles that may be present, thereby also helping to prevent any of them from agglomerating due to sticking together and caking.

[0093] When wetted with water, urine or synthetic urine, for example, during the use of litter particles in a litter box, etc., the undissolved cold water-soluble extruded modified starch water-activated moisture-curing binder dissolves at least partially or completely to form a flowable binder that flows along and between the contacting wet litter particles and adjacent wet litter particles, causing them to self-agglomerate together to form liftable agglomerates of at least multiple pairs, i.e., at least three wet litter particles. When the agglomerates are air-dried at room temperature to a water content of about 12% of the weight of the agglomerates, the formed liftable agglomerates have an agglomerate retention rate of at least 95%, preferably at least 97%, and more preferably at least 99%, and an agglomerate crush strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even most preferably 100 PSI.

[0094] In the wetting step of a preferred embodiment of the litter particle preparation method, the substrate microparticles are substantially simultaneously co-wetted by applying an aqueous liquid, which may be an aqueous solution but is preferably water. In a preferred wetting stage or step, while agitating the particles, the aqueous liquid, preferably water, is sprayed onto the substrate microparticles, for example, by shaking or rotating in a drum or rotary drum mixer such as a rotary drum cement mixer, to distribute the aqueous liquid, preferably water, more uniformly over substantially the entire outer surface of each microparticle and along it, thereby wetting each microparticle substantially uniformly with regions of the aqueous liquid, preferably water. In another preferred embodiment of the wetting step, the aqueous liquid, preferably water, one or more than one stream of the aqueous liquid, preferably water, is ejected from an injector onto the substrate microparticles while agitating the microparticles, for example, by shaking or rotating in a drum or rotary drum mixer, to distribute the aqueous liquid, preferably water, more uniformly over substantially the entire outer surface of each microparticle and along it, thereby wetting each microparticle substantially uniformly with regions of the aqueous liquid, preferably water.

[0095] During the wetting step, the amount of the aqueous liquid, preferably water, is controlled or regulated to ensure that a sufficient amount of the aqueous liquid, preferably water, is applied to wet substantially all of the outer surfaces of each substrate particle in the wetting chamber. The wetting chamber is preferably the drum of a rotary drum mixer, such as a rotary drum cement mixer, which rotates during the introduction of the aqueous liquid, preferably water, into the drum to agitate the substrate particles so as to more uniformly wet their outer surfaces with the aqueous liquid, preferably water. During the wetting step, the rotary drum is oriented about the general central axis of rotation of the drum such that the drum is tilted upwardly at an acute angle of 5° to 60°, preferably 7.5° to 50°, more preferably 10° to 45° relative to the horizontal plane, which not only facilitates the wetting of the outer surfaces of the substrate particles but also facilitates the subsequent mixing of the extruded self-agglomerating adsorbent material particles with the wetted substrate particles to cause their adhesion. In the process of implementing the method for manufacturing the self-agglomerating adsorbent pad particles of the present invention, when the extruded self-agglomerating adsorbent material particles are introduced into the drum, during the wetting step, the application step and the nucleation step, the orientation angle of the drum relative to the horizontal plane, the rotational speed of the drum, and the amount and / or rate of the aqueous liquid (preferably water) introduced into the drum, for example, by spraying or jetting, are adjusted in real time, which causes the extruded self-agglomerating adsorbent material particles to adhere thereto when the wetted substrate particles become nucleating agents, forming at least a partial area or coating of the extruded self-agglomerating adsorbent material on each substrate particle.

[0096] The amount of the aqueous solution, preferably water, used in the wetting step is an amount sufficient to substantially completely wet the outer surfaces of each substrate particle, and then smaller particles of the extruded adsorbent agglomerate material are applied thereto and / or thereon together with at least an additional 2%, preferably an additional 5%, of the aqueous liquid, preferably water, as will be disclosed in more detail below in the application step to ensure that there is an excess of water over that required to wet substantially all of the surface area of the outer surfaces of all of the substrate particles. An amount of the aqueous solution, preferably water, greater than that required to wet substantially the entire surface area of the outer surfaces of all of the substrate particles used to manufacture a batch of the self-agglomerating adsorbent pads of the present invention is applied to ensure that there is sufficient water to at least partially dissolve some but not all of the cold water-soluble extruded modified starch water-activated moisture-curing binder of the smaller particles of the extruded adsorbent agglomerate material in contact with the wetted outer surfaces of the substrate particles. This not only facilitates the adhesion of the smaller particles of the extruded adsorbent agglomerate material in contact with the wetted outer surfaces of each larger substrate particle, but also the partial dissolution of at least some but not all of the cold water-soluble extruded modified starch binder of the contacted extruded adsorbent agglomerate material particles firmly bonds the extruded adsorbent agglomerate material particles thereto.

[0097] In a further preferred method implementation, sufficient aqueous liquid, such as preferably water, is added to a mixture of substrate microparticles and smaller microparticles of the extruded self-agglomerating adsorbent material, and stirred, for example by shaking or rotating, to form a slurry consisting of the aqueous liquid, such as water, substrate microparticles, and microparticles of the extruded self-agglomerating adsorbent material. The slurry of the mixture of the substrate and the extruded self-agglomerating adsorbent material particles is continuously stirred, shaken or rotated, such that the substrate microparticles become nucleating agents, and the microparticles of the extruded self-agglomerating adsorbent material start to adhere thereto.

[0098] After completion of the wetting step or even during the wetting step, smaller microparticles of the extruded adsorbent agglomerated material are added during the application step, such that each wetted substrate microparticle is at least partially covered, at least partially coated, and / or at least partially encapsulated by at least some of the added smaller microparticles of the extruded adsorbent agglomerated material, and preferably mixed therewith, for example by using stirring, shaking, mechanical mixing or another mixing method and / or mixing device. After or during wetting the substrate microparticles with an aqueous solution, preferably water, smaller microparticles of the extruded adsorbent agglomerated material are added during the application step. During the nucleation sub-step, the wetted substrate microparticles become nucleating agents for the agglomerated adsorbent padding particles, whereby the smaller microparticles of the extruded adsorbent agglomerated material are attracted to the corresponding wetted substrate microparticles and even come into contact with them, including through surface tension acting between the water on the surface of the wetted outer substrate microparticles and the smaller microparticles of the extruded adsorbent agglomerated material in very close proximity thereto, capillary adhesion acting between the molecules of each substrate microparticle and the molecules of the extruded adsorbent microparticles in sufficiently close proximity and / or in contact therewith, and / or intermolecular forces such as preferably van der Waals forces and / or intermolecular adhesion, acting between the water molecules wetting the outer surface of each substrate microparticle and / or the molecules of the outer surface of each substrate microparticle and the molecules of the extruded adsorbent microparticles in very close proximity and / or in contact therewith. During the nucleation stage or sub-step of the application step of the extruded adsorbent agglomerated material, the initial regions of the microparticles of the extruded adsorbent agglomerated material are attracted to and come into contact with the water on the outer surface of each substrate microparticle wetted with the aqueous liquid, preferably water, until at least some of the water wetting the outer surface of the wetted substrate microparticles wets at least some of the microparticles of the extruded adsorbent agglomerated material in sufficiently close proximity and / or in contact therewith.

[0099] In the case where the nucleation sub-step overlaps with the wetting step, it only overlaps with a part of the wetting step, starting after at least half of the wetting step has been carried out, preferably after at least three-quarters of the wetting step has been carried out, more preferably after nearly 90% to 95% of the wetting step has been carried out. One advantage of starting the nucleation step during the wetting step is that the amount of water required to complete the wetting process can be adjusted to add an excess amount of water that is more than the amount required to merely wet the substrate microparticles, thereby ensuring that the nucleation sub-step reaches a stage where, by the time the wetting step is completed and the addition of water stops, at least 50%, preferably at least 65%, more preferably at least 75% of the extruded adsorbent agglomerate material microparticles adhere to the outer surface of the substrate microparticles.

[0100] After the wetting step is completed and the addition of water stops, the mixing or stirring step continues in order to continue the nucleation sub-step, where the non-adhered microparticles of the extruded adsorbent agglomerate material also adhere to (i) the part of the outer surface of the substrate microparticles to which no extruded adsorbent agglomerate material microparticles have adhered previously, and / or (ii) other parts of the outer surface of the substrate microparticles to which extruded adsorbent agglomerate material microparticles have already adhered, thereby increasing the thickness of the area to which the extruded adsorbent agglomerate material microparticles adhere. As the mixing or stirring step continues, more and more of the previously non-adhered extruded adsorbent agglomerate material microparticles adhere to (i) the previously non-adhered surface area of the substrate microparticles, and / or (ii) the surface area of the substrate microparticles to which the extruded adsorbent agglomerate material microparticles have already adhered, thereby further increasing the thickness of the area of the extruded adsorbent agglomerate material microparticles adhering thereto.

[0101] In a preferred method of manufacturing a self-agglomerating bedding, the self-agglomerating bedding is composed of self-agglomerating adsorbent bedding particles, and each self-agglomerating adsorbent bedding particle is formed from non-agglomerating substrate microparticles, to which smaller microparticles in the form of a powder or powdery substance of an extruded self-agglomerating adsorbent material composed of a cold-water-soluble extruded modified starch water-activated moisture-curing binder and a cold-water-swellable extruded modified starch are added, preferably in the form of a pre-gel of cold-water-swellable extruded modified starch, and the following steps are carried out:

[0102] Open the rotary drum mixer and add the substrate microparticles to be coated with the powder or powdery substance microparticles of the self-agglomerating adsorbent material to be extruded. Record the weight of the substrate placed in the rotary drum of the rotary mixer.

[0103] Change the angle of the drum to maximize the rolling agitation or rolling action of the substrate particles to be coated caused by the rotation of the drum of the mixer. Changing the angle means changing the acute angle defined by the central axis of rotation of the drum relative to the substantially horizontal ground on which the rotary mixer is supported, in such a way that the agitation or tumbling of the substrate particles within the rotating drum is maximized or optimized, and in such a way that during the wetting step, the substrate particles are uniformly wetted with water during the application of water into the drum;

[0104] During the rotation of the drum, the wetting step is initiated by adding sufficient water into the drum of the rotary mixer to completely wet the outer surface of the substrate particles. Let the water mix with the substrate particles and wet the substrate particles for up to 4 minutes, preferably not more than about 3 minutes, more preferably 1 minute to 3 minutes, and check for free water. The substrate particles should be well wetted, but not so wet that water will drain out and accumulate at the bottom of the drum of the mixer. Take a sample of the wetted substrate particles from the rotating drum, hold the sample in the hand, and squeeze the sample to try to form the sample into a ball while continuing to hold the sample in the hand and squeeze. Any ball formed when you open your hand should only hold the shape of the ball slightly or loosely, for example, slightly held together. Inorganic substrate particles, such as sand, perlite, rubber, glass, and sand, only need a few seconds, preferably less than five seconds, to stably absorb water, thus ensuring sufficient wetting with water. Organic substrate particles such as paper, wood fibers, wood pellets, and nut shells require a two-step wetting process, in which sufficient water is added to completely coat the organic substrate particles while the drum of the mixer continues to rotate for about 5 minutes. This provides sufficient time for the organic substrate particles to become completely wet while also allowing the particles to start absorbing at least some water, for example, preferably by sucking at least some water into the fibers of the organic substrate particles. Although the fibers on the outer surface of the organic substrate particles are immediately wetted, it takes time for some water to be drawn out through the outer fibers and wet the fibers inside the organic substrate particles. The organic substrate particles require additional time to allow the water to cross or pass through the outer fibers of each particle and start wetting additional areas under the outer surface of the particles. If this second step is not carried out to ensure that the wetting extends to the surface fibers of each particle and preferably to the fibers in the area below the outer surface, the actual area of the outer fiber surface of each organic substrate particle wetted by water will not be consistent or uniform. In other words, if this additional water wetting step or sub-step is not carried out, the water wetting the outside of each organic substrate particle will not have a consistent or uniform water coating on the outside of the fibers of each organic substrate particle. The roughness of the outer surface of the organic substrate particles will also affect this sub-step of water rewetting, because a rougher outer surface of the substrate particles will require additional rewetting cycles to allow sufficient water to penetrate the outer surface of each particle to ensure a uniform water coating finally wets the outside of the rough substrate particles. Therefore, depending on the roughness of the fiber surface of the substrate particles, we will need at least several times, and sometimes at least several more times, rewetting and adding additional water. Conduct multiple rewetting cycles, in which additional water is added to the drum during each rewetting cycle, keeping the outer surface of each organic substrate particle saturated with water, but doing so without overwetting or over-saturating each particle with water, which will cause water to pool at the bottom of the mixture of organic substrate particles at the bottom of the rotating drum. Record the total amount of water used throughout the wetting step, including any additional water used in any rewetting sub-steps.

[0105] In the application step, during or, more preferably, after the wetting step, the extruded self - caking adsorbent substrate coating powder or particulate powdery material is added to a rotating drum. The powder or particulate powdery material is controllably and gradually introduced into the drum, for example, preferably by sieving them into the rotating drum, to help ensure that the wetted outer surface of the substrate particles is coated with the powder or particulate powdery material, preferably substantially completely, e.g., completely coated.

[0106] During the application step, additional powder or particulate powdery material of the extruded self - caking adsorbent material continues to be added to the wetted substrate particles in the drum until the coated outer surface aggregated on the nucleating agent substrate particles becomes less and less sticky until the area aggregated on the substrate particles becomes substantially non - sticky, preferably completely non - sticky. The powder or particulate powdery material must be added continuously in a controllable and gradual manner while the drum is rotating, thereby agitating or rolling at least partially coated substrate particles to prevent the gel formed by the cold - water - soluble water - activated moisture - curing binder and cold - water - swellable starch from causing adjacent coated substrate particles in contact with each other during the agitation in the rotating drum to stick together and agglomerate. Importantly, any lumps formed due to this gel agglomeration phenomenon are sieved out during the rotation of the drum or after removing the final self - caking adsorbent bedding particles of the present invention from the drum mixer. During the subsequent particle size reduction process, a particle size reducer such as a counter - rotating roll particle size reducer or another type of particle size reducer such as a hammer mill is used to break up and re - size any smaller lumps from the gel agglomeration, e.g., any two - or three - pellet lumps.

[0107] The extruded self - caking adsorbent powder or particulate powdery material is an instant starch powder or particulate powdery material composed of a super - high - pressure extruded modified starch pre - gel, which preferably includes cold - water - swellable extruded modified starch. The powder or particulate powdery material also contains a sufficient amount of cold - water - soluble water - activated moisture - curing binder to ensure that during the application of the powder or particulate powdery material to the outer surface of the wetted substrate particles, not only some of the binder dissolves and adheres to it, but also some of the binder remains in the final self - caking adsorbent bedding particles of the present invention. Thus, when the actual bedding particles are wetted with water, urine, or synthetic urine, at least some of the water - soluble binder forms a flowable binder. The key is to maximize at least the starch damage in the extruded mixture and preferably the protein damage in the extruded starch mixture through the construction of the single - screw extruder used for extruding the extruded self - caking adsorbent powder or particulate powdery material, including by operating the single - screw extruder at a super - high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, and even more preferably 5000 PSI, thereby extruding the self - caking adsorbent powder or particulate powdery material, which contains at least some instant starch and at least some cold - water - swellable water - absorbent starch modified during the super - high - pressure extrusion process.

[0108] In preferred methods and embodiments for extruding self-agglomerating adsorbent powders or powdery substances, it is crucial to use an extruder barrel longer than twelve inches, preferably longer than fourteen inches, to ensure that the starch is modified during the ultra-high pressure extrusion process in a single-screw extruder. This is because the longer extruder barrel increases the residence time of the starch in the extruder, which thermally modifies a sufficient amount of the starch into instant starch, preferably into cold-water swellable water-absorbing extruded modified starch, more preferably into cold-water swellable water-absorbing extruded modified pregelatinized starch or cold-water swellable water-absorbing extruded modified starch pregelatinization. Using a longer extruder barrel in a single-screw extruder ensures that if some of the starch is not mechanically damaged and solubilized and / or pregelatinized during extrusion, the longer barrel will ensure that the starch has sufficient residence time or dwell time within the extruder barrel, such that a sufficient amount of the starch is modified by extrusion or during extrusion, preferably by being thermally modified during extrusion to form instant starch, which is preferably a cold-water swellable pregelatin. This maximizes the amount and quantity of the starch, which gels upon wetting when in contact with the water-wetted outer surface of the substrate microparticles, and coats the water-wetted outer surface of the substrate microparticles therewith, thereby adhering well thereto preferably by hydrogen bonding when the wet gel dries.

[0109] In the step of finishing the self - caking adsorbent bedding particles carried out after the coating step, an additional amount of extruded self - caking adsorbent powder or powder is applied, for example, by spraying or sprinkling the powder or powder on the outer surface of the coated substrate particles, i.e., on the outer surface of the self - caking adsorption bedding particles of the present invention, to ensure that there is at least one outer region of the extruded self - caking adsorbent powder or powder that has never been wetted, and when the final bedding particles are wetted by water, urine or synthetic urine during use in a bedding box, this outer region will contribute substantially all of the cold - water - soluble extruded modified starch water - activated moisture - curable binder. The finishing step of the coated self - caking adsorption bedding can and preferably is carried out when the outer surface of the self - caking adsorbent bedding particles is still wet or sticky, so as to promote the adhesion of the dry extruded self - caking adsorbent powder or powder region thereto. The finishing step of the coated self - caking adsorption bedding can and preferably is carried out when the drum of the mixer is rotating, to continue to stir the nearly final self - caking water - absorbing bedding particles of the present invention, thereby helping to ensure a more consistent and uniform distribution of the dry powder or powder particles, and thus forming an outer region with a more consistent and uniform thickness. In a preferred embodiment of the method for preparing the self - caking adsorption bedding particles of the present invention, when applying the region of the dry extruded self - caking adsorbent powder or powder, at least a part, preferably substantially all of the outer surface of the self - caking adsorption bedding particles is composed of a starch gel formed from at least some modified, preferably thermally modified, starch that is modified in the barrel of the extruder during the extrusion of the extruded self - caking adsorbent powder or powder, preferably thermally modified. In one such preferred embodiment of the method for preparing the self - caking adsorption bedding particles of the present invention, when applying the region of the dry extruded self - caking adsorbent powder or powder, at least a part, preferably substantially all of the outer surface of the self - caking adsorbent bedding particles is composed of such a starch gel that is still in the gel state, and preferably before the gel has been completely transformed, for example, preferably by the starch forming the gel retrograding from a semi - solid to a solid.

[0110] In this preferred embodiment of the method for preparing self - caking adsorbent bedding particles of the present invention, when applying a dry granular modified starch water - absorbing caking agent, preferably an extruded self - caking adsorbent powder or a powder - form substance, at least a part, preferably substantially all of the outer surface of the self - caking adsorbent bedding particles is composed of a still - moist and / or sticky starch gel. This not only facilitates the adhesion of the dry particles of the extruded self - caking adsorbent powder or powder because the outer gel surface is still wet and / or sticky, but also the application of the dry particles of the extruded self - caking adsorbent powder or powder absorbs at least some of the outer - surface moisture and makes the outer gel surface non - sticky, thus forming the self - caking bedding particles of the present invention, which have a dry - ready - to - wet self - caking adsorbent exterior. In addition, this starch of the dry extruded self - caking adsorbent powder or powder, which includes a cold - water - soluble extruded modified starch water - activated moisture - curing binder and a cold - water - swellable water - absorbing extruded modified starch, will advantageously not retrograde during the drying step of the self - caking adsorbent bedding particles when hot air is applied thereto. The final self - caking adsorbent bedding particles are preferably dried to a water content of not more than 8% of the particle weight, preferably a water content of less than 8% of the particle weight, to ensure that any residual moisture or remaining water is not sufficient to plasticize the starch in the outer region of the extruded self - caking adsorbent material of the bedding particles and is not sufficient to cause further retrogradation of the starch in this outer region of the particles.

[0111] Wherein the self - caking adsorbent bedding particles are formed from water - wetted nut - shell substrate microparticles, and a coating or region of an extruded self - caking water - absorbing powder or powder adheres to the substrate microparticles, forming an outer region of the extruded self - caking water - absorbing powder or powder, which outer region also contains a gel that promotes its adhesion to the substrate microparticles. The application of a dry extruded self - caking water - absorbing powder or powder region to the outer region of the self - caking water - absorbing bedding particles, when it is still wet and composed of a gel that is still in a gel state, promotes the adhesion of the dry powder or powder particles, thereby producing a dry shell on the outer gel region. This dry outer region adheres well to the outer gel region, which in turn adheres well to the outer surface of the substrate microparticles, preferably by adhesive attachment via hydrogen bonds between the outer gel region and the outer surface of the substrate microparticles.

[0112] During the drying step, preferably during or after the trimming step of self - caking the adsorbent pad material particles after coating, hot air is introduced into the cylinder to dry the self - caking water - absorbent pad material particles of the present invention. This not only facilitates the drying of the moistened gelatinized starch adhering to the outer surface of the base material particles, but also the hot air causes the retrogradation of the starch, including the starch gel, to be wetted by the water on the outer surface of the base material particles, hardening the internal region which adheres and preferably adheres to the outer surface of the base material particles. This outer surface is located between the outer surface of the base material particles and the outer region of the dried extruded self - caking water - absorbent powdery substance or powder, and this outer region adheres to and preferably bonds to the internal region, forming the final self - caking water - absorbent pad material particles of the present invention.

[0113] These and various other features, aspects, and advantages of the present invention will become apparent from the following description of the drawings. Description of the Drawings

[0114] One or more preferred exemplary embodiments of the present invention are illustrated in the drawings, wherein like reference numerals represent like parts throughout, and:

[0115] Figure 1 is an enlarged cross - sectional view of an adsorbent particle, which is a self - caking adsorbent pad material particle composed of internal base material particles at least partially covered, preferably substantially completely covered, with a modified starch adsorbent caking material, preferably a modified starch adsorbent caking agent;

[0116] Figure 2A is an enlarged micrograph of calcium - based bentonite particles used as a non - caking granular base material in one embodiment of the present invention;

[0117] Figure 2B is an enlarged micrograph of exemplary fine sand particles used as a non - caking granular base material in a second embodiment of the present invention;

[0118] Figure 2C is an enlarged micrograph of additional exemplary fine sand particles used as a non - caking granular base material in another second embodiment of the present invention;

[0119] Figure 2D is a micrograph of crushed walnut shell particles used as a non - caking granular base material in a third embodiment of the present invention;

[0120] Figure 2E is a micrograph of cellulose material particles, which are preferably paper or contain paper and are used as a non - caking granular base material in a fourth embodiment of the present invention;

[0121] Figure 2F is an enlarged micrograph of perlite particles used as a non - caking granular base material in a sixth embodiment of the present invention;

[0122] Figure 2G is an enlarged micrograph of wood microparticles used as a non-caking particulate substrate in the fifth embodiment of the present invention;

[0123] Figures 3 to 5 is an enlarged micrograph of multiple pairs of calcium-based bentonite substrate microparticles, each microparticle coated with an outer region of an extruded modified starch water-absorbing caking agent;

[0124] Figure 6 is a first video frame screenshot of at least a plurality of self-caking adsorbent bedding particles before being wetted with water, showing that each bedding particle is made of calcium-based bentonite substrate microparticles coated with an outer region of an extruded modified starch water-absorbing caking agent;

[0125] Figure 7 is what occurs at Figure 6 A second video frame screenshot at least a few seconds after the first video frame screenshot depicts the initial wetting of the bedding particles of Figure 6 with water, causing at least some of the outer regions of the extruded modified starch water-absorbing caking agent of at least a plurality of the wetted particles to at least partially dissolve in the water to form a flowable binder, which flows from the wetted particles into the water and towards contacting and adjacent bedding particles;

[0126] Figure 8 is what occurs at Figure 7 A third video frame screenshot at least a few seconds after the second video frame screenshot depicts the further wetting of the bedding particles of Figure 7 with water, causing some outer regions of the extruded modified starch water-absorbing caking agent of the wetted particles to absorb some water and swell, while causing the same outer regions of the extruded modified starch water-absorbing caking agent of some other wetted particles to be wetted to at least partially dissolve in the water and form a flowable binder, which flows from the wetted particles in the water towards contacting and adjacent bedding particles. Over time, the viscosity of the bedding particles increases and transforms into a binder gel that begins to coagulate the wetted binder, bringing adjacent particles into contact to form agglomerates, Figure 8 also illustrates that the viscosity of at least some of the binder gels initially formed from water-soluble binders further increases, thereby thickening the binder gel, which begins to bind the contacting wetted particles and even some adjacent particles, for example preferably using intermolecular forces such as liquid adhesion, surface tension, van der Waals forces and even some hydrogen bonds at the early stage of agglomeration formation of the wetted, contacting and adjacent bedding particles, Figure 8Also shown is how at least partially dissolved binder is converted into a flowable binder that flows from the wetted particles along contacting and adjacent particles and between contacting and adjacent particles, increasing in viscosity over time and thickening into a binder gel that promotes adhesion of contacting and adjacent particles during the initial stages of litter mass formation;

[0127] Figure 9 occurs at Figure 8 and is a fourth video frame screenshot at least several seconds after the third video frame screenshot of , depicting (a) further wetting of the litter particles with water, (b) generation of more flowable binder from at least partially soluble binder that wets some outer regions of the extruded modified starch water-absorbing agglomerant from each wetted particle, (c) even more swellable and even more gelling of the water-absorbing swollen extruded modified starch in some outer regions of the extruded modified starch water-absorbing agglomerant of each wetted particle, (d) conversion of the more flowable binder into a more slowly flowing flowable viscous gel, and (e) conversion of at least some and preferably an increasing amount of the binder gel into a stable, firm adhesion gel that flows very little, if at all; Figure 8

[0128] Figure 10 Figure 9 occurs at and is a fifth video frame screenshot at least several seconds after the fourth video frame screenshot of , depicting dissolution of at least some water-soluble binder present in at least some outer regions of the extruded modified starch water-absorbing agglomerant of each wetted particle, and swelling and gelling of at least some cold water-swellable cold water absorbent extruded modified starch during the water absorption process, said extruded modified starch also being present in at least some outer regions of the extruded modified starch water-absorbing agglomerant of each wetted particle;

[0129] Figure 11 Figure 10 occurs at and is a sixth video frame screenshot at least several seconds after the fifth video frame screenshot of , depicting extensive dissolution of the water-soluble binder into a flowable binder that wets the outer regions of the extruded modified starch water-absorbing agglomerant of all particles, and also illustrating extensive swelling and gelling of the volume swelling of the cold water-swellable cold water absorbent extruded modified starch through the outer regions of the extruded modified starch, with all particles of the starch water-absorbing agglomerant depicting substantially wetted particles coalescing into an amorphous gel mass where the boundaries of the wetted particles become increasingly indistinct;

[0130] Figures 12 to 15Shows a further development of the water-wetted self-agglomerating absorbent bedding particles of the present invention, in which further gelation and swelling occur, which include or result in a more flowable binder formed from at least partially water-soluble binders, along the bedding particles released from the bedding particles and adjacent particles, and in contact between the bedding particles and adjacent particles, the viscosity increases over time to form an adhesive gel, promoting the agglomeration of the bedding particles in contact with and adjacent to it, the viscosity further increases over time to form a bonding gel, bonding the bedding particles in contact with and adjacent to it together, while continuing the moisture curing, hardening, and finally, within 120 seconds, forming a mass of the bedding particles, wherein at least the bonding gel hardens into a substantially hard binder in the form of a vitreous material, producing a substantially rock-hard mass, which has a mass retention rate of at least 95%, preferably at least 97%, more preferably at least 99% when dried to a water content of about 12% of the mass weight, and has a mass crushing strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even more preferably at least 100 PSI.

[0131] Figure 16 Is an enlarged micrograph of a top view of a mass formed from at least multiple pairs of self-agglomerating bedding particles, each pair of self-agglomerating bedding particles having an outer region of an ultra-high pressure modified starch extrudate, the ultra-high pressure modified starch extrudate being composed of a modified starch water-absorbing caking agent coating and adhering to internal substrate microparticles, and all of the internal substrate microparticles being fine sand particles. Figure 5 Shows a top view of a mass of sand coated with extrudate after drying, particularly showing a large number of ultra-high pressure extruded modified starch spheres, preferably partially dissolved gel spheres of ultra-high pressure extruded modified starch, more preferably water-wetted pre-gelatinized starch spheres of ultra-high pressure extruded modified starch that are insoluble in water and / or partially soluble in water, and even more preferably water-wetted pre-gelatinized starch gel spheres of ultra-high pressure extruded modified starch that are insoluble in water. These starch spheres float to the top of the mass after being wetted with water or urine during the caking process, exposing at least some outer surfaces of the internal fine sand particles.

[0132] Figure 17 Is formed from at least multiple pairs of water- or urine-wetted self-agglomerating bedding particles Figure 16 An enlarged micrograph of the bottom view of the mass, each pair of bedding particles having an outer region of an ultra-high pressure modified starch extrudate, the extrudate being composed of a modified starch water-absorbing caking agent coating and adhering to internal substrate microparticles, and each substrate microparticle being a fine sand particle. In the bottom view of the sand particles coated with extrudate, there is a lack of free starch. For example, note the lack of free starch, only sand, showing the extruded modified starch spheres attached to the fine sand particles.

[0133] Figure 18 Is Figure 16 And Figure 17Magnified micrograph of a side view of a mass formed by at least multiple pairs of self - agglomerating bedding particles, each bedding particle having an outer region of an ultra - high - pressure modified starch extrudate, the ultra - high - pressure modified starch extrudate being composed of a modified starch water - absorbing agglomerant coating and adhering to fine sand particles or fine sand microparticles of the internal substrate, and the side view of the sand particles coated with the extrudate mass also shows extruded modified starch pellets that have floated to the top of the mass;

[0134] Figures 19 to 26 Are a series of video screenshots showing the water re - activation of at least partially soluble modified starch binders, which includes when the previously water - wetted self - agglomerating adsorbent bedding particles composed of fine sand particles as substrate microparticles of the present invention and covered with a modified starch adsorbent agglomerant material or the outer region of a modified starch adsorbent agglomerant are re - wetted with water, generating a water - re - activated moisture - re - solidified flowable binder, which sequentially shows the process of the flowable binder flowing out of the water - wetted particles. When water is absorbed into the outer region of the modified starch water - absorbing agglomerant material or agglomerant, the agglomerant material or agglomerant remaining on the sand grain substrate microparticles gels and swells its volume. After re - wetting and drying the flowable binder, at least some of the binder that has not dissolved in the re - wetting water and remains in the old region of the modified starch water - absorbing agglomerant material or agglomerant re - solidifies through moisture re - solidification and hardens into a substantially hard substance or agglomerate, transforming into a solid glass - like material state. Thus, when dried to a water content of about 12% of the mass weight, the substance or mass has a mass retention rate of at least 95%, preferably at least 97%, more preferably at least 99%, and a crushing strength or compressive strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even more preferably at least 100 PSI.

[0135] Figure 27 Is a magnified micrograph of crushed walnut shell microparticles before coating with an ultra - high - pressure extrudate composed of an extruded modified starch water - absorbing mass;

[0136] Figure 28 Is a magnified micrograph of crushed walnut shell microparticles each coated with an ultra - high - pressure extrudate, the ultra - high - pressure extrudate being or containing an extruded modified starch water - absorbing agglomerant, forming a thin outer coating that adheres to the outer surface of each crushed walnut shell substrate microparticle, forming the self - agglomerating adsorbent bedding and self - agglomerating adsorbent bedding particles of the present invention;

[0137] Figure 29 Is another magnified micrograph of crushed walnut shell microparticles, each microparticle coated with an ultra - high - pressure extrudate, the extrudate being or containing an extruded modified starch water - absorbing agglomerant, forming a thin outer coating that adheres to the outer surface of each crushed walnut shell substrate microparticle, forming the self - agglomerating adsorbent bedding and self - agglomerating adsorbent bedding particles of the present invention;

[0138] Figure 30 is an enlarged micrograph of crushed walnut shell particles, each coated with an ultra-high pressure extrudate that is or comprises an extruded modified starch water-absorbing caking agent, forming a thin outer coating that adheres to the outer surface of each crushed walnut shell substrate particle to form its self-caking bedding particles. After 10 grams of the self-caking bedding particles are washed for 20 seconds and then dried, the particle coating weight of the thin outer coating of the ultra-high pressure extrudate, i.e., the extruded modified starch water-absorbing caking agent that is or comprises about 15% to 16% of the particle coating weight (based on the weight of the bedding particles) per bedding particle, is reduced to about 4.5% of the particle coating weight (based on the weight of the bedding particles), such that each bedding particle still has sufficient coating to absorb water or urine and at least weakly cakes when wetted, and preferably still forms a cake when wetted; and

[0139] Figure 31 is an enlarged micrograph of crushed walnut shell particles, each coated with an ultra-high pressure extrudate that is or comprises an extruded modified starch water-absorbing caking agent, forming a thin outer coating that adheres to the outer surface of each crushed walnut shell substrate particle to form its self-caking bedding particles. After 20 grams of the self-caking bedding particles are washed for 20 seconds and then dried, the particle coating weight of the thin outer coating of the ultra-high pressure extrudate, i.e., the extruded modified starch water-absorbing caking agent that is or comprises about 15% to 16% of the particle coating weight (based on the weight of the bedding particles) per bedding particle, is reduced to about 5% of the particle coating weight (based on the weight of the bedding particles), such that each bedding particle still has sufficient coating to absorb water or urine and at least weakly cakes when wetted, and preferably still forms a cake when wetted.

[0140] Although the preferred embodiments of the method for preparing self-caking bedding using a particulate non-caking substrate according to the present invention have worked with many types of particulate non-caking substrates tried so far, it is expected that the bedding preparation method of the present invention will also work with many other types of substrate particles, including non-caking substrate particles and caking substrate particles.

[0141] Before explaining in detail one or more embodiments of the present invention, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of components set forth in the following description and shown in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Further, it is to be understood that the language and terminology used herein are for the purpose of description and should not be regarded as limiting. Detailed Description

[0142] Definition

[0143] Before explaining in detail one or more embodiments of the present invention, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of components set forth in the following description and shown in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways.

[0144] Before describing the materials, products, and methods of the present invention below, it should also be understood that the invention is not limited to the particular methods, protocols, materials, and reagents described, as these may vary. It should also be understood that the terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention, which is limited only by the appended claims.

[0145] It must be noted that, as used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Similarly, the terms "a", "one or more", and "at least one" may be used interchangeably herein. It should also be noted that the terms "comprises", "comprising", and "having" may be used interchangeably.

[0146] For the purposes of the present invention, terms indicating direction, such as "top", "bottom", "upper", "lower", "above", "below", "left", "right", "horizontal", "vertical", "up", "down", etc., and terms indicating location and orientation are for the convenience of describing the various embodiments of the present invention only. The embodiments of the present invention may also be oriented in various ways. For example, the diagrams, devices, etc. shown in the drawings may be flipped, rotated ninety (90) degrees in any direction, reversed, mirrored, etc.

[0147] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Although any methods and materials similar or equivalent to those described herein may be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications and patents specifically mentioned herein are incorporated herein by reference, including descriptions and disclosures of components, reagents, chemicals, devices, manufacturing, statistical analysis, and methods reported in the publications that may be used for all purposes of the present invention. All references cited in this specification should be considered as indicative of the level of skill in the art. Nothing herein should be construed as an admission that the present invention is not entitled to antedate such disclosure by virtue of prior invention.

[0148] Unless specifically stated otherwise, when the definition of any of the following terms deviates from its common meaning, the applicant intends to use the definitions provided below.

[0149] For the purposes of the present invention, a value or property is "based on" the satisfaction of a particular value, property, condition, or other factor if the value is obtained by performing a mathematical calculation or logical determination using that value, property, or other factor.

[0150] For the purposes of the present invention, the term "admixture" refers to a homogeneous or substantially homogeneous mixture of two or more solid materials. One or more of the materials in the admixture may be coated.

[0151] For the purposes of the present invention, the term "substantially homogeneous" means that the mixture has substantially the same density throughout the mixture.

[0152] For the purposes of the present invention, the term "homogeneous" refers to a mixture of two or more solid materials, wherein the measured density of the composition of ten or more samples of the mixture has a standard deviation of no greater than 2.0 lbs. / ft 3 throughout the composition. One or more of the solid materials may be coated.

[0153] For the purposes of the present invention, the term "homogeneous admixture" refers to an admixture that is homogeneous.

[0154] For the purposes of the present invention, the term "homogeneous mixture" refers to a mixture that is homogeneous.

[0155] For the purposes of the present invention, the term "wetting agent" or "infiltrating liquid" refers to a liquid that wets adsorbent particles, such as bedding particles. Examples of wetting agents or infiltrating liquids include liquids such as water, aqueous solutions, urine, synthetic urine, and the like.

[0156] For the purposes of the present invention, the term "cellulose-containing material" refers to a material in which at least 10% or more is composed of cellulose. Examples of cellulose-containing materials include paper, wood fibers, sawdust, fibers, husks, and the like.

[0157] For the purposes of the present invention, the term "caking additive" refers to a caking agent other than sodium-based bentonite.

[0158] For the purposes of the present invention, the term "caking agent" refers to a material that causes the particles containing the caking agent to cake together when wetted with a wetting agent, forming at least multiple pairs, i.e., at least three sticky agglomerates of wetted particles that become substantially hard when dried to a water content of no greater than 15% by weight of the hardened agglomerate.

[0159] For the purposes of the present invention, the term "caking strength" refers to the value of the average agglomerate compressive strength of agglomerates that have been dried to a water content of approximately 12% and crushed when measuring the compressive strength or crush strength, in pounds per square inch (PSI).

[0160] For the purposes of the present invention, the terms "filler" and "filler material" refer to materials in the bedding product other than the agglomerating agent, i.e., other than sodium bentonite or agglomerating additives. In one embodiment of the present invention, the filler material may be calcium bentonite. In another embodiment of the present invention, the filler material may be sandy soil. In other embodiments of the present invention, the filler material may be a cellulose-containing material.

[0161] For the purposes of the present invention, the term "fines" refers to particles generally less than 1 / 32 inch (equivalent to approximately 800 microns) but greater than 2 / 125 inch (equivalent to approximately 400 microns), which pass through a #20 US Mesh screen or sieve and remain on a #40 US Mesh screen or sieve.

[0162] For the purposes of the present invention, the term "flour" refers to particles smaller than fines and capable of passing through a #40 US Mesh screen or sieve.

[0163] For the purposes of the present invention, the term "fragrance" refers to compounds configured to emit a perceptibly pleasant odor, and / or compounds that neutralize or hide an unpleasant or undesired odor, for example, in the form of a masking fragrance. The term "fragrance" may refer to a coating containing the fragrance, for example, by addition to the coating or by the fragrance itself being the coating. The fragrance coating may include one or more other components or ingredients.

[0164] For the purposes of the present invention, the term "granular" refers to solid materials having a particle size below two (2) mesh. The solid materials used in the mixtures of the present invention may be crushed to form granular materials.

[0165] For the purposes of the present invention, the terms "granular filler" and "granular filler material" refer to fillers that are granular.

[0166] For the purposes of the present invention, the term "heterogeneous mixture" refers to a composition in which the components of the mixture can be easily separated from each other.

[0167] For the purposes of the present invention, the term "homogeneous mixture" refers to a composition that is uniform.

[0168] For the purposes of the present invention, the term "mixture" refers to a composition containing two or more different components that are mixed but not chemically bonded. The individual components of a heterogeneous mixture may contain two or more chemically bonded substances, for example, a substrate is a filler material coated with the adsorption-swelling and gelling starch-containing biopolymer agglomerating agent of the present invention.

[0169] For the purposes of the present invention, the term "non-calcium-based bentonite clay" refers to clays other than calcium-based bentonite. Since the filler material cannot be sodium-based bentonite, the "non-calcium-based bentonite clay" also cannot be sodium-based bentonite.

[0170] For the purposes of the present invention, the term "lump-removable" means that when exposed to a wetting agent or a wettable liquid, it forms lumps composed of at least multiple pairs of padding particles, the structural integrity and hardness of which are sufficient to withstand mechanical separation from the non-wetted padding for disposal, and when the lumps of padding particles are subjected to a drop test according to the standard padding drop test defined below, it has a lump retention rate of at least 98%, preferably at least 99%.

[0171] Introduction

[0172] The present invention relates to a granular swelling and gelling adsorbent composed of fine particles of an inorganic substrate or an organic substrate, the substrate can be a non-adsorbent substrate or a minimally adsorbent substrate, wherein the adsorbent particles form a nucleating agent, and its surface-treated modified starch water-absorbing caking agent is preferably a modified starch-based adsorbent swelling biopolymer gel. The resulting swellable and gellable adsorbent particles are preferably self-caking adsorbent padding particles, each of which is composed of an outer coating or region that at least partially covers and can substantially completely encapsulate the internal non-adsorbent substrate or minimally adsorbent substrate fine particles or particles. During the use of the adsorbent, wetting with a liquid, such as a preferred aqueous liquid, causes the outer region of the modified starch water-absorbing caking agent, which preferably includes the adsorbent swelling biopolymer gel of each swollen and gelled adsorbent particle, to adsorb at least some of the liquid and swell in size and volume, while substantially gelling simultaneously. Due to the combination of the liquid adsorption with the gel formed by the liquid adsorption and gelling of adjacent wetted swollen and gelling adsorbent particles, the gel formed by the liquid adsorption and gelling of each wetted swollen and gelling adsorbent particle swells and swells, forming an agglomeration or aggregate lump of the wetted swollen and gelling adsorbent particles. The wetted adsorbent swellable biopolymer gel of each swellable and gellable adsorbent particle not only swells and forms a water-activated moisture-cured binder gel when absorbing a liquid, preferably an aqueous liquid such as water, urine or an aqueous solution, but also swells in size and volume during adsorption and gelling, while bonding the wetted particles together when the moisture cures into a substantially hard binder, forming a substantially hard lump. When the lump is moisture-cured and dried to a moisture content of about 12% of the weight of the lump, its lump retention rate is at least 95%, preferably at least 97%, or preferably at least 99%, while also having a lump crushing strength or lump compressive strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even more preferably at least 100 PSI.

[0173] In a preferred embodiment, the wetted adsorbent swellable biopolymer gel not only forms an adhesive gel upon wetting, but also forms a water-activated moisture-curing modified starch flowable adhesive that flows from within the particles to the surrounding contacting and adjacent particles, agglomerating or aggregating the particles into their mass. Such a mass, when dried by moisture-curing to a moisture content of about 12% of the mass weight, has a mass retention of at least 95%, preferably at least 97%, or preferably at least 99%, while also having a mass crush strength or mass compressive strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even more preferably at least 100 PSI.

[0174] The present invention most preferably also relates to a self-agglomerating litter composed of self-agglomerating litter particles, each self-agglomerating litter particle being formed from non-agglomerating substrate microparticles to which is adhered a water-activated moisture-curing water-absorbing swellable and gelling polymer or biopolymer agglomerant composed of at least 5% water-soluble adhesive, the agglomerant not only imparting agglomerability to the non-agglomerating substrate particles, but also forming agglomerates of at least a plurality of pairs of wet self-agglomerating litter particles that form substantially hard, i.e., rock-hard, agglomerates upon drying.

[0175] The present invention also relates to a method for preparing granular adsorbents composed of water-absorbing gelling and swelling adsorbent particles of non-adsorbing or minimally adsorbing substrates, the substrates having an outer region composed of a starch-based water-absorbing gelling agent containing a modified starch water polymer adhesive that is water-activated and moisture-cures to a starch vitreous solid adhesive upon drying. The present invention most preferably relates to a method for preparing self-agglomerating litter composed of self-agglomerating litter particles, each self-agglomerating litter particle being formed from non-agglomerating substrate particles to which is adhered a water-activated moisture-curing water-absorbing swellable and gelling polymer or biopolymer agglomerant.

[0176] In an embodiment of the method for preparing water-absorbing gelling and swelling adsorbent particles, in the wetting step, non-water-absorbing or minimally water-absorbing substrate microparticles are wetted with a wetting liquid, preferably water or an aqueous solution, to prepare the outer surface of each substrate microparticle for adhering to a powdery starch-based water-absorbing gelling agent containing a modified starch water-soluble polymer binder applied thereto in the application step. In the application step, the powdery starch-based water-absorbing gelling agent containing the modified starch water polymer binder and the wetted substrate microparticles are mixed together until the outer region of the gelling agent containing the powdery starch-based water-absorbing modified starch water-soluble polymer binder adheres to each wetted substrate microparticle, resulting in the water-absorbing gelling and swelling adsorbent particles of the present invention. Preferably, the outer region of the gelling agent of the powdered starch-based water-absorbing modified starch containing the water-soluble polymer binder at least partially encapsulates each wetted substrate microparticle, preferably substantially completely encapsulates it. In the application step, at least some of the modified starch water-soluble polymer binders in the starch-based water-absorbing gelling agent powder in contact with each wetted substrate microparticle dissolve in the wetting liquid, preferably water or an aqueous solution, to adhere partially wetted and non-wetted water-absorbing gelling agent powder microparticles to each substrate microparticle. After the application step is completed, a moisture curing step is carried out, in which the moisture is preferably removed by drying so that the dissolved water-soluble polymer binder that has adhered the partially wetted and non-wetted water-absorbing gelling agent powder microparticles to each wetted substrate microparticle cures and adheres the regions of the water-absorbing gelling agent powder particles to each substrate microparticle.

[0177] The present invention also relates to a self-agglomerating adsorbent granular litter and a method for preparing the self-agglomerating adsorbent granular litter. The self-agglomerating adsorbent granular litter is composed of self-agglomerating adsorbent litter particles, and the self-agglomerating adsorbent litter particles generally include circular self-agglomerating adsorbent-coated substrate litter particles. Each integral circular self-agglomerating absorbent-coated substrate litter particle has a coating on the integral circular outer surface, and the outer surface at least partially, preferably substantially completely, fills the tiny water-absorption-enhancing protrusions such as spikes protruding from the outer surface of the particles during agglomeration. The outer surface of the coating of each generally circular self-agglomerating adsorbent-coated substrate litter particle is also configured to have numerous water-absorption-enhancing microcracks, which are formed on the outer surface during the curing process after agglomeration and during the post-agglomeration curing and drying process.

[0178] Each litter particle of the coated substrate is formed from an internal substrate in the form of a nucleating agent substrate particle and an external modified starch water-absorbing agglomerant, the agglomerant being configured to absorb water or urine during litter use, agglomerate and self-agglomerate into a removable and shovellable mass of wetted litter particles, the mass of wetted litter particles including at least multiple pairs of litter particles of the coated substrate, the litter particles being shovellable using a handled, porous litter shovel, having a mass retention rate of at least 95%, preferably at least 97%, more preferably at least 99% after drying, and having a mass crush strength of at least 40 pounds per square inch (PSI), preferably at least 60 PSI, more preferably 80 PSI, even more preferably 100 PSI. In a preferred embodiment of the self-agglomerating absorbent-coated substrate litter particles of the present invention, each coated substrate litter particle of the present invention has an outer coating of modified starch water-absorbing agglomerant that self-adheres to the outer surface of the internal substrate particles through an internal self-adhesive region using the agglomeration method of the present invention discussed in more detail below.

[0179] In a preferred embodiment, at least 20%, preferably at least 30%, and more preferably at least a majority, i.e., at least 50% of the litter weight of the self-agglomerating litter according to the present invention is composed of the self-agglomerating absorbent-coated substrate litter particles of the present invention, forming a multi-component litter, the multi-component litter may have a remainder composed of one or more other types of particulate components, such as non-agglomerating calcium-based bentonite particles and / or non-agglomerating organic particles, and still form a shovellable mass when wetted with water or urine, having a mass retention rate of at least 95%, preferably at least 97%, more preferably at least 99% and a mass crush strength of at least 40 PSI, preferably 60 PSI, more preferably 80 PSI, even more preferably 100 PSI when dry. Such self-agglomerating absorbent particulate litter, which may be a multi-component litter, composed of 20% to 100% of the self-agglomerating absorbent-coated substrate litter particles of the present invention, advantageously improves one or more properties and / or characteristics of past and present sodium-based bentonite litters and sodium-based bentonite-based litters, is lighter in weight, cheaper to prepare and transport, easier to handle during transport, easier for the user to lift, carry and dump, generates less dust, preferably is dust-free or even dust-suppressing, and produces round coated substrate litter particles that are not easily caught by a cat's claws, thus also advantageously reducing spillage from the litter box.

[0180] In the process of preparing coated substrate packing particles, the coating of the modified starch water-absorbing agglomerant adheres to the outer surface of the substrate microparticles by agglomeration, preferably wet agglomeration, and an internal self-adhesive region of the coating is formed using some but not all of the modified starch water-absorbing agglomerant directly adhered to the outer surface of the substrate microparticles. By wetting at least one of the outer surface and the modified starch water-absorbing agglomerant material applied to the outer surface, the internal self-adhesive region of the coating adheres directly to the outer surface of the substrate particles. This allows the remaining modified starch water-absorbing agglomerant in the outer region of the coating surrounding the internal self-adhesive region of the coating to be substantially unmodified and substantially unchanged and available for absorbing water and promoting agglomeration when wetted by water or urine during the use of the packing or absorbent. The internal adhesion region is self-adhesive because it is formed of the same modified starch water-absorbing agglomerant as the outer region, but some of its binder is activated to directly adhere the internal adhesion region to the outer surface of the substrate particles. In addition to at least one component of the modified starch water-absorbing agglomerant for each coated substrate coating being a water absorbent, the modified starch water-absorbing agglomerant has at least one other component for each coated substrate coating, which component is a water-activated binder, preferably a moisture-curing water-activated binder, which becomes activated by at least becoming sticky and preferably also becomes flowable when wetted with a water-containing wetting liquid such as water or urine, forming a flowable binder, and can also gel, i.e., thicken, during or after the flow.

[0181] In a preferred embodiment, the modified starch water-absorbing agglomerant has a first binder component and a second binder component, the first binder component being a once water-activated, once water-cured at least partially water-soluble binder, and the second binder component being a water-reactivated and water-re-cured at least partially water-soluble binder. The second binder component can preferably be water-reactivated and water-re-cured at least multiple times, preferably at least multiple pairs, i.e., at least three times. In a preferred embodiment, the first binder component is a starch at least physically modified during the extrusion process, i.e., a physically modified starch, and preferably a dextrinized starch, which can be or include dextrin, but not necessarily dextrin. In such a preferred embodiment, the second binder component is a starch modified during the extrusion to form a starch pre-gel or pre-gelatinized starch having binder properties.

[0182] The coating applied to the substrate particles or substrate microparticles contains both a first binder component and a second binder component. In a preferred embodiment, the coating applied to the substrate particles or substrate microparticles contains a first binder component, a second binder component, and a third water-absorbing component configured to absorb urine at room temperature or cat body temperature. In one embodiment, at least one of the first component, the second component, and the third component comprises or consists of cold-water-soluble starch, which can be an absorbent for water and urine and is at least partially soluble in urine at room temperature and cat body temperature. In another embodiment, at least both the first component and the second component consist of or comprise water-absorbing starch, which is an absorbent for water and urine and consists of or comprises modified starch that is at least partially soluble in urine at room temperature and cat body temperature.

[0183] In the preparation of coated substrate bedding particles, preferably by an agglomeration process, one or both of the outer surfaces of the modified starch water-absorbing caking agent and the substrate particles are wetted with an aqueous wetting liquid, preferably water, ultimately causing at least some of the modified starch water-absorbing caking agent to be wetted, activating some but not all of the water-activated binders in the modified starch water-absorbing caking agent, and forming an internal self-adhesive region. In at least one preferred embodiment of the modified starch water-absorbing caking agent, at least some of the binders activated by the aqueous wetting liquid become at least somewhat sticky, preferably sticky, causing at least some of the modified starch water-absorbing caking agent to adhere to and stick to the surface of the external substrate particles. In at least another preferred embodiment of the modified starch water-absorbing caking agent, at least some of the binders gelled and activated by the aqueous wetting liquid cause at least some of the modified starch water-absorbing caking agent to adhere to and stick to the surface of the external substrate particles, forming an internal self-adhesive region. In at least a further preferred embodiment of the modified starch water-absorbing caking agent, at least some of the binders activated by the aqueous wetting liquid become flowable, preferably forming a flowable binder, causing at least some of the modified starch water-absorbing caking agent to adhere to and stick to the surface of the external substrate microparticles, forming an internal self-adhesive region. In at least one preferred embodiment of the modified starch water-absorbing caking agent, at least some of the binders activated by the aqueous wetting liquid that wets the modified starch water-absorbing caking agent become sticky, at least some of the binders activated by the aqueous wetting liquid that gels the modified starch water-absorbing caking agent, and / or at least some of the binders activated by the aqueous wetting liquid that wets the modified starch water-absorbing caking agent form a flowable water-activated binder, causing at least some of the modified starch water-absorbing caking agent to adhere to and stick to the surface of the external substrate particles, forming an internal self-adhesive region.

[0184] This combination of tackiness and the tumbling action of using substrate particles during agglomeration, such as in a rotating drum to form the coated substrate litter particles of the present invention, results in the formation of an outer surface of the coated substrate litter particles that has a large number of raised protrusions, preferably including spikes, over substantially the entire outer surface of the coated substrate litter particles. These minute protrusions, including spikes, are minute in size and extend outwardly from the surface of the coated substrate litter particles no more than 5 microns, preferably no more than 2 microns, and more preferably no more than about 1 micron (1 micron ± 0.25 micron). Preferably, these minute protrusions, including spikes, are nanoscale or nano-sized and each extends outwardly from the outer surface no more than 1 micron. This tumbling action, such as that carried out in a drum, is also the reason for the production of the coated substrate litter particles of the present invention, which are round and can be substantially round, minimizing spillage by minimizing the likelihood of being picked up by cat claws during litter use. Because these protrusions, including any spikes, are so minute in size, they advantageously enhance absorption by more rapidly spreading and wetting water or urine, including the spikes, via capillary action or wicking substantially along the entire outer surface of the coated substrate litter particles, while still maintaining the overall round configuration or shape of the coated substrate litter particles, which minimizes spillage.

[0185] Thereafter, upon curing the protrusions, including spikes, they become rather hard and microcracks that enhance absorption are formed on the outer surface. These microcracks continue to form and expand after curing, during the drying process, and even during storage of the coated substrate litter particles after packing and before use. The length range of these microcracks can range from nanoscale or nano-sized, i.e., less than 1 micron, to as long as the multi-micron thickness of the binder coating that at least partially covers the substrate microparticles or substrate particles, which form the substrate-coated litter particles. In a preferred embodiment, the size of these microcracks is such that they have a root thickness of no more than about 1 micron and a length of no more than about 50 microns (50 microns ± 5 microns) down to a root thickness as small as about 5 nanometers (5 nanometers ± 3 nanometers) and a length as small as about 5 nanometers, e.g., a root thickness of about 5 nanometers to about 1 micron and a length of about 5 nanometers to about 50 microns. These microcracks further enhance absorption via capillary action or wicking to open a portion of the outer coating of the coated substrate litter particles when wetted with water or urine, thus rapidly increasing the order of magnitude of the surface area in contact with water or urine, which it can absorb. The protrusions, including spikes, work in concert with the microcracks to enhance absorption not only by accelerating absorption but also by accelerating the flow of the flowable binder from each wetted coated substrate litter particle, thus also enhancing agglomeration.

[0186] In preferred methods and embodiments, at least some of the binders of the first binder component of the modified starch water-absorbing agglomerant are activated and cured, thereby assisting in bonding the self-adhesive regions to the surfaces of the external substrate particles. At least some of the binders of the second binder component are also activated and cured, thereby also assisting in bonding the self-adhesive regions to the surfaces of the external substrate particles.

[0187] Preferred self-agglomerating litter of the present invention comprises substrate litter particles coated with a self-agglomerating absorbent, wherein the particulate coating weight of each internal substrate microparticle of each particle is from about 5% to about 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the weight of the coated substrate litter particle of a modified starch water-absorbing agglomerant, and which produces the self-agglomerating coated substrate litter particles of the present invention, each particle absorbing at least twice, preferably at least three times, more preferably at least four times, most preferably at least six times its coating weight of water, such as preferably room temperature water at a temperature of 68 degrees Fahrenheit to 72 degrees Fahrenheit, and urine, such as urine at a cat body temperature of about 100 degrees Fahrenheit to about 104 degrees Fahrenheit. The wetted coated substrate litter particles self-agglomerate with adjacent water- or urine-wetted litter particles to form agglomerates while doing so, and the agglomerates are scoopable with a handled porous litter scoop among other non-wetted or non-contaminated litter particles. The self-agglomerating absorbent-coated substrate litter particles of the present invention absorb at least one time its coating weight of water, preferably room temperature water or urine, preferably urine at cat body temperature, within one minute, i.e., sixty seconds, preferably within thirty seconds, more preferably within twenty seconds, after being wetted with water or urine, and this occurs during agglomeration with other wetted litter particles into agglomerates composed of at least multiple pairs of coated substrate litter particles. In such a preferred embodiment, each coated substrate particle is composed of from about 5% to about 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the weight of the particle of the modified starch water-absorbing agglomerant. In one such preferred embodiment and method of preparing the coated substrate litter particles of the present invention, the modified starch water-absorbing agglomerant is applied to each substrate particle until a particulate coating weight of the modified starch water-absorbing agglomerant on the substrate microparticles of 5% to 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the particle weight is obtained, such that each final coated substrate litter particle contains from 5% to 35%, preferably from about 5% to 50%, more preferably from about 5% to 85% of the weight of the particle of the modified starch water-absorbing agglomerant.

[0188] Each self - caking absorbent - coated substrate bedding particle of the present invention preferably has a particle coating weight of an external modified starch water - absorbing caking agent on the internal substrate particles that is about 5% to about 35%, preferably about 5% to 50%, more preferably about 5% to 85% of the particle weight. This particle coating weight is sufficient to produce a coating on the self - caking coated substrate bedding particles, and each particle absorbs at least one time the weight of water or urine of the coating weight of the coated substrate bedding particles. Also, compared to the volume of the bedding particles before wetting, when absorbing water or urine, the volume swells by at least 25%, preferably at least 35%, more preferably at least 50%, and most preferably at least 80%. In a preferred embodiment, each self - caking absorbent - coated substrate bedding particle of the present invention has a particle coating weight of an external modified starch water - absorbing caking agent on the internal substrate particles that is about 5% to about 35%, preferably about 5% to 50%, more preferably about 5% to 85% of the particle weight. This particle coating weight is sufficient to produce a coating on the self - caking coated substrate bedding particles, and each particle absorbs at least two times the coating weight of the coated substrate bedding particles of water or urine. Also, compared to the volume of the bedding particles before wetting, when absorbing water or urine, the volume swells by at least 25%, preferably at least 35%, more preferably at least 50%, and most preferably at least 80%.

[0189] Each self - caking absorbent - coated substrate litter particle of the present invention, preferably a swellable and gellable self - caking absorbent - coated substrate litter particle, wherein the outer region of the outer coating of its modified starch water - absorbing caking agent swells upon absorption of water or urine, preferably room - temperature water or urine at cat body temperature, wets the particle and also substantially simultaneously forms a gel thereon, is viscous along and below the outer surface of the coated substrate litter particle, preferably when wetted, and may be, include or preferably contain a water - activated moisture - curable adhesive, which promotes caking with other contacting litter particles through its viscosity or tackiness, generating an adhesive force between them, and this adhesive force bonds the contacting particles into agglomerates through moisture - curing, which is achieved by the moisture evaporating from the agglomerates during drying. In one embodiment of the coated substrate litter particles of the present invention, the outer coating of the modified starch water - absorbing caking agent of each wetted coated substrate litter particle at least partially dissolves in water or urine, preferably room - temperature water or urine at cat body temperature, to form a flowable water - activated moisture - curable adhesive, the viscosity of which remains low enough, preferably not more than 15000 centipoise, more preferably not more than 10000 centipoise, even more preferably not more than about 5000 centipoise, for a long enough time, preferably at least one second after wetting, more preferably at least 4 seconds after wetting, so that it flows along and between the contacting and adjacent particles from the water or urine wetted by the modified starch water - absorbing caking agent of the litter particle until the viscosity increases and reforms into a viscous semi - solid gel within 20 seconds after wetting, preferably within 10 seconds after wetting, more preferably within 5 seconds after wetting, the viscosity of which is at least about 30000 centipoise, preferably at least 50000 centipoise, more preferably at least 80000 centipoise. As the viscosity of the flowable adhesive increases, it gels (but at least remains slightly tacky) and hardens into a glassy material having a glassy material state at room temperature because the agglomerate moisture - cures during the drying process, thereby bonding the caked particles together. These bonds may include one of hydrogen bonds and covalent bonds, preferably covalent bonds. In any case, when the agglomerate is dried to a water content of about 12% (12% ± 1.5%) of the agglomerate weight, the formed agglomerate becomes hard enough to have an agglomerate retention rate of at least 95%, preferably at least 97%, more preferably at least 99% and an agglomerate crush strength of at least 40 PSI, preferably at least 60 PSI, more preferably 80 PSI, even more preferably at least 100 PSI.

[0190] Preferably, at least a portion of the modified starch water absorbent caking agent of each litter particle of the present invention is at least partially dissolved in urine at room temperature or cat body temperature, wets the particles by contact, and forms a flowable binder, which is preferably a flowable water-activated binder that is also moisture-curing and flows outward from the wetted particles along the contacting particles and adjacent particles of the litter and between them. The flowable binder initially has a flowable viscosity greater than that of water, and its viscosity increases over time and cures into a binder gel, which initially adheres the contacting pellets to it and to each other, for example, by surface tension, capillary action, liquid adhesion, and / or intermolecular forces such as van der Waals forces, and when dried, transforms into a more viscous binding gel with moisture curing, adhering the contacting pellets to it and to each other more strongly, for example, preferably at least by hydrogen bonds and / or preferably at least some covalent bonds. As the initially flowable binder transforms into a binder gel over time and then into a binding gel with further moisture curing, when it dries to a moisture content of less than 15% by weight, preferably not more than 12% by weight, it becomes a substantially fully cured solid binder, which is a vitreous material in a vitreous state and binds to the litter particles of the litter at least by hydrogen bonds, i.e., hydrogen bonding, and / or preferably by covalent bonds, i.e., covalent bonding. Such agglomerates are formed by at least multiple pairs, i.e., at least three, of the litter particles of the present invention wetted by water or urine and are bonded together by the solid binder formed from the initially flowable binder by a combination of hydrogen bonds, covalent bonds, or hydrogen bonds and covalent bonds, becoming substantially fully moisture-cured into rock-hard lumps, which have a lump moisture content of about 12% of the lump weight, which have a lump crush strength of at least 40 PSI, preferably at least 60 PSI, more preferably at least 80 PSI, and even more preferably at least 100 PSI, and a lump retention rate of at least 95%, preferably at least 97%, more preferably at least about 99%.

[0191] In a preferred embodiment of the modified starch water-absorbing caking agent for each coated substrate litter particle of the present invention, the modified starch water-absorbing caking agent is composed of the following components: (1) a water-swellable modified starch, preferably a cold-water-swellable modified starch, which is also water-absorbing and will swell when it absorbs water, absorbing at least 4.5 times, preferably at least six times the weight of the litter particle of room temperature water or cat body temperature urine, and (2) a water-soluble modified starch binder, preferably a cold-water-soluble modified starch binder, which is at least partially cold-soluble in room temperature water and at least partially soluble in cat body temperature urine, and becomes at least partially dissolved when forming a flowable mixture, flows out from the wetted litter particles, and its viscosity increases during the curing of the moisture into a binder gel, the binder gel is sticky and adheres the particles together through at least one of liquid adhesion force, hydrogen bond and / or other intermolecular forces, and its viscosity even further increases during the further curing of the moisture into a binding gel, adheres the particles together through at least one of hydrogen bond and covalent bond, and when substantially completely cured to a water content of less than 15% by weight, preferably not more than 12% by weight, the binder gel becomes a substantially solid binder, and the binder is a vitreous material in a vitreous material state. The water-swellable modified starch, preferably the cold-water-swellable modified starch, of the modified starch water-absorbing caking agent in each litter particle is composed of natural starch, such as natural starch from one or more cereals, such as natural starch from or from one or more corns or maize, rice, wheat, rye, barley, millet, triticale, oats, fonio and sorghum, and / or one or more leguminous crops, such as natural starch from or from one or more beans, soybeans, peas, chickpeas, peanuts, lentils, lupins, mesquite, carob, tamarind, alfalfa and / or clover, which is modified, preferably physically modified, so as to use a starch modification method or process such as extruding and degrading starch granules and / or reducing the molecular weight of one or both of the amylose and / or amylopectin molecules of natural starch, wherein the natural starch is processed in a starch modification machine, such as an extruder, preferably a single-screw extruder, so that the natural starch is subjected to an ultra-high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, even more preferably at least 5000 PSI, at an extrusion temperature of at least 100 degrees Fahrenheit, and the natural starch is modified into a modified starch in the extruder, and the modified starch is a water-swellable water-absorbing modified starch, preferably a cold-water-swellable cold-water-absorbing modified starch.At least a portion of the modified starch water-absorbing caking agent of each litter particle, a modified starch binder that is at least partially soluble, preferably at least partially cold-water soluble, is also composed of natural starch, such as natural starch from one or more cereals, such as one or more corns or maize, rice, wheat, rye, barley, millet, triticale, oats, fonio, and sorghum, and / or one or more leguminous crops, such as one or more beans, soybeans, peas, chickpeas, peanuts, lentils, lupins, mesquite, carob, tamarind, alfalfa, and / or clover, which is modified, preferably physically modified, so as to use a starch modification method or process such as extruding to degrade starch granules and / or reducing the molecular weight of one or both of the amylose and / or amylopectin molecules of the starch, wherein the natural starch is processed in a starch modification machine, such as an extruder, preferably a single-screw extruder, to subject the natural starch to an ultra-high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, and even more preferably at least 5000 PSI, at an extrusion temperature of at least 100 degrees Fahrenheit to modify the natural starch into a modified starch in the extruder, the modified starch being at least partially water-soluble modified starch, preferably at least partially cold-water soluble modified starch, which is composed of a water-activated moisture-curing binder that is activated by room temperature water and / or urine at the body temperature of a cat into a flowable adhesive having the above properties and characteristics.

[0192] In the process of preparing the coated substrate litter particles of the present invention, a modified starch water-absorbing caking agent in a pulverized form, preferably a ground form, i.e., prepared by grinding, is used, which has a relatively small particle size, even smaller than the smallest-sized substrate microparticles, which preferably has a particle size within the range of a powdery substance or powder size, such as passing through a 40-mesh sieve, preferably passing through a 60-mesh sieve, and even more preferably passing through a 40-mesh to 60-mesh sieve and remaining on a smaller sieve, such as an 80-mesh sieve. In doing so, the extruded pellets, such as pellets made using the above extrusion method and / or the methods disclosed elsewhere herein, are ground using a grinder into a powder or powdery substance having the sieve mesh sizes disclosed in this paragraph.

[0193] In a preferred embodiment and implementation of a method for preparing coated substrate padding granules, the extruded granules prepared according to at least one modified starch water absorbent agglomerant extrusion method disclosed herein can be used as a modified starch water absorbent agglomerant for the agglomeration with substrate granules or microparticles to prepare the coated substrate padding according to the present invention. In one such preferred embodiment and method implementation, the extruded granules can be mixed with water to form a slurry, which is applied to the substrate granules or substrate microparticles in a manner discussed in more detail below. In another such preferred embodiment and method implementation, water can be applied to the substrate granules or substrate microparticles in a coalescer or coater, preferably in a rotary or tumbling granulator or coater, before the extruded granules can be mixed with water to agglomerate the substrate microparticles or substrate microparticles into the coated substrate granules of the present invention, and the manner will also be discussed in more detail below.

[0194] In another preferred embodiment and method implementation, a high-speed high-shear mixer, such as a batch, in-line or granulator high-speed high-shear mixer, is used to crush the extruded granules into smaller modified starch water absorbent agglomerant microparticles. In one such preferred embodiment and method implementation, the extruded granules are crushed with water in such a high-shear mixer to form a substantially homogeneous slurry of smaller-sized granule microparticles of the modified starch water absorbent agglomerant, which is then applied to the substrate granules or substrate microparticles in the form of a slurry and stirred, preferably tumbled, in a rotary granulator or coater in a manner discussed in more detail below.

[0195] In still another preferred embodiment and method implementation, the modified starch water absorbent agglomerant is formed by a combination of a powder or powdery substance having the mesh size defined above and extruded granules prepared according to at least one modified starch water absorbent agglomerant extrusion method disclosed herein. In one such preferred embodiment and method implementation, a high-speed high-shear mixer, such as in the above manner, is used to homogenize the mixture of the powdered or powdered modified starch water absorbent agglomerant and the extruded granules into an aqueous slurry.

[0196] If desired, the modified starch water-absorbing caking agent can be in the form of fine particles of a cereal-based bedding, which particles are classified as being too small to be used in one or more extruded beddings disclosed in one or more co-owned U.S. Pat. Nos. 9,491,926; 10,028,481; 10,098,317; 10,882,238; 11,013,211; and / or 11,083,168, the entire contents of which are incorporated herein by reference. If desired, the fine particles of the modified starch water-absorbing caking agent from the waste particles of an extruded bedding prepared according to one or more methods can be further reduced in size, such as by grinding, such as hammer milling, using another particle size reduction machine, and / or using another particle size reduction or particle comminution method, such as the particle size reduction systems, devices, and methods disclosed in co-owned U.S. Pat. No. 11,013,211, the entire contents of which are incorporated herein by reference.

[0197] As described in more detail herein, in the method of preparing self-caking absorbent bedding particles of a preferred bedding according to the present invention, these relatively small powdery or dusty modified starch water-absorbing caking agent particles are wetted with an aqueous wetting liquid such as water, thereby activating some but not all of at least partially water-soluble binders in some but not all of the modified starch water-absorbing caking agent particles, resulting in some but not all of the modified starch water-absorbing caking agent particles adhering to the outer surface of each substrate particle when wetted, and then becoming adhered to the outer surface of each substrate particle when substantially completely moisture-cured upon drying, forming an internal adhesion region between the internal substrate particles and the outer region of the modified starch water-absorbing caking agent in each bedding particle. Wetting of the modified starch water-absorbing caking agent of substantially all of the particles activates some but not all of the at least partially water-soluble binders of the remaining non-adhered wetted particles of the modified starch water-absorbing caking agent, such that at least some but not all of the modified starch water-absorbing caking agent particles in contact with the internal adhesion region adhere to the internal adhesion region itself when wetted, and then adhere to the internal adhesion region when substantially completely moisture-cured upon drying, forming one or more additional regions in which the modified starch water-absorbing caking agent adheres to each of the fabricated bedding particles.

[0198] In a preferred method for manufacturing bedding particles, the wetting of the modified starch water-absorbing caking agent particles is achieved by mixing the dry powder-sized or powdered-sized particles of the modified starch water-absorbing caking agent with a water-containing wetting liquid, preferably water, to form a slurry, and then applying it to the substrate particles, preferably while tumbling, stirring or by other means, such as by using a mixer, coater, blender, or another mixing device or apparatus, so that an internal adhesion region is formed thereon before an outer region of the modified starch water-absorbing caking agent is formed on the outer surface of each substrate particle. In another preferred method for manufacturing bedding particles, the wetting of the modified starch water-absorbing caking agent particles is indirectly accomplished by wetting the substrate particles with a water-containing liquid, preferably water, before applying the dry powder-sized or powdered-sized particles of the modified starch water-absorbing caking agent to the wetted substrate particles, and preferably while doing so, flipping, stirring or otherwise mixing the wetted substrate particles and the applied modified starch water-absorbing caking agent particles, so that the water on the surface of the substrate particles wets the modified starch water-absorbing caking agent particles in contact therewith, thereby forming an internal adhesion region on the outer surface of each substrate particle. Preferably, one or more wetting cycles and application cycles are carried out, wherein during each rewetting cycle, an additional water-containing wetting liquid is applied to at least partially coated substrate particles, substantially simultaneously with or substantially immediately following another application cycle, in which additional dry powder-sized or powdered-sized particles of the modified starch water-absorbing caking agent are applied to the wetted and at least partially coated substrate particles, while tumbling, stirring or otherwise mixing the wetted and at least partially coated substrate particles, until one or more additional outer regions are added to the top of the internal adhesion region of each formed bedding particle.

[0199] Since an aqueous wettable liquid, preferably water, is applied at the start to the substrate particles and at least partially formed bedding particles until a coating of modified starch water-absorbing agglomerating agent particles of the desired thickness accumulates on each substrate particle to form the final bedding particles, the wetting of the modified starch water-absorbing agglomerating agent particles applied to each substrate particle causes the modified starch water-absorbing agglomerating agent particles in the outer region of each bedding particle surrounding its inner substrate particle to agglomerate into an amorphous region of substantially uniform modified starch water-absorbing agglomerating agent material which sticks together when substantially completely moisture-cured onto the inner substrate particles of the final bedding particles. The preferred self-agglomerating adsorbent particles of the present invention produced by the manufacturing method disclosed herein have an outer region of modified starch water-absorbing agglomerating agent with a thickness not greater than 1 mm, preferably not greater than 0.8 mm, and preferably not greater than about 0.5 mm, and even more preferably not greater than about 0.3 mm, and at least 50%, preferably at least 80%, more preferably at least 95%, and even more preferably substantially the entire outer surface of each substrate particle of each bedding particle is covered with modified starch water-absorbing agglomerating agent material. A preferred self-agglomerating absorbent particle of the present invention produced by the manufacturing method disclosed herein has an outer region of modified starch water-absorbing agglomerating agent with a thickness of 20 microns (i.e., 0.02 mm) to 1000 microns (i.e., 1 mm), preferably 20 microns (i.e., 0.02 mm) to 800 microns (i.e., 0.8 mm), more preferably 20 microns (i.e., 0.02 mm) to 500 microns (i.e., 0.5 mm), and even more preferably 20 microns (i.e., 0.02 mm) to 300 microns (i.e., 0.3 mm), and at least 50%, preferably at least 80%, more preferably at least 95%, and even more preferably substantially the entire outer surface of each substrate particle of each bedding particle is covered with modified starch water-absorbing agglomerating agent material.

[0200] In a preferred embodiment, the coated round substrate litter particles advantageously have a size that minimizes litter spillage from the litter box during the use and operation of the coated substrate litter of the present invention. During the use of the litter box, the round shape of the coated substrate litter particles helps prevent the coated substrate litter particles from getting caught in the cat's claws. In addition, the size of the coated substrate litter particles also helps prevent the litter from being carried away by the cat from the litter box during the use of the litter box. In a preferred embodiment, the coated substrate particles need to have a size greater than a 25-mesh screen, i.e., greater than a 25-mesh screen but not greater than a 10-mesh screen, i.e., not greater than a 10-mesh screen. At least 80% of the coated substrate litter particles should have a size less than 10 mesh and greater than 25 mesh (10 / 25). For example, in one embodiment, 60% to 95%, and preferably at least about 80% (80% ± 15%) of the particles pass through a 12-mesh screen and are greater than a 25-mesh screen. The remainder of the coated substrate litter particles will be greater than 10 mesh. Round coated substrate litter particles having a particle size distribution of 12 mesh to 20 mesh (12 / 20) provide the best feel for the cat's claws.

[0201] Thus, in a preferred embodiment of a coated substrate cat litter, the coated substrate litter particles are generally round, have raised protrusions, including spikes, and have a particle size distribution of 12 mesh to 20 mesh (12 / 20) to produce a preferred embodiment of a low-spill litter according to the present invention that minimizes litter spillage caused by the cat from the litter box. In another preferred embodiment of a coated substrate cat litter, the coated substrate litter particles are generally round, have raised protrusions, including spikes, and have a particle size distribution of 10 mesh to 25 mesh (10 / 25) to produce another preferred embodiment of a low-spill litter according to the present invention that minimizes litter spillage caused by the cat from the litter box.

[0202] In the method of applying the modified starch water-absorbing caking agent to the substrate microparticles to produce the self-caking absorbent-coated substrate microparticles of the present invention, according to the type and size of the substrate microparticles, for a given amount, such as a given weight or mass, of the substrate microparticles, a certain amount of a slurry containing a predetermined amount, such as a predetermined weight or mass, of the modified starch water-absorbing caking agent microparticles is applied. The respective predetermined amounts of the modified starch water-absorbing caking agent forming a slurry in water are selected according to the size or size range and the given amount of the substrate microparticles to be coated and turned into the self-caking adsorbent particles of the present invention. In a preferred method of preparing the self-caking absorbent padding particles of the present invention using a slurry of water and the modified starch water-absorbing caking agent microparticles, the slurry is applied to the substrate particles or microparticles tumbling within a rotating drum or cylinder of a drum mixer, a cement mixer, a drum coater, or a similar device. This process uses one or more spaced-apart spray heads, nozzles, atomizers, or another type of slurry applicator or slurry dispenser that is configured or operated to controllably discharge the slurry onto the substrate microparticles in the rotating mixer or coater drum during the production of the self-caking adsorbent padding particles of the present invention. In another preferred method of applying the modified starch water-absorbing caking agent to the substrate particles or microparticles to prepare the self-caking absorbent-coated substrate microparticles of the present invention, the substrate microparticles are wetted with a water-containing wettable liquid such as water, and the dry microparticles of the modified starch water-absorbing caking agent are applied while applying the substrate microparticles, the modified starch water-absorbing caking agent microparticles, and the water-containing wettable liquid, preferably water, and first applying the substrate microparticles, and then applying the substrate microparticles, the modified starch water-absorbing caking agent microparticles, and the water-containing wetting liquid, preferably water, and tumbling or stirring, for example, preferably in a rotating drum of a drum mixer, a cement mixer, a drum coater, etc., to mix all the substances together. One or more wetting cycles are carried out as needed by applying the water-containing wettable liquid, preferably water, to at least partially coated substrate microparticles, and then applying the modified starch water-absorbing caking agent microparticles until each substrate microparticle has the desired amount of particle coating weight, such as coverage, and / or the outer region thickness of the modified starch water-absorbing caking agent, thereby producing the final self-caking padding particles of the present invention. Thereafter, a moisture curing step, preferably a moisture removal step, is carried out on the at least partially wetted final self-caking water-absorbent padding particles, for example, by convective drying of the padding particles using flowing air, preferably turbulent flowing air, or by drying in a heating furnace using one or more types of radiant heat, hot air convection drying, or another type of heating drying method until the moisture curing in each padding particle is completed or substantially completed, at which time each particle is dried to a water content of not more than 12%, preferably more than 10%, and more preferably not more than 8% of the weight of the padding particle.

[0203] When the slurry is used to prepare the substrate particles coated with the self - caking absorbent of the present invention, the slurry is a slurry of water and relatively small modified starch water - absorbing caking agent particles, preferably having the size of a powder or powdery substance. Thus, the modified starch water - absorbing caking agent particles are mixed with water until a substantially homogeneous mixture or slurry is formed. As previously described, mixing can be carried out using a high - speed high - shear mixer. In a preferred slurry, when water is used as the aqueous wetting liquid, the ratio of the amount of the modified starch water - absorbing caking agent to water is about 1:1 ± 10% by weight. The slurry is applied to the substrate particles or substrate microparticles while stirring, tumbling, or otherwise mixing the substrate microparticles, such as in a rotating drum, roller, or bin of a mixer, coater, or agitator, so that the areas of the modified starch water - absorbing caking agent accumulate on each substrate microparticle until the desired area thickness or desired particle coating weight of the modified starch water - absorbing caking agent on the substrate microparticle is reached. Tumbling is preferably carried out in a rotating drum or roller - type mixer or coater because this also ensures that the resulting finally coated substrate bedding particles are rounded in the above - mentioned manner to minimize spillage from the bedding box. The water in the slurry activates at least some but not all of the water - soluble modified starch binders in the modified starch water - absorbing caking agent particles in the slurry, preferably cold - water - soluble modified starch binders, to produce a viscous gel and a flowable binder that adheres the modified starch water - absorbing caking agent particles to the substrate microparticles to which the slurry is applied. This viscosity helps to ensure the formation of protrusions, including spikes, on the outer surface of the coated substrate microparticles, thereby increasing the water absorption amount and rate during the use of the bedding. Applying the slurry to the substrate microparticles while stirring, tumbling, or mixing the substrate microparticles not only helps the modified starch water - absorbing caking agent particles to adhere more uniformly to each substrate microparticle, but also helps to prevent at least some of the coated substrate microparticles from caking during the preparation of the slurry - based self - caking absorbent bedding particles. When the substrate microparticles are tumbled, stirred, and / or mixed, the slurry is applied to the substrate microparticles until the modified starch water - absorbing caking agent particles on the substrate microparticles reach the desired thickness or particle coating weight. In a preferred method embodiment, the initial application of the slurry on the substrate microparticles causes each substrate microparticle to act as a bedding particle nucleating agent, resulting in the adhesion of the modified starch water - absorbing caking agent in the slurry to the outer surface of each substrate microparticle, forming an internal adhesion area, and the water - containing wetting of which more rapidly promotes the adhesion of another outer area of the modified starch water - absorbing caking agent.

[0204] In a preferred method of applying the slurry, depending on the type and size of the substrate particles, for a given quantity, such as a given weight or mass of the substrate particles, a quantity of slurry is applied that contains a predetermined quantity, such as a predetermined weight or mass of modified starch water-absorbing agglomerating agent particles, wherein the corresponding predetermined quantity of modified starch water-absorbing agglomerating agent forms a slurry in water, and the slurry is selected based on the size or size range and the given quantity of the substrate particles to be coated and turned into the self-agglomerating absorbent particles of the present invention. In a preferred method of preparing the self-agglomerating absorbent padding particles of the present invention using a slurry of water and modified starch water-absorbing agglomerating agent particles, the slurry is applied to the substrate particles or substrate microparticles tumbling within a rotating drum or cylinder of a drum mixer, a cement mixer, a drum coater, or a similar device, and the process uses one or more spaced-apart spray heads, nozzles, atomizers, or another type of slurry applicator or slurry dispenser that is configured or operated to controllably discharge the slurry onto the substrate microparticles in the rotating mixer or coater drum during the manufacture of the self-agglomerating absorbent padding particles of the present invention.

[0205] In an embodiment of the preferred method of applying the slurry, during the process of applying the slurry to the substrate microparticles, the quantity and preferably the rate, such as the volumetric rate or the metering, of the slurry applied to the substrate microparticles vary in real time so as to (a) control the weight coverage of the particle coating and / or the thickness of the modified starch water-absorbing agglomerating agent forming an outer region around each substrate microparticle, and (b) prevent the substrate microparticles covered by at least a portion of the modified starch water-absorbing agglomerating agent region from agglomerating during tumbling, stirring, or otherwise mixing. During the process of applying the slurry to the substrate microparticles, the ratio of the quantity of the modified starch water-absorbing agglomerating agent to the quantity of water can also be controllably adjusted or varied in real time by up to ±25%, such as from 1:1 up to +25% or from 1:1 down to -25%, to control (a) the water activation of at least a portion of the soluble modified starch binder, (b) the particle coating weight coverage rate of the modified starch water-absorbing agglomerating agent adhering to and / or covering each substrate microparticle, (c) the particle coating weight coverage of the modified starch water-absorbing agglomerating agent adhering to and / or covering each substrate microparticle, (d) the thickness of the outer region of the modified starch water-absorbing agglomerating agent adhering to and / or covering each substrate microparticle during the preparation of the padding particles of the present invention, (e) the viscosity of the slurry, and / or (f) prevent the agglomeration of the partially coated or partially formed padding particles during tumbling, stirring, or otherwise mixing.

[0206] In a preferred method embodiment, the slurry formed can be and preferably is in the following form: (a) a suspension constituted by mixing together an aqueous wetting liquid, preferably water, and dry particles of a modified starch water absorbent agglomerant, for example by using a high shear mixer, another suitable type of mixer or another suitable type of blender until a suspension is formed, or (b) an emulsion constituted by an aqueous wetting liquid, preferably water, and dry particles of a modified starch water absorbent agglomerant mixed together, for example by using a high shear mixer, another suitable type of blender or another suitable type of mixer until a suspension is formed. When using a slurry in the form of such a suspension, the suspension can include one or more surfactants, which include one or more super surfactants, to facilitate the suspension in the aqueous wetting liquid, preferably water, of the dry powder sized or powdery sized particles of the modified starch water absorbent agglomerant during the slurry suspension mixing step, in which all components of the suspension are mixed together. When using a slurry in the form of such an emulsion, the emulsion can include (1) one or more surfactants, which include one or more super surfactants, and / or (2) one or more emulsifiers to emulsify or facilitate all dry powder sized or powdery sized particles of the modified starch water absorbent agglomerant in the aqueous wetting liquid, preferably water, in which all components of the emulsion are mixed together. During the application of the slurry to the substrate particles, by preferably controlling in real time the ratio of water to the modified starch water absorbent agglomerant in the slurry suspension or emulsion during the application of the slurry suspension or emulsion to the substrate particles, at least one of the viscosity, the rate of increase of the modified starch water absorbent agglomerant coating thickness, the amount of the modified starch water absorbent agglomerant coating thickness, and / or the particle coating weight of the modified starch water absorbent agglomerant on each substrate particle can be controlled. Such a slurry suspension or emulsion, preferably a substantially uniform suspension or emulsion of modified starch water absorbent agglomerant particles suspended or emulsified in water, is applied to the substrate particles while stirring, tumbling or otherwise mixing the substrate particles so that areas of the modified starch water absorbent agglomerant build up on the outer surface of each substrate particle until the desired area thickness or desired particle coating weight of the modified starch water absorbent agglomerant on the substrate particles is reached. The water in the slurry activates at least some but not all of the water-soluble modified starch binders, preferably cold water soluble modified starch binders, in the modified starch water absorbent agglomerant particles in the slurry to produce one or more viscous gels and one or more flowable binders which adhere the modified starch water absorbent agglomerant in the suspension or emulsion to the substrate particles to which the slurry suspension or emulsion has been applied.While stirring, tumbling or mixing the substrate particles, applying a slurry suspension or emulsion to the substrate particles not only facilitates more uniform adhesion of the modified starch water-absorbing caking agent to each substrate particle, but also helps prevent agglomeration of at least partially coated substrate particles / partially completed bedding particles during the manufacturing of the slurry-based self-caking absorbent bedding particles while stirring, tumbling or otherwise mixing and during the application of the slurry suspension or emulsion.

[0207] While tumbling, stirring and / or mixing the substrate particles, applying a slurry, slurry suspension or slurry emulsion to the substrate particles until the modified starch water-absorbing caking agent particles on the substrate particles reach the desired thickness or particle coating weight, thereby producing the self-caking absorbent bedding particles of the present invention. Thereafter, reducing the moisture in the final bedding particles to moisture-cure at least partially soluble modified starch binder, which is activated during the slurry application and forms a flowable binder and gel, adhering one or more outer regions of the modified starch water-absorbing caking agent to each substrate particle. The water content of the final bedding particles is reduced to a water content of no more than 12%, preferably no more than 10% and more preferably no more than about 8% to substantially completely moisture-cure the water-activated at least partially soluble modified starch binder, the flowable binder and the gel, forming a vitreous solid binder that adhesively binds the outer regions of the modified starch water-absorbing caking agent to each inner substrate particle. In the outer regions of the modified starch water-absorbing caking agent of each completed self-caking absorbent bedding particle of the present invention, at least a portion of the at least partially soluble modified starch binder remains unactivated and / or uncured, thus being easily wetted by water, such as room temperature water, or urine, such as urine at cat body temperature, and at least partially dissolving into the flowable binder, which flows out of the wetted bedding particle, flows between the contacted bedding particle and the adjacent bedding particles, increases in viscosity during the initial moisture-curing process, becomes a binder or adhesive gel, and when further moisture-curing occurs, the binder or adhesive gel transforms into a bonding gel and finally into a vitreous starch-state solid binder, which binds the contacted bedding particle and the adjacent bedding particles together into a mass, and when the moisture-curing is completed due to moisture evaporation, the mass becomes substantially rock-hard. When the water content of the mass is no more than about 12% of the mass weight, the wet curing of the mass is preferably completed, which is due to the evaporation of moisture from the mass during the drying of the mass, such as air-drying the mass in a bedding box, producing a substantially rock-hard mass, which has a mass retention rate of at least 95%, preferably at least 97%, more preferably at least 99% and / or a mass transverse strength of at least 40 PSI, preferably 60 PSI, more preferably 80 PSI and even more preferably 100 PSI when completely moisture-cured.

[0208] The substrate particles or substrate microparticles can be organic, inorganic, smooth, rough, round, cylindrical, irregularly shaped, porous, non-porous, water-absorbent, water-impermeable, smooth and / or rough, and are preferably non-caking, i.e., composed of a material in which the microparticles do not agglomerate when the microparticles are wetted with water. Preferred substrate materials include nut shells or husks, wood, paper, sand, perlite, and bentonite, which are crushed, ground, milled, or otherwise comminuted into substrate microparticles of relatively small size, at least partially coated with a modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing caking promoting material, to form the self-caking bedding particles of the present invention, which particles have an outer region of the modified starch water-absorbing caking agent that at least partially covers and preferably substantially completely encapsulates each substrate particle. The modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing caking promoting material, is more preferably composed of a starch-modified, preferably by extrusion, more preferably by ultra-high pressure extrusion using a single screw extruder, so as to rapidly swell and absorb water and gel while doing so, and preferably further contains at least some previously natural or unmodified starch that is modified into at least partially water-soluble binder, which binder at least partially dissolves and flows when wetted with water, forming a flowable binder that adheres the swelling and gelling materials to the substrate particles during the manufacture of the bedding particles. In a preferred form of the starch-based water-absorbing caking promoting material, the preferred modified starch water-absorbing caking agent is more preferably a starch-based adsorbent swelling biopolymer gelling agent, e.g., composed of a gelling biopolymer or a biopolymer that gels upon wetting, preferably forming a gel, and composed of a cold water-soluble extrusion-type modified starch binder and a cold water-swellable extrusion-type modified adsorbent starch, the cold water-swellable extrusion-type modified adsorbent starch preferably being or including a cold water-swellable extrusion-type modified cold water adsorbent starch, which is crushed or otherwise reduced in particle size to become a powdery or powdered form that coats the substrate microparticles when wetted. If desired, the powder or powdered microparticles of such modified starch water-absorbing caking agent are pellets or microparticles of discarded or unused extruded cereal fines bedding that are classified as too small to be used in one or more of the bedding disclosed in one or more of the co-owned U.S. Pat. Nos. 9,491,926; 10,028,481; 10,098,317; 10,882,2238; 11,013,211; and / or 11,083,168, the contents of which are incorporated herein by reference in their entirety. The resulting bedding particles form the removable cakable bedding of the present invention because each particle has an outer self-caking water-absorbing region surrounding the internal substrate microparticles, whereby the outer region rapidly absorbs and swells upon contact with water, and at least some of the outer region at least partially dissolves and forms a flowable binder that flows along and between the contacting and adjacent bedding particles, and gelling also occurs during the process of wetting the bedding particles to agglomerate into a mass that can be shoveled from the bedding.

[0209] In the method of preparing the self - caking coated substrate bedding particles of the present invention, one can (a)(1) while stirring, wet a desired or predetermined amount of substrate microparticles with water, the particle size of the substrate microparticles falling within a desired particle size range or particle size distribution, (2) mix with a modified starch water - absorbing caking agent, the caking agent preferably being in the form of a starch - based water - absorbing caking agent promoting powder or powder, while continuing to stir, and while the water wets the outer surface of the substrate microparticles, resulting in (i) some but not all of the water - soluble binder dissolving at least partially to form a flowable binder, causing the starch - based water - absorbing caking agent promoting powder or powder to adhere to the outer surface of the substrate microparticles, and (ii) some but not all, at least a plurality of, preferably at least a plurality of pairs, i.e., at least three different types of modified starch, thereby coalescing the wetted powder or powder microparticles together into an amorphous and substantially uniform starch - based water - absorbent caking - promoting material mass that surrounds each substrate microparticle, forming an outer region thereon, producing the final bedding particles of the present invention, which are then dried, for example, with turbulent air, hot air, and / or radiant heat directed at and / or towards the final bedding particles. Drying is carried out to reduce the water content of the still - moist final bedding particles until each bedding particle has a water content of less than 12%, preferably less than 10%, more preferably not exceeding 8% of the particle weight. The water reduction is carried out to water - cure the water - soluble binder into a solid binder, bond the starch - based water - absorbent caking - promoting material of the outer region to the outer surface of each inner substrate microparticle, and prevent water - activation and / or further water - curing of at least some of the at least partially soluble binder of each final bedding particle, preferably by preventing its retrogradation, such that at least some water - activatable and at least partially soluble binder in each particle is still available to cake the particles together when wetted by water or urine.

[0210] The water - removal step, preferably the drying step, can and preferably is carried out while the newly - formed still - moist particles are continuously mixed, such as stirred, to cure the binder, bond the outer self - caking water - absorbent region to the inner substrate microparticles, and at the same time prevent water - activation of the binder within the outer region of the starch - based water - absorbing caking - promoting material that does not adhere to the outer surface of each substrate microparticle. The water - removal step, preferably the drying step, can and preferably is carried out when the partially - coated bedding particles, such as partially - completed bedding particles, are wetted and / or re - wetted, including further application of the dried starch - based water - absorbent caking - promoting powder or powder material while mixing all substances, for example, activating, such as mixing in the drum of a mixer or in a rotating cylinder. Although the water - removal step, such as the drying step, can be carried out when coating the substrate microparticles with a slurry of the starch - based water - absorbing caking - promoting powder or powder and water, including during the process of mixing all substances together, the water - removal step is preferably carried out after the slurry application step is completed.

[0211] In a preferred embodiment of the coated substrate padding and the coated substrate padding particles, the modified starch water-absorbing caking agent is in the form of a starch-based water-absorbing caking-promoting powdery substance or powder, which is composed of at least multiple types, preferably at least multiple pairs, that is, at least three different types of modified starches. The molecular weight of each different type of modified starch is different from, preferably less than, the unmodified or natural starch that forms the corresponding modified starch. Each different type of modified starch is formed from unmodified or natural starch, such as preferably unmodified amylose and amylopectin, in one or more cereals and / or legumes in a mixture containing cereals and / or legumes, wherein the unmodified or natural starch in the mixture is modified during extrusion using a single-screw extruder at an ultra-high extrusion pressure of at least 2500 PSI, preferably at least 3000 PSI, more preferably at least 4000 PSI, and even more preferably at least 5000 PSI, which modifies the unmodified or natural starch to produce a modified starch water-absorbing caking agent in the form of an extrudate of a starch-based water-absorbing caking-promoting material, and the extrudate is used in the form of a powdery substance or powder to manufacture the self-caking adsorbent padding particles of the present invention.

[0212] The method for wetting the substrate with water for preparing the coated substrate padding particles of the present invention involves wetting the substrate microparticles before applying the modified starch water-absorbing caking agent, preferably in the form of a starch-based water-absorbing caking-promoting powdery substance or powder, and the amount of water used is greater than the amount of the modified starch water-absorbing caking agent powdery substance or powder, preferably the amount of the starch-based water-absorbing caking-promoting powdery substance or powder used. Whether the caking agent is in the form of a powder or powdery substance, in the form of extruded pellets, or in the form of extruded pellets crushed using, for example, a high-speed high-shear mixer, water is added before adding any modified starch water-absorbing caking agent until the substrate particles or substrate microparticles start to agglomerate by themselves to achieve proper wetting.

[0213] In a method implementation, in the application step, water is used in a ratio of 6:1 to 10:1, preferably 7:1 to 9:1, more preferably about 8:1, with the water-absorbing caking agent powder or powder of modified starch, preferably the water-absorbing caking promoting powder or powder based on starch, to coat the substrate particles or substrate microparticles with the water-absorbing caking agent powder or powder of modified starch, preferably the water-absorbing caking promoting powder or powder based on starch. When implementi...

Claims

1. A self - caking adsorbent granular bedding composed of multiple adsorbent bedding particles that cak together when the adsorbent bedding particles are wetted. Each self - caking adsorbent bedding particle consists of: (a) Internal substrate microparticles; and (b) A modified starch caking agent that adhesively self - adheres to the internal substrate microparticles.

2. The self - caking adsorbent granular bedding according to claim 1, wherein the modified starch caking agent adhesively adheres to the substrate microparticles through an internal self - adhesion region composed of a modified starch water - absorbing caking agent.

3. The self - caking adsorbent granular bedding according to claim 2, wherein the modified starch caking agent includes an external region that surrounds the internal self - adhesion region and defines the outer surface of each adsorbent bedding particle.

4. The self - caking adsorbent granular bedding according to claim 3, wherein the outer surface consists of at least multiple pairs of protrusions formed on the outer surface that protrude from the outer surface, and the protrusions are configured to improve the absorption of water and urine by the adsorbent bedding particles.

5. The self - caking adsorbent granular bedding according to claim 4, wherein each of the protrusions is minute in size.

6. The self - caking adsorbent granular bedding according to claim 5, wherein each of the protrusions is of nano - size or in the nano - scale.

7. The self - caking adsorbent granular bedding according to claim 3, wherein the outer surface consists of at least multiple pairs of cracks formed on the outer surface, and the cracks are configured to improve the absorption of water and urine by the adsorbent bedding particles.

8. The self - caking adsorbent granular bedding according to claim 7, wherein each of the cracks is a micro - crack.

9. The self - caking adsorbent granular bedding according to claim 3, wherein the modified starch caking agent defines the outer surface of each adsorbent particle, and the outer surface of each adsorbent particle consists of at least multiple pairs of protrusions formed on the outer surface that protrude from the outer surface, and the protrusions are configured to improve the absorption of water and urine by the adsorbent bedding particles.

10. The self - caking adsorbent granular bedding according to claim 9, wherein substantially the entire outer surface of each adsorbent particle consists of the protrusions.

11. The self - caking adsorbent granular bedding according to claim 10, wherein each of the protrusions is minute in size.

12. The self - caking adsorbent granular bedding according to claim 3, wherein the modified starch caking agent defines the outer surface of each adsorbent particle, and the outer surface of each adsorbent particle consists of at least multiple pairs of micro - cracks formed on the outer surface, and the micro - cracks are configured to improve the absorption of water and urine by the adsorbent bedding particles.

13. The self - caking adsorbent granular bedding according to claim 3, wherein the modified starch caking agent defines the outer surface of each adsorbent particle, and the outer surface of each adsorbent particle consists of: (i) at least multiple pairs of minute protruding protrusions formed on the outer surface and protruding from the outer surface, and (ii) at least multiple pairs of micro - cracks formed on the outer surface, and the minute protruding protrusions and the micro - cracks are configured to improve the absorption of water and urine by the adsorbent bedding particles.

14. The self - caking adsorbent granular bedding according to claim 1, wherein the caking agent consists of (a) a first component and (b) a second component, the first component consists of a single - moisture - activated and single - moisture - cured binder, and the second component consists of a binder configured to be multi - moisture - activated, multi - moisture - cured, moisture - reactivated, and moisture - recured.

15. The self - caking adsorbent granular bedding according to claim 14, wherein the caking agent further consists of a third component, and the third component consists of a water adsorbent.

16. The self - caking adsorbent granular bedding according to claim 14, wherein the first component consists of cold - water - soluble starch, and the cold - water - soluble starch is at least partially water - soluble at a room temperature of 68°F to 72°F.

17. The self - caking adsorbent granular bedding according to claim 16, wherein the first component consists of extruded modified starch, and the extruded modified starch consists of starch in a mixture modified during extrusion.

18. The self - caking adsorbent granular bedding according to claim 17, wherein the first component consists of dextrinized starch.

19. The self - caking adsorbent granular bedding according to claim 14, wherein the second component consists of cold - water - soluble starch, and the cold - water - soluble starch is at least partially water - soluble at a room temperature of 68°F to 72°F.

20. The self - caking adsorbent granular bedding according to claim 19, wherein the second component consists of extruded modified starch, and the extruded modified starch consists of starch in a mixture modified during extrusion.

21. The self - caking adsorbent granular bedding according to claim 20, wherein the second component consists of pre - gelatinized starch or starch pre - gel.

22. The self - caking adsorbent granular bedding according to claim 14, wherein the first component consists of dextrinized starch, and the second component consists of pre - gelatinized starch or starch pre - gel.

23. The self - caking adsorbent granular bedding according to claim 1, wherein the modified starch water - absorbing caking agent adhesively self - adheres to the substrate particles through an internal self - adhesion region composed of the modified starch water - absorbing caking agent.

24. The self - caking adsorbent granular bedding according to claim 23, wherein the modified starch water - absorbing caking agent consists of: (a) a first type of starch, which is modified into a water - swellable modified starch and which is also a water absorbent, and (b) a second type of starch, which is modified into an at least partially water - soluble binder, and when the at least partially water - soluble binder is wetted with an aqueous liquid, the binder contains a water - activated adhesive.

25. The self - caking adsorbent granular bedding according to claim 24, wherein the water - activated adhesive contains a moisture - cured water - activated adhesive.

26. The self - caking adsorbent granular bedding according to claim 25, wherein the room - temperature moisture - cured water - activated adhesive consists of one of a room - temperature moisture - cured water - activated thermosetting adhesive and a room - temperature moisture - cured water - activated thermoplastic adhesive.

27. The self - caking adsorbent granular bedding according to claim 1, wherein the internal substrate particles have an outer surface, and an outer region of the modified starch water - absorbing caking agent adhesively self - adheres to the outer surface of the internal substrate particles through at least a portion of the outer region of the modified starch water - absorbing caking agent.

28. The self - caking adsorbent granular bedding according to claim 27, wherein the outer region of the modified starch water - absorbing caking agent consists of: (1) a cold - water - swellable water - absorbing modified starch, and (2) a cold - water - soluble modified starch binder, and the binder forms an at least partially water - soluble flowable binder when wetted with an aqueous liquid or solution consisting of water, and at least some of the binder adhesively self - adheres the outer region of the modified starch water - absorbing caking agent to the outer surface of the internal substrate particles.

29. The self - caking adsorbent granular bedding according to claim 27, wherein the outer region of the modified starch water - absorbing caking agent consists of: (a) a cold - water - swellable water - absorbing modified starch, and (b) a cold - water - soluble modified starch binder, and the binder forms an at least partially water - soluble flowable binder when wetted with an aqueous liquid or solution consisting of water, and at least some of the binder adhesively self - adheres the outer region of the modified starch water - absorbing caking agent to the outer surface of the internal substrate particles when one of the following occurs: (1) (i) the modified starch water - absorbing caking agent and (ii) the internal substrate particles are wetted with an aqueous wetting liquid consisting of water, (2) the wetted modified starch water - absorbing caking agent is placed in contact with the wetted outer surface of the internal substrate particles, and (3) the flowable binder is subsequently moisture - cured or solidified, including an internal self - adhesion region, which cures into a solid hardened binder in a glassy material state, bonding the outer region of the modified starch water - absorbing caking agent to the outer surface of the internal substrate particles.

30. The self - caking adsorbent granular bedding according to claim 29, wherein the flowable binder in the internal adhesion region is cured or solidified into a solid and becomes hard.

31. The self - caking adsorbent granular bedding according to claim 30, wherein the water content of the self - caking absorbent particles is reduced to transform the flowable binder in the internal adhesion region into a solid glass - like material.

32. The self - caking adsorbent granular bedding according to claim 31, wherein the water content of the self - caking absorbent particles is reduced until the flowable binder in the internal adhesion region is transformed from one of a flowable liquid and a gel into a solid glass - like material.

33. The self - caking adsorbent granular bedding according to claim 31, wherein the water content of the self - caking absorbent particles is reduced until the flowable binder in the internal adhesion region is transformed from one of a flowable liquid and a gel into a solid glass - like material that feels hard to the touch.

34. The self - caking adsorbent granular bedding according to claim 33, wherein the water content of the self - caking absorbent particles is reduced to no more than about 8% of the weight of the bedding particles to cure or solidify the flowable binder in the internal region and transform the flowable binder from one of a viscous liquid and a semi - solid gel into a solid glass - like material that feels hard to the touch.

35. A method of preparing a self - caking adsorbent granular bedding, the self - caking adsorbent granular bedding being composed of a plurality of adsorbent bedding particles that self - cake together when the adsorbent bedding particles are wetted, the method comprising: (a) providing substrate microparticles and a modified starch caking agent; (b) applying the modified starch caking agent to the substrate microparticles to form self - caking adsorbent bedding particles composed of the substrate microparticles and the modified starch caking agent that adhesively self - adheres to the substrate microparticles.

36. The method according to claim 35, wherein the modified starch caking agent adhesively self - adheres to the substrate microparticles through an internal self - adhesion region composed of the modified starch water - absorbing caking agent.

37. The method according to claim 36, wherein the modified starch caking agent includes an external region that surrounds the internal self - adhesion region and defines the outer surface of each adsorbent bedding particle.

38. The method according to claim 37, wherein the outer surface is composed of at least multiple pairs of protrusions that protrude from the outer surface and are formed on the outer surface, and the protruding protrusions are configured to improve the absorption of water and urine by the adsorbent bedding particles.

39. The method according to claim 38, wherein each of the protruding protrusions is minute in size.

40. The method according to claim 39, wherein each of the protruding protrusions is of nano - size or in the nano - scale range.

41. The method according to claim 37, wherein the outer surface is composed of at least multiple pairs of cracks formed on the outer surface, and the cracks are configured to improve the absorption of water and urine by the adsorbent bedding particles.

42. The method according to claim 41, wherein each of the cracks is a micro - crack.

43. The method according to claim 37, wherein the modified starch caking agent defines the outer surface of each adsorbent particle, and the outer surface of each adsorbent particle is composed of at least multiple pairs of protrusions formed on the outer surface that protrude from the outer surface, and the protrusions are configured to improve the absorption of water and urine by the adsorbent bedding particles.

44. The method according to claim 43, wherein substantially the entire outer surface of each adsorbent particle is composed of protrusions.

45. The method according to claim 44, wherein each of the protrusions is minute in size.

46. The method according to claim 37, wherein the modified starch caking agent defines the outer surface of each adsorbent particle, and the outer surface of each adsorbent particle is composed of at least multiple pairs of microcracks formed on the outer surface, and the microcracks are configured to improve the absorption of water and urine by the adsorbent bedding particles.

47. The method according to claim 37, wherein the modified starch caking agent defines the outer surface of each adsorbent particle, and the outer surface of each adsorbent particle is composed of: (i) at least multiple pairs of minute protrusions formed on the outer surface that protrude from the outer surface, and (ii) at least multiple pairs of microcracks formed on the outer surface, and the minute protrusions and the microcracks are configured to improve the absorption of water and urine by the adsorbent bedding particles.

48. The method according to claim 35, wherein the caking agent is composed of (a) a first component and (b) a second component, the first component is composed of a single - moisture - activated and single - moisture - cured binder, and the second component is composed of a moisture - reactivated and moisture - recured binder configured for multiple - moisture activation and multiple - moisture curing.

49. The method according to claim 48, wherein the caking agent is further composed of a third component, and the third component is composed of a water adsorbent.

50. The method according to claim 48, wherein the first component is composed of cold - water - soluble starch, and the cold - water - soluble starch is at least partially water - soluble at room temperature of 68 to 72 degrees Fahrenheit.

51. The method according to claim 50, wherein the first component is composed of extruded modified starch, and the extruded modified starch is composed of starch in a mixture modified during extrusion.

52. The method according to claim 51, wherein the first component is composed of dextrinized starch.

53. The method according to claim 48, wherein the second component is composed of cold - water - soluble starch, and the cold - water - soluble starch is at least partially water - soluble at room temperature of 68 to 72 degrees Fahrenheit.

54. The method according to claim 53, wherein the second component is composed of extruded modified starch, and the extruded modified starch is composed of starch in a mixture modified during extrusion.

55. The method according to claim 54, wherein the second component is composed of pre - gelatinized starch or starch pre - gel.

56. The method according to claim 48, wherein the first component consists of dextrinized starch and the second component consists of pregelatinized starch or starch pre-gel.

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