Biodegradable, compostable molding mass compositions, molded articles and methods of manufacture

Abstract

To provide improved specific compositions based on water, starch and fibers that improves the properties of fully biodegradable disposables; molding masses; molded articles; coating solutions; and systems and methods for production thereof.SOLUTION: A molding mass composition comprises: a water component; and a non-liquid soluble solid component; wherein the non-liquid soluble solid component includes a starch component and a fiber component; wherein a total liquid content in the molding mass composition is in a range of 57 wt. % to 65 wt. % based on a total mass of the molding mass composition; wherein a starch / fiber wt. % ratio is in a range of 94 wt. % of the starch component: 6 wt. % of the fiber component to 49 wt. % of the starch component: 51 wt. % of the fiber component; wherein the starch component includes a plurality of starch granules having a select granule diameter size range including a granule diameter lower limit and a granule diameter upper limit; and wherein the fiber component includes a plurality of fibers, each of the plurality of fibers having a fiber length in a range of 1 to 250 times the granule diameter upper limit.SELECTED DRAWING: Figure 12

Description

Detailed Description of the Invention

[0001] Background of the Invention Increasing volumes of waste streams characterize the handling and distribution of many products in everyday life. For example, in the food distribution and service industries, billions of large amounts of non-biodegradable items end up in waste streams on every continent. Polymer-coated carton-based or Styrofoam-based products have expected lifespans ranging from 10 to 100 years. Such items are manufactured using technologically mature mass production processes that do not optimize environmental costs.

[0002] It is widely recognized that there are environmental costs associated with these non-biodegradable materials, especially when the materials are considered from production to disposal, i.e., from cradle to grave, and these environmental costs, in some instances, can be significantly higher than biodegradable or environmentally neutral alternatives.

[0003] However, replacing non-biodegradable materials is complex. Modern processing, packaging, storage, delivery, service, and consumption require suitable packaging materials for a wide variety of fluids and solids. Delivery and consumption of food and beverages requires a variety of disposable containers, including, but not limited to, bowls, clamshells, containers, cups, baking pans, plates, trays, or other useful structures known in the art. While packaging must protect against environmental influences, degradation, and damage, the use of long-term packaging for short-term applications is increasingly considered environmentally irresponsible.

[0004] Each year, disposable containers are manufactured from plastic-coated paper or cardboard; various plastic materials such as polyethylene (PE), polypropylene (PP), polystyrene, and expanded polystyrene; glass; and metals for both food and non-food uses. After a relatively short useful life, billions of disposable containers enter the waste stream, many of which are not readily biodegradable. Furthermore, while there is widespread attention being paid to making such items lighter, the use of millions of tons of raw materials to produce such "lightweight" items has an environmental cost.

[0005] For example, expanded polystyrene is lightweight, stable, and environmentally friendly, optimized for current applications. The production of expanded polystyrene involves hazardous chemicals, including benzene and styrene for the polystyrene, and traditional blowing and expanding agents for the foaming. However, in recent years, efforts have been made to develop less harmful blowing agents.

[0006] Recycling of disposable container materials presents its own environmental and political complexities.

[0007] In response to the above challenges, molded biodegradable articles based on powders, fibers, and inert inorganic fillers have been increasingly discussed over the past 25 years. However, current technology for biodegradable articles does not appear to have widespread application. Challenges include identifying molded mass compositions that allow reliable thermoforming, post-thermal processing, and handling in industrial mass production. Furthermore, materials or articles that are sufficiently convenient and easy to use for the end user are necessary to motivate consumers to replace existing non-sustainable products with sustainable ones.

[0008] Current technology teaches the use of fluid or semi-liquid paste- or batter-like molded masses, or relatively stiff dough-like molded masses. The surface characteristics of the molded mass and mold, along with the temperature and pressure conditions of the molding process, can necessitate the use of mold release agents, which result in mold residues. Such mold residues can alter the surface properties of the mold after continued use. For example, thermal decomposition and polymerization of release lipids applied to the mold during the demolding process can result in residues on the mold. Mold residues create a less smooth, dull mold surface with potential changes in heat transfer properties, which in turn affect the surface smoothness and gloss of the molded part. Salt and fatty acid release agents require periodic removal by aggressive chemical and / or physical cleaning, necessitating production line shutdowns and can result in mineral residues that degrade the mold surface over time.

[0009] Furthermore, as taught in current technology, heat treatment of molding masses containing fluid or semi-liquid batters or pastes generates a lot of water vapor. The generated water vapor then affects the amount, size, and distribution of voids in the molded product. Thermoformed products are generally larger in the center of the product, decreasing in size toward the edges, and can contain at least some voids that are not optically present on the surface of the product. Internal pores whose size, quantity, and distribution are controlled during the thermoforming process by generating water vapor can result in molded products with improved mechanical properties, including, for example, greater stability against breakage and / or improved bend angles without breakage. The resulting molded products are lighter, thereby saving material. However, generating too much water vapor can result in too many and / or too large internal voids distributed in a non-uniform pattern. This uncontrolled generation of internal voids impairs the internal cohesion of the molded product.

[0010] As taught in current technology, a stiff, dough-like molding mass can lead to irregular division and incomplete molding. During the demolding process, a stiff, dough-like mass can result in plugged mold extrusion vents, trouble with the extruded material including bobbling, and / or frayed edges.

[0011] There is a need to improve the properties of fully biodegradable disposable items such as packaging containers, trays, plates, and bowls made from natural materials such as flour, fiber, and other ingredients.

[0012] Summary of the Invention The present invention features improved specific compositions based on water, starch, and fiber. The starch component can include a combination of native and pregelatinized starch, which can be in flour or powder form. The specific compositions can include a selected release agent for residue-free release of articles after thermoforming. The compositions are prepared for non-fluid molded masses having a first plastic-elastic texture and consistency. The molded masses are formed for the industrial production of molded biodegradable and compostable articles having a second plastic-elastic texture and consistency. The molded mass compositions, molded masses, and preparation and processing methods of the present invention enable the formation of molded articles and / or articles having a variety of shapes and structures. The present invention also features post-thermoforming processing and handling methods for forming finished articles and parts.

[0013] The following terms are defined for purposes of this application.

[0014] The term "plasticity" refers to the ability of a material to undergo an irreversible change in shape in response to a selected applied force without fracture.

[0015] The term "plastic" material refers to a material that can undergo an irreversible change in shape without rupture in response to selected applied forces, including stresses of intermediate magnitude.

[0016] The term "elasticity" refers to the ability of a material to reversibly change shape in response to altered forces without rupture.

[0017] The term "elastic material" refers to a material that can reversibly change shape without rupture in response to a selected applied force, including stresses of intermediate magnitude.

[0018] The term "plastic-elastic texture and consistency" refers to material properties that include at least some plasticity and at least some elasticity.

[0019] "Compostable" refers to compostable materials that meet the standards of ASTM International (hereafter "ASTM"), formerly known as the American Society for Testing and Materials. Compostable plastics are defined by ASTM D6400 as "plastics that decompose by biological processes during composting, producing carbon dioxide (CO2), water, inorganic compounds, and biomass at rates consistent with other known compostable materials, and leaving no visible, identifiable, or toxic residues." ASTM D6400 - Compostability Testing covers plastics and products made from plastics designed to be compostable in municipal and industrial aerobic composting facilities. ASTM D6400 - Compostability Test establishes requirements for labeling materials and products, including packaging, made from plastics as "compostable in municipal and industrial composting facilities." The properties tested in ASTM D6400 - Compostability Test determine whether plastics and products made from plastics will compost sufficiently, including biodegrading at rates comparable to known compostable materials. Furthermore, the properties in the standard are required to ensure that the degradation of these materials does not diminish the value or usefulness of the compost resulting from the composting process. Standard ASTM D6868-17 provides standard specifications for the labeling of end items incorporating plastics and polymers as coatings or additives with paper and other substrates designed to be aerobically composted in municipal or industrial facilities. This standard covers biodegradable plastics and products (including packaging) where a plastic film or sheet is attached to the substrate (either by direct lamination onto paper or by extrusion) and the entire product or package is designed to be composted in municipal and industrial aerobic composting facilities. The standard is intended to establish requirements for the labeling of materials and products, including packaging that uses biodegradable plastic coatings, as "compostable in municipal and industrial composting facilities."The characteristics in this standard are those required to determine whether a product (including packaging) that uses plastic film or sheeting will satisfactorily compost, including biodegrading at a rate comparable to known compostable materials. Furthermore, the characteristics in the standard are required to ensure that the degradation of these materials does not reduce the value or usefulness of the compost resulting from the composting process.

[0020] The term "compostable" also refers to compostable materials that meet ISO - International Organization for Standardization (International), hereafter "ISO" standards. The ISO 17088:2012 standard discusses the following characteristics: a) biodegradation; b) decomposition during composting; c) negative effects on the composting process and facilities; and d) negative effects on the quality of the resulting compost, including the presence of high levels of regulated metals and other harmful components.

[0021] The term "compostable" is used by the CEN-European Committee It further refers to compostable materials that meet the standards of the European Union for Standardization (hereafter "CEN"). The CEN-EN 13432 composting stability standard discusses the following characteristics: disclosure of all ingredients and chemical testing, including thresholds for heavy metals; biodegradability under controlled composting conditions (oxygen consumption and CO2 production): proof must be made that at least 90% of the organic material is converted to CO2 within six months; decomposition: after three months of composting and subsequent sieving through a 2 mm sieve, no more than 10% of the original mass can remain; practical testing of composting stability in semi-industrial (or industrial) composting facilities: no negative impact on the composting process is allowed; and ecotoxicity testing: testing of the resulting compost's impact on plant growth (agricultural testing).

[0022] The term "biodegradation" refers to the spontaneous breakdown of a substance by microorganisms such as bacteria and fungi or other biological activity. Biodegradation as a spontaneous process can be distinguished from composting, a human-directed process in which biodegradation occurs under a specific set of circumstances. The term "biodegradation" is consistent with ASTM D5526-18 (which includes a Standard Test Method for the Determination of Anaerobic Biodegradation of Plastic Materials under Accelerated Landfill Conditions), ASTM D5511-18 (which includes a Standard Test Method for the Determination of Anaerobic Biodegradation of Plastic Materials under High Solids Anaerobic Digestion Conditions), and ASTM D5338-15 (which includes a Standard Test Method for the Determination of Aerobic Biodegradation of Plastic Materials under Controlled Composting Conditions, Incorporating Temperature).

[0023] The term "one or more articles" refers to or relates to finished products and / or parts of a corresponding finished product that can be used to assemble the corresponding finished product.

[0024] The term "molded article" refers to or relates to a finished article and / or portion that has undergone thermoforming and, in some cases, may be subjected to post-thermoforming processing to form a finished article and / or part of a finished article.

[0025] The term "finished article" refers to or relates to an article and / or portion of an article that is fully completed for use and / or assembly for use.

[0026] The term "hydrate" refers to or relates to the attachment of water to a non-liquid soluble solid component of a formed mass composition.

[0027] The term "pore(s)" refers to or relates to the controlled creation of void(s) therein, for non-limiting example, a molded article during a thermoforming process.

[0028] The term "void" refers to any type of air-, water vapor-, gas-, water-, and / or liquid-filled hole within an otherwise solid article.

[0029] The present invention can enable large-scale, industrial-scale mass production of molded biodegradable and compostable articles. Specific or selected molded mass compositions are described, including water, starch flour, fiber, and other optional or minor ingredients. A new mold release system is provided. The present invention features a substantially air-free, non-flowable, plasto-elastic molded mass produced by mixing and kneading. Process requirements are provided for thermoforming the molded mass into a biodegradable article, as well as for further post-heat treatment and handling. Molded biodegradable and compostable articles include, by way of non-limiting example, various types of containers, such as bowls, clamshells, containers, cups, egg trays, meat trays, baking pans, plates, trays for any item, or other useful object structures known in the art.

[0030] The composition of the molded biodegradable and compostable articles is such that they are environmentally neutral and pose no additional environmental hazards even when disposed of in conventional manner via waste incineration or landfill.

[0031] Thus, the present invention overcomes the challenges in industrial production of biodegradable articles as described above.

[0032] Objects of the present invention include providing a biodegradable and compostable molded mass composition comprising water, starch flour, fibers, and minor or optional ingredients for stable continuous thermoforming processing and possible further post-thermoforming processing to achieve or provide compressive, tensile, flexural, and cohesive strength, porosity, hardness, stiffness, and surface property requirements of the molded and ultimately finished article.

[0033] Objects of the present invention include providing a mold release system that avoids substantial fouling of the corresponding mold at thermoforming temperatures of about 200° C., up to 225° C., preferably up to 215° C., in the range of 185° C. to 225° C., preferably in the range of 190° C. to 215° C., more preferably in the range of 190° C. to 210° C. Avoidance of mold fouling by polymeric and / or inorganic residues avoids undesirable modification of the surface of the corresponding mold in continuous operation.

[0034] Objects of the present invention include providing a formed mass with improved internal cohesion and predetermined hydrophobicity by means of a selected size or size system for a plurality of selected starch granules and fibers of the formed mass composition.

[0035] Objects of the present invention include providing a molded mass that can be prepared to a substantially smooth first plastic-elastic texture and consistency, which can then be selected and / or divided and / or dispensed into substantially precise portions onto corresponding target molds while substantially reducing or eliminating the risk or likelihood of underfilling or overfilling the corresponding target molds.

[0036] The objectives of the present invention include providing a molding mass that can substantially uniformly fill a corresponding target mold by using a selected sizing system for the molding mass. The molding mass sizing system eliminates and / or avoids large fibrous contaminants that would otherwise become unevenly embedded in the matrix of the molded article and / or clog the extrusion opening of the corresponding target mold. At the same time, the risk of fraying at the article edges during the demolding process is substantially reduced.

[0037] Objects of the present invention include providing a molded mass that avoids excessive and / or excessive generation of water vapor during heat treatment, thereby producing a controlled size distribution of pores within the structural matrix of the molded article, and reducing and / or eliminating the risk of forming voids in the molded article that are oversized, excessive in amount and / or have an unevenly distributed pattern.

[0038] Objects of the present invention include providing a molded mass having a first plastic-elastic texture and consistency for relatively fast thermoforming from about 200°C to 225°C, preferably up to 215°C, more preferably from 190°C to 210°C, wherein the molded mass can be characterized by a texture and consistency for relatively easy and substantially uniform distribution in the target mold, and the avoidance of components or properties that can cause changes in the color of the molded article due to thermal browning or caramelization reactions.

[0039] Objects of the present invention include providing a process for mixing, portioning, and precise deposition of a molding mass.

[0040] Objects of the present invention include providing a dedicated apparatus for continuous in-line mass production of molded and finished parts.

[0041] The object of the present invention involves the formation of shaped articles suitable for applications that include degradability and durability criteria after prescribed administration.

[0042] In one embodiment, the invention features a molded mass composition that includes: a liquid component, wherein the liquid component includes a water component; and a non-liquid soluble solid component, wherein the non-liquid soluble solid component includes a starch component and a fiber component; wherein the total liquid content in the molded mass composition is in the range of 57% to 65% by weight; a starch / fiber weight percent ratio is in the range of 94% by weight, based on the total weight of the starch composition, 6% by weight of the fiber composition to 49% by weight of the starch composition, 51% by weight of the fiber composition; the starch composition includes a plurality of starch granules having a selected granule size range including a lower granule size limit and an upper granule size limit; and the fiber composition includes a plurality of fibers, each of the plurality of fibers having a fiber length in the range of 1 to 250 times the upper granule size limit.

[0043] In one embodiment, the invention features a molded mass composition in which the fiber component has a size distribution ranging from 10 to 2500 microns.

[0044] In one embodiment, the invention features a formed mass composition in which the starch component has a size distribution ranging from 1 μm to 120 μm.

[0045] In one embodiment, the invention features a formed mass composition, wherein the starch component is selected from the group consisting of native starch, chemically modified native starch, physically modified native starch, genetically modified native starch, and combinations of at least two of the foregoing starch components.

[0046] In one embodiment, the invention features a forming mass composition, wherein the starch component includes native potato starch.

[0047] In one embodiment, the invention features a formed mass composition including a physically modified starch in which the starch component has a pregelatinized form.

[0048] In one embodiment, the mold mass composition further comprises a mold release agent.

[0049] In one embodiment, the release agent comprises a saturated long chain fatty acid having a chain length of at least 12 carbon atoms.

[0050] In one embodiment, the invention features a mold mass composition, wherein the mold release agent includes an acid selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, and arachidic acid.

[0051] In one embodiment, the invention features a mold mass composition in which the release agent is in the form of a powder having a plurality of release particles, each particle having a mesh size of less than 80 mesh.

[0052] In one embodiment, the invention features a mold mass composition in which the mold release agent is present in an amount of 0.1 to 2.4 weight percent, based on the total weight of the non-liquid soluble solid components in the mold mass composition.

[0053] In one embodiment, the cast mass composition further comprises a texturizer.

[0054] In one embodiment, the invention features a molded mass composition in which the texturizer is selected from the group consisting of a reactive inorganic component, a non-reactive inorganic component, and a combination of the two foregoing components.

[0055] In one embodiment, the invention features a molded mass composition, the molded mass composition including a texturizer that includes an inorganic component, wherein the amount of inorganic component in the molded mass composition is in the range of 0 to 16.5 weight percent, based on the total non-liquid soluble solid components of the molded mass composition.

[0056] According to one embodiment, the molded mass composition further comprises a plasticizer additive, wherein the plasticizer is urea.

[0057] In one embodiment, the invention features a formed mass composition having a concentration of urea in the range of greater than 0% to 9% by weight, based on the total weight of the starch component.

[0058] In one embodiment, the formed mass composition further comprises a plurality of borate ions at a concentration ranging from 0 to greater than 2 mmol borate per kg of starch component.

[0059] In one embodiment, the invention features a molded mass composition, the molded mass composition undergoes a mixing and kneading process to form a molded mass having a first plastic-elastic texture and consistency.

[0060] In another aspect, the invention features a method of preparing a molded mass, including selecting liquid components, the liquid component including a water component, and selecting a non-liquid soluble solid component, the non-liquid soluble solid component including a starch component and a fiber component, wherein the starch / fiber weight percent ratio is in the range of 94% by weight of the starch component, 6% to 49% by weight of the fiber component, and 51% by weight of the fiber component, the starch component including a plurality of starch granules having a selected granule diameter range including a lower granule diameter limit and an upper granule diameter limit, the fiber component including a plurality of fibers, each of the plurality of fibers having a fiber length in the range of 1 to 250 times the upper granule diameter limit; and mixing and kneading the liquid components and the non-liquid soluble solid component using a preparation system to form a molded mass having a first plastic-elastic texture and consistency characterized by a total liquid content in the molded mass including a liquid content in the range of 57 to 65% by weight, based on the total weight of the molded mass composition.

[0061] In one embodiment, the invention features a method for preparing a molded mass, in which the mixing and kneading step includes incrementally adding a liquid component to a non-liquid soluble solid component during the mixing and kneading step.

[0062] In one embodiment, the method for preparing a formed mass further comprises creating a vacuum in the preparation system to substantially remove or prevent gas from entering the formed mass.

[0063] In one embodiment, the method of preparing a molded mass further includes providing a target mold in an open configuration and depositing a selected portion of the molded mass into the target mold to fill a detail of the mold, the selected portion having a selected portion volume that is smaller than the volume of the target mold.

[0064] In one embodiment, the method for preparing a molded mass further includes closing the target mold if necessary, and heating the target mold filled with the molded mass to a closed-cure temperature in the range of 185°C to 225°C for a closed-cure time to heat-cure the molded mass to form a molded article having a second plastic-elastic texture and consistency characterized by a molded article residual liquid content of 6% by weight or more based on the total weight of the molded article, wherein after heat-cure, no substantial vapor pressure remains in the structural matrix of the molded article and the molded mass is solidified above the glass point of the structural matrix of the molded article.

[0065] In one embodiment, the method for preparing a shaped mass further comprises passing the shaped article through an enclosed humidifying section or chamber and providing a stream of moist air within the humidifying section or chamber until the shaped article has a water activity in the range of 0.45 to 0.70, wherein safe microbiological conditions are maintained within the enclosed humidifying section or chamber.

[0066] In another aspect, the invention features a biodegradable, compostable coating solution for a molded article that includes a compostable liquid solvent-based portion and a compostable solid portion.

[0067] In one embodiment, the invention features a biodegradable, compostable coating solution, wherein the compostable liquid solvent base includes water.

[0068] In yet another aspect, the invention features a biodegradable, compostable coating system that includes a coating zone that includes a spray device and a heating device.

[0069] These and other aspects, features, advantages, and objects will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and accompanying drawings.

[0070] MODE FOR CARRYING OUT THE INVENTION The accompanying drawings support the detailed description of the invention and refer to exemplary embodiments, and are not to be construed as limiting the full scope of the invention in any way.

[0071] In the drawings: FIG. 1 shows a perspective view of a molded article including a tray according to an exemplary, non-limiting embodiment of the present invention; FIG. 2 shows a perspective view and a top view of a molded article according to a non-limiting embodiment; FIG. 3 shows a perspective view of the bottom of a molded article including a tray according to an exemplary embodiment of the present invention; FIG. 4 illustrates a process for manufacturing a molded article according to a non-limiting embodiment; FIG. 5 is a block diagram illustrating a process for preparing a molded mass according to a non-limiting embodiment; FIG. 6 is a block diagram illustrating a process including post-heat treatment and processing steps, according to an exemplary non-limiting embodiment; FIG. 7 illustrates a perspective view of an empty bottom mold section according to an exemplary embodiment; FIG. 8 shows a perspective view of an empty mold with a hinged cover according to an exemplary embodiment of the present invention; FIG. 9 shows a perspective view of a thermosetting system for performing thermosetting of a molded mass according to an exemplary embodiment of the present invention; FIG. 10 shows a transport belt for transporting molded articles to a coating spray area according to an exemplary embodiment of the present invention; FIG. 11 shows a schematic diagram of the heat resistance test assembly as described in Example 6 of the detailed description, and FIG. 12 shows the conversion of organic carbon to carbon dioxide for the control compost sample and the three test samples.

[0072] Detailed Description of the Invention Current technology involves different approaches to the production of molded biodegradable articles based on water-mediated molding of dough or batter-like molded masses.

[0073] Some current technology approaches teach compositions dominated by fibrous materials. The flour component provides the adhesive that connects the wet fiber preform to a stable matrix. The fibrous material provides mechanical stability and cohesion during the molding stage. The molding mass is inserted into a target mold. A narrow massless space is maintained within the mold to allow water vapor to escape or exit during the thermal drying and molding process, where the molding mass has a higher density compared to the molded article.

[0074] Examples of such techniques include WO 2005 / 021633 to E. Helou et al. and WO 2010 / 118249 A1 to E. Helsel et al. This current technology teaches primarily medium, long, or extra-long fibers for the molding mass. Furthermore, this current technology teaches wax emulsions and organic or inorganic crosslinking components at levels up to 20%. This current technology teaches that high-fiber compositions allow the deposition of the molding mass into a target mold that includes a mass-free gap for the escape or exit of water vapor without providing an extrusion vent in the mold. The molding mass material is held in the mold by the fibers.

[0075] Other current technologies teach compositions dominated by a high percentage of inorganic powders as fillers, with much lower percentages of fiber and starch flour components that bond and / or adhere the wet preform to a stable matrix.

[0076] Examples of such approaches include publications WO 9419172 A1, WO 9412328 A1, WO 9605254 A1, WO 9612606 A1, and WO 9723333 A1 by Per Andersen and Simon Hodson, and US 5705239. This current technology essentially teaches molding that involves pressing an inorganic composition into an article.

[0077] Still other current technologies teach molded articles based on sheet or cone wafer manufacturing principles. Non-gelatinized starch powder is the primary component of the molded mass. The mold includes dedicated openings for the escape or egress of both material and steam. The mold chamber holds enough material for substantially complete filling and for small amounts of material to be extruded during the initial steaming and foaming stage. During the initial steaming and foaming stage, a porous, lightweight article is initially formed. After an additional drying period, demolding occurs. The matrix of the molded article primarily comprises gelatinized starch powder. The article is optionally reinforced with other materials (e.g., small amounts of fiber or fillers, for example).

[0078] Examples of this current technology include U.S. Patent No. 5,376,320 to Tiefenbacher et al. This current technology teaches the production of thin-walled compostable molded bodies made from a substantially fat-free fluid starch batter according to the wafer baking principle. The primary components include starch and water. This current technology teaches the additional application of relatively small amounts of metal salts of fatty acids and other release agents for release.

[0079] Further current technology teaches the application of hydrocolloids together with starch flour, fibrous materials of indefinite size, fiber length, and fiber thickness, and mineral fillers to produce biodegradable articles. Examples of this current technology include publications CA 2654771 by Donald W. Wren, US 2007 / 0292643 A1 and US 2009 / 0263601 A1, and US 7,618,485 and US 7,700,172. This current technology teaches the selection of hydrocolloids for stabilizing the article after the heating step. This current technology further teaches that a high proportion of water is required to form the hydrocolloid into a moldable mass. Therefore, this current technology lacks a technically feasible and relatively rapid process for producing a final dry article consistent with industrial mass production. Furthermore, the current art's teaching regarding the addition of foaming aids, such as surfactants, can be problematic because foaming aids promote rapid moisture migration into the molded article, and moisture content above a certain percentage can soften and destabilize the structure of the molded article. Therefore, coating with any of the current art's water-based coating materials can result in severe deformation of the article. Furthermore, such coatings can fail in the presence of hot liquids, where high temperatures increase moisture migration into the article.

[0080] The present invention features biodegradable and compostable formed mass compositions, formed masses, and formed and finished articles, including formed trays for non-limiting embodiments, as shown in the perspective view of formed trays (2, 4, 6, 8, and 10) in Figure 1. Referring to Figure 2, the formed and finished biodegradable and compostable articles of the present invention include different types of containers having different sizes and shapes, such as, in non-limiting embodiments, bowls (12), clamshells as shown in open (14) and closed (16) configurations, plates (18), cups (20), trays for meals (22, 24) and / or trays for other items (26), meat trays (28), egg trays (30), baking pans (32), and other disposable containers known in the art for relatively short-term containment of items. Figure 3 shows a perspective view of the bottom (34) of a formed tray (36) according to a non-limiting exemplary embodiment.

[0081] The articles of the invention include homogeneous molded and finished articles that have relatively high smoothness, stability, and flexibility. The invention also features methods of making the biodegradable and compostable molded and finished articles of the invention.

[0082] The manufacturing method (40) of the present invention includes preparing a molding mass (42), dividing, discharging, and depositing the thereby prepared molding mass into a target mold (44), heat curing the molding mass to form a molded article (46), and heat treating and post-treatment steps (48), as shown in the block diagram of Figure 4. Referring to the block diagram of Figure 5, the molding material preparation step (50) includes selecting the components of the molding material composition (52), mixing and kneading the composition to prepare the molding material (54), and allowing the mixed and kneaded molding material to rest for a selected period of time before depositing it into the target mold (56). Referring to Figure 6, the post-heat treatment and handling step (60) can include ejecting the molded article from the target mold (62), optionally conditioning the molded article, including actively controlling moisture in the molded article (64), optionally modifying the properties of the molded article by coating and / or sealing, impregnation, and / or lamination processes (66), and ejecting the finished article for further handling and / or distribution as needed (68). In an alternative embodiment, the molded article is not ejected from the target mold before post-heat treatment. This manufacturing method is suitable for mass production, is cost-effective in terms of manufacturing costs and environmental costs, and the molded article and finished product are environmentally sustainable.

[0083] The technical parameters for thermoforming, including additional components for curing, post-heat treatment handling of the molded article after demolding, and modification of stability parameters, can be selected and / or varied depending on the desired end use or application of the molded finished product. Formulations for molding mass formulations according to the present invention include necessary or essential components or collections of components that act synergistically based on their physical and chemical properties for the desired material parameters of the molded and / or finished product and ease of in-line manufacturing. Additionally, additional optional components and / or ingredients are discussed for modifying surface properties, weight, flexibility, and color, by way of non-limiting example.

[0084] The main components or ingredients of the formed mass composition of the present invention include a liquid component which comprises a water component and a non-liquid soluble solid component which comprises a starch component and a fiber component.

[0085] The liquid component, including the water component, is selected in an amount that allows for a first plastic-elastic texture and consistency after mixing and kneading. The first plastic-elastic texture and consistency allows for relatively easy and accurate division of the formed mass within the target mold for rapid dispensing, while simultaneously avoiding substantial formation of interstitial voids between the non-liquid soluble solid components. The liquid component hydrates the non-liquid soluble solid components. During hydration, the liquid component adheres to the non-liquid soluble solid components. Non-limiting examples of such liquid adhesion include substantially covering all of the non-liquid soluble solid components with a minimal layer of the liquid component. Other non-limiting examples of hydration liquid adhesion include one or more chemical interactions, hydrogen bonding reactions, and / or capillary suction interactions between the liquid component and the non-liquid soluble solid components.

[0086] Hydration-related liquid deposition is a function of the porosity or swelling capacity of the non-liquid soluble solid component. During hydration-related liquid deposition, the liquid component can fill interstitial voids in the non-liquid soluble component (including, for non-limiting examples, interstitial voids in the non-liquid soluble component).

[0087] After adding the water component to the non-liquid soluble solid component and mixing, a formed mass having a dough-like texture and consistency is obtained. Further kneading of the formed mass using a continuous mixer and / or a batch mixer results in a formed mass having a smooth, first plastic-elastic texture and consistency. The mixing and kneading steps are carried out for a selected equilibrium time until the formed mass has a substantially smooth appearance, the solid components are substantially homogeneously distributed, and the formed mass is substantially free of air-filled voids.

[0088] Mixing and kneading is carried out according to principles of mixing and kneading known to those skilled in the art, taking into account, by way of non-limiting example, the composition, density, viscosity, and volume of the formed mass, the type of mixing and kneading tool, including, by way of non-limiting example, the type of propellant, the size of the vessel, the composition of the equipment, the intensity and duration of mixing, and the mass loading of the mixer relative to the energy introduced through the mixing tool. In a non-limiting exemplary embodiment, the selected equilibration time is in the range of 5 to 50 minutes, preferably 8 to 35 minutes. After mixing and kneading, the moisture content of the formed mass is equal to the moisture content of its constituents. A minimum time and mixing intensity are required to ensure substantially equal hydration of the starch component of the formed mass composition, as well as primarily the fiber component. Uniform hydration can be improved with increasing temperature. The temperature of the formed mass composition can be increased by increasing the temperature of one or more components of the formed mass composition and / or by incorporating energy transferred through the mixing and kneading tool. The temperature of the formed mass composition should not exceed 45°C, preferably not exceed 40°C, to avoid any premature gelatinization of the starch component in the formed mass composition.

[0089] The liquid component may contain, in addition to the water component, soluble and / or emulsifiable ingredients and / or additives. The water component can substantially and homogeneously disperse any soluble and emulsifiable ingredients. Therefore, the amount of water component is selected to achieve any necessary dissolution and / or dispersion to adjust or enable a soft molded mass having a first plastic-elastic texture and consistency after selected mixing and kneading.

[0090] In a preferred embodiment, the total liquid content in the formed mass composition, including the added water component and the moisture content of the starch and fiber component or components, and / or the liquid content of any other water soluble and / or emulsifiable ingredients, is in the range of 57-65% by weight, preferably in the range of 57.8-64.9% by weight, more preferably in the range of 59-64% by weight, and most preferably in the range of 59.3-63.4% by weight, relative to or based on the total weight of the formed mass composition.

[0091] The starch component of the formed mass composition comprises a starch selected from native starch, chemically modified native starch, physically modified native starch, genetically modified native starch, and a combination of at least two of the foregoing starches. The starch component can include starch in the form of a flour, also known as a powder and / or starch flour. A starch flour is composed of a plurality of starch granules. In a non-limiting embodiment, the starch granules can be derived from a milled or ground starch source, such as, in non-limiting examples, a wheat source and / or a corn source.

[0092] The native starch component is based on a source plant or part of a source plant that has a relatively high starch content compared to other plants or other parts of the respective source plant. Non-limiting examples of native source plants include wheat, corn, rice, pea, potato, and cassava. Non-limiting examples of native source plant parts include tubers, roots, seeds, and / or fruits. Table 1 below shows the typical starch content of non-limiting examples of native starch plants for use in the present invention.

[0093] [Table 1]

[0094] Cultivated Plants, Primarily as a Food Source - Vol. Primarily AS FOOD SOURCES - Vol. I - Starch Bearing Crops as a Food Source - Krisztina. R. Vegh, c Encyclopedia of Life Support Systems (EOLSS), STARCH BEARING CROPS as food sources, 2011; GFuleky (Ed.) Plants grown primarily as a food source, EOLSS Publishing Company, 2009, pp.253-287: KRVegh Starch bearing crops as food sources.

[0095] Thus, the starch component of the formed mass composition of the present invention can consist of wheat starch, corn starch, rice starch, peach starch, potato starch, tapioca-type cassava starch, or two or more of the above starches. Starch, a polymer of glucose, can be found in most plants organized into granules ranging from 1 to 140 μm in size. The following table lists various starch types that can be used in the starch component of the formed mass composition of the present invention. The starch processing techniques or preparation prior to use in the present invention vary depending on the starch's base raw material.

[0096] [Table 2]

[0097] In a preferred embodiment, the formed mass composition comprises a starch component comprising native potato starch. In a more preferred embodiment, the formed mass composition comprises a starch component comprising native potato starch in an amount by weight of at least 50% based on the total weight of the solid ingredients.

[0098] In a preferred embodiment, the starch component comprises a moisture content characteristic of the native starch comprising the starch component. By way of non-limiting example, a starch component comprising potato starch has a moisture content in the range of 18% to 21% by weight, based on the total weight of the starch component. In another non-limiting example, a starch component comprising corn starch has a moisture content in the range of 10 to 15% by weight, based on the total weight of the starch component.

[0099] In one embodiment, the starch component has a gelatinization temperature in the range of 50°C to 70°C, preferably in the range of 52°C to 66°C.

[0100] The starch component may be prepared using processes known to those skilled in the art, including, by way of non-limiting example, milling, extraction, drying and / or grinding processes. The starch component may comprise a plurality of starch granules having a sizing distribution in the range of 1 to 120 μm, preferably in the range of 2 to 100 μm.

[0101] The starch component can include, by way of non-limiting example, starches that produce a relatively high viscosity increase during gelatinization, such as potato-based starch, tapioca-based starch, and / or starches with a high degree of cross-linking. The preferred viscosity increase during gelatinization for either native or cross-linked starch is equal to or greater than that of tapioca-type cassava starch. Preferred cross-links utilize bifunctional or multifunctional reagents to induce the formation of intramolecular and / or intermolecular cross-links between adjacent starch chains within the starch granule. Starch cross-linking reactions can strengthen the structure of swollen granules during gelatinization and impart resistance to viscosity breakdown. Preferred cross-linked starches have one cross-link per 100-3000 glucosyl units. A relatively low level of cross-linking stabilizes the granule structure, allowing for greater granule swelling during heating, resulting in higher observed paste peak viscosities. Gradually higher cross-sectional levels can be achieved, but higher cross-sectional levels are generally not preferred in the present invention as they reduce granule swelling.

[0102] Chemically modified natural starches can include, by way of non-limiting example, esterified starches, etherified starches, dialdehyde starches, ionic starches, high-amylose starches, high-amylopectin starches, waxy starches having about 100% amylopectin by weight, and combinations of two or more of the foregoing chemically modified starches. The degree of substitution (DS) of chemically modified starches for use in the present invention ranges from 0.005 to 0.2, preferably from 0.02 to 0.18. Chemically modified starches containing amylopectin for use in the present invention contain amylopectin in the range of 70% by weight, up to 99% by weight, preferably from 75% to 99% by weight, based on the total weight of the starch component.

[0103] Physically modified starch components can include, by way of non-limiting example, pregelatinized starch, dextrin, extruded starch, precooked starch, and redried starch. Pregelatinized starch is substantially incapable of gelatinizing and / or swelling in liquids when heated in the presence of moisture.

[0104] In a preferred embodiment, the starch component comprises pregelatinized starch. It has been observed that the pregelatinized starch in the starch component results in improved surface quality, stability, and the absence of voids in the molded article and / or the finished product. It is hypothesized that the water-binding and / or swelling properties of the pregelatinized starch immobilize water, which is then advantageously available to more efficiently gelatinize the non-pregelatinized starch component during thermal treatment, including the thermoforming step. The swollen pregelatinized starch further contributes to a more elastic and cohesive molded mass, which aids in the substantially uniform distribution of the molded mass throughout the mold, while simultaneously limiting or avoiding the occurrence of voids during the molded mass deposition process.

[0105] In an alternative embodiment, the starch component comprises pregelatinized starch in the range of 0 to 30% by weight, preferably in the range of 2 to 26% by weight, more preferably in the range of 4 to 26% by weight, and most preferably in the range of 5 to 22% by weight, based on the total weight of the starch component.

[0106] The fiber component includes a plurality of fibers. The fibers can be selected from the group consisting of fibers derived from non-genetically modified plant sources, fibers derived from genetically modified plant sources, synthetic fibers, and combinations of the aforementioned fibers. Synthetic fibers can include fibers derived from carbon-based materials. The plurality of fibers can include a plurality of cellulosic fibers. The cellulosic fibers can include fibers selected from wood, shrubs, and grasses. The cellulosic fibers can include fibers based on wood, cotton, hemp, jute, flax, bamboo, ramie, sisal, bagasse, banana, cereal straw, fiber plants, and combinations of at least two of the aforementioned cellulosic fibers.

[0107] In other embodiments, the fiber component can include fibers comprising natural fiber materials, refined natural fiber materials, processed natural fiber materials, synthetic fiber materials, genetically modified fiber materials, and combinations of the foregoing fibers. The fibers of the fiber component of the present invention can include natural, refined, and / or processed natural fiber materials containing lignin, hemicellulose, or other by-products. In other non-limiting examples, the fiber component can include natural, refined, and / or processed fiber materials including bran and / or materials from grains, legumes, and other seeds. In other non-limiting examples, the fiber component of the present invention can include fiber materials comprising refined, processed, and / or synthetic fiber materials, including fibers produced or regenerated from natural cellulose, carbon fiber, polylactide-based fiber, polyhydroxyalkanoate-based fiber, and / or other synthetic fibers.

[0108] As a non-limiting example, as described in the above-referenced publication by E. Helou, in contrast to the current art which teaches biodegradable articles comprising a combination of short, medium, and long size fibers for a claimed fiber reinforcement effect, the fiber component of the present invention comprises a plurality of fibers each having a length in the range of 1 to 250, preferably in the range of 2 to 100, and most preferably in the range of 2 to 40 times the diameter of a starch granule contained in a plurality of starch granules in the starch component of the present invention. The selected ratio of fiber length to starch granule diameter allows for embedding of the fibers, thus strengthening the matrix of the molded article and / or finished article.

[0109] As a non-limiting example, assuming a starch granule having a diameter of 10 microns, the fiber component comprises a plurality of fibers each having a length in the range of about 10 to 2500 microns, preferably in the range of about 20 to 1000 microns, and most preferably in the range of about 20 to 400 microns.

[0110] The current state of the art teaches that a combination of long, medium, and short fibers is optimal for fiber reinforcement effects, including flexural, impact, and tensile strength. See, as a non-limiting example, WO 2005 / 021633, which specifies long to very long fibers having lengths ranging from 4 to 25 mm, medium-length fibers having lengths ranging from 0.5 to 5 mm, and short fibers having lengths ranging from 0.5 mm or less.

[0111] Surprisingly, it has been found that the use of very long, long, or medium-sized fibers, as defined by the current art, produces a matrix that is less favorable for the molded article and / or the finished article. It is presumed or assumed that embedding larger or longer fibers within the article matrix results in a more non-uniform structure. Furthermore, the longer the fibers, the greater the chance of blocking at the extrusion holes in the mold. Embedding long fibers within the matrix around the extrusion holes increases the risk of frayed article edges during the demolding process. By selecting short fiber lengths for the present invention, the risk of fraying at the article edges during demolding is minimized.

[0112] The percentage of fibers in the fiber component is selected or varied depending on the desired flexural, impact, and tensile strength of the article structural matrix, and the amount of starch component is selected for the desired internal cohesion and surface quality, where the starch component is presumed to at least partially connect, glue, and / or embed the fibers of the fiber component and any filler component in the molding composition.

[0113] The present invention features a formed mass composition comprising a starch / fiber weight percent ratio ranging from 94% starch:6% fiber to 49% starch:51% fiber, and preferably ranging from 88% starch:12% fiber to 55% starch:45% fiber, and more preferably ranging from 83:17 to 57:43.

[0114] The fibers of the fiber component can be selected for their fiber properties, including, by way of non-limiting example, high tensile strength, high flexibility, improved embedding properties, and / or other specific fiber properties selected according to the desired properties of the molded and / or finished article. The amount or proportion of a particular group of fibers having a particular property or characteristic can be selected to modify, i.e., increase or decrease, enhance or minimize, a corresponding property of the molded and / or finished article, such as, for non-limiting examples, flexibility, stiffness, and / or impact strength.

[0115] The selected weight percent ratio of the starch component to the fiber component allows for a synergistic effect of the two components for a more uniform formed mass and improved fiber embedding. The improved and / or increased formed mass uniformity and fiber embedding contributes to improved structural stability of the molded article and / or finished product.

[0116] In a non-limiting example, selection of a fiber or group of fibers in the fiber component that has relatively short fiber length characteristics can result in easier packing or more uniform aggregation of the starch granules in the molded mass, and ultimately in the molded and / or finished product.

[0117] In addition to the water and solids components, including the starch and fiber components, the formed mass composition may include the following additional optional ingredients or components:

[0118] The current art teaches compositions containing natural proteins or other natural latexes. Non-limiting examples of proteins or latexes applied in the art include wheat protein (gluten), corn protein (zein), animal-based gelatin, or rubber latex. In the present invention, it is preferred not to add natural proteins or any natural latex to the molding mass because such proteins or natural latexes can interfere with the thermal processing of the molding mass and, as a non-limiting example, can cause mold residues.

[0119] The current art teaches the use of mold release agents. However, each of the current art release agents has its own drawbacks or limitations. For example, the current art teaches the use of release agents containing fats and / or oils derived from animal or plant sources in the production of edible corn or sheet wafers. Such release agents have inherent thermal instability. The use of such release agents can lead to the formation of mold residues. Such mold residues disadvantageously require periodic cleaning and / or removal from the mold. Otherwise, the mold residues may accumulate, resulting in a decrease in the smoothness of the mold surface. Accordingly, a less smooth mold surface reduces the smoothness of the surface of the molded product formed with the mold.

[0120] The current art also teaches the use of hard fat release agents, including fully hydrogenated oils or other fats, in the manufacture of biodegradable articles. These release agents are typically in the form of flakes, powders, or emulsions in water with various emulsifiers. The emulsifiers increase the moisture absorption of the molded article, increasing its softness and / or flexibility while reducing its impact strength.

[0121] The current technology also teaches release agents containing wax. Uniform distribution of wax-based release agents in water-based molding masses requires emulsifying, flowable wax, and / or emulsifying wax powder. As noted above, emulsifiers increase moisture absorption. Molding masses containing wax release agents at dosages of a few percent by weight of the total molding mass do not provide any moisture resistance to the molded article. Molding masses containing wax release agents at dosages greater than a few percent by weight of the total molding mass can add slippage to the molding mass during distribution in the hot molding mold, potentially disrupting the molding process. As the wax dosage increases beyond a few percent by weight of the total molding mass, a glossy surface from excess wax develops on the surface of the molding mass. This glossy surface can cause material slippage, excessive or under-extrusion of material through the extrusion vent, and ultimately, holes in the formed article near the extrusion vent. The current technology teaches release agents containing wax emulsions based on natural sources. However, the additional emulsifier required again compromises the moisture stability of the molded article.

[0122] Current technology teaches that release agents containing fats, oils, and / or waxes are hydrophobic and therefore provide moisture protection to molded and / or finished articles. However, such teachings fundamentally fail to understand the dynamics of mixtures of hydrophilic materials, such as starch flour and fiber. Mixtures of hydrophilic materials, such as gelatinized starch, with fibers embedded in strongly hydrophobic fats or waxes result in phase separation. Furthermore, the proportion of the hydrophobic phase must be low relative to the total molded mass in hot molding operations. Otherwise, material slippage, water vapor escape disturbances, and other operational problems may occur, thereby hindering a successful molding process. A low proportion of the hydrophobic phase does not provide substantial moisture protection to the molded article. Furthermore, any moisture diffusion or absorption will migrate through the main hydrophilic phase, easily bypassing the small hydrophobic regions. A high proportion of hydrophilic fiber and starch materials allows moisture migration into the molded article. Furthermore, any emulsifiers added to wax release agents further increase moisture migration into the molded article. As mentioned above, moisture migration reduces the impact strength of the molded product.

[0123] The current art also teaches release agents containing monoglycerides or diglycerides of fatty acids, citric acid esters of fatty acids, lecithin, and / or other emulsifiers with a hydrophilic-lipophilic balance or HLB value oriented toward the lipophilic side, i.e., from zero to about 7. The current art teaches that lecithin applied to wafer recipes leads to mold staining problems. The ability of emulsifiers to mediate moisture diffusion and migration is a negative factor for moisture-sensitive articles such as those mentioned above.

[0124] Current technology teaches mold release agents containing inorganic powders such as talcum and similar silicates. These agents slowly build up, forming a residue that adheres to the mold surface, mediated by some of the gelatinized starch. There are potential safety concerns due to the suspected cancer risk associated with talcum. Current technology also teaches that other inorganic powder mold release agents include metal oxides and carbonates (e.g., magnesium oxide and carbonate hydroxide). Magnesium oxide and carbonate hydroxide can be applied in wafer recipes. However, magnesium oxide and carbonate hydroxide also present mold staining problems.

[0125] Current technology also teaches the use of metal stearates, such as magnesium stearate, as mold release agents in the production of biodegradable articles based on starch, fiber, and similar materials. Preferred mold release agents for such applications include zinc, calcium, or aluminum stearates. Over time, molding residues develop, necessitating periodic cleaning and / or removal from the mold surface. The reaction of metal counterions with the mold surface at high molding temperatures during multiple molding cycles remains important for continuous industrial manufacturing. Metal counterions can intercalate into cast iron, modifying the metal composition of the mold at the mold surface and / or binding to charged groups in the molded mass, thereby accumulating mold residues within a relatively small number of molding cycles. Such molds are then characterized by a hazy, white-like surface.

[0126] In contrast to current technology, the present invention features a special release agent for continuous thermoforming processes, including hot forming at temperatures above 190°C. The release agent of the present invention provides excellent release without producing mold residue. The release agent of the present invention includes saturated straight-chain fatty acids, preferably those with a carbon chain length of 12 carbons or more, such as lauric acid, myristic acid, palmitic acid, stearic acid, or arachidic acid, and similar 12+C straight-chain fatty acids. In a preferred embodiment, the release agent comprises pure saturated long-chain fatty acids. In another preferred embodiment, the saturated long-chain fatty acid release agent is in the form of a powder. The powder can be easily incorporated into the molding mass. Preferably, the saturated long-chain fatty acid release agent powder contains particles each having a mesh size of less than 80 mesh, more preferably less than 100 mesh, the latter corresponding to a nominal granule diameter of 149 μm.

[0127] In the present invention, potential mold residues resulting from the release agents of the present invention are removed by flushing at high temperatures based on their flash points and equilibrium vapor pressures. Because the saturated long-chain fatty acids in the release agents volatilize at 90-100°C, even in the case of overdosage, the mold remains substantially clean. Therefore, the risk of adhesion and / or buildup of mold residues is avoided. Avoiding buildup of mold residues in continuous operations is particularly advantageous because it avoids the tediousness, production line shutdowns, and associated cleaning procedures characteristic of current technology.

[0128] The present invention features a molded mass composition comprising a saturated long-chain fatty acid release agent in an amount ranging from 0.1 to 2.4 wt. %, preferably from 0.1 to 1.4 wt. %, and more preferably from 0.1 to 1.0 wt. %, based on the total weight of the solid components in the molded mass composition. In a preferred embodiment, the molded mass composition comprises a saturated long-chain fatty acid release agent comprising an acid selected from the group consisting of palmitic acid, stearic acid, and arachidic acid.

[0129] The preferred saturated long-chain fatty acid release agents are in powder form for easy application, undergo substantially complete melting in the molding process, and any mold residue resulting from the release agent is removed by steam demolding and / or flashing during hot molding, unlike current technology release agent residues that remain on the hot mold surface after demolding. The linear fatty acid release agents of the present invention can be used in other types of hot molding or hot baking applications and are not limited to hot molding operations.

[0130] In contrast to current technology, no molding residue containing metal oxides or polymerized lipids remains after flushing. In contrast to current technology's use of metal stearates, higher dosages do not result in the accumulation of whitish molding residue. In contrast to current technology, the application or addition of saturated long-chain fatty acid powder to the molding mass composition does not require an emulsifier for distribution, thus avoiding the negative moisture sorption effect mediated by the emulsifiers used in current technology.

[0131] Furthermore, in contrast to many mold release agents taught in the current art, there is no substantial change in mold surface slip even when the straight chain fatty acid mold release agents of the present invention are overdosed in amounts greater than 2.4 wt. % and up to 10 wt. % based on the total weight of the non-liquid soluble solid components in the molded mass.

[0132] The absence of mold surface slippage allows for continuous, repeatable industrial production. In contrast, mold surface slippage in current technology rapidly and dramatically changes the surface characteristics and properties of molded parts, making the use of related current technology release agents unsuitable for continuous, repeatable, non-industrial production.

[0133] However, the selected dosage of the straight chain fatty acid mold release agent of the present invention is preferred, even though it is expensive to dose and may unnecessarily increase water vapor fuming during heat treatment.

[0134] According to one embodiment, the mold mass composition of the present invention includes a texture. The texturizer can include reactive or non-reactive inorganic additives, as known to those skilled in the art. Non-limiting examples of texturizers that can be used in the present invention include gypsum, calcium carbonate, magnesium carbonate, silicates, titanium dioxide, clay additives, and combinations of the aforementioned texturizers. Texturizers containing low levels of talcum additives are an option, but are not preferred given the potential safety concerns due to the suspected cancer risk associated with talcum, as discussed above.

[0135] In an alternative embodiment, the molded mass composition comprises a texturizer comprising an inorganic additive in the range of 0 to 16.5 wt. %, preferably 0 to 12.5 wt. %, more preferably 0 to 10 wt. %, based on the total weight of the solid components.

[0136] No molding mass is required, and therefore the molding mass composition does not contain a gas release agent under molding processing conditions, including but not limited to the use of bicarbonate, or other gas-releasing carbonate, or other gas-releasing agent. The optional texturizers, including calcium carbonate and magnesium carbonate, mentioned above as optional texturizers, are non-gas-releasing carbonates due to their stability under molding processing conditions.

[0137] In one embodiment, the molding mass composition includes a sizing agent. The sizing agent can be selected from the group consisting of rosin-based sizing agents, alkyl ketene dimer-based sizing agents, and combinations of the aforementioned sizing agents. The use of the selected sizing agent can result in improved internal cohesion of the article's structural matrix. This improves the stability of the article when exposed to or in close proximity to moisture.

[0138] In a preferred embodiment, the molded mass composition comprises a sizing agent comprising a rosin-based sizing agent having a concentration in the range of 0.15 to 0.3 weight percent based on the total weight of the non-liquid soluble components of the molded mass composition.

[0139] In another preferred embodiment, the molded mass composition comprises a sizing agent comprising an alkyl-ketene dimer-based sizing agent having a concentration in the range of 0.1 to 0.2 weight percent based on the total weight of the non-liquid soluble components of the molded mass composition.

[0140] The molding mass composition may include additional modifiers or additives to directly affect the molding process and / or the stability and flexibility of the molded and / or finished article.

[0141] In one embodiment, the molding mass composition includes a plasticizer, i.e., a substantially secondary or non-aqueous plasticizer, in addition to the water component. In a preferred embodiment, the secondary plasticizer includes urea. The urea may act differently from the water component. It is believed that the urea promotes at least some chain movement in the starch component, thereby reducing any cracking in the molded article. At a selected urea concentration relative to the starch component, the molded article and / or the finished product have improved smoothness and stability. In an alternative embodiment, the molding mass composition includes a secondary or non-aqueous plasticizer, preferably including urea, at a concentration ranging from 0 to 6% by weight. More preferably, the concentration ranges from 0 to 4.5% by weight, and most preferably, from 0 to 3% by weight, based on the total weight of the starch component.

[0142] In one embodiment, the molding mass composition can include a modifier containing multiple borate ions. Adding borate to the molding mass composition at a selected concentration relative to the starch component can affect the weight and pore structure of the molded and / or finished product. However, adding borate can also affect the gelatinization temperature of the starch component. Therefore, borate addition can be added in a selected amount to optimize selected properties of the molded and / or finished product and to affect the gelatinization temperature of the starch component. In an alternative embodiment, the molding mass composition includes a modifier containing multiple borate ions, preferably at a concentration ranging from 0 to 2 mmol of borate per kilogram of starch component, more preferably from 0 to 0.2 mmol of borate per kilogram of starch component.

[0143] Current technology teaches the use of gums, including but not limited to polysaccharides of vegetable, animal, or microbial origin, as thickeners, stabilizers, gelling agents, and emulsifiers in the food and chemical industries. Gum structure determines its use and purpose due to specific properties such as viscosity, intrinsic viscosity, stability, gelling properties, and emulsifying properties. In the production of shaped articles from fluid batters, current technology teaches the use of gums to control the homogeneity of the batter and to prevent breakdown of the shaped mass during the preforming stage.

[0144] In contrast to current technology, the initial plastic-elastic properties of the molded masses of the present invention can make the use of gums less desirable. In one embodiment of the present invention, however, the molded mass composition can include a modifier comprising a polymer. The selective addition of polymer to the molded mass composition can selectively affect the texture of the molded mass, the distribution of the mass in the hot mold, the control of extrusion of the molded mass through the extrusion vent, and the properties of the molded article.

[0145] In one embodiment, the molded mass composition can include a modifier comprising a polymer comprising a cellulose derivative. The cellulose derivative can include at least one of a cellulose ester and a cellulose ether. The cellulose derivative can optionally include one or more additional ionic groups. In an alternative embodiment, the molded mass composition can include a modifier comprising a polymer selected from the group consisting of cellulose derivatives, cellulose esters, cellulose ethers, agar, alginic acid, alginates, carrageenan, chitosan, curdlan, guar, konjac, konjac derivatives, locust bean gum, high ester pectin, low ester pectin, amidated pectin, and xanthan.

[0146] According to one embodiment, the liquid-insoluble solids of the molding mass composition can include a modifier comprising polyvinyl alcohol. Polyvinyl alcohol has excellent film-forming and adhesion properties for selectively modifying the stability and flexibility of the molded article and / or the finished product. The molding mass composition can include the polyvinyl alcohol modifier at a concentration ranging from 0 to 12% by weight. Preferably, the concentration ranges from 0 to 6% by weight based on the total weight of the liquid-insoluble solids in the molding mass composition.

[0147] The cast mass composition can include modifications including colorants, which can include colorants selected from the group consisting of colorants included on the Federal Food, Drug, and Cosmetic (FD&C) list of colorants, E numbered coloring agents regulated by the Federal Food and Drug Administration, E numbered coloring agents regulated by the European Union, natural colorants, magnetite colorants, and combinations of two or more of the foregoing colorants.

[0148] In one embodiment, the colorant can include an additive that includes magnetite, which can be in the form of a powder. The use of magnetite can make the molded article more suitable for electrostatic processing.

[0149] In other embodiments, the formed mass composition can include additives including, by way of non-limiting example, agents that undergo Maillard browning reactions, such as proteins; agents that undergo extended Maillard browning reactions, such as most sugars and amino acids; agents that undergo caramelization reactions; one or more selected sugars at selected sugar concentrations; one or more selected amino acids at selected amino acid concentrations; and / or one or more selected proteins at selected protein concentrations. The selected sugar concentration is less than 1.5% by weight, preferably less than 1% by weight, based on the total weight of the solid components of the formed mass composition. The selected amino acid concentration is less than 2% by weight, preferably less than 1% by weight, based on the total weight of the solid components of the formed mass composition. The selected protein concentration is less than 16% by weight, preferably less than 11% by weight, based on the total weight of the solid components of the formed mass composition.

[0150] After selecting ingredients, including the liquid and non-liquid soluble solid components, as described above, a molded mass can be prepared from the molded mass composition. Preparing the molded mass includes, for example, a mixing and kneading step performed using a mixing and kneading system. The mixing and kneading step can be performed in a batch process or in a continuous mixing and kneading system to prepare a molded mass having a first plastic-elastic texture and consistency (including homogeneous incorporation of fibers) and substantially free of air or other gas-filled voids within the molded mass.

[0151] During the first step of the mixing and kneading process, the non-liquid soluble solid components are substantially evenly distributed throughout the liquid phase. The non-liquid soluble solid components absorb a significant portion of the liquid phase. The composition becomes increasingly plastic. During the second step of the mixing and kneading process, the composition is kneaded to further mix the components.

[0152] The mixing and kneading process can be carried out using procedures known to those skilled in the art. Such procedures include thorough mixing of the fibers together with the starch granules and any other non-liquid soluble solid ingredients, as well as intensive kneading, including optional high-shear mixing, during or under incorporation of the liquid ingredients, including the water ingredient and any dissolved solutes or dispersed emulsions. The mixing and kneading process can include incremental addition of the liquid ingredients to uniformly incorporate the fibers into the formed mass. The incremental addition of the liquid ingredients, according to methods known to those skilled in the art, can facilitate increased shear forces in the high-shear mixing and can break down or destroy any nesting of the fibers.

[0153] The method can include substantially preventing the introduction of air or other gases into the formed mass and / or removing air or other gases from the formed mass. In one embodiment, the removal and / or removal of air or other gases includes creating a vacuum within the mixing / kneading system. In a non-limiting example, creating a vacuum can be achieved using a continuous mixer either during or at the end of the continuous mixing and kneading steps. The use of a continuous mixer can allow for precise component dosing according to the weight, mass, volume percentage, or ratio of the components added.

[0154] Automatic metering can be applied using batch, continuous, and / or extrusion-type equipment systems to mix, degas, and prepare a molding mass having a first plastic-elastic texture and consistency. Mixers, kneaders, and / or extruders of current technology known to those skilled in the art can be used. The molding mass can then be portioned or applied to a portioning system for deposition into a target mold.

[0155] The time required for the mixing and kneading process depends on the type of mixer, the geometry of the respective mixing and kneading tools, the fill volume, and the rotation speed of the mixer. In a non-limiting exemplary embodiment, the time for the mixing and kneading process ranges from 4 minutes to 16 minutes. The mixing and kneading time is adjusted and / or optimized to produce a relatively soft molded mass with uniformly distributed fibers and a first plastic-elastic texture and consistency.

[0156] As described above, after preparing the desired formed mass having a first plastic-elastic texture and consistency, the formed mass undergoes an optional rest period that can vary depending on the composition and preparation method of the formed mass. In a non-limiting exemplary embodiment, the rest period comprises at least 15 minutes, preferably at least 10 minutes, and more preferably at least 5 minutes.

[0157] The components of the molded mass composition of the present invention are selected and prepared to produce a relatively soft molded mass having a plastic-elastic, non-fluid texture and consistency. The composition and preparation of the molded mass of the present invention have several advantages: The inclusion of residual air in the molded mass mixture is minimized by using a starch component that preferably includes a plurality of granules, particles, grains, and / or granules in powder form. The powder form of the starch component avoids inconsistent air-filled voids from forming and / or being transferred to the structural matrix of the molded article. While apparently non-flowable, the first plastic-elastic texture and consistency of the molded mass of the present invention allows it to flow and expand, completely filling the mold. Surprisingly, it has been found that the molded mass of the present invention has a relatively low proportion of extruded waste material and can fill each mold relatively quickly, with substantially no voids. Therefore, weight fluctuations during division of the molded mass within the mold are minimized, thereby reducing the proportion of waste material extruded through the mold's extrusion vent.

[0158] The molding materials of the present invention are suitable for rapid, high-temperature molding at temperatures exceeding 190°C to maximize production per mold. At such high molding temperatures, the potential for discoloration or color change due to thermal browning or caramelization reactions is substantially reduced. The cure time is selected to avoid residual internal vapor pressure within the molding mass and to intersect what is known in the art as the glass point of the article's matrix during processing. For a complete operating cycle, the cure time for the article typically ranges from 60 to 155 seconds, preferably from 75 to 140 seconds, and more preferably from 85 to 125 seconds. The cure time is selected as a function of the composition of the molding mass and the desired target wall thickness or range of wall thicknesses for the molded article. The 85 to 125 second cure temperature range is more typical for rolls with relatively thick walls. In contrast, current technology typically requires cure times of about 2 minutes or longer to form articles from fluid, batter-based molding masses. The maximum cure temperature is 225°C, preferably 215°C, and more preferably 190 to 210°C.

[0159] The molded masses of the present invention are substantially devoid of free moisture, and the corresponding molded and / or finished articles are devoid of external vapor-filled voids, cracks or similar irregularities, in contrast to current technology.

[0160] Once primed and rested, the formed mass can be divided, if desired. Dividing includes dividing the formed mass into selected portions using a plastic elastic material dividing system known to those skilled in the art. Non-limiting examples of dividing devices that can be used in accordance with the present invention include wire cutters, bun dividers, and / or piston-based volumetric dough dividers. In preferred embodiments, the dividing device has the ability to divide the formed mass of the present invention to an accuracy of at least plus or minus 1 gram.

[0161] The method includes depositing a mold mass into one or more molds according to one or more selected portions. The selected volume deposited within the corresponding target mold is smaller than the volume of the respective target mold. The degree of water vapor-mediated expansion during the heat curing process can occur depending on or as a function of the composition of the mold mass.

[0162] The dividing step can be performed adjacent to a continuously operating mold. The mold is prepared immediately after ejecting the previously molded article and removing excess material associated with the operation of an automatic mechanical scraping device and / or blower. The divided pieces of the molded mass are introduced into the mold in an ordered manner by orienting the divided pieces toward the center of the bottom of each empty or open mold.

[0163] The mold in the fully automated molding machine can be placed in baking tongs. A non-limiting exemplary empty base of a casting mold (70) is shown in FIG. 7. In an alternative non-limiting embodiment, the target mold can be hinged on one side and locked on the other side immediately after deposition of the piece of the segmented molding mass. A non-limiting example of a target mold (72) having a hinged lid (74) is shown in FIG. 8. Such an exemplary mold can, as one example, open at a 90° angle for demolding and refilling. In an alternative non-limiting embodiment, the top end of the mold is not hinged but can open horizontally. This latter non-limiting molding example is preferred for molding relatively shallow articles. Non-shallow articles include items whose shortest dimension exceeds one inch.

[0164] The mold accurately reflects the shape of the intended or target article. The wall thickness of the article is preferably within the range of 0.9-3.5 mm, more preferably within the range of 1.2-3.0 mm, and most preferably within the range of 1.5-2.8 mm. Regions of different thickness within the article are possible to form rims, structural reinforcing elements, or logos.

[0165] Molds for hot forming processes can include metallic materials such as, by way of non-limiting example, steel, cast iron, aluminum, brass, and mixtures of two or more of the foregoing metallic materials. The entire mold or molds can be made from a single metallic material or different metallic materials using inserts within a steel or cast iron frame.

[0166] The edge of the mold may include an array of one or more extrusion vents or holes (76), as shown in the non-limiting exemplary target mold (72) shown in FIG. 8. The extrusion vents provide a passageway for the escape of water vapor and optional extrusion of small amounts of solid material through the extrusion vents. The extrusion vents are preferably arranged in a symmetrical pattern following the closing edge of the different part molds, including one-, two-, and three-part molds, for non-limiting examples. For articles having a thickness of any dimension equal to or less than one inch, a two-part mold is preferred. For articles having a thickness of any dimension greater than one inch, a three-part or more mold is preferred.

[0167] Each mold can be attached to a conveying chain cycle mechanism for sequentially passing the mold through deposition phases: depositing the molding mass into the mold, closing the mold and filling the mold details; heat curing the filled mold at a selected cure temperature; ejection; opening the heat cured mold and ejecting the molded article; and cleaning phases for removing any extruded solids remaining on the mold.

[0168] In the deposition stage, the molding mass is deposited into the mold, if necessary, and the mold is closed. The first plastic-elastic material of the molding mass is distributed substantially evenly within the mold cavity or enclosure. Uniform distribution can be enhanced by mechanical squeezing and slight initial steaming. A small amount of molding mass material may be extruded or passed through the extrusion vents in the mold.

[0169] Current technology teaches the immediate single or multiple reopening and reclosing of the mold, known as breathing. As an example, in the production of biodegradable articles or food wafers containing flowable molded masses, current technology teaches such breathing operations to rapidly reduce some of the moisture content in order to reduce the total molding time and improve the final stability of these articles.

[0170] In contrast to current technology, such a bleeding operation is not required in the present invention due to the excellent distribution of the first plastic-elastic texture and consistency of the molding mass. It is assumed or presumed that the portion of the selected mold release agent located close to the surface of the molding mass and easily melting at the curing temperature helps the molding mass to surprisingly and unexpectedly distribute and substantially completely fill the molding mold. Therefore, the ability of the molding mass of the present invention to distribute well and substantially completely fill the target mold characterizes and supports the theoretical basis of the present invention.

[0171] During the heat cure stage, the filled mold is placed into or passed through a heat cure system, and heat is applied to the mold at a selected cure temperature for a selected cure time. Figure 7 shows an exemplary empty mold (70) prior to filling with a prepared mold mass. In an alternative non-limiting embodiment, an empty mold is placed inside or passed through a heat cure system and subsequently filled with a prepared mold mass. Figure 9 shows a heat cure system (78) including an empty mold (80) placed therein.

[0172] Heat stored in the thick metal of the mold is transferred to the formed mass through the mold surface. The formed mass surface in direct contact with the hot mold surface is almost immediately set. Vapor-filled voids form on the formed mass surface almost immediately. The moisture in the formed mass rapidly vaporizes into foamed steam within the structural matrix of the article. The foamed steam coincides very closely with the gelatinization of any non-gelatinized starch components. The steam is transformed or passes through the extrusion holes in the mold via the still, soft internal structure of the formed mass. Some pressure builds within the mold, as evidenced by a hissing sound that can be heard within the first third of the setting process.

[0173] The article includes mold details, such as mold edges or logos, for non-limiting examples. Internal steam-filled pores are formed in a substantially controlled distribution pattern until gelatinization of the starch component along with rapid moisture loss values ​​locks the structure into a stable internal matrix. The internal steam pores allow for lighter weight molded articles.

[0174] Heating the molded mass to temperatures from about 200°C up to 225°C provides relatively rapid and substantially complete gelatinization of the starch component, uniform distribution, and rapid settling of the internal cavities blown by the generated water vapor, as well as final hardening of the structure. The present invention generally involves a set time preferably ranging from 75 seconds to 140 seconds, more preferably from 85 seconds to 125 seconds, depending on the composition of the molded mass and the wall thickness or thickness range of the molded article. A relatively fast set time contributes to the efficiency of the heat-setting process and ultimately to an efficient manufacturing process. Current technology's more fluid, batter-like molded masses generally require set times of 2 minutes or more, as noted above. Any internal portions of the molded article are dried to a few percent residual moisture. Thus, at the completion of the heat-setting step, substantially no vapor pressure remains in the structural matrix of the molded article. The structural matrix of the molded article solidifies beyond what is known in the art as the glass point of the structural matrix. Concurrent with the drying and hardening process, the structural matrix of the molded article shrinks, which aids in subsequent demolding during the article ejection step. The heat-curing step is continued until the molded article has a second plastic-elastic texture and consistency characterized by a residual moisture content ranging from 6 to 1% by weight, preferably 3.5 to 1.5% by weight based on the total mass of the molded article. Any excessive curing can result in excessive shrinkage and / or the development of micro- or possibly visible tears, which can impair the article. The cure stop point for a particular article can be selected according to principles known to those skilled in the art.

[0175] In a continuous process, heat curing can occur while the mold is cycled through a heating chamber where the mold temperature ranges from 185°C to 225°C, preferably from 190°C to 215°C, and more preferably from 190°C to 210°C. This mold temperature refers to the actual effective temperature at the surface of the mold. The ideal heat curing temperature is selected to maintain high throughput while avoiding degradation of the organic material, including, by way of non-limiting example, heat browning or even decomposition. Heat for the heat curing process can be provided by, by way of non-limiting example, gas burners, electromagnetic induction, and other heating systems known to those skilled in the art.

[0176] The temperature difference between the mold temperature at the top and bottom of the mold can be in the range of 10°C or less.

[0177] For a complete operating cycle or heat-setting stage, the curing time of the article is generally within the range of 60 to 155 seconds, preferably within the range of 75 to 140 seconds, and more preferably within the range of 85 to 125 seconds, depending on or according to the composition of the article's molded mass and its wall thickness or thickness range. The heat-setting time is selected so that no vapor pressure remains in the structural matrix of the article and the article solidifies above a critical point, called the glass point, of its structural matrix.

[0178] The method can include hot-forming the formed mass. The hot-forming step involves forming intrinsically linked with heat curing in a one-step process. The hot-forming can be carried out in a fully automatic hot-forming machine. The fully automatic hot-forming machine can include at least one, and preferably two or more, single molds, each having the shape or form of the target molded article and / or finished product. Following hot-forming, the molded articles and / or article components can be separated or joined together as needed.

[0179] The release step can begin when the molded article is sufficiently stable or in a sufficiently stable form and the residual moisture content of the article is in the range of 6 to 1% by weight. This is preferably in the range of 3.5 to 1.5% by weight, more preferably 3 to 1.5% by weight, based on the total mass of the molded article. Selective control of the residual moisture content is important to avoid structural defects in the molded article. For non-limiting examples, structural openings in the article can occur if blown water vapor remains in the internal structure of the article at a rate higher than the allowable residual moisture content. Excessive shrinkage can occur if the article is dried or cured below the allowable residual moisture content. Excessive shrinkage can then lead to microcracks or visible crack defects in the molded article.

[0180] When the top or first section of the mold is opened, the molded article can remain in the bottom or second section of the mold, or alternatively, can rise slightly during mold opening. This slight rise can be related to the introduction of air into the mold and / or the release mechanism of the release agent selected according to the present invention. An air blower can be used to assist in demolding.

[0181] The articles can then be safely removed or ejected from the corresponding molds. Ejection can be accomplished, as a non-limiting example, by pivoting robotic arms, each supporting one or more suction cups. A single robotic arm can be deployed per article, or an array of robotic arms can be deployed to retrieve multiple articles from multiple molds substantially simultaneously. Each robotic arm can then place the corresponding retrieved article in a selected device as needed for further transport. Non-limiting examples of apparatus for systematically conveying include conveyor belts, transport systems with dedicated receiving enclosures or cavities, or other apparatus for systematically conveying and / or conveying known to those skilled in the art.

[0182] Alternatively, in applications involving automatic demolding, the mold or top of the mold may be opened and the article may be preferably lifted, removed, or otherwise ejected from the mold using a vacuum suction device, which has safety advantages.

[0183] Other methods of demolding and sequenced transport known to those skilled in the art of biodegradable packaging or wafer baking manufacturing can be used.

[0184] During the molding stage, prior to or in conjunction with transport and / or conveyance, a suitable air blow can be used to remove any bobbles containing extruded material remaining in and / or around the mold.

[0185] The demolded article can then be cooled to a temperature in the range of 25-45°C by exposure to the ambient environment or by a forced cooling mechanism.

[0186] After molding, optional additional post-molding processing steps can be performed, one non-limiting example being characterized by actively controlling the moisture content of the molded article to enable selected flexibility and breaking strength of the molded article.

[0187] Molded articles containing carbohydrate polymers, including fiber and starch, absorb and desorb moisture from the environment. Sources of such moisture can include, by way of non-limiting example, the relative humidity of air and / or contact with moist or liquid contents containing different percentages of moisture, each with a corresponding different water activity. The rate of moisture absorbed and / or desorbed by a carbohydrate-based article is physically regulated according to what can be called the sorption isotherm of the material. The moisture content of the article affects the mechanical properties of the molded article.

[0188] As non-limiting examples, carbohydrate-based molded articles having a relatively low moisture content may be brittle, articles having a relatively moderate moisture content may be flexible, and articles having a relatively high moisture content of more than 15% by weight, and sometimes more than 10% by weight, based on the total mass of the article may be soft or damp. Such sorption and / or desorption of carbohydrate articles may be a drawback compared to most types of non-biodegradable and non-compostable plastic-based articles, and selected control of moisture sorption may be used to enable and / or enhance biodegradability and / or compostability, as needed.

[0189] In the humidity range of 0-100% relative humidity, the sorption isotherm of carbohydrate-based molded articles has an S-shape. Under dry conditions, carbohydrate-based molded articles can lose moisture at low relative humidity. Under wet conditions, carbohydrate-based molded articles can gain moisture at high relative humidity. While moisture gain can enable biodegradable and compostable properties, excessive moisture gain can adversely affect the physical stability of the molded article.

[0190] Thus, the mechanical properties of carbohydrate-based molded articles can vary with the relative humidity of the environment, depending on the article's composition. For molding compositions of the present invention at temperatures up to 50°C and relative humidity below 45%, the article can be brittle and flexible at relative humidity of about 45-75%, and soft at relative humidity of 80% or higher. Temperature has a less significant effect compared to the relative humidity at which the article is hot-formed, but moisture loss can occur as the temperature increases above ambient unless the relative humidity is sufficiently high, in the range of about 45%-70%.

[0191] Additionally, the dimensions of the article can change as a function of moisture sorption and / or desorption, allowing the article to expand with moisture gain and shrink with moisture loss. The maximum length / width shrinkage of a carbohydrate-based article is approximately 0.1% for a 1% change in the moisture content of the article. In a non-limiting example, a 200 mm long article may experience a 0.1% gain / loss of 2 mm for every 1% of moisture gained / lost.

[0192] In contrast to current technology, the present invention features active control of moisture content in biodegradable and compostable molded articles, which is required for many applications of such articles. In one embodiment, the present invention features a post-thermal cure treatment that includes a conditioning process. Such conditioning involves actively controlling moisture content in the molded article. After molding, or after molding and cooling, the molded article can be arranged in an orderly manner and passed through an enclosed humidification section or chamber. In the enclosed humidification section, the article is exposed to a humid air stream. The amount of water vapor made available to the article through the humid air stream is controlled by controlling the temperature, relative humidity, and flow rate and distribution of the incoming humid air stream while maintaining controlled and safe microbiological conditions within the humidification section or chamber. Furthermore, active control of moisture in the molded article is further controlled by selecting the dimensions of the molded article, including, in embodiments, its thickness and surface area. Active control of moisture in the molded article is further controlled by selecting the humidification time, i.e., the time for treating the article enclosed within the activation section or chamber. The higher the relative humidity of the incoming moist air, the higher the temperature of the incoming moist air, and the smaller the overall mass and wall thickness of the molded part, allowing the molded part to absorb water more quickly and achieve the desired moisture level in the molded part.

[0193] In a non-limiting exemplary embodiment, the molded article, after heat curing, has a moisture content in the range of 3 to 1.5 weight percent, based on the total weight of the molded article. Such articles can typically be humidified for 15 to 60 minutes, preferably 20 to 50 minutes, and most preferably 20 to 45 minutes. After humidification, the water activity of the molded article, including its water absorption capacity, is preferably in the range of 0.45 to 0.70. More preferably, the water activity of the molded article after humidification is in the range of 0.50 to 0.70. The target water activity of the article is selected according to the corresponding target application of the article. The relative humidity of the denaturation chamber is preferably maintained between 80% and 99%, more preferably between 85% and 98%, to enable relatively rapid humidification of the molded article. Selecting a higher relative humidity allows for greater humidity exposure for the article, allowing the target water activity to be reached more quickly. Any condensation of water droplets on the molded article must be eliminated.

[0194] Other post-forming processes can include selectively modifying the properties of the article by coating and / or sealing, impregnating, and / or laminating with compostable coatings. Coating and / or laminating processes can be selected to make the article smoother, glossier, more flexible, and / or waterproof.

[0195] In one embodiment, post-molding processing involves forming and / or impregnating at least a portion of a molded article with a biodegradable, compostable coating and / or seal, e.g., for the wall surface, to modify surface properties and / or stabilize the article for a particular application. By way of non-limiting example, coating and / or sealing an article with a biodegradable, compostable layer can improve surface smoothness, gloss, and sheen, protect against moisture and / or oil absorption, and / or improve the article's mechanical strength properties, such as impact strength, flexibility, or puncture resistance. In another non-limiting example, the biodegradable, compostable coating and / or seal can provide water repellency or waterproofing to at least a portion of the exterior surface or side of the exterior and / or interior of the molded article.

[0196] The coating and / or sealing process can be accomplished according to different coating and sealing methods and materials known to those skilled in the art. As a non-limiting example, the coating and / or sealing process can include applying a biodegradable, compostable coating and / or seal to the molded article by spraying, curtain coating, dipping, and / or impregnating the inner matrix of the molded article with a solution.

[0197] The coating and / or sealing process can be applied using a coating fluid. The coating fluid can be a water-based solvent or a non-water-based solvent, or a combination of both, and the non-water-based solvent can be miscible with water. Non-limiting examples of coating fluids that can be used in the present invention include, by way of non-limiting example, the coatings discussed in publications WO 2014105641, WO 2010085569, and US 5,576,049.

[0198] The present invention features a unique biodegradable, compostable coating solution. The biodegradable, compostable coating solution comprises a selected liquid solvent base and a selected ratio of a selected solids portion. In a preferred embodiment, the selected liquid solvent base comprises water.

[0199] The present invention also features a novel system and method for applying a biodegradable, compostable coating solution to a molded article. The system includes a coating zone including a spraying device and a heating device. The method involves first spraying the molded article with the biodegradable, compostable coating solution, followed by heating the sprayed molded article to a selected temperature for a selected drying time. In another embodiment, spraying and heating can occur simultaneously.

[0200] The spraying device includes a sprayer that emits a spray of multiple droplets of the biodegradable, compostable coating solution onto the molded article.

[0201] The heating device may include an infrared dryer, which is used to heat the sprayed article to a selected temperature to achieve a target water activity in the coated article.

[0202] After application of the biodegradable and compostable coating solution, the coated article has a target water activity.

[0203] In an exemplary, non-limiting embodiment, FIG. 10 shows a transport belt that can transport molded articles to a coating area where a biodegradable, compostable coating can be applied to the molded articles.

[0204] In another embodiment, the post-forming step can include applying a biodegradable and compostable film to the article. Applying the film can include laminating the biodegradable and compostable film to at least a portion of the exterior surface of the article. In a preferred embodiment, the laminated film comprises a non-uniform, defect-free film of sufficient thickness to affect at least one selected change in the surface property of the article.

[0205] The step of applying the film can include bonding at least one additional layer to at least a portion of the outer surface of the molded article. The film can be bonded to the molded article by heat-mediated bonding, application of pressure, suction, wet bonding, dry bonding, the use of a binder, or a combination of two or more of the aforementioned bonding methods. The bonding method can be selected based on the material of the layer, the shape and amount of the article to be coated, the desired thickness of the layer, and other parameters known to those skilled in the art.

[0206] Non-limiting examples of laminated membranes that can be used in the present invention are described in US Patent Application Publication No. 2015 / 0337094 and US Patent Application Publication No. 6573340 B.

[0207] Other post-molding processes can include, by way of non-limiting example, modifying the surface of the article by printing and / or attaching stickers.

[0208] After molding and any post-molding steps, the articles can be stacked, sealed, marked, and / or packaged as needed, and then loaded onto pallets and / or otherwise prepared for storage and / or distribution as needed, according to procedures known to those skilled in the art.

[0209] The following examples more particularly illustrate the molding mass composition and its preparation, the molded articles, and the molding method, including any post-molding steps, according to the present invention.

[0210] Examples 1-12 below refer to the information provided in corresponding Tables 3-14, respectively, included in Appendix A of this application.

[0211] Example 1 Referring to Table 3, a total of eight experiments were performed, each containing the ingredients with the size dispersion listed in the Component column. The weight (g) of each ingredient is shown in the corresponding column for each experiment. The term "WF" refers to wheat fiber from Rettenmaier, Germany, and the WF number refers to a selected distribution of fiber lengths.

[0212] Experimental Procedure: For each experiment, the soluble phase was first prepared according to Table 1. Cold water was weighed out. Soluble ingredients, including sizing salts (e.g., borates, alum), urea, colorants, etc., to carry out the experiment were dissolved in water. The sizing agent(s) was dispersed in the soluble or aqueous phase.

[0213] The solid phase was then prepared for each experiment according to Table 1. The fiber, starch powder and release agent powder were briefly blended using a kitchen assistant mixer with a kneading arm at a low speed of about 30 rpm.

[0214] The soluble phase was mixed into the container holding the solid phase and blended until substantially homogeneous. After approximately 1 minute of mixing and blending, the mixture became plastic in texture and consistency. The intensity of the kneading arms was increased to a range of approximately 300-600 rpm as a function of the volume contained in the mixer, and kneading was carried out for approximately 3 minutes.

[0215] The mixture was allowed to stand at ambient temperature for a period ranging from 5 to 30 minutes.

[0216] Aliquots of 60 grams ± 0.5 grams were divided into corresponding molds.

[0217] The molded masses were cured at curing temperatures ranging from 22°C to 26°C for curing durations ranging from 5 minutes to 25 minutes.

[0218] An indication of the resulting color, molding quality, and any mold residue is provided for each experiment.

[0219] Example 2: Referring to Table 4, a total of eight experiments were performed, including the components with the size dispersion listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment.

[0220] The experimental method outlined in Example 1 was followed.

[0221] An indication of the resulting color, molding quality, and any mold residue is provided for each experiment.

[0222] Example 3: Referring to Table 5, a total of eight experiments were performed, including the components with the size dispersions listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment. The term E133 refers to water-soluble food colors named according to the EU food additive numbering system, which includes the E number. The term "TC" refers to cellulose fiber products from Jeluwerk, Germany. For fiber lengths, see https: / / www.jelu-werk.com / de / technische-industrie / produkte / funktionelle-cellulose / jelucel-tc / jelucel-tc / The experiment was carried out according to the experimental method outlined in Example 1.

[0223] An indication of the resulting color, molding quality, and any mold residue is provided for each experiment.

[0224] Example 4: Referring to Table 6, a total of eight experiments were performed, including the components with the size dispersion listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment.

[0225] The experiment was carried out according to the experimental method outlined in Example 1.

[0226] An indication of the resulting color, molding quality, and any mold residue is provided for each experiment.

[0227] Example 5: Referring to Table 7, a total of eight experiments were performed, including the components with the size dispersion listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment.

[0228] The experimental method outlined in Example 1 was followed.

[0229] The resulting color, molding quality, and an indication of any template residues are provided for each experiment.

[0230] Example 6: Referring to Table 8, a total of eight experiments were performed, with the ingredients, including the size dispersion, listed in the ingredient column. The weight (g) of each ingredient is shown in the corresponding column for each experiment. The term "DS" refers to degree of substitution, and the number immediately following the term "DS" indicates the degree of substitution that characterizes the modified starch used.

[0231] The experimental method outlined in Example 1 was followed.

[0232] The resulting color, molding quality, and an indication of any template residues are provided for each experiment.

[0233] Example 7: Referring to Table 9, a total of eight experiments were performed, with the components containing the size dispersions listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment. The term "pregelled pd." refers to the powder before pregelatinization.

[0234] The experimental method outlined in Example 1 was followed.

[0235] The resulting color, molding quality, and an indication of any template residues are provided for each experiment.

[0236] Example 8: Referring to Table 10, a total of eight experiments were performed, with the ingredients, including the size dispersion, listed in the Component column. The weight (g) of each ingredient is shown in the corresponding column for each experiment.

[0237] The experimental method outlined in Example 1 was followed.

[0238] The resulting color, molding quality, and efficacy of any template residues are provided for each experiment.

[0239] Example 9: Referring to Table 11, a total of eight experiments were performed, with the components containing the size dispersion listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment.

[0240] The experimental method outlined in Example 1 was followed.

[0241] The resulting color, molding quality, and an indication of any template residues are provided for each experiment.

[0242] Example 10: Referring to Table 12, a total of eight experiments were performed, with the components containing the size dispersion listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment.

[0243] The experimental method outlined in Example 1 was followed.

[0244] The resulting color, molding quality, and an indication of any template residues are provided for each experiment.

[0245] Example 11: Referring to Table 13, a total of eight experiments were performed, including the ingredients with the size dispersion listed in the Component column. The weight (g) of each ingredient is shown in the corresponding column for each experiment.

[0246] The experimental method outlined in Example 1 was followed.

[0247] The resulting color, molding quality, and an indication of any template residues are provided for each experiment.

[0248] Example 12: Referring to Table 14, a total of eight experiments were performed, with the components including the sizing dispersion listed in the component column. The weight (g) of each component is shown in the corresponding column for each experiment.

[0249] The experimental method outlined in Example 1 was followed.

[0250] The resulting color, molding quality, and an indication of any template residues are provided for each experiment.

[0251] Example 13: Crush strength and heat resistance measurements were performed on Styrofoam cups, paper cups, and prototype biodegradable and compostable cups of the present invention.

[0252] Each cup type was tested for breaking strength in two different directions. For the first-directional test, each cup type was tested by applying a force perpendicular to the base and rim of the cup. Both the Styrofoam cup and the prototype cup failed in the ribbed area. The paper cup exceeded the applicable force of the testing machine. For the second-directional test, each cup type was tested by applying a force to the side of the cup. None of the cups failed the second-directional test. However, none of the cups responded to the applied force other than simply bending. The peak force required to bend each cup type was recorded.

[0253] Thermal resistance was measured for each cup type. Referring to Figure 11, for each cup, thermocouples were attached to the inside and outside surfaces of the cup. Each probe of the inside thermocouple was attached directly opposite the corresponding probe of the outside thermocouple. Sand was inserted into each cup and a 4.5 watt heating element was placed in the center of the sand. The entire perimeter of this assembly for each cup was insulated. The heating element in each cup was powered and the temperature difference between the two thermocouples was recorded. Thermal resistance was calculated using the following formula: R=T / Q a where R is the thermal resistance, T is equal to the temperature difference across the thickness of the material, and Q a is the heat flow per unit area, and R is in ft 2 Measured or calculated in °F / Btu. Values ​​are given for actual material thickness and on a per inch basis. Table 13 provides a summary of the results.

[0254] [Table 3]

[0255] Table 15 shows that the biodegradable and compostable cup of the present invention has a higher side crush strength compared to both Styrofoam and paper cups, and an ultimate breaking strength that is more than twice that of a Styrofoam cup, despite being less than that of a paper cup. The heat resistance of the biodegradable and compostable cup of the present invention is lower than that of a Styrofoam cup, but achieves the same heat resistance as a paper cup.

[0256] Example 14 A control compost sample and three test samples A, B, and C were prepared according to Table 15 in Attachment A, and the biodegradability of the control and test samples was evaluated using ASTM D5538. A summary of the test results is provided in Table 16 included in Attachment A and is shown graphically in Figure 12.

[0257] Although the present invention has been described in detail herein according to certain preferred embodiments, modifications and variations therein may be effected by those skilled in the art without departing from the spirit of the invention. It is therefore intended to be limited only by the scope of the appended claims, and not by the details and instrumentalities describing the embodiments shown herein.

[0258] It is to be understood that variations and modifications can be made in the compositions, articles, devices, systems, and methods without departing from the concepts of the present invention, and that such concepts are intended to be encompassed by the following claims unless those claims in their language expressly state otherwise.

[0259] A wide range of further embodiments of the present invention are possible without departing from its spirit and essential characteristics. The embodiments discussed herein are to be considered in all respects only as illustrative and not restrictive. The following claims, rather than the foregoing description, indicate the scope of the invention.

[0260] Attachment A

[0261] [Table 4]

[0262]

Table 5

[0263]

Table 6

[0264]

Table 7

[0265]

Table 8

[0266]

Table 9

[0267]

Table 10

[0268]

Table 11

[0269]

Table 12

[0270]

Table 13

[0271]

Table 14

[0272] [Table 15]

[0273] [Table 16] TIFF2025128171000018.tif174170

[0274] [Table 17] [Brief explanation of the drawings]

[0275] [Figure 1] FIG. 1 shows a perspective view of a molded article including a tray according to an exemplary, non-limiting embodiment of the present invention. [Figure 2] FIG. 2 shows a perspective view and a top view of a molded article according to a non-limiting embodiment. [Figure 3] FIG. 3 shows a perspective view of the bottom of a molded article including a tray according to an exemplary embodiment of the present invention. [Figure 4] FIG. 4 is a diagram illustrating a process for manufacturing a molded article according to a non-limiting embodiment. [Figure 5] FIG. 5 is a block diagram illustrating a process for preparing a molded mass according to a non-limiting embodiment. [Figure 6] FIG. 6 is a block diagram illustrating a process including post-heat treatment and processing steps, according to an exemplary, non-limiting embodiment. [Figure 7] FIG. 7 illustrates a perspective view of an empty bottom mold section according to an exemplary embodiment. [Figure 8] FIG. 8 shows a perspective view of an empty mold with a hinged cover according to an exemplary embodiment of the present invention. [Figure 9] FIG. 9 shows a perspective view of a thermosetting system for thermosetting a molded mass according to an exemplary embodiment of the present invention. [Figure 10] FIG. 10 illustrates a transport belt for transporting molded articles to a coating spray area according to an exemplary embodiment of the present invention. [Figure 11] FIG. 11 shows a schematic diagram of the heat resistance test assembly as described in Example 6 of the detailed description. [Figure 12] FIG. 12 shows the conversion of organic carbon to carbon dioxide for the control compost sample and the three test samples.

Claims

1. 1. A molded mass composition comprising: Contains liquid components, The liquid component includes a water component and a non-liquid soluble solid component, the non-liquid soluble solid component comprises a starch component and a fiber component; the total liquid content in the molded mass composition is in the range of 57% to 65% by weight, based on the total weight of the molded mass composition; The weight percent ratio of starch and fiber is: 94% by weight of the starch component and 6% by weight of the fiber component, The starch component is in the range of 49% by weight and the fiber component is in the range of 51% by weight, the starch component comprises a plurality of starch granules, the plurality of starch granules having a selected granule diameter size in a range including a lower granule diameter limit and an upper granule diameter limit; A molded mass composition wherein the fiber component comprises a plurality of fibers, each of the plurality of fibers having a fiber length within the range of 1 to 250 times the granule diameter upper limit.

2. The molded mass composition of claim 1, wherein the fiber component has a size distribution in the range of 10 to 2500 μm.

3. 10. The molded mass composition of claim 1, wherein the starch component has a size distribution ranging from 1 μm to 120 μm.

4. 2. The molded mass composition of claim 1, wherein the starch component is a starch component selected from the group consisting of native starch, chemically modified native starch, physically modified native starch, genetically modified native starch, and combinations of at least two of the foregoing starch components.

5. 10. The molded mass composition of claim 1, wherein the starch component comprises native potato starch.

6. 10. The molded mass composition of claim 1, wherein the starch component comprises a physically modified starch having a pregelatinized form.

7. The mold mass composition of claim 1 further comprising a mold release agent.

8. 8. The mold mass composition of claim 7, wherein the mold release agent comprises a saturated long chain fatty acid having a chain length containing a minimum of 12 carbon atoms.

9. 9. The mold mass composition of claim 8, wherein the mold release agent comprises an acid selected from the group consisting of lauric acid, myristic acid, palmitic acid, stearic acid, and arachidic acid.

10. 8. The mold mass composition of claim 7, wherein the release agent is in the form of a powder having a plurality of release particles, each particle having a mesh size of less than 80 mesh.

11. 8. The mold mass composition of claim 7, wherein the mold release agent is present in an amount of 0.1 to 2.4% by weight, based on the total weight of the non-liquid soluble solid components in the mold mass composition.

12. The molded mass composition of claim 1 further comprising a texturizer.

13. 13. The molded mass composition of claim 12, wherein said texturizer is selected from the group consisting of a reactive inorganic component, a non-reactive inorganic component, and a combination of said two components.

14. the molded mass composition comprises a texturizer comprising an inorganic component; 10. The molded mass composition of claim 1, wherein the content of the inorganic component in the molded mass composition is in the range of from greater than 0 to 16.5 weight percent, based on the total non-liquid soluble solid components of the molded mass composition.

15. further comprising a plasticizer additive; The molded mass composition of claim 1 wherein the plasticizer is urea.

16. 15. The molded mass composition of claim 14, wherein the urea has a concentration ranging from greater than 0% to 9% by weight, based on the total weight of the starch component.

17. 10. The molded mass composition of claim 1, further comprising a plurality of borate ions at a concentration ranging from greater than 0 to 2 mmol of borate per kg of the starch component.

18. 1. A method for preparing a molded mass composition comprising: selecting a liquid component; selecting a non-liquid soluble solid component; The liquid component includes a water component, the non-liquid soluble solid component comprises a starch component and a fiber component; The weight percent ratio of starch and fiber is: 94% by weight of the starch component and 6% by weight of the fiber component, The starch component is in the range of 49% by weight and the fiber component is in the range of 51% by weight, the starch component comprises a plurality of starch granules, the plurality of starch granules having a selected granule diameter size in a range including a lower granule diameter limit and an upper granule diameter limit; the fiber component includes a plurality of fibers, each of the plurality of fibers having a fiber length within a range of 1 to 250 times the granule diameter upper limit value; 1. A method for preparing a molded mass composition, comprising: mixing and kneading the liquid components and the non-liquid soluble solid components using a preparation system to form a molded mass having a first plastic-elastic texture and consistency characterized by a total liquid content in the molded mass composition comprising a liquid content in the range of 57% to 65% by weight, based on the total weight of the molded mass composition.

19. 20. The method of claim 18, wherein said mixing and kneading step comprises the step of gradually adding said liquid component to said non-liquid soluble solid component during said mixing and kneading step.

20. 20. The method for preparing a molded mass composition of claim 18, further comprising creating a vacuum in the preparing system to substantially remove or prevent gas from entering the molded mass composition.

21. providing a target mold in an open configuration; depositing a selected portion of the molding mass composition into the target mold to fill the mold detail; 20. The method for preparing a mold mass composition of claim 18, wherein the selected portion has a selected portion volume that is smaller than the volume of the target mold.

22. closing the target mold as needed; and heating the target mold to a selected cure temperature in the range of 185°C to 225°C for a selected cure time to thermally cure the molded mass composition to form a molded body having a second plastic-elastic texture and consistency, wherein the molded body has a residual liquid content of 6% by weight or less, based on the total weight of the molded body; after thermal curing, no substantial vapor pressure remains in the structural matrix of the compact; 22. The method for preparing a molded mass composition of claim 21, wherein after heat curing, the molded mass composition solidifies above the glass point of the structural matrix of the molded body.

23. passing the formed body through an enclosed humidifying section or chamber; and supplying a moist air flow to the humidifying section or chamber until the formed body has a water activity in the range of 0.45 to 70; 23. The method for preparing a molded mass composition of claim 22, wherein safe microbiological conditions are maintained within the enclosed humidified section or chamber.

24. A molded mass comprising the molded mass composition of claim 1, A molded mass, wherein said molded mass composition is subjected to a mixing and kneading process to form said molded mass having a first plastic-elastic texture and consistency.

25. A biodegradable and compostable coating solution for molded bodies, comprising: A compostable liquid solvent base; a compostable solid portion.

26. 26. The biodegradable and compostable coating solution of claim 25, wherein the compostable liquid solvent base comprises water.

27. A biodegradable and compostable coating system comprising a coating zone including a spraying device and a heating device.

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