Hydroentangled fibrous web and wipe products made therefrom

Abstract

The present disclosure relates to nonwoven fibrous webs particularly suitable for use as wiping products that can be constructed without the inclusion of synthetic polymeric fibers. In one aspect, the fibrous web is made from a blend of cellulose pulp fibers and regenerated cellulose fibers. The nonwoven fibrous web can be formed in a foam-forming process in combination with one or more hydroentanglement steps.

Description

Background Technology

[0001] Household and industrial wipes are typically used to absorb liquids and pick up debris. Wipes have been designed to be used dry or as pre-wetted products for cleaning and / or disinfecting purposes. In the past, many attempts have been made to produce nonwoven wipes made of nonwoven fibers, which are typically designed for use and disposal. Such wipes should have a good balance of properties, including good physical strength and abrasion resistance, to withstand the tearing, tensile, and abrasive forces frequently applied during use.

[0002] In the past, many nonwoven wipes were constructed by combining wood pulp fibers with synthetic fibers, such as polymer fibers. For example, wood pulp fibers, such as cork fibers, have historically been hydroentangled with synthetic polymer fibers to produce resilient wipes. Synthetic polymer fibers have included polyester fibers, polypropylene fibers, and others. However, polymer synthetic fibers are naturally hydrophobic and have poor absorbency. The wipes also require significant amounts of polymers, particularly fossil-based polymers, for their construction.

[0003] In light of the above, there is a need for nonwoven fiber webs that can be produced with high strength while minimizing the amount of synthetic polymer fibers. There is also a need for a wiping product that minimizes the amount of synthetic polymer fibers while still possessing excellent cleaning properties to absorb fluids and wipe away sticky substances and / or food debris. Summary of the Invention

[0004] This disclosure relates generally to nonwoven fiber webs, and more particularly to spunlace nonwoven fiber webs containing little or no synthetic polymer fibers (especially fibers made from fossil-based polymers). In one embodiment, for example, the nonwoven fiber web may be configured to be completely free of polyolefin fibers, polyester fibers, or other synthetic polymer fibers. Nonwoven fiber webs are ideally suited for use as wiping products and exhibit excellent strength properties when dry or wet.

[0005] In one embodiment, this disclosure relates to a wiping product comprising a substrate containing about 70% to about 90% by weight, such as about 75% to about 85% by weight, of cellulose pulp fibers. The cellulose pulp fibers are blended with regenerated cellulose fibers. The regenerated cellulose fibers comprise short fibers and may optionally include crimped fibers. The regenerated cellulose fibers are present in the substrate in an amount of about 10% to about 30% by weight, such as about 15% to about 25% by weight. The substrate comprises a spunlace substrate and may have a basis weight of about 40 gsm to about 120 gsm. In one aspect, the basis weight may be about 44 gsm to about 64 gsm. In another aspect, the basis weight may be about 90 gsm to about 120 gsm. In one embodiment, in addition to being spunlace, the substrate may also comprise a foam-formed fiber web.

[0006] Cellulose pulp fibers may include any suitable pulp fibers, such as wood pulp fibers. In one embodiment, cellulose pulp fibers include softwood fibers, hardwood fibers, or mixtures thereof. Alternatively, cellulose pulp fibers may include non-wood fibers.

[0007] Regenerated cellulose fibers may have an average fiber length of about 5 mm to about 18 mm, such as about 10.5 mm to about 17 mm. Regenerated cellulose fibers may have a fractional density of about 0.7 g / 10,000 m to about 2.5 g / 10,000 m, such as about 1 g / 10,000 m to about 2 g / 10,000 m. When the fibers are crimped, regenerated cellulose fibers may contain about 2 crimps / cm to about 10 crimps / cm.

[0008] The wiping products disclosed herein may include a non-layered, single-layer sheet fiber web. In one embodiment, cellulose pulp fibers and regenerated cellulose fibers together constitute more than about 90% by weight, such as more than about 95% by weight, of the total fiber content contained in the substrate. As described above, the substrate may be free of polyolefin fibers, polyester fibers, or other synthetic polymer fibers. The substrate typically has a bulk volume of about 5 g / cc to about 25 g / cc. The substrate may exhibit a thickness per basis weight greater than about 0.009 mm / gsm, such as greater than about 0.010 mm / gsm. For example, at a basis weight of about 50 gsm to about 60 gsm, such as about 52 gsm to about 56 gsm, the thickness of the substrate may be greater than about 0.57 mm, such as greater than about 0.58 mm, and less than about 1 mm.

[0009] The wiping product of this invention may include any suitable wiping product, such as industrial wipes, paper towels, etc. The wiping product may be housed in a spiral winding roller, or the wipes may be in the form of multiple individual sheets stacked together. In one embodiment, the wiping product may be pre-saturated with a cleaning solvent.

[0010] Other features and aspects of this disclosure are discussed in more detail below. Attached Figure Description

[0011] The full and practical disclosure of this invention is set forth in more detail in the remainder of the specification, including with reference to the accompanying drawings, in which:

[0012] Figure 1 This is a diagram of one embodiment of the process for producing a substrate according to this disclosure;

[0013] Figure 2 yes Figure 1 A magnified view of the process shown.

[0014] Figure 3The following is a graphical representation of some of the results obtained in the embodiments; and

[0015] Figure 4 The following is a graphical representation of some of the results obtained in the embodiments.

[0016] The repeated use of reference numerals in this specification and drawings is intended to indicate the same or similar features or elements of the invention.

[0017] definition

[0018] As used herein, the term "longitudinal" refers to the direction of travel of the shaped surface on which the fibers are deposited during the formation of the nonwoven fiber web.

[0019] As used in this article, the term "lateral" refers to a direction perpendicular to the longitudinal direction as defined above.

[0020] As used herein, the term "nonwoven fiber web or material" refers to a fiber web having an individual fiber structure in which the fibers are interwoven, but not in a identifiable manner as in knitted or woven fabrics. Nonwoven materials include, for example, carded fiber webs, wet-laid fiber webs, air-laid fiber webs, foam-formed fiber webs, etc.

[0021] As used herein, the term "pulp" generally refers to multiple cellulose fibers that have been processed through a pulping process to make these fibers individual and having an elongated shape, wherein the apparent length is greater than the apparent width. Pulp fibers can be fibrillated and can have a measurable degree of freeness.

[0022] As used herein, the term "thickness" refers to the representative thickness of the slide and is typically measured as described in the Test Methods section below. Thickness is usually measured in millimeters or micrometers.

[0023] As used herein, the term "fiber length" typically refers to the length-weighted average fiber length (LWAFL) of fibers measured using an OpTest Fiber Quality Analyzer model FQA-360 (OpTest Equipment, Inc., Hawkesbury, ON), as described in the Test Methods section below. Fiber length is typically expressed in millimeters.

[0024] Test methods

[0025] Fiber properties

[0026] Fiber properties such as length, thickness, and the fraction of extra-long fibers are typically determined using the OpTest Fiber Quality Analyzer-360 (OpTest Equipment, Inc., Hawkesbury, ON) according to the manufacturer's instructions. Samples are usually prepared by first accurately weighing a pulp sample. The sample mass can be from about 10 mg to about 50 mg (occasionally dry) and can be taken from a hand-made sheet or pulp sheet. The weighed sample is diluted to a known consistency (from about 2 mg / L to about 10 mg / L). Aliquots of the diluted sample (typically 200 ml) are further diluted to a final volume of 600 ml and placed in the analyzer. The sample is then analyzed according to the manufacturer's instructions, and the analyzer output is recorded, such as length-weighted average fiber length and a histogram illustrating the distribution of various fiber properties for a given sample. Typically, each reported fiber property is the average of three parallel determinations.

[0027] The output of the fiber quality analyzer is used to calculate the Very Long Fiber (VLF) fraction, which is the sum of the number of fibers from 6 mm to 14.95 mm divided by the total number of fibers. Typically, the set data output by the instrument (which provides the number of individual fibers counted within a given fiber length range) is used to determine the VLF. The set data determines the total number (N) of individual fibers counted and the total number (n) of individual fibers counted with a length of 6 mm or greater. %VLF = n / N*100.

[0028] The output of the fiber quality analyzer is also used to calculate the length-weighted average fiber length (L). w ) and number-average fiber length (L n The ratio of L. w and L n The following equation is used by the FQA software to calculate:

[0029]

[0030] Where n and L are determined by the instrument during sample analysis. Length-weighted average fiber length (L) w ) and number-average fiber length (L n The ratio indicates the fiber length distribution of the sample. A higher ratio indicates a wider fiber length distribution. A value of 1 indicates that all fibers in the sample have the same length.

[0031] thickness

[0032] As used herein, the term "thickness" refers to the representative thickness of a single sheet measured using a ProGage 500 thickness gauge (for sheet products comprising one or more layers, the thickness is the thickness of a single sheet of a sheet product comprising all layers) according to TAPPI test method T402. The micrometer has an anvil diameter of 2.22 inches (56.4 mm) and an anvil pressure of 132 g / cm² (2.0 kPa per 6.45 cm²).

[0033] Basis weight

[0034] Typically, the slides are dried and prepared for the tests described in TAPPI T 205 sp-02. The slides can be tested as is. The oven-dry basis weight is usually measured by first cutting the sample into approximately 19.05 cm × 19.05 cm pieces using a suitable cutting tool. The cut sample is then placed on a balance in an oven preheated to 105 °C ± 2 °C. Once the sample weight has stabilized, the weight is recorded to an accuracy of 0.01 g. The oven-dry basis weight is equal to the measured weight (W) multiplied by 27.56. Detailed Implementation

[0035] Those skilled in the art will understand that this discussion is merely a description of exemplary embodiments and is not intended to limit the broader aspects of this disclosure.

[0036] Generally speaking, this disclosure relates to spunlace nonwoven fiber webs with excellent strength properties while minimizing or eliminating the use of polymer synthetic fibers. Spunlace nonwoven fiber webs or sheet materials prepared according to this disclosure have all different types of uses and applications, and are particularly suitable for use as wiping materials. The product can be used as a dry product or pre-wetted and sold as a wet wiping material.

[0037] Generally, the nonwoven fiber web prepared according to this disclosure contains cellulose pulp fibers blended with regenerated cellulose fibers. The nonwoven fiber web can be hydroentangled and may include foam-formed fiber webs, as opposed to wet-laid or air-laid fiber webs. In one aspect, the regenerated cellulose fibers are short fibers and may optionally include crimped fibers. It has been found that combining specific fiber compositions with the manner in which the nonwoven fiber web is formed can produce a number of beneficial properties and advantages. Specifically, the nonwoven fiber web prepared according to this disclosure has wiping properties as good or better than many conventional wiping products containing synthetic polymer fibers. However, the nonwoven fiber web prepared according to this disclosure is sustainable and more readily biodegradable. In one aspect, the nonwoven fiber web prepared according to this disclosure can be configured to be "plastic-free," meaning that the fiber web does not contain any polymers derived from petrochemical fuels or resources.

[0038] While any suitable process (e.g., conventional wet web forming) can be used to form the substrate, in one embodiment as described above, the spunlace substrate of this disclosure is produced according to a foam forming process. For example, in some embodiments, the foam forming process is well-suited for processing longer fibers. The foam forming process is also well-suited for processing three-dimensional fibers, such as crimped fibers. Furthermore, compared to conventional wet web forming processes, the foam forming process requires less water and produces a substrate that can be dried more efficiently. Therefore, the foam forming process also contributes to further environmental benefits and sustainability.

[0039] As described above, the substrate prepared according to this disclosure may primarily comprise cellulose pulp fibers. Suitable cellulose pulp fibers include, but are not limited to, non-wood fibers such as cotton, abaca, kenaf, sabaigrass, flax, esparto grass, rice straw, jute, bagasse, milkweed fiber, and pineapple leaf fiber; and wood fibers or pulp fibers, such as those obtained from deciduous and coniferous trees, including softwood fibers such as northern and / or southern softwood kraft paper fibers; and hardwood fibers such as eucalyptus, maple, birch, and aspen. The pulp fibers can be prepared in high-yield or low-yield forms and can be pulped by any known method, including kraft paper pulping, sulfite pulping, high-yield pulping methods, and other known pulping methods. Fibers prepared by organic solvent pulping methods may also be used.

[0040] Chemically treated natural cellulosic fibers, such as mercerized pulp, chemically hardened or cross-linked fibers, or sulfonated fibers, can be used. To obtain good mechanical properties when using papermaking fibers, it may be desirable for the fibers to be relatively undamaged and substantially unrefined or only lightly refined. While recycled fibers can be used, virgin fibers are generally useful due to their mechanical properties and lack of contaminants. In some embodiments that enable high bulk volume and good compressibility, the fibers may have a Canadian standard freeness of at least 200, more specifically at least 300, even more specifically at least 400, and most specifically at least 500.

[0041] Other papermaking fibers that can be used in this disclosure include high-yield fibers. High-yield pulp fibers are those papermaking fibers produced by pulping processes that provide a yield of about 65% or higher, more specifically about 75% or higher, and even more specifically about 75% to about 95%. Yield is the amount of processed fiber obtained as a percentage of the initial wood mass. Such pulping processes include bleached chemithermomechanical pulp (BCTMP), chemithermomechanical pulp (CTMP), pressure / pressure thermomechanical pulp (PTMP), thermomechanical pulp (TMP), thermomechanical chemical pulp (TMCP), high-yield sulfite pulp, and high-yield kraft pulp, all of which result in fibers with a high lignin content. High-yield fibers are well known for their stiffness in both dry and wet conditions relative to typical chemically pulped fibers.

[0042] In one aspect, cellulose pulp fibers include wood pulp fibers, such as softwood fibers, hardwood fibers, or mixtures thereof. In an alternative embodiment, the cellulose pulp fibers present in the substrate include non-wood pulp fibers. In one embodiment, for example, all cellulose pulp fibers comprise non-wood pulp fibers.

[0043] Cellulose pulp fibers are typically present in the substrate in amounts greater than 50% by weight and at most about 90% by weight, including all increments of 1% by weight in between. For example, cellulose pulp fibers may be present in the substrate in amounts greater than about 70% by weight, such as greater than about 72% by weight, such as greater than about 75% by weight, such as greater than about 77% by weight, and in amounts less than about 88% by weight, such as less than about 85% by weight, such as less than about 83% by weight.

[0044] Cellulose pulp fibers are blended with regenerated cellulose fibers. In one embodiment, for example, all fibers contained in the substrate comprise cellulose pulp fibers or regenerated cellulose fibers.

[0045] As is known in the art, regenerated fibers are artificial filaments obtained by extruding or otherwise processing regenerated or modified cellulose materials from woody or non-woody plants. For example, but not limited to, regenerated fibers may include one or more of lyocell fibers, viscose fibers, rayon, etc. Regenerated cellulose fibers can be produced by dissolving cellulose in a suitable solvent and subsequently extruding the solution through a suitable fiber manufacturing apparatus, such as a spinneret, to produce continuous filaments. The continuous filaments are then cut to desired lengths to produce short fibers.

[0046] Regenerated cellulose fibers can be contained in a nonwoven fiber web in the form of short fibers. For example, the average fiber length of the regenerated cellulose fibers can be greater than about 5 mm, such as greater than about 6.5 mm, such as greater than about 8.5 mm, such as greater than about 9 mm, such as greater than about 9.5 mm, such as greater than about 10 mm, such as greater than about 10.5 mm. The average fiber length can be less than about 20 mm, such as less than about 19 mm, such as less than about 18 mm, such as less than about 17 mm, such as less than about 16 mm, such as less than about 15 mm, such as less than about 14 mm.

[0047] In some embodiments, the regenerated fiber may have a fractional density in the range of about 0.7 g / 10,000 m to about 2.5 g / 10,000 m. Furthermore, the fractional density may be greater than about 1 g / 10,000 m, such as greater than about 1.2 g / 10,000 m, such as greater than about 1.4 g / 10,000 m, such as greater than about 1.5 g / 10,000 m. The fractional density may be less than about 2.5 g / 10,000 m, such as less than about 2.3 g / 10,000 m, such as less than about 2 g / 10,000 m, such as less than about 1.9 g / 10,000 m. In a suitable embodiment, the regenerated fiber is not fibrillated.

[0048] Regenerated cellulose fibers, such as lyocell fibers, are produced in their natural, uncrimped state. However, in one aspect, the regenerated cellulose fibers incorporated into the substrate of this disclosure may optionally include crimped fibers. The regenerated cellulose fibers can be crimped using any suitable mechanical or chemical method. In one aspect, for example, the regenerated cellulose fibers can be crimped using dry steam.

[0049] The crimped regenerated cellulose fibers incorporated into the substrate can have a crimp rate of about 2 crimps / cm to about 10 crimps / cm. For example, the fibers can have a crimp rate greater than about 2.2 crimps / cm, such as greater than about 2.5 crimps / cm, such as greater than about 2.7 crimps / cm, and less than about 8 crimps / cm, such as less than about 6 crimps / cm, such as less than about 5 crimps / cm, such as less than about 4 crimps / cm. The crimp in the regenerated cellulose fibers can be determined by taking about 200 tex of fineness from the dry filament bundle and applying sufficient tension to pull out the crimps. Marks can be made on the sample every 10 cm. The tension can be removed and the number of crimps between the marks can be counted. The ratio of tensioned length to untensioned length also provides strength or crimp rate. The crimp strength of the crimped regenerated cellulose fibers can, for example, be greater than about 0.8, such as greater than about 1, such as greater than about 1.1, such as greater than about 1.2, and less than about 5.

[0050] The amount of short fibers (such as regenerated cellulose fibers) contained in the substrate prepared according to this disclosure is typically less than about 50% by weight. In one aspect, the amount of short fibers (such as regenerated cellulose fibers) contained in the substrate prepared according to this disclosure can be relatively low. For example, a substrate can be constructed according to this disclosure containing less than about 30% by weight of regenerated cellulose short fibers. For example, the substrate may contain less than about 28% by weight, such as less than about 25% by weight, such as less than about 23% by weight, such as less than about 21% by weight of regenerated cellulose fibers. Regenerated cellulose fibers can typically be present in the substrate in an amount greater than about 10% by weight, such as greater than about 13% by weight, such as greater than about 15% by weight, such as greater than about 18% by weight.

[0051] Optionally, the short fibers may comprise polymeric synthetic fibers in combination with or as a substitute for regenerated cellulose fibers. However, in one aspect, the sheet products of this disclosure may be configured to be free of any thermoplastic polymers, particularly fossil-based polymers. For example, the sheet products of this disclosure may be free of polyolefin polymers and / or polyester polymers.

[0052] As described above, the substrate or nonwoven fiber web prepared according to this disclosure can be formed using any suitable process. For example, the process can be a wet web-forming process including hydroentanglement blasting, or a foam forming process including hydroentanglement blasting. In one aspect, a foam forming process particularly suitable for accommodating longer fibers is used. For example, Figure 1 and Figure 2 This describes one embodiment of a foam forming process that can be used to produce substrates according to this disclosure. However, it should be understood that... Figure 1 and Figure 2 The embodiments shown are for illustrative purposes only.

[0053] In one aspect, the process includes first selecting a fiber batch primarily composed of cellulose pulp fibers blended with crimped regenerated cellulose fibers. The fiber batch is then fed into a fiber web forming process, which may be a foam forming process, wherein the newly formed fiber web also undergoes a hydroentangling step. After hydroentangling, the nonwoven fibers can then be fed into a drying process. The drying process may include a ventilated dryer, a rotary dryer, or a combination thereof.

[0054] When the substrate is foamed, fiber ingredients can be combined with the foam to form a foamed suspension. For example, fibers can be blended with water and a foaming agent.

[0055] The blowing agent may, for example, contain any suitable surfactant. In one embodiment, the blowing agent may, for example, comprise sodium lauryl sulfate, also known as sodium lauryl polyoxyethylene ether sulfate or sodium lauryl ether sulfate. In one embodiment, the blowing agent is a nonionic surfactant that may comprise alkyl polyglycosides. For example, the blowing agent may be a C8 alkyl polyglycoside, a C10 alkyl polyglycoside, or a mixture of C8 and C10 alkyl polyglycosides.

[0056] Other blowing agents include sodium dodecyl sulfate or ammonium lauryl sulfate. In other embodiments, the blowing agent may contain any suitable cationic and / or amphoteric surfactants. For example, other blowing agents include fatty acid amines, amides, amine oxides, fatty acid quaternary compounds, etc.

[0057] The foaming agent is typically mixed with water in an amount greater than about 0.1% by weight, such as greater than about 1% by weight, such as greater than about 2% by weight, such as greater than about 3% by weight. One or more foaming agents are typically present in an amount less than about 50% by weight, such as less than about 10% by weight, such as less than about 8% by weight, such as less than about 4% by weight.

[0058] Once the foaming agent and water are mixed, the mixture is either blended or otherwise subjected to forces capable of forming foam. Foam generally refers to a porous matrix, which is an aggregate of hollow units or bubbles that can interconnect to form channels or capillaries.

[0059] Foam density can vary depending on the specific application and various factors, including the fiber composition used. In one embodiment, for example, the foam density may be greater than about 200 g / L, such as greater than about 250 g / L, such as greater than about 300 g / L. Foam density is typically less than about 600 g / L, such as less than about 500 g / L, such as less than about 400 g / L, such as less than about 350 g / L. In one embodiment, for example, a lower density foam is used, whose foam density is typically less than about 350 g / L, such as less than about 340 g / L, such as less than about 330 g / L. The foam will typically have an air content greater than about 30%, such as greater than about 40%, such as greater than about 50%, such as greater than about 60%. The air content is typically less than about 80% by volume, such as less than about 70% by volume, such as less than about 65% by volume.

[0060] To form a nonwoven fiber web, foam is combined with selected fiber ingredients and any auxiliaries. The foamed fiber suspension is then pumped into a tank and fed from the tank into a headbox. For example, Figure 1 and Figure 2 An embodiment of a process for forming a fiber web according to this disclosure is shown. Figure 2 As specifically shown, the foamed fiber suspension can be fed into tank 12 and then into headbox 110. The foamed fiber suspension flows from headbox 110 onto a ring-moving forming fabric 26 supported and driven by rollers 28 to form a fiber web 10. Figure 2 As shown, the forming plate 14 may be located below the fiber web 10, adjacent to the headbox 110. Once formed on the forming fabric 26, the foam-formed fiber web may have a consistency of less than about 50%, such as less than about 20%, such as less than about 10%, such as less than about 5%. In fact, the forming consistency may be less than about 2, such as less than about 1.8, such as less than about 1.5. The forming consistency is typically greater than about 0.5, such as greater than about 0.8. The forming consistency indicates the ability to produce a fiber web according to this disclosure while minimizing the amount of water required during forming.

[0061] Once the wet fiber web is formed on the shaped fabric 26, the web is conveyed downstream and dehydrated. The process may optionally include multiple vacuum devices 16, such as vacuum chambers and vacuum rollers. Vacuum chambers help remove moisture from the newly formed fiber web 10.

[0062] like Figure 2 As shown, the formed fabric 26 can also be connected to a steam box 18 located above a pair of vacuum rollers 20. For example, the steam box 18 can increase dryness and reduce transverse moisture variation. The steam applied from the steam box 18 heats the moisture in the wet fiber web 10, making it easier for water to drain from the web, especially in conjunction with the vacuum rollers 20. Figure 1In the illustrated embodiment, the newly formed fiber web 10 is conveyed downstream from the formed fabric 26, subjected to hydroentangling, and dried on a ventilated dryer.

[0063] After the foam-formed fiber web has been produced, the fiber web is subjected to one or more hydroentangling steps. Figure 2 In the illustrated implementation, for example, the fiber web 10 undergoes two different hydroentangling steps. Specifically, in Figure 2 In this process, the fiber web 10 is hydroentangled on a first surface during a first hydroentangling step, and then hydroentangled on an opposing second surface during a second hydroentangling step. For example... Figure 2 As shown, for example, the process may include a first hydroentangling device 30 and a second hydroentangling device 32. Hydroentangling occurring at each hydroentangling station can be accomplished using conventional hydroentangling equipment. Hydroentangling of the foam-formed fiber web can be performed using any suitable working fluid, such as water. The working fluid flows through a manifold that uniformly distributes the fluid through a series of individual orifices or openings. For example, exemplary orifices or openings may have a diameter of about 10 micrometers to about 200 micrometers. For example, the manifold may include a strip of orifices with a diameter of about 20 micrometers to about 50 micrometers. The manifold may contain about 20 to about 40 orifices per inch and may include 1 to 3 rows of orifices. Many other manifold configurations and combinations can be used. For example, in Figure 2 In the illustrated embodiments, the hydroentangling device 30 includes a plurality of ejectors 34, while the hydroentangling device 32 includes a plurality of ejectors 36. The ejectors 34 and 36 may be part of a manifold and may be in communication with a working fluid source. Figure 1 and Figure 2 In the illustrated embodiment, the first water-jet device 30 includes four rows of water jets or sprayers 34, and the second water-jet device 32 also includes four rows of water jets or sprayers 36. However, it should be understood that each water-jet device may include a single row, two rows, three rows, four rows, five rows, six rows, or more rows of water jets.

[0064] During the hydroentangling process, the working fluid can pass through the orifice at pressures ranging from about 10 bar to about 300 bar, such as from about 20 bar to about 250 bar. The bonds between the fibers of the nonwoven fiber web are formed through hydroentangling. Therefore, hydroentangling can increase strengths, such as the dry and wet strengths of the nonwoven fiber web or substrate. Increasing the pressure during hydroentangling can increase the strength of the resulting fiber web.

[0065] Fluid impact can be supported on porous surfaces or wires, or on porous drum surfaces or fiber webs. Figure 2 In the illustrated implementation, for example, hydroentanglement occurs on the first rotating drum 38 and the second rotating drum 40.

[0066] When supported on a porous surface or wire during hydroentangling, the wire may have a mesh size of about 40×40 to about 100×100. The wire or surface may also be a multilayer mesh with a mesh size of about 50×50 to about 200×200. In one aspect, only one side of the fiber web 10 is hydroentangled.

[0067] As described above, alternatively, during hydroentangling, the fiber web 10 can be placed directly on the surfaces of the rotating drum 38 and the rotating drum 40. Each rotating drum may include multiple openings or vacuum channels for extracting excess water. These openings or vacuum channels may also form patterns in the fiber web 10 during the hydroentangling process. For example, a pattern may be formed on one surface of the fiber web at a first hydroentangling station, and a pattern may be formed on an opposing second surface of the fiber web at a second hydroentangling station. The patterns formed on each surface of the fiber web 10 can be highly unique and can increase the aesthetic appeal of the nonwoven material made from the fiber web. Furthermore, the patterns formed on the fiber web can be three-dimensional, including hills and valleys. This three-dimensional morphology can further improve various properties of the material.

[0068] Once the foam-formed fiber web 10 has been hydroentangled once or multiple times, a non-compression drying process can be used to dry the fiber web. For example, as Figure 1 As shown, a ventilated dryer can be used to dry foam-molded fiber webs.

[0069] See Figure 1 The foam-formed and hydroentangled fiber web 10 is transferred from the drum 40 to the penetrating dry fabric 44 by means of a vacuum transfer roller 46 or a vacuum transfer shoe. If desired, the penetrating dry fabric can be run at a slower speed than the fiber web 10 to further enhance the stretch. The transfer can be performed with vacuum assistance to ensure that the sheet deforms to conform to the penetrating dry fabric, thereby producing the desired build-up volume and appearance (if desired).

[0070] exist Figure 1 In the illustrated embodiment, the foam-formed fiber web 10 is transferred to the penetrating dryer fabric 44. Alternatively, the foam-formed fiber web may be transferred to a porous metal sleeve forming the circumference of the penetrating dryer 48.

[0071] Alternatively, the foam-formed fiber web 10 may be conveyed on a penetrating-drying fabric 44 on the circumference of the penetrating dryer 48. The penetrating-drying fabric may contain high and long embossed knots. For example, the penetrating-drying fabric may have about 5 to about 300 embossed knots per square inch, which protrude at least about 0.005 inches above the fabric plane. During drying, the fiber web may be further macroscopically arranged to conform to the surface of the penetrating-drying fabric. However, a flat surface may also be used in this disclosure.

[0072] The side of the fiber web that contacts the penetrating dried fabric is generally referred to as the "fabric side" of the nonwoven fiber web. As mentioned above, the fabric side of the nonwoven fiber web can have a shape that conforms to the surface of the penetrating dried fabric after the fabric has been dried in the penetrating dryer. On the other hand, the opposite side of the nonwoven fiber web is generally referred to as the "air side". During normal penetrating drying, the air side of the fiber web is usually smoother than the fabric side.

[0073] The vacuum level used for transferring the web can be from about 3 inches to about 15 inches of mercury (75 mm to about 380 mmHg), preferably about 5 inches (125 mm) of mercury. In addition to or as an alternative to using a vacuum to draw the web onto the next fabric, a vacuum shoe or roller (negative pressure) can be supplemented or replaced by using positive pressure from the opposite side of the web to blow the web onto the next fabric.

[0074] Finally, the fiber web is dried to approximately 94% or higher consistency via a through-dryer 48 and then transferred to carrier fabric 50. The dried substrate 52 is conveyed to reel 54 using carrier fabric 50 and optionally carrier fabric 56. Optional pressure guide rollers 58 can be used to facilitate the transfer of the fiber web from carrier fabric 50 to fabric 56. Suitable carrier fabrics for this purpose are Albany International 84M or 94M and Asten 959 or 937, all of which are relatively smooth fabrics with fine patterns. Although not shown, reel calendering or subsequent offline calendering can be used to improve the smoothness and softness of the substrate.

[0075] The basis weight of the fiber web prepared according to the present invention can vary depending on the final product. Generally, the basis weight of the product can vary between about 40 gsm and about 120 gsm. For example, the basis weight can be greater than about 44 gsm, such as greater than about 48 gsm, such as greater than about 50 gsm, such as greater than about 52 gsm, and generally less than about 80 gsm, such as less than about 70 gsm, such as less than about 64 gsm, such as less than about 60 gsm. However, in one aspect, a higher basis weight fiber web with a basis weight of about 90 gsm to about 120 gsm can be formed.

[0076] The method disclosed herein can also produce fiber webs with good bulk volume characteristics. For example, the dry bulk volume is typically greater than about 3 cc / g, such as greater than about 5 cc / g, such as greater than about 8 cc / g, and typically less than about 20 cc / g, such as less than about 15 cc / g.

[0077] The substrate can exhibit an enhanced thickness per basis weight greater than about 0.009 mm / gsm, such as greater than about 0.010 mm / gsm. For example, at basis weights of about 50 gsm to about 60 gsm, such as about 52 gsm to about 56 gsm, the substrate thickness can be greater than about 0.57 mm, such as greater than about 0.58 mm and less than about 1 mm. It is believed that the method of this disclosure, combined with fiber formulations, produces a fiber web with greater thickness and an open structure, resulting in better feel and better cleaning properties.

[0078] In one embodiment, the nonwoven material may be cut into individual sheets. The wipes may have any suitable size and shape. In one embodiment, the wipes may have a width of about 8 cm to about 100 cm, such as about 10 cm to about 50 cm, such as about 20 cm to about 25 cm. The length of the wipes may be about 10 cm to about 200 cm, such as about 20 cm to about 100 cm, such as about 35 cm to about 45 cm. Alternatively, the nonwoven material may be spirally wound into a roller and periodically perforated to produce torn individual sheets.

[0079] The wipes prepared according to this disclosure can be dispensed as dry wipes or as wet wipes. In one aspect, the wipes can be pre-wetted with a wetting solution (such as water, solvent, anhydrous hand sanitizer, or any other suitable liquid). The liquid may contain preservatives, surfactants, emollients, humectants, etc. Generally, based on the dry weight of the wipes, each wipe contains more than about 100% by weight, in some embodiments about 150% to about 1500% by weight, and in some embodiments about 300% to about 1200% by weight of liquid.

[0080] Wipes can be packaged in a variety of forms, materials, and / or containers, including but not limited to spiral-wound rollers, boxes, drums, flexible packaging materials, etc. Some examples of suitable containers include rigid drums, film bags, etc.

[0081] The present disclosure can be better understood by referring to the following embodiments.

[0082] Example

[0083] The following examples illustrate some of the advantages and beneficial effects of this disclosure. It has been found that nonwoven fiber webs, particularly foam-formed fiber webs, prepared according to this disclosure provide an open structure with excellent absorbency, flexibility, and consistent performance. These advantages are based not only on the manner in which the fiber web is formed, but also on the basis weight and fiber formulation, to produce an overall wiping product exhibiting excellent performance without containing any synthetic polymer fibers.

[0084] According to this disclosure, a foam-formed substrate containing a combination of cellulose pulp fibers and regenerated cellulose short fibers was produced. The cellulose pulp fibers used are cork kraft paper fibers. The regenerated cellulose short fibers comprise crimped TENCEL lyocell fibers purchased from Lenzing. The regenerated cellulose fibers have a fractional density of 1.7 g / 10,000 m and an average fiber length of 12 mm. The nonwoven fiber web has a basis weight of 54 gsm and contains 80% by weight of cellulose pulp fibers and 20% by weight of regenerated cellulose fibers. The substrate was prepared using a foam forming process including a hydroentangling step. The substrate was hydroentangled on one side from four rows of fluid jets.

[0085] The nonwoven fiber web prepared according to this disclosure was then subjected to two sets of comparative tests. In the first set of tests, the nonwoven fiber web was cut to a size of 12.6 inches × 12.5 inches and packaged in a pop-up box. The nonwoven fiber web of this disclosure was compared with a commercially available wipe sold under the name WYPALL X60 hydroknit (available from Kimberly-Clark).

[0086] In the second set of tests, a nonwoven fiber web was packaged in a spiral winding roller that was perforated to supply sheets having dimensions of 16.5 inches × 15 inches. The spiral-wound product prepared according to this disclosure was compared with a cleaning cloth sold by Tork under product designation 510104.

[0087] Usage tests were completed during each set of comparative tests. During the usage tests, the product's ability to remove water, chocolate syrup, and food crumbs was compared. Results are as follows: Figure 3 and Figure 4 exemplified. Figure 3 The results compared to the WYPALL product are shown, while Figure 4 The results are shown in comparison with Tork cleaning cloths.

[0088] As shown in the figure, the nonwoven fiber web prepared according to this disclosure is preferred by the user.

[0089] It is foreseeable that, due to the absence of any synthetic polymer fibers, the nonwoven fiber web prepared according to this disclosure will not perform as well as the comparative samples in stress / strength tests. However, the nonwoven fiber web exhibits sufficient strength for its intended use in the product.

[0090] These and other modifications and variations of the invention can be practiced by those skilled in the art without departing from the spirit and scope of the invention, which are more specifically set forth in the appended claims. Furthermore, it should be understood that aspects of the various embodiments are interchangeable in whole or in part. Moreover, those skilled in the art will understand that the foregoing description is merely illustrative and is not intended to limit the invention further described in the appended claims.

Claims

1. A wiping product, comprising: A substrate containing about 70% to about 90% by weight of cellulose pulp fibers, the cellulose pulp fibers being blended with regenerated cellulose fibers, the regenerated cellulose fibers comprising short fibers, the regenerated cellulose fibers being present in the substrate in an amount of about 10% to about 30% by weight; and The substrate is hydroentangled and has a basis weight of about 40 gsm to about 120 gsm, and the substrate exhibits a basis weight thickness greater than about 0.009 mm / gsm.

2. The wiping product according to claim 1, wherein the substrate comprises a foam-molded fiber web.

3. The wiping product according to any one of the preceding claims, wherein the substrate exhibits a thickness per basis weight greater than about 0.010 mm / gsm.

4. The wiping product according to any one of the preceding claims, wherein the cellulose pulp fiber comprises wood pulp fiber.

5. The wiping product according to claim 4, wherein the cellulose pulp fiber comprises cork pulp fiber.

6. The wiping product according to claim 1, 2 or 3, wherein the cellulose pulp fiber includes non-wood pulp fiber.

7. The wiping product according to any one of the preceding claims, wherein the regenerated cellulose fibers have an average fiber length of about 5 mm to about 18 mm.

8. The wiping product according to any one of the preceding claims, wherein the regenerated cellulose fibers have an average fiber length of about 10.5 mm to about 17 mm.

9. The wiping product according to any one of the preceding claims, wherein the regenerated cellulose fiber has a fraction of about 0.7 g / 10,000 m to about 2.5 g / 10,000 m.

10. The wiping product according to any one of the preceding claims, wherein the regenerated cellulose fiber has a fractional density of about 1 g / 10,000 m to about 2 g / 10,000 m.

11. The wiping product according to any one of the preceding claims, wherein the regenerated cellulose fiber comprises crimped fiber.

12. The wiping product of claim 11, wherein the crimped fibers contain about 2 crimps / cm to about 10 crimps / cm.

13. The wiping product according to any one of the preceding claims, wherein the wiping product comprises a non-layered single-layer sheet fiber web.

14. The wiping product according to any one of the preceding claims, wherein the substrate has a basis weight of about 44 gsm to about 64 gsm.

15. The wiping product according to any one of the preceding claims, wherein the substrate has a basis weight of about 90 gsm to about 120 gsm.

16. The wiping product according to any one of the preceding claims, wherein the substrate contains about 75% to about 85% by weight of cellulose pulp fibers and about 15% to about 25% by weight of the regenerated cellulose fibers.

17. The wiping product according to any one of the preceding claims, wherein the cellulose pulp fibers and the regenerated cellulose fibers together constitute more than about 90% by weight, such as more than about 95% by weight, of the total amount of fibers contained in the substrate.

18. The wiping product according to any one of the preceding claims, wherein the substrate is free of polyolefin fibers and polyester fibers.

19. The wiping product according to any one of the preceding claims, wherein the substrate does not contain synthetic polymer fibers.

20. The wiping product according to any one of the preceding claims, wherein the substrate has a bulk volume of about 5 g / cc to about 25 g / cc.

21. The wiping product according to any one of the preceding claims, wherein the wiping product includes industrial wiping materials.

22. The wiping product of claim 21, wherein the industrial wiping material comprises a plurality of individual sheets stacked together.

23. The wiping product according to any one of the preceding claims, wherein the wiping product is pre-saturated with a cleaning solvent.

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