Water-soluble non-woven composite material structure

Abstract

The present disclosure provides nonwoven composite articles, which include: a first layer including a first nonwoven fabric, the first nonwoven fabric including a first plurality of fibers having a first diameter; a second layer including a second nonwoven fabric, the second nonwoven fabric including a second plurality of fibers having a second diameter; and a first interface including at least a portion of the first nonwoven fabric and at least a portion of the second nonwoven fabric, wherein the portions of the first nonwoven fabric and the second nonwoven fabric are fused together, and wherein the second diameter is less than the first diameter, and the first plurality of fibers, the second plurality of fibers, or both include a water-soluble polyvinyl alcohol fiber-forming material. Also provided are flushable paper towels and absorbent articles including nonwoven fabrics, the nonwoven fabrics including fibers comprising a water-soluble polyvinyl alcohol fiber-forming material.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 908,310, filed Sep. 30, 2019, under 35 U.S.C. § 119(e), the entire content of which is incorporated herein by reference. Field of the Invention

[0003] The present disclosure generally relates to nonwoven composite structures, flushable paper towels, and absorbent articles. More specifically, the present disclosure relates to nonwoven composite materials including water-soluble fibers (including polyvinyl alcohol fiber-forming materials). Background of the Invention

[0004] Nonwoven fabrics have traditionally been used in a variety of disposable consumer products, including personal care products such as diaper components, feminine care, and adult incontinence products, and disposable paper towels such as for industrial, medical, cleaning, and personal / baby care applications. Conventional chemical materials used in such products, such as rayon, polypropylene, or cotton fibers, are generally non-durable, non-biodegradable, potentially produce microplastics, and are often disposed of incorrectly, such as being flushed down the toilet and entering wastewater treatment and sewage facilities. Known paper towels must be discarded in a trash bin, which may be unhygienic or inconvenient for the user. Improper disposal of these items can cause blockages in household plumbing, resulting in the formation of "fat balls" in residential and municipal wastewater systems or the accumulation of clumps of biodegradable and non-biodegradable materials (constituted by congealed grease and cooking fats and disposable paper towels), causing marine microplastics and requiring a change in consumer behavior.

[0005] Accordingly, it is advantageous to provide nonwoven structures using chemical materials that are more biodegradable, do not produce microplastics, are even water-soluble, have mechanical properties suitable for withstanding stresses applied to disposable consumer products (such as rubbing a paper towel or moving a child wearing a diaper), and have liquid storage chambers for, for example, loading a lotion onto a paper towel and / or holding a liquid in a liquid collection layer. Summary of the Invention

[0006] One aspect of the present disclosure provides a nonwoven composite article having: a first layer of a first nonwoven fabric including a first plurality of fibers having a first diameter; a second layer of a second nonwoven fabric including a second plurality of fibers having a second diameter; and a first interface including at least a portion of the first nonwoven fabric and at least a portion of the second nonwoven fabric, wherein the portions of the first nonwoven fabric and the second nonwoven fabric are fused together, and wherein the second diameter is less than the first diameter, and the first plurality of fibers, the second plurality of fibers, or both include a water-soluble polyvinyl alcohol fiber-forming material.

[0007] Another aspect of the present disclosure provides a wearable absorbent article including an absorbent core having a side facing a wearer and a side facing the exterior; and a liquid collection layer, wherein the liquid collection layer includes a nonwoven fabric including a plurality of fibers including a water-soluble polyvinyl alcohol fiber-forming material.

[0008] Another aspect of the present disclosure provides an absorbent article including a liquid-permeable top sheet, a liquid-impermeable back sheet, an absorbent core, and a liquid collection layer including a nonwoven fabric including a plurality of fibers including a water-soluble polyvinyl alcohol fiber-forming material.

[0009] Another aspect of the present disclosure provides a flushable wipe including the nonwoven composite article of the present disclosure.

[0010] Another aspect of the present disclosure provides the use of the composite article of the present disclosure for a flushable wipe.

[0011] Another aspect of the present disclosure provides the use of the composite article of the present disclosure for a wearable absorbent article.

[0012] Another aspect of the present disclosure provides a method of forming the composite article of the present disclosure, the method including depositing a second layer including a second nonwoven fabric on a first layer including a first nonwoven fabric under conditions sufficient to fuse at least the portion of the first nonwoven fabric with the portion of the second nonwoven fabric, thereby forming a first interface.

[0013] Another aspect of the present disclosure provides a liquid-containing nonwoven article including: a core nonwoven fabric including a first plurality of fibers including a first polyvinyl alcohol fiber-forming material, wherein the core nonwoven fabric contains a liquid including an active agent; and an outer nonwoven fabric including a second plurality of fibers including a second polyvinyl alcohol fiber-forming material, wherein the outer nonwoven fabric encloses the core nonwoven fabric.

[0014] Another aspect of the present disclosure provides a method of forming a liquid-containing nonwoven article of the present disclosure, the method comprising: contacting a core nonwoven fabric with a liquid containing an active agent, encapsulating the core nonwoven fabric with an outer nonwoven fabric, and sealing the outer nonwoven fabric enclosing the core nonwoven fabric.

[0015] For the compositions described herein, optional features selected from the various aspects and embodiments provided herein are contemplated, including (but not limited to) their ingredients and compositional ranges, fiber-forming materials, fiber diameter ranges, various layer configurations, fiber geometries, and / or mechanical properties.

[0016] Other aspects and advantages will be apparent to those of ordinary skill in the art upon review of the following detailed description. Although the composite structures, flushable tissues, and absorbent articles of the present disclosure may take different forms of embodiments, the following description includes specific embodiments, and it should be understood that the present disclosure is illustrative and not intended to limit the present disclosure to the specific embodiments described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To further facilitate understanding of the present disclosure, 3 drawings are attached.

[0018] Figure 1 Cross-sections showing different fiber shapes are shown, where the straight lines represent the fiber diameters.

[0019] Figure 2 It is a diagram of a nonwoven fabric, which indicates the outer surfaces of the fabric, such as 100 and 101.

[0020] Figure 3 An interface 200 is shown, where a first nonwoven fabric 201 overlaps a second nonwoven fabric 202.

[0021] Figure 4A It is a diagram of a nonwoven fabric, which indicates the machine direction 301 and the cross-machine direction 300, and includes a second nonwoven fabric 302 having the same length as the nonwoven fabric in the machine direction 301.

[0022] Figure 4B It is a diagram of a nonwoven fabric wrapping the second nonwoven fabric 302 along the machine direction 301.

[0023] Figure 5A It is a diagram of a nonwoven fabric wrapping and enclosing a second nonwoven fabric (not shown), which has sealing portions 303 at multiple points along the machine direction and along the transverse edge 304.

[0024] Figure 5B It is a diagram of a nonwoven fabric wrapping and enclosing a second nonwoven fabric (not shown), which has sealing portions 303 at multiple points along the machine direction, and has been cut 305 to form a unit dose 306 with a flange 307.

[0025] Figure 6 It is an illustration of a method for folding a nonwoven fabric.

[0026] Figure 7 It is an illustration of a method for folding a nonwoven fabric.

[0027] Figure 8 Shows multiple views of a configuration for a horizontal wicking test.

[0028] Figure 9A It is a graph showing how the Washburn Slope of the fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the fabric.

[0029] Figure 9B It is a graph showing how the wicking rate of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the fabric.

[0030] Figure 9C It is a graph showing how the absorption rate of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the fabric.

[0031] Figure 10 It is an interval graph showing how the liquid absorption capacity of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the fabric.

[0032] Figure 11A It is a graph showing how the Washburn Slope of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article.

[0033] Figure 11B It is a graph showing how the wicking rate of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article.

[0034] Figure 11C It is a graph showing how the absorption rate of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article.

[0035] Figure 12 It is an interval graph showing how the liquid absorption capacity of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article.

[0036] Figure 13A It is a graph showing how the Washburn Slope of the nonwoven fabric of the present disclosure varies with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article.

[0037] Figure 13BGraph showing the capillary rise rate of the nonwoven fabric of the present disclosure varying with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article.

[0038] Figure 13C Graph showing the absorption rate of the nonwoven fabric of the present disclosure varying with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article.

[0039] Figure 14 Interval graph showing the liquid absorption capacity of the nonwoven fabric of the present disclosure varying with the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material in the multi-layer article. Detailed Description

[0040] The present disclosure provides nonwoven composite articles, flushable tissues, absorbent articles, nonwoven articles containing liquids, and methods for their manufacture and use. The nonwoven composite article of the present disclosure includes: a first layer including a first nonwoven fabric, the first nonwoven fabric including a first plurality of fibers having a first diameter; a second layer including a second nonwoven fabric, the second nonwoven fabric including a second plurality of fibers having a second diameter; and a first interface including at least a portion of the first nonwoven fabric and at least a portion of the second nonwoven fabric, wherein the portions of the first nonwoven fabric and the second nonwoven fabric are fused together, and wherein the second diameter is less than the first diameter, and the first plurality of fibers, the second plurality of fibers, or both include a water-soluble polyvinyl alcohol fiber-forming material.

[0041] The nonwoven composite article of the present disclosure can provide one or more advantages, including (but not limited to) improved liquid collection relative to single-layer nonwoven articles, improved detergent loading and retention relative to single-layer nonwoven articles, improved biodegradability relative to conventional nonwoven articles, improved flushability relative to conventional nonwoven articles, improved softness relative to conventional nonwoven articles, improved mechanical properties (such as modulus, tensile strength, elongation, toughness, and / or breaking strength) relative to single-layer carded nonwoven fabrics including the same water-soluble fibers, and / or improved dispersibility and solubility relative to conventional nonwoven articles. The flushable tissue of the present disclosure can provide one or more advantages, including (but not limited to) improved detergent loading and retention relative to conventional tissues, improved liquid collection relative to conventional tissues, improved softness relative to conventional tissues, improved flushability relative to conventional tissues, and / or improved biodegradability, dispersibility, and / or solubility relative to conventional tissues. The absorbent article of the present disclosure can provide one or more advantages, including (but not limited to) improved liquid collection relative to conventional liquid collection layers of absorbent articles, improved liquid retention relative to conventional liquid collection layers of absorbent articles, improved softness relative to conventional liquid collection layers, and / or improved biodegradability, dispersibility, and / or solubility relative to conventional tissues.

[0042] As used herein and unless otherwise specified, the term "nonwoven fabric" refers to a fabric or sheet that comprises fibers arranged (e.g., by a carding process) and bonded to one another, consists of or consists essentially of such fibers. Additionally, as used herein, "nonwoven fabric" includes any structure, including nonwoven fabrics or sheets, including, for example, nonwoven fabrics or sheets with a film laminated on the surface. Methods for preparing nonwoven fabrics from fibers are well known in the art, such as those described in Nonwoven Fabrics Handbook, written by Ian Butler and edited by Subhash Batra et al., Printing by Design, 1999, which is incorporated herein by reference in its entirety. As used herein and unless otherwise specified, the term "film" refers to a continuous film or sheet, such as those prepared by casting or extrusion processes.

[0043] As used herein and unless otherwise specified, the term "water-soluble" refers to any fiber, nonwoven fabric, nonwoven composite article, or film that has a dissolution time of 300 seconds or less at a specified temperature, as determined according to MSTM-205, as set forth herein. For example, at a temperature of about 80°C, about 70°C, about 60°C, about 50°C, about 40°C, about 20°C, or about 10°C, the dissolution time may optionally be 200 seconds or less, 100 seconds or less, 60 seconds or less, or 30 seconds or less. In embodiments where the dissolution temperature is not specified, water-soluble fibers, nonwoven fabrics, or nonwoven composite articles have a dissolution time of 300 seconds or less at a temperature not greater than about 80°C. As used herein and unless otherwise specified, the term "cold water-soluble" refers to any fiber, nonwoven fabric, or nonwoven composite article that has a dissolution time of 300 seconds or less at 10°C, as determined according to MSTM-205. For example, at 10°C, the dissolution time may optionally be 200 seconds or less, 100 seconds or less, 60 seconds or less, or 30 seconds. In an embodiment, a "water-soluble film" refers to a film that, at a thickness of 1.5 mils, dissolves in 300 seconds or less at a temperature not greater than 80°C. For example, a 1.5 mil (about 38 μm) thick water-soluble film may have a dissolution time of 300 seconds or less, 200 seconds or less, 100 seconds or less, 60 seconds or less, 30 seconds or less, or 20 seconds or less at a temperature of about 70°C, about 60°C, about 50°C, about 40°C, about 30°C, about 20°C, or about 10°C.

[0044] As used herein, "comprising" refers to the different components, ingredients or steps that can be used together when implementing the present disclosure. Thus, the term "comprising" encompasses the more restrictive terms "consisting essentially of" and "consisting of". The compositions of the present invention may comprise any of the essential and optional ingredients disclosed herein, consist essentially of them or consist of them. The inventions illustratively disclosed herein may be suitably practiced in the absence of any ingredient or step not specifically disclosed herein.

[0045] All percentages, parts and ratios mentioned herein are based on the total dry weight of the fibers, nonwoven fabrics, nonwoven composite articles, flushable paper towels or absorbent articles of the present disclosure, as the case may be, and unless otherwise specified, all measurements are made at about 25 °C. Unless otherwise specified, all such weights relating to the listed ingredients are based on the active level and thus do not include carriers or by-products that may be included in commercially available materials.

[0046] All ranges set forth herein include all possible subsets of the range and any combination of such subset ranges. Unless otherwise specified, the default range includes the recited endpoints. Where a range of values is provided, it is to be understood that each intermediate value between the upper and lower limits of that range, and any other recited value or intermediate value within that recited range, is encompassed within the present disclosure. The upper and lower limits of these smaller ranges may independently be included in a smaller range and are also encompassed within the present disclosure, subject to any specific excluded limits within the recited range. Where the range includes one or both of the limits, ranges excluding either or both of those included limits are also contemplated as part of the present disclosure.

[0047] It is specifically contemplated that for any numerical value described herein, e.g., as a parameter of the subject matter or as part of a range associated with the subject matter, an alternative portion forming part of the description is a functionally equivalent range around the specific numerical value (e.g., when the dimension is disclosed as "40 mm", alternative embodiments "about 40 mm" are contemplated). Similarly, a value described with "about" explicitly includes the specific value itself as an alternative embodiment (e.g., when the endpoint is described as "about 40", the alternative embodiment "40" is contemplated).

[0048] As used herein and unless otherwise specified, the terms "wt.%" and "wt%" mean the composition ("dry" (anhydrous) weight parts) of the identified ingredient in the whole fiber, nonwoven fabric, nonwoven composite article, flushable paper towel or absorbent article.

[0049] As used herein and unless otherwise specified, the term "PHR" ("phr") means the composition (parts per hundred parts of polymer resin or parts per hundred parts of fiber-forming material, whether PVOH or other polymer resin) of the identified component in a water-soluble fiber, nonwoven fabric, nonwoven composite article, flushable tissue, or absorbent article.

[0050] Fiber - forming Material

[0051] Generally, the fibers of the present disclosure can include a single fiber-forming material or a combination of fiber-forming materials (i.e., a blend). A single fiber can include one or more water-soluble fiber-forming materials, one or more water-insoluble fiber-forming materials, or a combination of a water-soluble fiber-forming material and a water-insoluble fiber-forming material. The fibers of the present disclosure can generally include synthetic fiber-forming materials, natural fiber-forming materials, plant-based fiber-forming materials, bio-based fiber-forming materials, biodegradable fiber-forming materials, compostable fiber-forming materials, or combinations thereof. Plant-based fiber-forming materials can be naturally occurring (e.g., cotton) or regenerated (e.g., bamboo).

[0052] Water-soluble fiber-forming materials

[0053] Generally, water-soluble fiber-forming materials can be water-soluble polymers. Water-soluble polymers can include (but are not limited to) polyvinyl alcohol, polyacrylates, water-soluble acrylate copolymers, polyvinylpyrrolidone, polyvinylimine, pullulan, water-soluble natural polymers (including (but not limited to) guar gum, gum arabic, xanthan gum, carrageenan, and water-soluble starches), water-soluble polymer derivatives (including (but not limited to) modified starches, ethoxylated starches, and hydroxypropylated starches), copolymers of the foregoing, and combinations of any of the foregoing. Other water-soluble polymers can include polyalkylene oxides, polyacrylamides, polyacrylic acids and their salts, water-soluble celluloses, cellulose ethers, cellulose esters, cellulose amides, polyvinyl acetates, polycarboxylic acids and their salts, polyamino acids, polyamides, gelatin, methylcellulose, carboxymethylcellulose and its salts, dextrin, ethylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, maltodextrin, polymethacrylates, and combinations of any of the foregoing. Such water-soluble polymers (whether PVOH or others) are available from a variety of sources.

[0054] In an embodiment, the water-soluble fiber-forming material comprises polyvinyl alcohol, polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, cellulose amide, or a combination thereof. In an embodiment, the water-soluble fiber-forming material comprises polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, cellulose amide, or a combination thereof.

[0055] Polyvinyl alcohol is a synthetic polymer that is typically prepared by the alcoholysis (commonly referred to as hydrolysis or saponification) of polyvinyl acetate. Fully hydrolyzed PVOH, in which nearly all acetate groups have been converted to alcohol groups, is a strongly hydrogen-bonded, highly crystalline polymer that dissolves only in hot water at greater than about 140°F (about 60°C). If a sufficient number of acetate groups are allowed to remain after hydrolysis of polyvinyl acetate (i.e., partial hydrolysis of the PVOH polymer), the polymer has weaker hydrogen bonds, lower crystallinity, and is generally soluble in cold water at less than about 50°F (about 10°C). Thus, the partially hydrolyzed polymer is a vinyl alcohol-vinyl acetate copolymer, i.e., a PVOH copolymer, but is commonly referred to as PVOH.

[0056] In some embodiments, the polyvinyl alcohol includes modified polyvinyl alcohol, such as a copolymer. The modified polyvinyl alcohol can include a copolymer or a higher polymer (e.g., a terpolymer) that includes one or more monomers other than vinyl acetate / vinyl alcohol groups. Optionally, the modification is neutral, such as provided by ethylene, propylene, N-vinyl pyrrolidone, or other uncharged monomeric substances. Optionally, the modification is cationic modification, such as provided by a positively charged monomeric substance. Optionally, the modification is anionic modification, such as provided by a negatively charged monomeric substance. Thus, in some embodiments, the polyvinyl alcohol includes anionic-modified polyvinyl alcohol. The anionic-modified polyvinyl alcohol can include a partially or fully hydrolyzed PVOH copolymer that includes anionic monomer units, vinyl alcohol monomer units, and optionally present vinyl acetate monomer units (i.e., when the hydrolysis is incomplete). In some embodiments, the PVOH copolymer can include two or more types of anionic monomer units. General classes of anionic monomer units that can be used in the PVOH copolymer include vinyl polymerization units corresponding to the following: vinyl sulfonic acid monomers and their esters, monocarboxylic acid vinyl monomers, their esters and anhydrides, dicarboxylic acid monomers having a polymerizable double bond, their esters and anhydrides, and alkali metal salts of any of the foregoing. Examples of suitable anionic monomer units include vinyl polymerization units corresponding to the following: vinyl anionic monomers, including vinyl acetic acid, maleic acid, monoalkyl maleates, dialkyl maleates, maleic anhydride, fumaric acid, monoalkyl fumarates, dialkyl fumarates, itaconic acid, monoalkyl itaconates, dialkyl itaconates, citraconic acid, monoalkyl citraconates, dialkyl citraconates, citraconic anhydride, mesaconic acid, monoalkyl mesaconates, dialkyl mesaconates, glutaconic acid, monoalkyl glutaconates, dialkyl glutaconates, glutaconic anhydride, alkyl acrylates, (alkyl)acrylic esters, vinyl sulfonic acid, allyl sulfonic acid, ethanedisulfonic acid, 2-acrylamido-1-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methylacrylamido-2-methylpropanesulfonic acid, 2-sulfoethyl acrylate, alkali metal salts of the foregoing (e.g., sodium, potassium, or other alkali metal salts), esters of the foregoing (e.g., methyl ester, ethyl ester, or other C1-C4 or C6 alkyl esters), and combinations of the foregoing (e.g., multiple types of anionic monomers, or equivalent forms of the same anionic monomer). In some embodiments, the PVOH copolymer can include two or more types of monomer units selected from neutral, anionic, and cationic monomer units.

[0057] The extent to which one or more anionic monomer units are incorporated into the PVOH copolymer is not particularly limited. In embodiments, the amount of one or more anionic monomer units present in the PVOH copolymer ranges from about 1 mol% or 2 mol% to about 6 mol% or 10 mol% (e.g., in various embodiments, at least 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, or 4.0 mol% and / or at most about 3.0, 4.0, 4.5, 5.0, 6.0, 8.0, or 10 mol%).

[0058] Polyvinyl alcohol can undergo changes in solubility characteristics. Those skilled in the art know that the acetate groups in a copolymerized (vinyl acetate - vinyl alcohol) polymer (PVOH homopolymer) can be hydrolyzed by acid or base hydrolysis. As the degree of hydrolysis increases, the polymer composition made from the PVOH homopolymer will have increased mechanical strength, but at lower temperatures, the solubility decreases (e.g., hot water temperature is required to achieve complete dissolution). Thus, exposure of the PVOH homopolymer to an alkaline environment (e.g., caused by a laundry bleach additive) can transform the polymer from one that dissolves quickly and completely in a given aqueous environment (e.g., cold water medium) to one that dissolves slowly and / or incompletely in the aqueous environment, potentially resulting in undissolved polymer residues at the end of the wash cycle.

[0059] A PVOH copolymer having a carboxyl group attached thereto, such as a vinyl alcohol / sodium salt of hydrolyzed methyl acrylate polymer, can form a lactone ring between adjacent attached carboxyl groups and alcohol groups, thereby reducing the water solubility of the PVOH copolymer. In the presence of a strong base, the lactone ring can open within a few weeks under relatively warm (ambient) and higher humidity conditions (e.g., via a lactone ring - opening reaction to form attached carboxyl and alcohol groups with increased water solubility). Thus, contrary to the effects observed in the presence of PVOH homopolymers, it is believed that such PVOH copolymers become more soluble during storage due to chemical interactions between the polymer within the sachet and the alkaline composition. Thus, as it ages, the sachet may become increasingly prone to premature dissolution during a hot wash cycle (nominal 40 °C), and may, due to the presence of bleach and the resulting pH decrease, subsequently reduce the efficacy of certain laundry surfactants.

[0060] Certain sulfonic acids and their derivatives having polymerizable vinyl bonds can be copolymerized with vinyl acetate to obtain cold water-soluble PVOH polymers that are stable in the presence of strong bases. The base-catalyzed alcoholysis products of these copolymers used in water-soluble fiber formulations are rapidly soluble vinyl alcohol-sulfonate copolymers. The sulfonate groups in the PVOH copolymers can be restored to sulfonic acid groups in the presence of hydrogen ions, but the sulfonic acid groups still enable the polymer to achieve excellent cold water solubility. In the examples, the vinyl alcohol-sulfonate copolymers do not contain residual acetate groups (i.e., are fully hydrolyzed) and thus do not undergo hydrolysis by acid or base hydrolysis.

[0061] Generally, as the amount of modification increases, water solubility increases. Thus, sufficient modification via sulfonate or sulfonic acid groups inhibits hydrogen bonding and crystallinity, enabling dissolution in cold water. In the presence of acidic or basic substances, the copolymers are generally unaffected, except for the sulfonate or sulfonic acid groups therein, which maintain excellent cold water solubility even in the presence of acidic or basic substances. Examples of suitable sulfonic acid comonomers (and / or their alkali metal salt derivatives) include vinyl sulfonic acid, allyl sulfonic acid, ethanedisulfonic acid, 2-acrylamido-1-methylpropanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, 2-methacrylamido-2-methylpropanesulfonic acid, and 2-sulfoethyl acrylate, and the preferred comonomer is the sodium salt of 2-acrylamido-2-methylpropanesulfonic acid (AMPS).

[0062] Water-soluble polymers (whether polyvinyl alcohol polymers or others) can be blended. When the polymer blend includes a polyvinyl alcohol polymer blend, the PVOH polymer blend can include: a first PVOH polymer ("first PVOH polymer"), the first PVOH polymer can include a PVOH homopolymer or a PVOH copolymer (such as a PVOH terpolymer (or higher copolymer)) containing one or more types of anionic monomer units; and a second PVOH polymer ("second PVOH polymer"), the second PVOH polymer can include a PVOH homopolymer or a PVOH copolymer (such as a PVOH terpolymer (or higher copolymer)) containing one or more types of anionic monomer units. In some aspects, the PVOH polymer blend only includes the first PVOH polymer and the second PVOH polymer (such as a binary blend of two polymers). Alternatively or additionally, the PVOH polymer blend or the fibers or nonwoven fabrics made therefrom can be characterized by being free or substantially free of other polymers (such as other water-soluble polymers in general, especially other PVOH-based polymers, or both). As used herein, "substantially free" means that the first and second PVOH polymers account for at least 95 wt.%, at least 97 wt.%, or at least 99 wt.% of the total amount of water-soluble polymers in the water-soluble fibers or films. In other aspects, the water-soluble fibers or nonwoven fabrics can include one or more additional water-soluble polymers. For example, the PVOH polymer blend can include a third PVOH polymer, a fourth PVOH polymer, a fifth PVOH polymer, etc. (such as one or more additional PVOH homopolymers or PVOH copolymers with or without anionic monomer units). For example, the water-soluble fibers or nonwoven fabrics can include at least a third (or fourth, fifth, etc.) water-soluble polymer in addition to the PVOH polymer (such as in addition to a PVOH homopolymer or a PVOH copolymer with or without anionic monomer units).

[0063] The degree of hydrolysis (DH) of the PVOH homopolymers and PVOH copolymers included in the water-soluble fibers and nonwoven fabrics of the present disclosure can be in the range of about 75% to about 99.9% (e.g., about 79% to about 92%, about 80% to about 90%, about 88% to 92%, about 86.5% to about 89%, or about 88%, 90% or 92%, for example, for cold water-soluble compositions; about 90% to about 99%, about 92% to about 99%, about 95% to about 99%, about 98% to about 99%, about 98% to about 99.9%, about 96%, about 98%, about 99% or greater than 99%). As the degree of hydrolysis decreases, the mechanical strength of the fibers or films made from the polymer decreases at temperatures below about 20°C, but they dissolve faster. As the degree of hydrolysis increases, the fibers or films made from the polymer tend to have stronger mechanical strength, and the thermoforming ability tends to decrease. The degree of hydrolysis of PVOH can be selected such that the water solubility of the polymer is temperature-dependent, and thus also affects the solubility of the fibers or films made from the polymer and additional components. In one option, the fibers or films have cold water solubility. For (vinyl acetate vinyl alcohol) copolymers that do not include any other monomers (e.g., homopolymers that are not copolymerized with anionic monomers), cold water-soluble fibers or films that are soluble in water at temperatures less than 10°C may include PVOH with a degree of hydrolysis in the range of about 75% to about 90% or in the range of about 80% to about 90% or in the range of about 85% to about 90%. In another option, the fibers or films have hot water solubility. For (vinyl acetate vinyl alcohol) copolymers that do not include any other monomers (e.g., homopolymers that are not copolymerized with anionic monomers), hot water-soluble fibers or films that are soluble in water at temperatures of at least about 60°C may include PVOH with a degree of hydrolysis of at least about 98%.

[0064] The degree of hydrolysis of the polymer blend can also be characterized by the arithmetically weighted average degree of hydrolysis For example, the of a PVOH polymer comprising two or more PVOH polymers is calculated according to the formula where W i is the weight percentage of the corresponding PVOH polymer and H i is the corresponding degree of hydrolysis. When referring to a polymer having a specific degree of hydrolysis, the polymer can be a single polyvinyl alcohol polymer having the specified degree of hydrolysis or a polyvinyl alcohol polymer blend having the specified average degree of hydrolysis.

[0065] The viscosity (μ) of the PVOH polymer is determined by measuring the freshly prepared solution using a Brookfield LV viscometer with a UL adapter, as described in the Brookfield test method in Annex E of British Standard EN ISO 15023-2:2006. It is an international convention to state the viscosity of a 4% aqueous solution of polyvinyl alcohol at 20 °C. Unless otherwise specified, all viscosities given in centipoise (cp) in this text are understood to refer to the viscosity of a 4% aqueous solution of polyvinyl alcohol at 20 °C. Similarly, when a polymer is described as having (or not having) a specific viscosity, unless otherwise specified, it is meant that the specified viscosity is the average viscosity of the polymer, which inherently has a corresponding molecular weight distribution, i.e., the weighted natural logarithm average viscosity as described below. It is well known in the art that the viscosity of the PVOH polymer is related to the weight average molecular weight of the PVOH polymer and the viscosity is often used as a representative of

[0066] For reference, in a polymer blend, a first PVOH polymer is represented as having a first 4% solution viscosity (μ1) at 20 °C, and a second PVOH polymer is represented as having a second 4% solution viscosity (μ2) at 20 °C. In various embodiments, the first viscosity μ1 can be in the range of about 4 cP to about 70 cP (e.g., at least about 4, 8, 10, 12, or 16 cP and / or up to about 12, 16, 20, 24, 28, 30, 32, 35, 37, 40, 45, 48, 50, 56, 60, or 70 cP, e.g., about 4 cP to about 70 cP, about 4 cP to about 60 cP, about 4 cP to about 46 cP, about 4 cP to about 24 cP, about 10 cP to about 16 cP, or about 10 cP to about 20 cP, or about 20 cP to about 30 cP). Alternatively or additionally, the second viscosity μ2 can be in the range of about 4 cP to about 70 cP (e.g., at least about 4, 8, 10, 12, or 16 cP and / or up to about 12, 16, 20, 24, 28, 30, 32, 35, 37, 40, 45, 48, 50, 56, 60, or 70 cP, e.g., about 12 cP to about 30 cP, about 10 cP to about 16 cP, or about 10 cP to about 20 cP, or about 20 cP to about 30 cP). When the PVOH polymer blend includes three or more PVOH polymers selected from PVOH polymers and PVOH copolymers, the above viscosity values can be individually applied to the various PVOH polymers or PVOH copolymers. Thus, the weight average molecular weight of the water-soluble polymer (including the first PVOH copolymer and the second PVOH copolymer) can be in the range of, for example, about 30,000 to about 175,000, or about 30,000 to about 100,000, or about 55,000 to about 80,000. When referring to the average viscosity of the PVOH polymer blend, the weighted natural logarithm average viscosity is used. of PVOH polymers including two or more PVOH polymers is calculated according to the formula where μ ι is the viscosity of the corresponding PVOH polymer.

[0067] non-water-soluble fiber-forming material

[0068] The fibers of the present disclosure may include a water-insoluble fiber-forming material. Generally, a water-insoluble fiber-forming material includes any material that does not dissolve at a temperature of 80 °C or lower within 300 seconds or less, as determined according to MSTM-205. Suitable water-insoluble fiber-forming materials include (but are not limited to) cotton, cellulose, polyester, polyethylene (such as high-density polyethylene and low-density polyethylene), polypropylene, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyamide, thermoplastic polyurethane, wood pulp, staple pulp, abaca, rayon, polylactic acid, nylon 6, cellulose, starch, hemp, jute, flax, ramie, sisal, bagasse, banana fiber, lacebark, silk, tendon, catgut, wool, seaweed fiber, mohair, angora, cashmere, collagen, actin, nylon, Dacron, rayon, bamboo fiber, modal, diacetate fiber, triacetate fiber, and combinations thereof.

[0069] In an embodiment, the water-insoluble fiber-forming material comprises cotton, cellulose, hemp, jute, flax, ramie, sisal, bagasse, banana fiber, lacebark, silk, tendon, catgut, wool, seaweed fiber, mohair, angora, cashmere, collagen, actin, nylon, Dacron, rayon, bamboo fiber, modal, diacetate fiber, triacetate fiber, polypropylene, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyamide, thermoplastic polyurethane, rayon, or combinations thereof. In an embodiment, the water-insoluble fiber-forming material comprises cotton, cellulose, wool, bamboo fiber, polypropylene, polycarbonate, rayon, or combinations thereof. In an embodiment, the water-insoluble fiber-forming material comprises cellulose, wool, polypropylene, rayon, or combinations thereof.

[0070] Auxiliary components

[0071] The fibers of the present disclosure may include other auxiliaries and treating agents, including (but not limited to) plasticizers, plasticizer compatibilizers, surfactants, lubricants, mold release agents, fillers, extenders, crosslinking agents, anti-caking agents, antioxidants, anti-sticking agents, defoaming agents, liquid absorbent materials (such as superabsorbent polymers), exfoliating agents, nanoparticles (such as layered silicate-type nanoclays (such as sodium montmorillonite)), bleaching agents (such as sodium metabisulfite, sodium bisulfite or others), repellents (such as bittering agents (such as denatonium salts (such as denatonium benzoate, denatonium saccharides and denatonium chloride); sucrose octaacetate; quinine; flavonoids such as quercetin and naringenin; and carotenoids such as quassin and brucine)) and pungent agents (such as capsaicin, piperine, allyl isothiocyanate, and resiniferatoxin), and other functional components, the content of which is suitable for their intended purposes. Specific such auxiliaries and treating agents may be selected from those formulations suitable for water-soluble fibers, or those formulations suitable for water-soluble nonwovens.

[0072] In embodiments, the fibers of the present disclosure contain a plasticizer. A plasticizer is a liquid, solid or semi-solid that is added to a material (usually a resin or elastomer) to make the material softer, more flexible (by lowering the glass transition temperature of the polymer) and easier to process. Internal plasticization of the polymer can be achieved by chemically modifying the polymer or monomer (such as grafting the plasticizer onto the polymer backbone). Additionally or alternatively, external plasticization of the polymer can be achieved by adding a suitable plasticizer to the fiber-forming material. Additionally or alternatively, the plasticizer can be added as a coating on the formed fibers or nonwovens. Water is considered to be a very efficient plasticizer for PVOH and other polymers; including (but not limited to) water-soluble polymers. However, the volatility of water limits its utility because polymer fibers, nonwovens and films need to have at least some resistance (robustness) to a variety of environmental conditions, including low and high relative humidity.

[0073] Plasticizers may include (but not limited to) glycerol, diglycerol, sorbitol, ethylene glycol, diethylene glycol, triethylene glycol, dipropylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol up to 400 MW, neopentyl glycol, trimethylolpropane, polyether polyols, sorbitol, 2-methyl-1,3-propanediol Ethanolamine and its mixtures. The total amount of non-aqueous plasticizer provided in the fibers can be in the following ranges based on the total weight of the fibers: from about 1 wt.% to about 45 wt.%, or from about 5 wt.% to about 45 wt.%, or from about 10 wt.% to about 40 wt.%, or from about 20 wt.% to about 30 wt.%, from about 1 wt.% to about 4 wt.%, or from about 1.5 wt.% to about 3.5 wt.%, or from about 2.0 wt.% to about 3.0 wt.%, such as about 1 wt.%, about 2.5 wt.%, about 5 wt.%, about 10 wt.%, about 15 wt.%, about 20 wt.%, about 25 wt.%, about 30 wt.%, about 35 wt.% or about 40 wt.%.

[0074] In embodiments, the fibers of the present disclosure include surfactants. Surfactants for use in fibers are well known in the art. Optionally, the surfactant is included to assist in the dispersion of the fibers during processing (such as carding). Surfactants suitable for the fibers of the present disclosure include (but are not limited to) dialkyl sulfosuccinates, lactylated fatty acid esters of glycerol and propylene glycol, lactate esters of fatty acids, sodium alkyl sulfates, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, alkyl polyethylene glycol ethers, lecithin, acetylated fatty acid esters of glycerol and propylene glycol, sodium lauryl sulfate, acetylated esters of fatty acids, myristyl dimethylamine oxide, trimethyl tallow alkyl ammonium chloride, quaternary ammonium compounds, alkali metal salts of higher fatty acids containing from about 8 to 24 carbon atoms, alkyl sulfates, alkyl polyethoxylated sulfates, alkyl benzene sulfonates, monoethanolamine, ethoxylated lauryl alcohol, propylene glycol, diethylene glycol, their salts, and combinations of any of the foregoing.

[0075] Suitable surfactants can include nonionic, cationic, anionic, and zwitterionic classes. Suitable surfactants include (but are not limited to) propylene glycol, diethylene glycol, monoethanolamine, polyoxyethylated polyoxypropylene glycol, alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylenic glycols, and alkanolamides (nonionic), polyoxyethylated amines, quaternary ammonium salts, and quaternized polyoxyethylated amines (cationic), alkali metal salts of higher fatty acids containing about 8 to 24 carbon atoms, alkyl sulfates, alkyl polyethoxylated sulfates, and alkylbenzene sulfonates (anionic), and amine oxides, N-alkyl betaines, and sulfobetaines (zwitterionic). Other suitable surfactants include sodium dioctyl sulfosuccinate, lactylated fatty acid esters of glycerol and propylene glycol, lactate esters of fatty acids, sodium lauryl sulfate, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, lecithin, acetylated fatty acid esters of glycerol and propylene glycol, and acetylated esters of fatty acids, and combinations thereof. The surfactant can be included in or added to the fiber-forming material. In various embodiments, the amount of surfactant in the fiber is in the range of about 0.01 wt.% to about 2.5 wt.%, about 0.1 wt.% to about 2.5 wt.%, about 1.0 wt.% to about 2.0 wt.%, about 0.01 wt% to 0.25 wt%, or about 0.10 wt% to 0.20 wt%.

[0076] In an embodiment, the fibers of the present disclosure are substantially free of auxiliaries. As used herein and unless otherwise specified, "substantially free of auxiliaries" means that the fibers include less than about 0.01 wt%, less than about 0.005 wt.%, or less than about 0.001 wt.% auxiliaries, based on the total weight of the fibers.

[0077] Activator

[0078] In embodiments, the fiber may include one or more active agents as part of the fiber or may include one or more active agents on its surface. The active agent provides additional functionality to the fiber when present in the fiber in an amount of at least about 1 wt% or in the range of about 1 wt% to about 99 wt%. In embodiments, the active agent is selected from the group consisting of: enzymes, oils, fragrances, colorants, odor absorbers, aromatics, pesticides, fertilizers, oxidants, exfoliants, liquid absorbent materials, activation factors, acid catalysts, metal catalysts, ion scavengers, detergents, disinfectants, surfactants, plasticizers, bleaching agents, bleaching components, fabric softeners, and combinations thereof. In embodiments, the active agent is selected from the group consisting of: enzymes, oils, fragrances, colorants, odor absorbers, aromatics, pesticides, oxidants, exfoliants, liquid absorbent materials, detergents, disinfectants, surfactants, plasticizers, bleaching agents, bleaching components, fabric softeners, and combinations thereof. In embodiments, the active agent is selected from the group consisting of: enzymes, oils, odor absorbers, aromatics, exfoliants, liquid absorbent materials, detergents, disinfectants, and combinations thereof.

[0079] In certain embodiments, the active agent may comprise an enzyme. Suitable enzymes include enzymes classified in any of the six conventional classes of the Enzyme Commission (EC), namely, oxidoreductases of EC 1 (which catalyze oxidation / reduction reactions), transferases of EC 2 (which transfer functional groups such as methyl or phosphate groups), hydrolases of EC 3 (which catalyze the hydrolysis of various bonds), lyases of EC 4 (which cleave various bonds by means other than hydrolysis and oxidation), isomerases of EC 5 (which catalyze intramolecular isomerization changes), and ligases of EC 6 (which join two molecules via a covalent bond). Examples of such enzymes include dehydrogenases and oxidases of EC 1; transaminases and kinases of EC 2; lipases, cellulases, amylases, mannanases, and peptidases (also known as proteases or proteolytic enzymes) of EC 3; decarboxylases of EC 4; isomerases and mutases of EC 5; and synthases and synthetases of EC 6. Suitable enzymes of various classes are described, for example, in U.S. Patent No. 9,394,092, the entire disclosure of which is incorporated herein by reference.

[0080] Enzymes for cleaning applications may include one or more of the following: proteases, amylases, lipases, dehydrogenases, transaminases, kinases, cellulases, mannanases, peptidases, decarboxylases, isomerases, mutases, synthases, synthetases, and oxygen radical reductases, including oxygen radical reductases that catalyze the formation of bleaching agents.

[0081] It is contemplated that the enzymes used herein can be from any suitable source or combination of sources, such as bacterial, fungal, plant or animal sources. In one type of embodiment, a mixture of two or more enzymes will be from at least two different types of sources. For example, a mixture of protease and lipase can be from a bacterial (protease) and a fungal (lipase) source.

[0082] Optionally, the enzymes used herein, including (but not limited to) any enzyme class or member described herein, are enzymes that function under alkaline pH conditions, such as when used in cleaning applications, for example, at a pH in the range of about 8 to about 11. Optionally, the enzymes used herein, including (but not limited to) any enzyme class or member described herein, are enzymes that function at a temperature in the range of about 5°C to about 45°C.

[0083] Another class of embodiments includes one or more odor absorbers as active agents. Odor absorbers suitable as active agents according to the present disclosure include (but are not limited to) zeolites, and complex zinc salts of ricinoleic acid. The deodorizing active agent can also contain fixatives, which are well known in the art as most aromatics that are odor neutral, including (but not limited to) extracts of labdanum, styrax, and rosin acid derivatives.

[0084] Another class of embodiments includes one or more fragrances as active agents. As used herein, the term fragrance refers to any suitable material that is volatile enough to produce a scent. Embodiments including a fragrance as an active agent can include fragrances with a pleasant scent, or alternatively, fragrances that can repel people, animals, and / or insects. Suitable fragrances include (but are not limited to) fruits, including (but not limited to) lemon, apple, cherry, grape, pear, pineapple, orange, strawberry, raspberry, musk, and floral scents, including (but not limited to) lavender-like, rose-like, iris-like, and carnation-like scents. Optionally, the fragrance is a fragrance that is not also a flavoring. Other fragrances include herbaceous scents, including (but not limited to) rosemary, thyme, and sage; and woodland scents derived from pine, spruce, and other forest odors. Fragrances can also be derived from a variety of oils, including (but not limited to) essential oils, or from plant materials, including (but not limited to) peppermint, spearmint, and the like. Suitable aromatic oils can be found in U.S. Patent No. 6,458,754, which is incorporated herein by reference in its entirety. Suitable aromatic oils include (but are not limited to) 4-(2,2,6-trimethylcyclohex-1-en-1-yl)-2-en-4-one, acetaldehyde styrenyl propyl acetal, 2,6,10-trimethyl-9-undecenal, 2-propenyl hexanoate, 1-octen-3-ol, trans-anethole, (z)-2-methyl-2-butenoic acid isobutyl ester, anisaldehyde diethyl acetal, 3-methyl-5-propyl-cyclohexene-1-one, 2,4-dimethyl-3-cyclohexene-1-carboxaldehyde, trans-4-decenal, decanal, 2-pentylcyclohexanone, ethyl anthranilate, eugenol, 3-(3-isopropylphenyl)butanol, methyl 2-octynoate, isoeugenol, methyl cis-3-hexenyl carbonate, linalool, methyl 2-nonenoate, 2-hydroxy methyl benzoate, nonanal, octanal, 2-nonenitrile, 4-nonolactone, 9-decen-1-ol, and 10-undecen-1-al. Suitable fragrances can also be found in U.S. Patent Nos. 4,534,981, 5,112,688, 5,145,842, 6,844,302, and Perfumes Cosmetics and Soaps, Second Edition, edited by W.A. Poucher, 1959, all of which are incorporated herein by reference in their entirety. These fragrances include gum arabic, cinnamon, chypre, cyclamen, fern, gardenia, hawthorn, heliotrope, honeysuckle, hyacinth bean, jasmine, clove, lily, magnolia, mimosa, narcissus, newly cut hay, neroli, orchid, mignonette, sweet pea, alfalfa (clover), tuberose, vanilla, violet, wallflower, and the like.

[0085] The fragrance may include perfume. The perfume may comprise pure perfume, encapsulated perfume, or a mixture thereof. Preferably, the perfume includes pure perfume. A portion of the perfume may be encapsulated in a core / shell encapsulation. In another type of embodiment, the perfume is not encapsulated in a core / shell encapsulation.

[0086] As used herein, the term "perfume" encompasses perfume raw materials (PRMs) and perfume compositions. As used herein, the term "perfume raw material" refers to a compound having a molecular weight of at least about 100 g / mol and which, alone or in combination with other perfume raw materials, is suitable for imparting an odor, aroma, essence, or fragrance. As used herein, the terms "perfume ingredient" and "perfume raw material" are interchangeable. As used herein, the term "composition" refers to a mixture of two or more PRMs.

[0087] Typical PRMs include, inter alia, alcohols, ketones, aldehydes, esters, ethers, nitrites, and olefins such as terpenes. A list of common PRMs can be found in a variety of reference sources, e.g., "Perfume and Flavor Chemicals", Volumes I and II; Steffen Arctander, Allured Pub. Corp. (1994); and "Perfumes: Art, Science and Technology", Miller, P.M. and Lamparsky, D., Blackie Academic and Professional (1994). PRMs are characterized by their boiling point (B.P.) measured at atmospheric pressure (760 mm Hg) and their octanol / water partition coefficient (P). Based on these characteristics, PRMs can be classified as Quadrant I, Quadrant II, Quadrant III, or Quadrant IV perfumes.

[0088] Suitable insect-repellent fragrances include one or more of the insecticides dichlorvos, pyrethrin, allethrin, naled, and / or fenthion disclosed in U.S. Patent No. 4,664,064, which is incorporated herein by reference in its entirety. Suitable insect repellents are citronellal (3,7-dimethyloctanal), N,N-diethyl-3-methylbenzamide (DEET), vanillin, and volatile oils extracted from turmeric (Curcuma longa), kaffir lime (Citrushystrix), lemongrass (Cymbopogon winterianus), and Ocimum americanum. Additionally, suitable insect repellents can be mixtures of insect repellents.

[0089] In an alternative embodiment, the active agent can optionally be an ion scavenger. Suitable ion scavengers include, but are not limited to, zeolites. Optionally, zeolites can be added as a water softener to an aqueous-soluble package containing a laundry detergent or dishwashing detergent, which is encapsulated within the aqueous-soluble package.

[0090] Inorganic and organic bleaches are cleaning active agents suitable for use herein. Inorganic bleaches include peroxygenate salts, including, but not limited to, perborates, percarbonates, perphosphates, persulfates, and persilicates. Inorganic peroxygenate salts are generally alkali metal salts. Alkali metal percarbonates, particularly sodium percarbonate, are peroxygenates suitable for use herein. Organic bleaches can include organic peroxyacids, including diacyl and tetraacyl peroxyacids, particularly, but not limited to, diperoxydodecanedioic acid, diperoxytetradecanedioic acid, and diperoxyhexadecanedioic acid. Benzoyl peroxide is a suitable organic peroxyacid according to the present disclosure. Other organic bleaches include peroxyacids, specific examples being alkyl peroxyacids and aryl peroxyacids.

[0091] In one class of embodiments, the active agent can include a bleach activator, including an organic peracid precursor that enhances bleaching during the cleaning process at 60° C. and lower temperatures. Bleach activators suitable for use herein include compounds that, under perhydrolysis conditions, yield aliphatic peroxycarboxylic acids having 1 to 10 carbon atoms, or 2 to 4 carbon atoms, and / or optionally substituted perbenzoic acid. Suitable materials carry an O-acyl and / or N-acyl and / or optionally substituted benzoyl group having the specified number of carbon atoms. Suitable materials include (but are not limited to) polyacylated alkanediamines, specifically tetraacetylethylenediamine (TAED); acylated triazine derivatives, specifically 1,5-diacetyl-2,4-dioxohexahydro-1,3,5-triazine (DADHT); acylated glycolurils, specifically tetraacetylglycoluril (TAGU); N-acylimides, specifically n-nonanoylsuccinimide (NOSI); acylated phenolsulfonates, specifically n-nonanoyl or isononanoyloxylbenzenesulfonate (n- or iso-NOBS); carboxylic anhydrides, specifically phthalic anhydride; acylated polyols, specifically triacetin, ethylene diacetate, and 2,5-diacetoxy-2,5-dihydrofuran, and triethylacetylcitrate (TEAC).

[0092] In embodiments that include a fabric softener as the active agent, a different sufficient wash fabric softener can optionally be used, specifically the untouchable swelling stone clay of U.S. Patent 4,062,647 (incorporated herein by reference in its entirety), and other softening clays known in the art, to provide the benefits of a fabric softener while the fabric is being cleaned. The clay softener can be used in combination with amines and cationic softeners as disclosed in, for example, U.S. Patents 4,375,416 and 4,291,071 (incorporated herein by reference in their entireties).

[0093] In embodiments, the active agent can include a disinfectant. Disinfectants suitable for use herein can include (but are not limited to) hydrogen peroxide, inorganic peroxides and their precursors, sodium metabisulfite, quaternary ammonium cation-based compounds, chlorine gas, activated carbon, and hypochlorites.

[0094] In embodiments, the active agent may include a surfactant. Surfactants suitable herein may include (but are not limited to) propylene glycol, diethylene glycol, monoethanolamine, polyoxyethylated polyoxypropylene glycol, alcohol ethoxylates, alkylphenol ethoxylates, tertiary acetylenic glycols, and alkanolamides (nonionic), polyoxyethylated amines, quaternary ammonium salts, and quaternized polyoxyethylated amines (cationic), alkali metal salts of higher fatty acids containing from about 8 to 24 carbon atoms, alkyl sulfates, alkyl polyethoxylated sulfates, and alkylbenzene sulfonates (anionic), amine oxides, N-alkyl betaines, and sulfobetaines (zwitterionic), sodium dioctyl sulfosuccinate, lactylated fatty acid esters of glycerin and propylene glycol, lactic acid esters of fatty acids, sodium lauryl sulfate, polysorbate 20, polysorbate 60, polysorbate 65, polysorbate 80, lecithin, acetylated fatty acid esters of glycerin and propylene glycol, and acetylated esters of fatty acids, and combinations thereof.

[0095] The active agent can be solid or liquid. The solid active agent can have, for example, an average particle size (such as Dv50) of at least about 0.01 μm, or dimensions in the range of about 0.01 μm to about 2 mm.

[0096] In embodiments, the fibers of the nonwoven fabric, composite article, flushable tissue, liquid-containing article, and absorbent article of the present disclosure include water-soluble fibers, water-insoluble fibers, or combinations thereof, wherein the fibers can have the same or different diameters, lengths, tenacities, shapes, rigidities, elasticities, solubilities, melting points, glass transition temperatures, and / or fiber-forming materials.

[0097] In embodiments where the fibers comprise water-soluble fibers, the water-soluble fibers can include any of the water-soluble polymer fiber-forming materials disclosed herein. Generally, the water-soluble fibers can comprise a single water-soluble polymer fiber-forming material, or a blend of water-soluble fiber-forming materials. In embodiments, the water-soluble fibers consist of a single water-soluble polymer fiber-forming material. In embodiments, the water-soluble fibers include a blend of water-soluble polymers.

[0098] In embodiments, the plurality of water-soluble fibers includes a polyvinyl alcohol (PVOH) fiber-forming material. In one modification of the above embodiment, the water-soluble fiber-forming material includes a PVOH homopolymer. In another modification of the above embodiment, the water-soluble fiber-forming material includes a PVOH copolymer. In embodiments, the water-soluble fibers include a blend of polyvinyl alcohol fiber-forming materials. In one modification of the above embodiment, the water-soluble fibers include one or more PVOH homopolymer fiber-forming materials. In another modification of the above embodiment, the water-soluble fibers include one or more PVOH copolymer fiber-forming materials. In yet another modification of the above embodiment, the water-soluble polymer includes one or more PVOH homopolymer fiber-forming materials and one or more PVOH copolymer fiber-forming materials.

[0099] In embodiments where the water-soluble fiber comprises a blend of a polyvinyl alcohol homopolymer and a polyvinyl alcohol copolymer, the polyvinyl alcohol homopolymer may be present in the total weight of the water-soluble polymer blend in an amount of from about 15 wt.% to about 70 wt.%, such as at least about 15 wt.%, at least about 20 wt.%, at least about 25 wt.%, at least about 30 wt.%, at least about 40 wt.%, at least about 50 wt.% or at least about 60 wt.% and at most about 70 wt.%, at most about 60 wt.%, at most about 50 wt.%, at most about 40 wt.% or at most about 30 wt.%, and may be a single homopolymer, or a blend of one or more homopolymers (e.g., differing in viscosity and / or degree of hydrolysis). Based on the total weight of the water-soluble polymer blend, the water-soluble polyvinyl alcohol copolymer may be present in the total weight of the water-soluble polymer blend in an amount of from about 30 wt.% to about 85 wt.%, such as at least about 30 wt.%, at least about 40 wt.%, at least about 50 wt.%, at least about 60 wt.%, at least about 70 wt.%, at least about 75 wt.% or at least about 80 wt.% and at most about 85 wt.%, at most about 80 wt.%, at most about 70 wt.%, at most about 60 wt.%, at most about 50 wt.% or at most about 40 wt.%, and may be a single copolymer, or a blend of one or more copolymers. The blend may consist of a polyvinyl alcohol homopolymer and a polyvinyl alcohol copolymer. The blend may consist of a polyvinyl alcohol homopolymer and a plurality of polyvinyl alcohol copolymers. The blend may consist of more than one polyvinyl alcohol homopolymer and more than one polyvinyl alcohol copolymer.

[0100] Biodegradability

[0101] Polyvinyl alcohol polymers are generally biodegradable due to their decomposition in the presence of water and enzymes, under aerobic, anaerobic, soil and composting conditions (in the presence of water). Generally, as the degree of hydrolysis of the polyvinyl alcohol polymer is increased up to about 80%, the biodegradation activity of the polyvinyl alcohol polymer increases. Without wishing to be bound by theory, it is believed that increasing the degree of hydrolysis above 80% has no significant effect on biodegradability.

[0102] Without wishing to be bound by theory, it is believed that while the degree of polymerization of the polyvinyl alcohol polymer has little to no effect on the biodegradability of the fibers or nonwovens prepared from the polymer, the polymerization temperature can affect the biodegradability of the film or nonwoven, as the polymerization temperature can affect the crystallinity and aggregation state of the polymer. Specifically, as the crystallinity decreases, the hydroxyl groups of the polymer chains become less aligned in the polymer structure and the polymer chains become more disordered, which allows the chains to accumulate as amorphous aggregates, thereby reducing the availability of the ordered polymer structure. Thus, it is expected that the biodegradation activity will decrease due to soil and / or compost biodegradation mechanisms in which the polymer does not dissolve.

[0103] In addition, the hydroxyl tacticity of the polyvinyl alcohol polymer has a significant effect on the level of biodegradation activity, and the more isotactic the hydroxyl groups of the polymer sequence, the higher the degradation activity. Without wishing to be bound by theory, it is believed that since the hydroxyl tacticity of the polyvinyl alcohol polymer has a significant effect on the level of biodegradation activity, it is expected that substitution with functional groups other than hydroxyl groups (such as anionic AMPS functional groups, carboxylic ester groups or lactone groups) will reduce the level of biodegradation activity (relative to a polyvinyl alcohol homopolymer having the same degree of hydrolysis), unless the functional group itself is also biodegradable, in which case the substitution can increase the biodegradability of the polymer. In addition, it is believed that while the level of biodegradation activity of the substituted polyvinyl alcohol will be less than that of the corresponding homopolymer, the substituted polyvinyl alcohol will still exhibit biodegradability. In addition, without wishing to be bound by theory, for soil and / or compost biodegradation, it is believed that the level of biodegradation activity of nonwovens prepared from polyvinyl alcohol fibers will be higher than that of water-soluble films prepared from similar polyvinyl alcohol polymers, as the nonwoven provides an increased polymer surface area relative to the film.

[0104] Methods for determining biodegradation activity are known in the art. Suitable standards include OECD 301B (ready biodegradability), OECD 302B (inherent biodegradability), OECD 311 (anaerobic), and ASTM D5988 (soil).

[0105] Fiber Properties

[0106] Multiple fibers can be prepared by any process known in the art, such as wet cooling gel spinning, thermoplastic fiber spinning, meltblowing, spunbonding, electrospinning, rotary spinning, continuous filament production operations, tow fiber production operations, and combinations thereof.

[0107] In embodiments, the fibers comprise water-soluble fibers prepared by wet-cooling gel spinning, meltblowing, spunbonding, or a combination thereof. In embodiments, the fibers comprise water-soluble fibers that are prepared by wet-cooling gel spinning and carded into a nonwoven fabric. In embodiments, the fibers comprise water-soluble fibers and the nonwoven fabric prepared therefrom is formed by a continuous meltblowing process. In embodiments, the fibers comprise water-soluble fibers and the nonwoven fabric prepared therefrom is formed by a continuous spunbonding process. In the art, standards refer to fibers and nonwoven fabrics made by the processes used to prepare nonwoven fabrics. Thus, any reference herein to, for example, "meltblown fibers" or "carded nonwoven fabric" should not be construed as the product being limited to a particular meltblowing or carding method, but rather as merely identifying a particular fiber or fabric. Thus, the term processing can be used to distinguish fibers and / or nonwoven fabrics without limiting the fibers and / or nonwoven fabrics to the preparation of any particular process.

[0108] The fibers of the present disclosure can be bicomponent fibers. As used herein and unless otherwise specified, "bicomponent fiber" does not refer to a fiber that includes a blend of fiber-forming materials, but rather to a fiber that includes two or more different regions of fiber-forming materials, wherein the composition of the fiber-forming materials varies by region. Examples of bicomponent fibers include (but are not limited to) core / sheath bicomponent fibers, sea-island bicomponent fibers, and side-by-side bicomponent fibers. Core / sheath bicomponent fibers generally include a core of a fiber-forming material having a first composition (e.g., a single fiber-forming material, or a first blend of fiber-forming materials) and a sheath layer of a fiber-forming material having a second composition (e.g., a single fiber-forming material different from the core material, or a second blend of fiber-forming materials different from the first blend of fiber-forming materials of the core). Sea-island bicomponent fibers generally include a first continuous "sea" region of a fiber-forming material having a first composition and discrete "island" regions of a fiber-forming material having a second composition different from the first composition dispersed therein. Side-by-side bicomponent fibers generally include a first region that extends the length of the fiber and includes a fiber-forming material having a first composition; and at least a second region adjacent thereto that extends the length of the fiber and includes a fiber-forming material having a second composition different from the first composition. Such bicomponent fibers are well known in the art.

[0109] The fibers of the present disclosure can be hydrophobic and / or hydrophilic fibers. As used herein and unless otherwise specified, "hydrophobic fiber" refers to any fiber having a hydrophobic surface. The fiber can have a hydrophobic surface, in which case the fiber includes, for example, a hydrophobic fiber-forming material, the fiber is a core / sheath type bicomponent fiber, the sheath of which includes a hydrophobic fiber-forming material, and / or the fiber has been surface-treated to include a hydrophobic surfactant on its surface. Similarly, as used herein and unless otherwise specified, "hydrophilic fiber" refers to any fiber having a hydrophilic surface. The fiber can have a hydrophilic surface, in which case the fiber includes, for example, a hydrophilic fiber-forming material, the fiber is a core / sheath type bicomponent fiber, the sheath of which includes a hydrophilic fiber-forming material, and / or the fiber has been surface-treated to include a hydrophilic material on its surface. Without wishing to be bound by theory, it is believed that the hydrophilic fibers of the nonwoven fabric can promote the capillary action / wicking of liquids on the nonwoven fabric surface, relative to the same nonwoven fabric that does not include hydrophilic fibers, such that liquid collection is improved.

[0110] The fibers of the present disclosure can comprise one or more of the fiber-forming materials disclosed herein. When the fiber includes one PVOH polymer fiber-forming material, the degree of hydrolysis of the fiber is the same as the degree of hydrolysis of the PVOH polymer. When the fiber includes two or more PVOH polymer fiber-forming materials, the degree of hydrolysis of the fiber is the arithmetic weighted average of the degrees of hydrolysis of the individual PVOH polymers. Without wishing to be bound by theory, it is believed that as the degree of hydrolysis of the fiber increases, the hydrophilicity of the fiber increases and, as a result, the wicking rate of the fiber increases. Thus, nonwoven fabrics comprising fibers with a relatively high average degree of hydrolysis can be particularly suitable for applications where the wicking rate is a major factor, such as wearable articles where it is desired to quickly wick liquids away from the consumer's skin. In embodiments where the wicking rate is a major factor, the fibers of the present disclosure can have a degree of hydrolysis (average value) of from about 95% to about 99.9%.

[0111] The fiber shape is not particularly limited and can have a cross-sectional shape including but not limited to the following: circular, oval (also known as ribbon-shaped), triangular (also known as △), trilobal, and / or other multi-lobal shapes.( Figure 1 ). It should be understood that the fiber shape is not necessarily a perfect geometric shape. For example, a fiber having a circular cross-sectional shape does not necessarily have a perfect circle in the cross-sectional area, and a fiber having a triangular cross-sectional shape typically has rounded corners. Without wishing to be bound by theory, it is believed that hydrophilic fibers in the nonwoven fabric having a shape that provides capillary or channel-type oriented channels for liquids (such as trilobal fibers) can promote the capillary action / wicking of liquids on the nonwoven fabric surface, relative to the same nonwoven fabric whose fiber shape does not include capillary or channel-type oriented channels, such that liquid collection is improved.

[0112] It should be understood that the fiber diameter refers to the cross-sectional diameter of the fiber along its longest cross-sectional axis. When a fiber is described as having (or not having) a specific diameter, unless otherwise specified, it is meant that the specified diameter is the average diameter of the specific fiber type mentioned, i.e., a plurality of fibers formed from the polyvinyl alcohol fiber-forming material have an arithmetic average fiber diameter of the plurality of fibers. For shapes that are not typically considered to have a "diameter" (such as triangular or multi-lobed shapes), the diameter refers to the diameter of a circle circumscribing the fiber shape( Figure 1 ).

[0113] The fibers of the present disclosure typically have a diameter in the range of about 10 microns to 300 microns, such as at least 10 microns, at least 15 microns, at least 20 microns, at least 25 microns, at least 50 microns, at least 100 microns or at least 125 microns, and at most about 300 microns, at most about 275 microns, at most about 250 microns, at most about 225 microns, at most about 200 microns, at most about 100 microns, at most about 50 microns, at most about 45 microns, at most about 40 microns or at most about 35 microns, such as in the range of about 10 microns to about 300 microns, about 50 microns to about 300 microns, about 100 microns to about 300 microns, about 10 microns to about 50 microns, about 10 microns to about 45 microns, or about 10 microns to about 40 microns. In an embodiment, the water-soluble fibers used to prepare the water-dispersible nonwoven fabric of the present disclosure may have a diameter greater than 100 microns to about 300 microns. In an embodiment, the fibers comprise cellulose having a diameter in the range of about 10 microns to about 50 microns, about 10 microns to about 30 microns, about 10 microns to about 25 microns, about 10 microns to about 20 microns or about 10 microns to about 15 microns. In an embodiment, the fibers comprise a water-soluble fiber-forming material and have a diameter of about 50 microns to about 300 microns, about 100 microns to about 300 microns, about 150 microns to about 300 microns or about 200 microns to about 300 microns. In an embodiment, the plurality of water-soluble fibers used to prepare the water-dispersible nonwoven fabric of the present disclosure have a substantially uniform diameter. As used herein, if the difference in diameter between fibers is less than 10% (such as 8% or less, 5% or less, 2% or less, or 1% or less), the fiber diameters are "substantially uniform". Fibers with substantially uniform diameters can be prepared by a wet cooling gel spinning process or a thermoplastic fiber spinning, as described herein. Additionally, when using a fiber blend, the average fiber diameter can be determined using a weighted average of the individual fibers.

[0114] The fibers of the present disclosure for preparing the nonwoven fabrics and nonwoven composite articles of the present disclosure can generally have any length. In embodiments, the fiber length can be in the range of about 20 mm to about 100 mm, about 20 to about 90, about 30 mm to about 80 mm, about 10 mm to about 60 mm, or about 30 mm to about 60 mm, such as at least about 30 mm, at least about 35 mm, at least about 40 mm, at least about 45 mm or at least about 50 mm and at most about 100 mm, at most about 95 mm, at most about 90 mm, at most about 80 mm, at most about 70 mm or at most about 60 mm. In embodiments, the length of the water-soluble fiber can be less than about 30 mm or in the range of about 0.25 mm to less than about 30 mm, such as at least about 0.25 mm, at least about 0.5 mm, at least about 0.75 mm, at least about 1 mm, at least about 2.5 mm, at least about 5 mm, at least about 7.5 mm, or at least about 10 mm and at most about 29 mm, at most about 28 mm, at most about 27 mm, at most about 26 mm, at most about 25 mm, at most about 20 mm or at most about 15 mm. The fibers can be made to any length by cutting and / or crimping the extruded polymer blend. In embodiments, the fibers can be continuous filaments, such as continuous filaments prepared by processes such as spunbonding, meltblowing, electrospinning, and vortex spinning, where the continuous filaments are prepared in fabric form and provided directly. Additionally, when using a fiber blend, the average fiber length can be determined using the weighted average of the individual fibers.

[0115] The fibers of the present disclosure can generally have any length-to-diameter ratio. In embodiments, the length-to-diameter ratio of the fibers can be greater than about 2, greater than about 3, greater than about 4, greater than about 6, greater than about 10, greater than about 50, greater than about 60, greater than about 100, greater than about 200, greater than about 300, greater than about 400, or greater than about 1000.

[0116] The fibers used to prepare the nonwoven fabrics of the present disclosure can generally have any toughness. Fiber toughness is related to fiber roughness. Generally speaking, when the fiber toughness decreases, the fiber roughness increases. The fibers used to prepare the nonwoven fabrics of the present disclosure can have a toughness within the following ranges: about 1 to about 100 cN / dtex, or about 1 to about 75 cN / dtex, or about 1 to about 50 cN / dtex, or about 1 to about 45 cN / dtex, or about 1 to about 40 cN / dtex, or about 1 to about 35 cN / dtex, or about 1 to about 30 cN / dtex, or about 1 to about 25 cN / dtex, or about 1 to about 20 cN / dtex, or about 1 to about 15 cN / dtex, or about 1 to about 10 cN / dtex, or about 1 to about 5 cN / dtex, or about 3 to about 8 cN / dtex, or about 4 to about 8 cN / dtex, or about 6 to about 8 cN / dtex, or about 4 to about 7 cN / dtex, or about 10 to about 20, or about 10 to about 18, or about 10 to about 16, or about 1 cN / dtex, about 2 cN / dtex, about 3 cN / dtex, about 4 cN / dtex, about 5 cN / dtex, about 6 cN / dtex, about 7 cN / dtex, about 8 cN / dtex, about 9 cN / dtex, about 10 cN / dtex, about 11 cN / dtex, about 12 cN / dtex, about 13 cN / dtex, about 14 cN / dtex or about 15 cN / dtex. In embodiments, the fibers can have a toughness of about 3 cN / dtex to about 10 cN / dtex. In embodiments, the fibers can have a toughness of about 7 cN / dtex to about 10 cN / dtex. In embodiments, the fibers can have a toughness of about 4 cN / dtex to about 8 cN / dtex. In embodiments, the fibers can have a toughness of about 6 cN / dtex to about 8 cN / dtex.

[0117] In embodiments where the fibers are prepared using a wet cooling gel spinning process, the resulting fibers can generally have any toughness as described herein. In an improvement of the above embodiments, the fibers can have a toughness within the following ranges: about 3 to about 15, about 3 to about 13, about 3 cN / dtex to about 10 cN / dtex, about 5 cN / dtex to about 10 cN / dtex, or about 6 cN / dtex to about 10 cN / dtex, about 7 cN / dtex to about 10 cN / dtex, about 4 cN / dtex to about 8 cN / dtex, or about 6 cN / dtex to about 8 cN / dtex.

[0118] The fibers used to prepare the nonwoven fabrics of the present disclosure can generally have any fineness. The fineness of a fiber is related to the mass per unit length of the fiber. The main physical unit of fiber fineness is 1 tex, which is equal to 1 g of fiber for 1000 m. Typically, the unit dtex is used, which represents 1 g of fiber for 10,000 m. To provide nonwoven fabrics having suitable hardness / handle, torsional stiffness, light reflection and interaction, absorption of dyes and / or other active agents / additives, ease of fiber spinning in the manufacturing process, and uniformity of the finished product, the fineness of the fibers can be selected. Generally speaking, when the fineness of the fibers increases, the nonwoven fabrics obtained therefrom exhibit higher uniformity, improved tensile strength, ductility, and luster. Additionally, without wishing to be bound by theory, based on density, it is believed that finer fibers result in slower dissolution times compared to larger fibers. Additionally, without wishing to be bound by theory, when using a fiber blend, the average fineness of the fibers can be determined using the weighted average of the individual fiber components. Fibers can be characterized as very fine (dtex ≤ 1.22), fine (1.22 ≤ dtex ≤ 1.54), medium (1.54 ≤ dtex ≤ 1.93), slightly coarse (1.93 ≤ dtex ≤ 2.32), and coarse (dtex ≥ 2.32). The nonwoven fabrics of the present disclosure can include very fine, fine, medium, slightly coarse, or a combination thereof. In embodiments, the fibers have a fineness in the range of about 1 dtex to about 10 dtex, about 1 dtex to about 7 dtex, about 1 dtex to about 5 dtex, about 1 dtex to about 3 dtex, or about 1.7 dtex to about 2.2 dtex. In embodiments, the fibers have a fineness of about 1.7 dtex. In embodiments, the fibers have a fineness of about 2.2 dtex.

[0119] Multiple water-soluble fibers can be prepared by any process known in the art, such as thermoplastic fiber spinning, wet cooling gel spinning, meltblowing, spunbonding, electrospinning, rotary spinning, continuous filament production operations, tow fiber production operations, and combinations thereof.

[0120] Wet cooling gel spinning

[0121] In embodiments, the multiple fibers include fibers prepared according to a wet cooling gel spinning process, the wet cooling gel spinning process comprising the following steps

[0122] (a) Dissolving a fiber-forming polymer (or polymer) in a solution to form a polymer mixture, the polymer mixture optionally including an auxiliary agent;

[0123] (b) Extruding the polymer mixture through a spinneret nozzle into a coagulation bath to form an extruded polymer mixture;

[0124] (c) Passing the extruded polymer mixture through a solvent exchange bath;

[0125] (d) Optionally, the polymer mixture wet-spun and extruded; and

[0126] (e) Finish-processing the extruded polymer mixture to provide the fibers.

[0127] The solvent in which the fiber-forming polymer is dissolved may suitably be any solvent in which the polymer is soluble. In an embodiment, the solvent for dissolving the polymer includes polar aprotic solvents. In an embodiment, the solvent for dissolving the polymer includes dimethyl sulfoxide (DMSO).

[0128] Generally, the coagulation bath includes a cooling solvent for gelling the extruded polymer mixture. The coagulation bath can generally be at any temperature that promotes the coagulation of the extruded polymer mixture. The coagulation bath can include a mixture of a solvent in which the polymer is soluble and a solvent in which the polymer is insoluble. The solvent in which the polymer is insoluble is generally the main solvent, where the solvent in which the polymer is insoluble accounts for more than 50% of the mixture.

[0129] After passing through the coagulation bath, the extruded polymer mixture can pass through one or more solvent exchange baths. The solvent exchange baths are provided to replace the solvent in which the polymer is soluble with a solvent in which the polymer is insoluble to further coagulate the extruded polymer mixture, and to replace the solvent in which the polymer is soluble with a solvent that evaporates more readily, thereby shortening the drying time. The solvent exchange baths can include: a series of solvent exchange baths having a solvent gradient in which the solvent in which the polymer is soluble is replaced with a solvent in which the polymer is insoluble; a series of solvent exchange baths having only the solvent in which the polymer is insoluble; or a single solvent exchange bath having only the solvent in which the polymer is insoluble.

[0130] The finished fibers are sometimes referred to as staple fibers, ultra-short fibers, or pulp. In an embodiment, the finish-processing includes drying the extruded polymer mixture. In an embodiment, the finish-processing includes cutting or crimping the extruded polymer mixture to form individual fibers. Wet-spinning the extruded polymer mixture provides a substantially uniform diameter for the extruded polymer mixture and thus for the fibers cut therefrom. As is well known in the art, spinning is different from extrusion. Specifically, extrusion refers to the operation of forcing a resin mixture through a spinneret to make fibers, while spinning refers to mechanically pulling the fibers in the processing direction to promote the orientation and crystallinity of the polymer chains to increase the strength and toughness of the fibers.

[0131] In embodiments of preparing fibers using a wet cooling gel spinning process, the fiber-forming polymer can generally be any fiber-forming polymer or blends thereof, such as two or more different polymers, as generally described herein. In an improvement of the above embodiments, the polymer can have any degree of polymerization (DP), for example in the range of 10 to 10,000,000, such as at least 10, at least 20, at least 50, at least 100, at least 200, at least 300, at least 400, at least 500, at least 750 or at least 1000, and at most 10,000,000, at most 5,000,000, at most 2,500,000, at most 1,000,000, at most 900,000, at most 750,000, at most 500,000, at most 250,000, at most 100,000, at most 90,000, at most 75,000, at most 50,000, at most 25,000, at most 12,000, at most 10,000, at most 5,000 or at most 2,500, for example in the following ranges: 1000 to about 50,000, 1000 to about 25,000, 1000 to about 12,000, 1000 to about 5,000, 1000 to about 2,500, about 50 to about 12,000, about 50 to about 10,000, about 50 to about 5,000, about 50 to about 2,500, about 50 to about 1000, about 50 to about 900, about 100 to about 800, about 150 to about 700, about 200 to about 600, or about 250 to about 500. In an embodiment, the DP is at least 1,000. In an embodiment, the fiber-forming polymer comprises a polyvinyl alcohol polymer having a DP in the following ranges: 1000 to about 50,000, 1000 to about 25,000, 1000 to about 12,000, 1000 to about 5,000, 1000 to about 2,500, about 50 to about 12,000, about 50 to about 10,000, about 50 to about 5,000, about 50 to about 2,500, about 50 to about 1000, about 50 to about 900, about 100 to about 800, about 150 to about 700, about 200 to about 600, or about 250 to about 500. In an embodiment, the fiber-forming polymer comprises polyvinyl alcohol having a DP in the range of 1000 to about 50,000, 1000 to about 25,000, 1000 to about 12,000, 1000 to about 5,000 or 1000 to about 2,500.

[0132] Thermoplastic fiber spinning

[0133] Thermoplastic fiber spinning is well known in the art. Briefly, thermoplastic fiber spinning includes the following steps:

[0134] (a) Preparing a polymer blend comprising a fiber-forming polymer, which optionally includes additives;

[0135] (b) Extrude the polymer mixture through a spinneret nozzle to form an extruded polymer mixture;

[0136] (c) Optionally draw the extruded polymer mixture; and

[0137] (d) Finish processing the extruded polymer mixture to provide the fiber.

[0138] The staple fibers that are the finished product of the thermoplastic fiber spinning process can be finish processed by drying, cutting, and / or crimping to form individual fibers. Drawing the extruded polymer mixture mechanically pulls the fiber in the processing direction, promoting polymer chain orientation and crystallinity to increase fiber strength and toughness. Preparing the polymer mixture into thermoplastic fibers typically includes (a) preparing a solution of the fiber-forming material and a volatile solvent so that after the solution is extruded through a spinneret, the solution contacts a hot air stream and the solvent easily evaporates leaving solid fibers, or (b) melting the polymer so that after the hot polymer is extruded through a spinneret, the polymer is solidified by quenching with cold air. The thermoplastic fiber spinning method differs from the wet cooling gel spinning method at least in that (a) in the thermoplastic fiber spinning method, the extruded fiber is solidified by solvent evaporation or by quenching the hot solid fiber with cold air rather than by using a coagulation bath; and (b) in the wet cooling gel spinning method, drawing is optionally carried out while the fiber is in a gel state rather than a solid state.

[0139] The fiber-forming material for preparing fibers using the thermoplastic fiber spinning process can generally be any fiber-forming polymer or its blend, such as two or more different polymers, provided that the polymer or its blend has a suitable solubility in a volatile solvent and / or has a melting point below and different from its degradation temperature. Additionally, when manufacturing fibers using a blend of fiber-forming polymers, the fiber-forming material must have a similar solubility in the volatile solvent and / or have a similar thermal profile. In contrast, the fiber-forming material for preparing fibers using the wet cooling gel spinning process is not restricted, and the fibers can be prepared from a blend of any two or more polymers dissolved in the same solvent system, and the solvent system does not necessarily have to be a single solvent or even a volatile solvent.

[0140] The fiber-forming polymer for preparing thermoplastic fiber spinning can have a degree of polymerization (DP) in the range of, for example, 10 to 10,000, such as at least 10, at least 20, at least 50, at least 100, at least 200, at least 300, at least 400, at least 500, at least 750, or at least 1000 and at most 10,000, at most 5,000, at most 2,500, at most 1,000, at most 900, at most 750, at most 500, or at most 250. In an embodiment, the DP is less than 1,000.

[0141] Melt spinning

[0142] Melt spinning is well known in the art and is to be understood to mean both the spunbond process and the meltblown process. Melt spinning is a continuous process which directly produces a nonwoven fabric while forming the fibers. Thus, the fibers formed by melt spinning are not subjected to finishing and cutting to any constant length (e.g., staple fibers are not produced by these processes). Additionally, melt spinning does not include a drawing step, and thus the only control over the diameter of the resulting melt spun fibers is the size of the orifice through which the fiber forming material is extruded, and the polymer chains typically are not oriented in any specific orientation.

[0143] Briefly, melt spinning comprises the following steps:

[0144] (a) preparing a polymer blend comprising a fiber forming polymer, which optionally comprises additives;

[0145] (b) extruding the polymer blend into a die assembly to form an extruded polymer blend;

[0146] (c) quenching the extruded polymer blend;

[0147] (d) depositing the quenched, extruded polymer blend onto a conveyor belt to form a nonwoven fabric; and

[0148] (e) bonding the nonwoven fabric.

[0149] In the spunbond process, the extruded polymer blend is drawn into the die assembly as a molten polymer and quenched by cold air after passing through the die assembly. In the meltblown process, the extruded polymer blend is drawn into a die assembly that is sprayed with hot air and quenched when it exits the die assembly and contacts ambient temperature air. In both processes, the fibers are continuously dripped onto a conveyor belt or drum, which is typically facilitated by evacuating the area beneath the conveyor belt or drum.

[0150] The diameter of spunbond fibers typically ranges from about 0.1 to about 50 microns, such as at least about 0.1 micron, at least about 1 micron, at least about 2 microns, at least about 5 microns, at least about 10 microns, at least about 15 microns or at least about 20 microns and at most about 50 microns, at most about 40 microns, at most about 30 microns, at most about 25 microns, at most about 20 microns, at most about 15 microns, at most about 10 microns, from about 0.1 micron to about 50 microns, from about 0.1 micron to about 40 microns, from about 0.1 micron to about 30 microns, from about 0.1 micron to about 25 microns, from about 0.1 micron to about 20 microns, from about 0.1 micron to about 15 microns, from about 0.1 micron to about 10 microns, from about 0.1 micron to about 9 microns, from about 0.1 micron to about 8 microns, from about 0.1 micron to about 7 microns, from about 0.1 micron to about 6 microns, from about 0.1 micron to about 6 microns, from about 5 microns to about 35 microns, from about 5 microns to about 30 microns, from about 7.5 microns to about 25 microns, from about 10 microns to about 25 microns, or from about 15 microns to about 25 microns. It is well known in the art that the meltblowing process can provide fine fibers with an average diameter in the range of about 1 to 10 microns. However, there is a very high variation in the fiber diameters obtained by the meltblowing process, such as a 100 - 300% variation. Additionally, it is well known in the art that spunbond fibers can have a relatively large average fiber diameter, for example typically about 15 to about 25 microns, but with improved uniformity between the fibers, such as about 10% variation.

[0151] The fiber-forming materials used in thermal extrusion processes (such as melt spinning, thermoplastic fiber spinning) are more restricted than those used in wet cooling gel spinning processes. Generally, the degree of polymerization in thermal extrusion processes is limited to the range of about 200 to about 500. When the degree of polymerization is reduced below 200, the viscosity of the fiber-forming material is too low, and the individual fibers prepared by sucking the material through the die assembly cannot maintain sufficient separation after leaving the die assembly. Similarly, when the degree of polymerization is increased above 500, the viscosity is too high to efficiently suck the material through small enough holes in the die assembly, thus preventing the process from running at high speed, resulting in the loss of process efficiency and the uniformity of the fibers and / or nonwoven fabric. Additionally, since homopolymers generally do not have the required thermal stability, processes that require heating the fiber-forming material are not suitable for polyvinyl alcohol homopolymers. Moreover, it is known that polymers that can be melt processed are those with a viscosity of 5 cP or less. Therefore, the wet cooling gel spinning process can advantageously provide fibers from polymers (including polyvinyl alcohol homopolymers and copolymers) with a viscosity greater than 5 cP that would otherwise be unable to be processed into fibers.

[0152] The wet cooling gel spinning process advantageously provides one or more benefits, such as providing fibers including water-soluble polymer blends, providing control over fiber diameter, providing fibers of relatively large diameter, providing control over fiber length, providing control over fiber toughness, providing high-strength fibers, providing fibers of polymers having a large degree of polymerization, and / or providing fibers that can be used to provide self-supporting nonwoven fabrics. Continuous processes (such as spunbond, meltblown, electrospinning, and vortex spinning) generally do not contemplate blending water-soluble polymers (e.g., due to difficulties in matching the melt indices of different polymers), forming large diameter (e.g., greater than 50 microns) fibers, controlling fiber length, providing high-strength fibers, and using polymers having a high degree of polymerization. Additionally, the wet cooling gel spinning process has the advantage of not being limited to only melt-processable polymers and can thus obtain fibers made from fiber-forming materials having an extremely high molecular weight, high melting point, low melt flow index, or a combination thereof, providing fibers with physical properties stronger than those of fibers prepared by the hot extrusion process and different chemical functional groups.

[0153] Non - woven Fabric

[0154] The nonwoven fabrics of the present disclosure are generally sheet-like structures having two outer surfaces, and the nonwoven fabrics include a plurality of fibers. As used herein and unless otherwise specified, the "outer surface" of a nonwoven fabric refers to the surface of the sheet-like structure, at Figure 2are represented as 100 and 101 in the figure. A nonwoven fabric generally refers to an arrangement of fibers bonded to each other, where the fibers are neither woven nor knitted. Generally, multiple fibers can be arranged in any orientation. In an embodiment, the multiple fibers are randomly arranged (i.e., without a certain orientation). In an embodiment, the multiple fibers are arranged in a unidirectional orientation. In an embodiment, the multiple fibers are arranged in a bidirectional orientation. In some embodiments, the multiple fibers are in multiple directions and have different arrangements in different regions of the nonwoven fabric. In an embodiment, the nonwoven fabric can include a single type of water-soluble fiber. In an embodiment, the nonwoven fabric can include a single type of non-water-soluble fiber. In an embodiment, the nonwoven fabric can include a single type of water-soluble fiber and one or more different types of non-water-soluble fibers. In an embodiment, the nonwoven fabric can include one or more different types of water-soluble fibers and one or more different types of non-water-soluble fibers. In an embodiment, the nonwoven fabric can be composed of or substantially composed of water-soluble fibers. In an embodiment, the nonwoven fabric can be composed of or substantially composed of non-water-soluble fibers. In some embodiments, the nonwoven fabric can include not only a single type of fiber-forming material (i.e., all fibers have the same composition of fiber-forming material), but also fibers prepared by one or more fiber-forming processes, such as wet cooling gel spinning, thermoplastic fiber spinning, meltblowing, spunbonding, or a combination thereof. In some embodiments, the nonwoven fabric can include a single type of fiber-forming material and the fibers are made by a single fiber-forming process. In some embodiments, the nonwoven fabric can include two or more fiber-forming materials (such as a fiber blend of fiber-forming materials with different compositions, fibers including a fiber-forming material blend, or both) and the fibers can be prepared by one or more fiber-forming processes, such as wet cooling gel spinning, thermoplastic fiber spinning, meltblowing, spunbonding, or a combination thereof. In some embodiments, the nonwoven fabric can include two or more fiber-forming materials and the fibers are made by a single fiber-forming process. In an embodiment, the fibers of the nonwoven fabric can have substantially the same diameter or different diameters.

[0155] In embodiments where the nonwoven fabric of the present disclosure includes a blend of water-soluble fibers (including a first water-soluble fiber and a second water-soluble fiber), the first and second water-soluble fibers can differ in diameter, length, toughness, shape, rigidity, elasticity, solubility, melting point, glass transition temperature (T g ), fiber-forming material, color, or a combination thereof. In embodiments where the nonwoven fabric of the present disclosure includes a blend of non-water-soluble fibers (including a first non-water-soluble fiber and a second non-water-soluble fiber), the first and second non-water-soluble fibers can differ in diameter, length, toughness, shape, rigidity, elasticity, solubility, melting point, glass transition temperature, fiber-forming material, color, or a combination thereof.

[0156] Generally, a nonwoven fabric can be characterized by the average degree of hydrolysis of the polyvinyl alcohol fiber-forming material used to make the nonwoven fabric fibers. If the nonwoven fabric consists of a single fiber type, the degree of hydrolysis of the nonwoven fabric is the same as that of the single fiber type. In embodiments, the nonwoven fabrics of the present disclosure can include a fiber blend in which the various fibers have different degrees of hydrolysis. In such cases, the degree of hydrolysis of the nonwoven fabric is the arithmetic weighted average of the degrees of hydrolysis of the individual fiber types. In embodiments in which the nonwoven fabric is layered to prepare a nonwoven article, the degree of hydrolysis of the nonwoven article is the arithmetic weighted average of the degrees of hydrolysis of the individual fabric layers. In embodiments in which the nonwoven fabric or article is to be used for wicking (e.g., a wearable where liquid is drawn away from the user's skin), the fabric or article can have an average degree of hydrolysis in the range of about 95-99.9%, about 96-99%, or about 97-98%. In embodiments in which the nonwoven fabric or article is to be used for liquid absorption capacity (e.g., a paper towel for cleaning up spills), the fabric or article can have an average degree of hydrolysis in the range of about 93-97%, about 94-96%, or about 95% and can additionally be bonded with air-laid bonding rather than calender bonding. As shown in the examples below, when a nonwoven fabric with a similar composition is bonded with air-laid bonding compared to a nonwoven fabric bonded with calender bonding, the liquid absorption capacity is significantly increased. The air-laid bonded nonwoven fabric includes a thermoplastic fiber material in an amount of 5 wt.% or less (based on the total weight of the fibers) to facilitate bonding. Without wishing to be bound by theory, it is believed that the higher the degree of bonding of the nonwoven fabric, the lower the liquid absorption capacity. Therefore, it is further believed that the bonding conditions can be selected to increase the liquid absorption capacity of the nonwoven fabric prepared from a specified fiber type. Without wishing to be bound by theory, it is believed that air-laid bonding provides a nonwoven fabric with greater absorbency than calender bonding, and as the residence time of the calender-bonded nonwoven fabric increases, the absorption capacity decreases.

[0157] Nonwoven Fabric Manufacturing Method

[0158] Any method known in the art can be used to prepare the nonwoven fabrics of the present disclosure from fibers. As is known in the art, when fibers are spunbonded or meltblown, the fibers are continuously laid down to form a nonwoven fabric, and then the fibers are bonded.

[0159] To provide a nonwoven fabric, staple fibers can be carded or airlaid and bonded. The methods of carding and air laying are well known in the art. Additionally, as is known in the art, since the strength of a carded fabric in the machine direction is typically greater than that in the cross direction due to the orientation of the fibers during carding, the carding process typically uses two doffer cylinders to provide a double-layer type carded fabric having a first layer with a first strength in the cross direction and a second layer with a second strength in the cross direction to impart additional strength in the cross direction to the entire carded nonwoven fabric. As used herein and unless otherwise specified, the term "carded nonwoven fabric" encompasses single-layer type carded nonwoven fabrics as well as multi-layer type (e.g., two-layer, three-layer, etc.) carded nonwoven fabrics. Thus, it should be understood that when such a double-layer type carded nonwoven fabric is used as a layer in the composite articles of the present disclosure, the double-layer type carded nonwoven fabric is considered a single layer. As is known in the art, air laying is similar to carding, but in which the fibers are blown by a cylinder onto a conveyor belt or drum using a vacuum, and due to air disturbance, the airlaid nonwoven fabric typically does not have a directionality when the fibers are oriented. Thus, the strength of the airlaid nonwoven fabric in the machine direction and the cross direction is typically equal.

[0160] Methods for bonding nonwoven fabrics are well known in the art. Generally, bonding can include thermal bonding, mechanical bonding, and / or chemical bonding. Thermal bonding can include (but is not limited to) calendering, embossing, air guiding, and ultrasonic. Mechanical bonding can include (but is not limited to) hydroentanglement (spunlace), needling, and stitch bonding. Chemical bonding can include (but is not limited to) solvent bonding and resin bonding.

[0161] Thermal bonding is typically achieved by applying heat and pressure and typically maintains the pore size, shape, and orientation generated by the carding / melt spinning process. One of ordinary skill in the art can readily determine the thermal bonding conditions. Generally speaking, if the applied heat and / or pressure is too low, the bonding of the fibers is insufficient to form a self-standing fabric, and if the heat and / or pressure is too high, the fibers start to weld together. The fiber chemistry determines the upper and lower limits of the heat and / or pressure used for thermal bonding. Without wishing to be bound by theory, it is believed that above a temperature of 235 °C, polyvinyl alcohol-based fibers degrade. Calender bonding, also known as hot spot bonding in the art, utilizes an engraved calender roll and a smooth counter roll to locally apply heat and pressure to form a film-like reinforcement structure throughout the nonwoven fabric. Calendering can be used with nonwoven fabrics formed by any of the methods disclosed herein. Generally, calendered melt-spun nonwoven fabrics have a typical bonding area of about 10-25% of the nonwoven fabric surface, and calendered carded nonwoven fabrics have a typical bonding area of about 20% or greater. The bonding point arrangement can be hexagonal, rectangular, etc., and each point of the bonding pattern can be shaped, for example, like a rhombus and an ellipse. It is well recognized in the art that elliptical bonding makes the bonding area smoother and increases the strength. Embossing methods for fiber thermal bonding are known. Embossing can be single-sided embossing or double-sided embossing. Typically, embossing of water-soluble fibers includes single-sided embossing using a single embossing roll composed of an ordered circular array and a steel roll with a flat surface. As the embossing increases (e.g., as surface features are imparted to the fabric), the surface area of the fabric increases. Without wishing to be bound by theory, it is expected that as the surface area of the fabric increases, the solubility of the fabric increases. Thus, changing the surface area by embossing can advantageously regulate the dissolution properties of the nonwoven fabric.

[0162] Airflow bonding typically requires a high thermoplastic content and two materials with different melting points in the nonwoven fabric. In airflow bonding, the non-bonded nonwoven fabric rotates around a drum while hot air flows from the outside of the drum towards the center of the drum. Airflow bonding can provide nonwoven fabrics with low density and a relatively high basis weight (e.g., greater than 20 to about 2000 g / m 2 ). Nonwoven fabrics bonded by the air bonding method are typically very soft.

[0163] Hydroentanglement, also known as hydrospun or spunlace in the art, is achieved by bringing the nonwoven fabric into contact with an array of high-pressure water jets that physically entangle the fibers of the nonwoven fabric. Nonwoven fabrics bonded by the hydrospun method are generally soft and have cloth-like properties, can have a high elongation rate in the cross-direction, can have high strength in the machine direction, and do not contain chemical binders and do not contain embossing as a result of thermal bonding.

[0164] Chemical bonding generally includes solvent bonding and resin bonding. Specifically, chemical bonding typically utilizes an adhesive solution of a solvent and a resin (such as the latex or waste polymer left over from fiber preparation). The nonwoven fabric can be coated with the adhesive solution and heat and pressure are applied to cure the adhesive and bond the nonwoven fabric. The adhesive solution can be applied as follows: immersing the nonwoven fabric in an adhesive solution bath, spraying the adhesive solution onto the nonwoven fabric, extruding the adhesive solution onto the fabric (foam bonding), and / or applying the adhesive solution in a printing or gravure printing manner.

[0165] Relative to the pores generated by carding / melt spinning, chemical bonding can produce smaller and less ordered pores. Without wishing to be bound by theory, it is believed that if the resin solution used for chemical bonding has a sufficient concentration and / or sufficient pressure is applied, a pore-free water-dispersible nonwoven fabric can be formed. The solvent used for chemical bonding induces partial dissolution of the existing fibers in the fabric to weld and bond the fibers together. Thus, generally speaking, the solvent used for chemical bonding can be any solvent capable of at least partially dissolving one or more of the fiber-forming materials of the nonwoven fabric fibers. In an embodiment, the solvent is selected from the group consisting of water, ethanol, methanol, DMSO, glycerol, and combinations thereof. In an embodiment, the solvent is selected from the group consisting of water, glycerol, and combinations thereof. In an embodiment, the adhesive solution contains a solvent selected from the group consisting of water, ethanol, methanol, DMSO, glycerol, and combinations thereof, and further contains a resin selected from the group consisting of polyvinyl alcohol, latex, and polyvinylpyrrolidone. The adhesive provided in the solution helps with the welding process to provide a mechanically more robust fabric. The temperature of the polymer solution is not particularly limited and can be provided at room temperature (about 23 °C).

[0166] In some embodiments, a second layer of fibers can be used to bond the nonwoven fabric. In an embodiment, at least one nonwoven layer of the composite article of the present disclosure is bonded using a second nonwoven fabric / fiber. In an embodiment, at least two nonwoven layers of the composite article of the present disclosure are bonded using another nonwoven fabric / fiber. In an embodiment, at least one nonwoven layer of the composite article of the present disclosure is bonded using heat bonding, mechanical bonding, or chemical bonding alone or in addition to bonding using another nonwoven fabric / fiber.

[0167] Basis weight / porosity

[0168] Nonwoven fabrics can be characterized by basis weight. The basis weight of a nonwoven fabric is the mass per unit area of the nonwoven fabric. As is known in the art, the basis weight can be modified by changing the manufacturing conditions. The nonwoven fabric can have the same basis weight before and after bonding. Alternatively, the bonding method can change the basis weight of the nonwoven fabric. For example, in the case of bonding by applying heat and pressure, the thickness (and thus the area) of the nonwoven fabric can be reduced, thereby increasing the basis weight. Thus, as used herein and unless otherwise specified, the basis weight of a nonwoven fabric refers to the basis weight of the nonwoven fabric after bonding.

[0169] The nonwoven fabrics of the present disclosure can generally have any basis weight within the following ranges: from about 0.1 g / m 2 to about 700 g / m 2 、from about 0.5 g / m 2 to about 600 g / m 2 、from about 1 g / m 2 to about 500 g / m 2 、from about 1 g / m 2 to about 400 g / m 2 、from about 1 g / m 2 to about 300 g / m 2 、from about 1 g / m 2 to about 200 g / m 2 、from about 1 g / m 2 to about 100 g / m 2 、from about 30 g / m 2 to about 100 g / m 2 、from about 20 g / m 2 to about 100 g / m 2 、from about 20 g / m 2 to about 80 g / m 2 ,or from about 25 g / m 2 to about 70 g / m 2 。

[0170] In an embodiment, the nonwoven fabric can be carded and have a basis weight of from about 5 g / m 2 to about 15 g / m 2 、from about 7 g / m 2 to about 13 g / m 2 、from about 9 g / m 2 to about 11 g / m 2 、or about 10 g / m 2 。In an embodiment, the nonwoven fabric can be carded and can have a basis weight of 30 g / m 2 or greater, such as from 30 g / m 2 to about 70 g / m 2 、from about 30 g / m2 to about 60 g / m 2 、about 30 g / m 2 to about 50 g / m 2 、about 30 g / m 2 to about 40 g / m 2 、or about 30 g / m 2 to about 35 g / m 2 in the basis weight range. In an embodiment, the nonwoven fabric can be melt-spun and have a basis weight of about 1 g / m 2 to about 20 g / m 2 、about 2 g / m 2 to about 15 g / m 2 、about 3 g / m 2 to about 10 g / m 2 、about 5 g / m 2 to about 15 g / m 2 、about 7 g / m 2 to about 13 g / m 2 、about 9 g / m 2 to about 11 g / m 2 or about 10 g / m 2 in the basis weight range. In an embodiment, the nonwoven fabric can be melt-spun and can have a basis weight of about 0.1 g / m 2 to about 10 g / m 2 、about 0.1 g / m 2 to about 8 g / m 2 、about 0.2 g / m 2 to about 6 g / m 2 、about 0.3 g / m 2 to about 4 g / m 2 、about 0.4 g / m 2 to about 2 g / m 2 or about 0.5 g / m 2 to about 1 g / m 2 of the basis weight.

[0171] Related to the basis weight are the fiber volume density and porosity of the nonwoven fabric. A nonwoven fabric that has been prepared and prior to bonding typically has a fiber density of about 30 volume % or less, i.e., for a specified volume of the nonwoven fabric, 30% or less of the volume is composed of fibers and the remaining volume is air. Thus, the porosity of the nonwoven fabric is typically high. The fiber volume density and porosity of the nonwoven fabric are inversely related characteristics. For example, a nonwoven fabric having a fiber volume density of about 30 volume % will have a porosity of about 70 volume %. It is well understood in the art that as the fiber volume density increases, the porosity decreases. The fiber volume density can be increased by increasing the basis weight of the nonwoven fabric, for example, by applying heat and pressure to effect bonding, thereby potentially reducing the thickness (and thus the volume) of the nonwoven fabric. Thus, as used herein and unless otherwise specified, the fiber volume density and porosity of the nonwoven fabric refer to the fiber volume density and porosity of the nonwoven fabric after bonding.

[0172] The nonwoven fabrics of the present disclosure can generally have any porosity in the range of about 50% to about 95%, such as at least about 50%, at least about 60%, at least about 70%, at least about 75% or at least about 80% and at most about 95%, at most about 90%, at most about 85%, at most about 80%, at most about 75%, at most about 70%, or any porosity in the range of about 50% to about 95%, about 50% to about 80%, about 50% to about 70%, about 60% to about 75%, about 60% to about 80%, about 60% to about 90%, about 75% to about 85%, about 75% to about 90% or about 75% to about 95%.

[0173] The pore size can be determined using high magnification and ordered surface analysis techniques, including (but not limited to) the Brunauer-Emmett-Teller theory (BET), small angle X-ray scattering (SAXS), and molecular adsorption.

[0174] The nonwoven fabrics of the present disclosure can generally have any thickness. Suitable thicknesses can include (but are not limited to) from about 5 to about 10,000 μm (1 cm), from about 5 to about 5,000 μm, from about 5 to about 1,000 μm, from about 5 to about 500 μm, from about 200 to about 500 μm, from about 5 to about 200 μm, from about 20 to about 100 μm, or from about 40 to about 90 μm, or from about 50 to 80 μm, or from about or about 60 to 65 μm, such as 50 μm, 65 μm, 76 μm or 88 μm. The nonwoven fabrics of the present disclosure can be characterized as high-loft or low-loft. Generally speaking, loft refers to the ratio of thickness to basis weight. High-loft nonwoven fabrics can be characterized by a high ratio of thickness to basis weight. As used herein, "high-loft" means that the nonwoven fabrics of the present disclosure have a basis weight as defined herein and a thickness of more than 200 μm. The thickness of the nonwoven fabric can be determined in accordance with ASTM D5729-97, ASTM D5736 and ISO 9073-2:1995 and can include, for example, applying a 2 N load to the nonwoven fabric and measuring the thickness. High-loft materials can be used according to methods known in the art, such as airlaid bonding or cross-laying, where cross-laying is folding the unbonded fabric on itself using a cross-laying machine to build loft and basis weight. Without wishing to be bound by theory, it is not believed that the solubility of nonwoven fabrics comprising water-soluble fibers depends on the thickness of the fabric, as opposed to water-soluble films where the film solubility can depend on the film thickness. In this regard, it is believed that the parameter that limits water access to the fibers and thus limits the dissolution of the fibers in the water-soluble nonwoven fabric is the basis weight, since the surface area provided by the individual fibers is higher than that of the water-soluble film, regardless of the thickness of the film.

[0175] The water solubility of the nonwoven fabric of the present disclosure is generally related to the type of fibers used to prepare the fabric and the basis weight of the nonwoven fabric. Without wishing to be bound by theory, it is believed that the solubility characteristic curve of the nonwoven fabric follows the same solubility characteristic curve of the fibers used to prepare the nonwoven fabric, and the solubility characteristic curve of the fibers generally follows the same solubility characteristic curve of the fiber-forming polymer. For example, for a nonwoven fabric containing PVOH fibers, the degree of hydrolysis of the PVOH polymer can be selected such that the water solubility of the nonwoven fabric is also affected. Generally, at a given temperature, as the degree of hydrolysis of the PVOH polymer increases from partial hydrolysis (88% DH) to complete hydrolysis (≥98% DH), the water solubility of the polymer generally decreases. Thus, in one option, the nonwoven fabric is soluble in cold water. For a (vinyl acetate vinyl alcohol) copolymer that does not include any other monomers (e.g., not copolymerized with anionic monomers), a cold water-soluble fabric that is soluble in water at a temperature below 10 °C may include PVOH fibers having a degree of hydrolysis in the range of about 75% to about 90% or in the range of about 80% to about 90% or in the range of about 85% to about 90%. In another option, the nonwoven fabric is soluble in hot water. For a (vinyl acetate vinyl alcohol) copolymer that does not include any other monomers (e.g., not copolymerized with anionic monomers), a hot water-soluble fabric that is soluble in water at a temperature of at least about 60 °C may include PVOH fibers having a degree of hydrolysis of at least about 98%.

[0176] PVOH modification generally increases the solubility of the PVOH polymer. Thus, it is expected that at a given temperature, the solubility of a nonwoven fabric prepared from a PVOH copolymer will be higher than that of a nonwoven fabric prepared from a PVOH homopolymer having the same degree of hydrolysis as the PVOH copolymer. Following these trends, water-soluble nonwoven fabrics with specific solubility characteristics can be designed by blending the polymers within the fibers and / or the fibers within the nonwoven fabric.

[0177] Incorporating non - water - soluble fibers into the non - woven fabric can also be used to design non - woven fabrics with specific solubility and / or delayed decomposition (e.g., when the non - woven fabric is incorporated into a flushable tissue). Without wishing to be bound by theory, it is believed that as the weight percentage of non - water - soluble fibers contained in the non - woven fabric increases (based on the total weight of the non - woven fabric), the solubility of the non - woven fabric generally decreases and the stability of the flushable wet wipe increases, thereby preventing decomposition during use and maintaining the flushing ability of the tissue. After contact with water at a temperature at or above the dissolution temperature of the water - soluble fibers, the non - woven fabric containing water - soluble fibers and non - water - soluble fibers begins to disperse as the water - soluble fibers dissolve, thereby causing the fabric structure to decompose and / or increasing the porosity of the non - woven fabric. Similarly, the delayed decomposition and / or dissolution of the non - woven fabrics of the present disclosure can be achieved using blends of water - soluble fibers having different dissolution characteristics and / or different dissolution temperatures. In embodiments where the non - woven fabric includes water - soluble fibers and non - water - soluble fibers, the ratio of soluble fibers to insoluble fibers is not particularly limited. The water - soluble fibers can account for about 1 wt% to about 99 wt%, about 20 wt% to about 80 wt%, about 40 wt% to about 90 wt%, about 50 wt% to about 90 wt%, or about 60 wt% to about 90 wt% of the total weight of the fibers, and the non - water - soluble fibers can account for about 1 wt% to about 99 wt%, about 20 wt% to about 80 wt%, about 10 wt% to about 60 wt%, about 10 wt% to about 50 wt%, or about 10 wt% to about 40 wt% of the total weight of the fibers.

[0178] In addition, for water - soluble non - woven fabrics, if the fiber composition remains constant, then as the basis weight of the fabric increases, the dissolution rate of the fabric decreases because there is more material to dissolve. For example, at a given temperature, it is expected that a water - soluble non - woven fabric prepared from fibers having a basis weight of, for example, 40 g / m 2 will have a slower dissolution rate than an otherwise identical water - soluble non - woven fabric having a basis weight of, for example, 30 g / m 2 . Therefore, the solubility characteristics of the non - woven fabric can also be adjusted using the basis weight. The non - woven fabric can generally have any basis weight within the following ranges: about 1 g / m 2 to about 700 g / m 2 , about 1 g / m 2 to about 600 g / m 2 , about 1 g / m 2 to about 500 g / m 2 , about 1 g / m 2 to about 400 g / m 2 , about 1 g / m 2 to about 300 g / m 2 , about 1 g / m 2 to about 200 g / m 2 to about 1 g / m2 to about 100 g / m 2 、about 30 g / m 2 to about 100 g / m 2 、about 20 g / m 2 to about 100 g / m 2 、about 20 g / m 2 to about 80 g / m 2 ,or about 25 g / m 2 to about 70 g / m 2 。

[0179] Without wishing to be bound by theory, it is believed that the solubility of the water-soluble nonwoven fabric (in terms of the time to achieve complete dissolution) is expected to exceed that of a water-soluble film of the same size (L×W) and / or mass prepared from the same PVOH polymer. This is due to the higher surface area found in the nonwoven fabric, which causes faster dissolution.

[0180] Mechanical properties

[0181] As is well understood in the art, the term machine direction (MD) refers to the direction in which the fabric travels when the nonwoven fabric is produced (e.g., on a commercial nonwoven fabric manufacturing apparatus). Similarly, the term cross direction (CD) refers to the direction in the plane of the fabric that is perpendicular to the machine direction. For a nonwoven composite article, a tissue, an absorbent article, or other article that includes the nonwoven composite article of the present disclosure, the terms refer to the corresponding directions of the article with respect to the nonwoven fabric used to produce the article.

[0182] The toughness of the nonwoven fabric can be the same as or different from the toughness of the fibers used to prepare the fabric. Without wishing to be bound by theory, it is believed that the toughness of the nonwoven fabric is related to the strength of the nonwoven fabric, where higher toughness provides higher strength to the nonwoven fabric. Generally, the toughness of the nonwoven fabric can be adjusted by using fibers with different toughnesses. Processing can also affect the toughness of the nonwoven fabric. Generally, the nonwoven fabrics of the present disclosure can have a relatively high toughness, i.e., the nonwoven fabric is a self-supporting fabric that can be used as a separate material to prepare articles and / or sacks. In an embodiment, the nonwoven fabric is a self-supporting fabric. In contrast, nonwoven fabrics prepared according to meltblown, electrospinning, and / or spinning processes typically have low toughness and may not be self-supporting or capable of being used as a separate fabric to form articles or sacks. Thus, in some embodiments, the nonwoven fabric is not self-supporting and is used in combination with a second nonwoven fabric.

[0183] In embodiments, the ratio of the toughness of the nonwoven fabric of the present disclosure in the machine direction to the toughness in the cross direction (MD:CD) is in the range of about 0.5 to about 1.5, about 0.75 to about 1.5, about 0.80 to about 1.25, about 0.90 to about 1.1, or about 0.95 to about 1.05 or about 1. In embodiments, the MD:CD toughness ratio of the nonwoven fabric of the present disclosure is from about 0.8 to about 1.25. In embodiments, the MD:CD toughness ratio of the nonwoven fabric of the present disclosure is from about 0.9 to about 1.1. In embodiments, the toughness of the nonwoven fabric of the present disclosure is about 1. Without wishing to be bound by theory, it is believed that when the MD:CD toughness ratio approaches 1, the durability of the nonwoven fabric increases, thus excellently resisting the decomposition of the nonwoven fabric when stress is applied to the nonwoven fabric during use (e.g., scrubbing with a flushable tissue containing the nonwoven fabric of the present disclosure, or traction / dragging of the nonwoven fabric caused by movement while wearing a wearable absorbent article).

[0184] Generally, the nonwoven fabric of the present disclosure has a rougher surface than a water-soluble film, thereby reducing the contact between the surface and the nonwoven fabric compared to the contact between the surface and the water-soluble film. Advantageously, this surface roughness results in a lower coefficient of kinetic friction of the nonwoven fabric and a lower ratio of the coefficient of static friction to the coefficient of kinetic friction compared to a similar film, improves the consumer's feel (i.e., a softer cloth-like feel rather than a rubbery feel), and / or improves the aesthetics (i.e., less gloss than a water-soluble film). Thus, the fibers should be rough enough to provide surface roughness to the resulting nonwoven fabric without being so rough as to cause drag.

[0185] Auxiliary components

[0186] The present disclosure may include adjuvants and / or treatment agents. When incorporated into the nonwoven fabric, the adjuvants and treatment agents may be dispersed throughout the fabric, such as between the fibers, or applied to one or more surfaces of the nonwoven fabric. The adjuvants may be added to the nonwoven fabric during the melt spinning process, as is well known in the art, which uses the "coform" process developed by Kimberly Clark. The adjuvants and treatment agents may include, but are not limited to, plasticizers, plasticizer compatibilizers, surfactants, lubricants, mold release agents, fillers, extenders, crosslinking agents, anti-caking agents, antioxidants, anti-sticking agents, defoaming agents, nanoparticles (such as layered silicate-type nanoclays (such as sodium montmorillonite)), bleaching agents (such as sodium metabisulfite, sodium bisulfite or others), repellents (such as bittering agents (such as denatonium salts, such as denatonium benzoate, denatonium saccharide and denatonium chloride; sucrose octaacetate; quinine; flavonoids, such as quercetin and naringenin; and carotenoids, such as amarogentin and strychnine) and pungent agents (such as capsaicin, piperine, allyl isothiocyanate, and resiniferatoxin), and other functional components, in amounts suitable for their intended purposes. Specific such adjuvants and treatment agents may be selected from those formulations suitable for water-soluble fibers or those formulations suitable for water-soluble films.

[0187] In an embodiment, the nonwoven fabric includes a plasticizer. When incorporated into the nonwoven fabric / onto the nonwoven fabric, the plasticizer may be, for example, any plasticizer or combination thereof described herein for use in combination with the fibers of the present disclosure. The total amount of the non-aqueous plasticizer included may be in the range of from about 1 wt.% to about 45 wt.%, or from about 5 wt.% to about 45 wt.%, or from about 10 wt.% to about 40 wt.%, or from about 20 wt.% to about 30 wt.%, from about 1 wt.% to about 4 wt.%, or from about 1.5 wt.% to about 3.5 wt.%, or from about 2.0 wt.% to about 3.0 wt.%, such as about 1 wt.%, about 2.5 wt.%, about 5 wt.%, about 10 wt.%, about 15 wt.%, about 20 wt.%, about 25 wt.%, about 30 wt.%, about 35 wt.% or about 40 wt.%, based on the total weight of the nonwoven fabric.

[0188] In an embodiment, the nonwoven fabric includes a surfactant. When incorporated into the nonwoven fabric / onto the nonwoven fabric, the surfactant may be, for example, any surfactant or combination thereof described herein for use in combination with the fibers of the present disclosure. In different embodiments, the surfactant may be provided in an amount in the range of from about 0.01 wt.% to about 2.5 wt.%, from about 0.1 wt.% to about 2.5 wt.%, from about 1.0 wt.% to about 2.0 wt.%, from about 0.01 wt% to 0.25 wt%, or from about 0.10 wt% to 0.20 wt%, based on the total weight of the nonwoven fabric.

[0189] In an embodiment, the nonwoven fabric of the present disclosure is substantially free of auxiliaries. As used herein and unless otherwise specified, "substantially free of auxiliaries" means that the nonwoven fabric includes less than about 0.01 wt%, less than about 0.005 wt%, or less than about 0.001 wt% of auxiliaries based on the total weight of the nonwoven fabric.

[0190] In an embodiment, the water-dispersible nonwoven fabric can be colored, dyed, and / or stained to provide improved aesthetic effects (relative to water-soluble films). Suitable colorants can include indicator dyes such as pH indicators (e.g., thymol blue, bromothymol, thymolphthalein, and phenolphthalein), moisture / water indicators (e.g., inks or leuco dyes that change color upon contact with water), or thermochromic inks, where the color of the ink changes when the temperature increases and / or decreases. Suitable colorants include (but are not limited to) triphenylmethane dyes, azo dyes, anthraquinone dyes, perylene dyes, indigo dyes, food, drug, and cosmetic (FD&C) colorants, organic pigments, inorganic pigments, or combinations thereof. Examples of colorants include (but are not limited to) FD&C Red #40; Red #3; FD&C Black #3; Black #2; mica-based pearlescent pigments; FD&C Yellow #6; Green #3; Blue #1; Blue #2; titanium dioxide (food grade); jet black; and combinations thereof.

[0191] When included in the water-soluble fibers, the colorant can be provided in an amount of 0.01% to 25% by weight of the water-soluble polymer mixture, such as 0.02%, 0.05%, 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, and 24% by weight of the water-soluble polymer mixture.

[0192] Active agent

[0193] In an embodiment, the nonwoven fabric of the present disclosure can include an active agent. The active agent can generally be any of the active agents described herein used in combination with the fibers of the present disclosure. The active agent can be added to the nonwoven fabric during the carding of staple fibers, the deposition of continuous fibers, and / or can be added to the nonwoven fabric prior to bonding. The active agent added to the fibers during carding or deposition can be distributed throughout the nonwoven fabric. The active agent can be added to the nonwoven fabric during the melt spinning process, as is well known in the art, using the "coform" process developed by Kimberly Clark. The active agent added to the nonwoven fabric after carding or deposition and before or after bonding can be selectively added to one or both surfaces of the nonwoven fabric. Additionally, the active agent can be added to the surface of a tissue, an absorbent article, or other articles prepared from the nonwoven fabric.

[0194] When the active agent is present in the nonwoven fabric in an amount of at least about 1 wt% or in the range of about 1 wt% to about 99 wt%, it provides additional functions to the nonwoven fabric. In embodiments, the active agent is selected from the group consisting of: enzymes, oils, fragrances, colorants, odor absorbers, aromatics, pesticides, fertilizers, oxidants, exfoliants, liquid absorbent materials, activation factors, acid catalysts, metal catalysts, ion scavengers, detergents, disinfectants, surfactants, plasticizers, bleaching agents, bleaching components, fabric softeners, and combinations thereof, as described herein. In embodiments, the active agent is selected from the group consisting of: enzymes, oils, fragrances, colorants, odor absorbers, aromatics, pesticides, oxidants, exfoliants, liquid absorbent materials, detergents, disinfectants, surfactants, plasticizers, bleaching agents, bleaching components, fabric softeners, and combinations thereof. In embodiments, the active agent is selected from the group consisting of: enzymes, oils, odor absorbers, aromatics, exfoliants, liquid absorbent materials, detergents, disinfectants, and combinations thereof.

[0195] The active agent can be solid or liquid. The solid active agent can have, for example, an average particle size (e.g., Dv50) of at least about 0.01 μm, or a size in the range of about 0.01 μm to about 2 mm. The liquid active agent can be applied directly to the nonwoven fabric, mixed with a carrier powder, or microencapsulated. In embodiments that include a carrier powder, the average particle size of the carrier powder can be, for example, at least about 0.01 μm, or in the range of about 0.01 μm to about 2 mm.

[0196] In one class of embodiments, the active agent is encapsulated to allow for controlled release of the active agent. Suitable microcapsules can include or be made from one or more of the following: melamine formaldehyde, polyurethane, urea formaldehyde, polyglucosamine, polymethyl methacrylate, polystyrene, polysulfone, polytetrahydrofuran, gelatin, gum arabic, starch, polyvinylpyrrolidone, carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, arabinogalactan, polyvinyl alcohol, polyacrylic acid, ethyl cellulose, polyethylene, polymethacrylate, polyamide, poly(ethylene vinyl acetate), cellulose nitrate, silicone, poly(lactide-co-glycolide), paraffin wax, carnauba wax, cetyl wax, beeswax, stearic acid, stearyl alcohol, stearic acid glyceride, shellac, cellulose acetate phthalate, zein, and combinations thereof. In one type of embodiment, the microcapsules are characterized by an average particle size (e.g., Dv50) of at least about 0.1 micron or in the range of about 0.1 micron to about 200 microns. In alternative embodiments, the microcapsules can form aggregates of individual particles, for example, where the individual particles have an average particle size of at least about 0.1 micron, or in the range of about 0.1 micron to about 200 microns.

[0197] In embodiments where the active agent is applied to one or more surfaces of the nonwoven fabric or to the article, the active agent can be applied in any suitable manner. In one embodiment, one or more stationary powder guns direct a stream of active agent powder onto the fabric or article from one or more than one direction, while the fabric or article is transported through the coating section by means of a belt conveyor. In an alternative embodiment, the article is transported by suspending the active agent powder in air. In yet another alternative embodiment, the article is tumbled and mixed with the active agent powder in a trough-like device. In another embodiment that can be combined with any other embodiment, electrostatic forces are employed to enhance the attraction between the active agent powder and the article. This type of process typically involves charging the powder particles negatively and directing these charged particles towards the grounded article. In other alternative embodiments, the active agent powder is applied to the article by a secondary transfer tool (including but not limited to a rotating brush in contact with the powder) or by a glove for coating powder that can transfer the powder from a container to the article. In yet another embodiment, the active agent powder is applied as follows: the powder is dissolved or suspended in a non-aqueous solvent or carrier and then atomized and sprayed onto the nonwoven fabric or article. In one type of embodiment, the solvent or carrier then evaporates, leaving the active agent powder. In one class of embodiments, the active agent powder is applied to the nonwoven fabric or article in an accurate dosage. Such embodiments employ a closed system dry lubricant application mechanism, such as the powder applicator PM 700D from PekuTECH. In this process, the active agent powder is optionally fed into the feed trough of the application mechanism in a batch or continuous manner. The nonwoven fabric or article is transferred from the output belt of a standard drum bag-making machine to the conveyor belt of the powder applicator, where a controllable dosage of the active agent is applied to the nonwoven fabric or article.

[0198] A liquid active agent can be applied to the nonwoven fabric or article, for example, by spin casting, spraying a solution (such as an aerosolized solution), roll coating, flow coating, curtain coating, extrusion, knife coating, and combinations thereof.

[0199] Composite Article

[0200] The composite material article of the present disclosure includes at least two nonwoven fabric layers. The composite material article of the present disclosure may have a first layer of a first nonwoven fabric including a first plurality of fibers having a first diameter; a second layer of a second nonwoven fabric including a second plurality of fibers having a second diameter; and a first interface including at least a portion of the first nonwoven fabric and at least a portion of the second nonwoven fabric, wherein the portions of the first nonwoven fabric and the second nonwoven fabric are fused together, and wherein the second diameter is less than the first diameter, and the first plurality of fibers, the second plurality of fibers, or both include a water-soluble polyvinyl alcohol fiber-forming material. Any nonwoven layer of the composite material article may include a water-soluble film laminated thereto. The water-soluble film may be prepared from any polymer described herein as a water-soluble fiber-forming material.

[0201] The composite material article of the present disclosure may provide one or more advantages including, but not limited to, increased mechanical strength relative to a nonwoven fabric of the same as a single layer of the composite material article alone, enhanced liquid collection function relative to a nonwoven fabric of the same as a single layer of the composite material article alone (e.g., the liquid collection layer of a diaper, or a spill-absorbing tissue), and / or enhanced retention of fluids and / or active compositions relative to a nonwoven fabric of the same as a single layer of the composite material article alone (e.g., an active lotion for a wet wipe).

[0202] The first interface including at least a portion of the first nonwoven fabric and at least a portion of the second nonwoven fabric is a composite material region where the first nonwoven fabric overlaps the second nonwoven fabric and the first plurality of fibers are intertwined with the second plurality of fibers, as Figure 3 depicted. Generally, as Figure 3 shown, the portion of the first nonwoven fabric 201 forming the first interface 200 is the outer surface of the first nonwoven fabric. In an embodiment, the first interface is 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 10% or less, 5% or less, 2.5% or less, or 1% or less of the thickness of the first nonwoven fabric. In an embodiment, the first interface is at least 0.1%, at least 0.5%, at least 1%, or at least 5% of the thickness of the first nonwoven fabric. In an embodiment, the first interface is from about 0.1% to about 25% of the thickness of the first nonwoven fabric. Generally, as Figure 3As shown, the portion of the second nonwoven fabric 202 that forms the interface is the outer surface of the second nonwoven fabric. In an embodiment, the interface accounts for 75% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, or 15% or less of the thickness of the second nonwoven fabric. In an embodiment, the first interface accounts for at least 1%, at least 5%, at least 10%, at least 20%, at least 25%, at least 30%, or at least 40% of the thickness of the second nonwoven fabric. In an embodiment, the first interface accounts for from about 1% to about 75% of the thickness of the second nonwoven fabric.

[0203] As used herein and unless otherwise specified, two nonwoven fabric layers "fuse" if at least a portion of the fibers of each fabric are bonded to the fibers of the other fabric. As described herein, bonding of the fibers includes entanglement of the fibers. The two nonwoven fabric layers can be fused using any suitable method. In an embodiment, a portion of the first nonwoven fabric and a portion of the second nonwoven fabric are fused thermally, are fused with a solvent, or both. In an embodiment, a portion of the first nonwoven fabric is fused with a portion of the second nonwoven fabric thermally. Thermal fusion can include the use of heat and / or pressure. In an embodiment, one or both of the two discrete nonwoven fabrics can be heated until the fibers soften, and then the fabrics can be pressed together such that when the fibers cool, at least a portion of the fibers of each fabric are bonded to at least a portion of the fibers of the other fabric. In an embodiment, one or both of the first and second nonwoven fabrics can be melt spun and applied in-line such that the heated soft fibers are applied directly onto a preformed nonwoven fabric after passing through a die assembly and are fused with the fibers of the preformed nonwoven fabric, thereby forming a fused interface. In an embodiment, a portion of the first nonwoven fabric is fused with a portion of the second nonwoven fabric with a solvent. Solvent fusion can include: applying an adhesive solution to one or both of the nonwoven fabrics, and subsequently bringing the nonwoven fabrics into contact such that when dry, at least a portion of the fibers of each fabric are bonded to at least a portion of the fibers of the other fabric. Solvent fusion can be carried out as an individual process (including two individual preformed fabrics) or can employ an in-line process, where the adhesive solution is applied onto a preformed nonwoven fabric and a second nonwoven fabric is formed on the preformed nonwoven fabric by a continuous process. The adhesive solution used for solvent fusing the nonwoven fabric can be any of the adhesive solutions described herein with respect to bonding. As used herein and unless otherwise specified, "preformed nonwoven fabric" encompasses nonwoven fabrics that have been formed but not bonded and nonwoven fabrics that have been formed and bonded. As used herein and unless otherwise specified, "individual nonwoven fabric" encompasses nonwoven fabrics formed by carding or air laying short fibers or by a continuous process, and the nonwoven fabric can or can not be bonded. In an embodiment, the melting of one or both of the two nonwoven fabrics can also be utilized to bond the nonwoven fabrics.

[0204] In an embodiment, the first interface is solvent-fused and the solvent is selected from the group consisting of water, ethanol, methanol, DMSO, glycerol, and combinations thereof. In an embodiment, the first interface is solvent-fused and the solvent is selected from the group consisting of water, glycerol, and combinations thereof. In an embodiment, the first interface is solvent-fused using an adhesive solution comprising polyvinyl alcohol and water, glycerol, or a combination thereof. In an embodiment, the first interface is solvent-fused using an adhesive solution comprising polyvinyl alcohol, latex, or a combination thereof and water, glycerol, or a combination thereof.

[0205] As used herein and unless otherwise specified, if the average fiber diameter of a fiber of a recognized type is less than the average fiber diameter of another recognized type of fiber, then the diameter of the fiber of the recognized type is "less than" the diameter of the other recognized type of fiber. For example, the fiber of the recognized type may have an overlapping diameter size distribution relative to another type of fiber and still have a smaller diameter as long as the average fiber diameter of the fiber of the recognized type is less than the average fiber diameter of the other type of fiber. In an embodiment, the average fiber diameter of the smaller fiber type is less than the smallest diameter in the diameter size distribution of the larger fiber type. There is a difference in diameter, and at this time, the difference can be visualized using projection microscope imaging as outlined in ISO137:2015. In an embodiment, the diameter difference between the smaller fiber type and the larger fiber type can be on the order of sub-microns, for example when using multiple melt-spun layers. In an embodiment, the diameter difference between the smaller fiber type and the larger fiber type can be from about 1 micron to about 300 microns, from about 5 microns to about 300 microns, from about 5 microns to about 250 microns, from about 5 microns to about 200 microns, from about 10 microns to about 150 microns, from about 10 microns to about 100 microns, from about 10 microns to about 90 microns, from about 15 microns to about 80 microns, from about 15 microns to about 70 microns, from about 20 microns to about 60 microns, from about 20 microns to about 50 microns, or from about 25 microns to about 45 microns. In an embodiment, the diameter difference between the smaller fiber type and the larger fiber type can be from about 5 microns to about 75 microns. In an embodiment, the diameter difference between the smaller fiber type and the larger fiber type can be from about 20 microns to about 80 microns. Without wishing to be bound by theory, it is believed that providing a composite of two nonwoven fabrics (where the nonwoven fabrics are fused together and the fiber diameter of the second nonwoven fabric is less than that of the first nonwoven fabric) can advantageously improve the adsorption / absorption rate and fluid capacity of the composite article, improve direct adsorption / absorption from larger diameter fibers to smaller diameter fibers to preferentially move the fluid; increase the surface area to volume ratio of the nonwoven composite article compared to a single diameter material, thereby increasing the loading capacity; and / or improve the dispersibility and / or total solubility of the nonwoven composite article compared to a nonwoven fabric having a single diameter material. The average fiber diameter in an individual fabric layer can be any diameter provided herein. In an embodiment, the first plurality of fibers in the first layer of the first nonwoven fabric can have a diameter from about 10 microns to about 300 microns, from about 50 microns to about 300 microns, or from greater than about 100 microns to about 300 microns. In an embodiment, the first plurality of fibers can have an average diameter greater than about 100 microns to about 300 microns. In an embodiment where the nonwoven layer of the nonwoven composite comprises a blend of fiber types having different diameters, if the fiber diameter distribution is unimodal, the average fiber diameter refers to the average fiber diameter of the blend. The fiber diameter distribution of the blend of each type of fiber in the nonwoven layer is bimodal or more peaked.When the diameter distribution of the fiber blend is bimodal or more peaked, when the average fiber diameter of one fiber is less than the average of the minimum diameter distribution of the blend fibers, the diameter of the fiber is less than that of the blend fibers, and when the average fiber diameter of one fiber is greater than the average of the larger diameter distribution of the blend fibers, the fiber is greater than the blend fibers.

[0206] In an embodiment, the composite article further includes a third layer of a third nonwoven fabric, the third nonwoven fabric including a third plurality of fibers. In embodiments where the nonwoven composite article includes a third layer of a third nonwoven fabric, the second layer can be disposed between the first layer and the third layer and at least a second portion of the second nonwoven fabric can be fused with at least a portion of the third nonwoven fabric to provide a second interface. The second interface including at least a second portion of the second nonwoven fabric and at least a portion of the third nonwoven fabric is a composite material region where the second nonwoven fabric and the third nonwoven fabric overlap and the second plurality of fibers and the third plurality of fibers are interwoven together. In some embodiments, depending on the thickness of the second layer of the second nonwoven fabric, the first plurality of fibers and the third plurality of fibers can be intertwined and / or fused together such that there is no clear boundary between the first interface and the second interface. Generally, the portion of the second nonwoven fabric forming the second interface is the outer surface of the second nonwoven fabric, the outer surface being opposite the outer surface of the second nonwoven fabric fused with the first nonwoven fabric. In an embodiment, the second interface is 75% or less, 70% or less, 60% or less, 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, or 15% or less of the thickness of the second nonwoven fabric. In an embodiment, the second interface is at least 1%, at least 5%, at least 10%, at least 20%, at least 25%, at least 30%, or at least 40% of the thickness of the second nonwoven fabric. In an embodiment, the second interface is about 1% to about 75% of the thickness of the second nonwoven fabric. In an embodiment, the portion of the third nonwoven fabric forming the second interface is the outer surface of the third nonwoven fabric. In an embodiment, the second interface is 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 10% or less, 5% or less, 2.5% or less, or 1% or less of the thickness of the third nonwoven fabric. In an embodiment, the second interface is at least 0.1%, at least 0.5%, at least 1%, or at least 5% of the thickness of the third nonwoven fabric. In an embodiment, the second interface is about 0.1% to about 25% of the thickness of the third nonwoven fabric.

[0207] In an embodiment, a second portion of the second nonwoven fabric and a portion of the third nonwoven fabric are fused thermally, fused with a solvent, or both. In an embodiment, a second portion of the second nonwoven fabric is fused thermally with a portion of the third nonwoven fabric. In an embodiment, a second portion of the second nonwoven fabric is fused with a solvent with a portion of the third nonwoven fabric.

[0208] In an embodiment, the second interface is fused with a solvent and the solvent is selected from the group consisting of: water, ethanol, methanol, DMSO, glycerol, and combinations thereof. In an embodiment, the second interface is fused with a solvent and the solvent is selected from the group consisting of water, glycerol, and combinations thereof. In an embodiment, the second interface is solvent-fused using an adhesive solution comprising polyvinyl alcohol and water, glycerol, or a combination thereof. In an embodiment, the second interface is solvent-fused using an adhesive solution comprising polyvinyl alcohol, latex, or a combination thereof and water, glycerol, or a combination thereof.

[0209] In an embodiment, the first layer of the first nonwoven fabric and the second layer of the second nonwoven fabric have different porosities. As used herein and unless otherwise specified, two nonwoven fabrics have "different porosities" when the difference in porosity of the nonwoven fabrics is at least about 1%. In an embodiment, the difference in porosity between two nonwoven fabric layers in a composite article can be from about 1% to about 20%. For example, one nonwoven fabric layer in a composite article can have a porosity of about 80%, while a second nonwoven fabric layer in the composite article can have a porosity of about 85%, with a 5% difference in porosity. In an embodiment, the porosity of the second nonwoven fabric is less than the porosity of the first nonwoven fabric. In an embodiment, the porosity of the second nonwoven fabric is the same as the porosity of the first nonwoven fabric. As used herein and unless otherwise specified, if the difference in porosity values between two nonwoven fabrics is less than 1%, the two nonwoven fabrics have "the same porosity".

[0210] In embodiments where the composite article includes a third layer of a third nonwoven fabric, the third nonwoven fabric may have the same or different porosity as the first nonwoven fabric. In an embodiment, the third nonwoven fabric may have the same porosity as the first nonwoven fabric. In an embodiment, the third nonwoven fabric may have a different porosity from the first nonwoven fabric. In an embodiment, the porosity of the third nonwoven fabric may be less than that of the first nonwoven fabric. In an embodiment, the third nonwoven fabric may have the same porosity as the second nonwoven fabric. In an embodiment, the third nonwoven fabric may have a different porosity from the second nonwoven fabric. In an embodiment, the porosity of the third nonwoven fabric may be less than that of the second nonwoven fabric. In an embodiment, the porosity of the second nonwoven fabric may be less than that of the first nonwoven fabric, and the porosity of the third nonwoven fabric may be less than that of the second nonwoven fabric. In an embodiment, the nonwoven composite article may have a porosity gradient between the layers of the nonwoven fabric, where one outer surface of the composite structure may have the greatest porosity and the other outer surface of the composite structure may have the least porosity. In an embodiment, the composite structure may have a porosity gradient between the layers of the nonwoven fabric, where the outer surface of the composite structure may have the greatest porosity and the intermediate layer of the composite structure may have the least porosity. In an embodiment, the composite structure may include a fourth or higher layer of nonwoven fabric such that the intermediate layer may include the second and third layers of nonwoven fabric (for a four-layer composite structure), or the third layer of nonwoven fabric (for a five-layer composite structure).

[0211] Without wishing to be bound by theory, it is believed that when the porosity of the composite structure includes a gradient, the composite structure advantageously enhances the wicking of liquid from the outer surface with high porosity to the outer surface with low porosity or the intermediate layer with low porosity.

[0212] The plurality of fibers in any designated nonwoven layer of the composite article may be any of the fibers disclosed herein and may be the same or different. In an embodiment, the composition of the fiber-forming material in the first plurality, second plurality, and third plurality of fibers may be the same or different, such as in diameter, length, toughness, shape, rigidity, elasticity, solubility, melting point, glass transition temperature (T g) There are no differences in terms of the fiber-forming material, color, or a combination thereof. The following table presents the composite material articles under consideration, where the nonwoven layer may include fibers having three different fiber compositions, where each letter "A", "B", and "C" refers to a specific fiber composition and "-" means that the composite material article under consideration does not include a third layer of nonwoven fabric. Each of the fiber compositions A, B, and C can be (a) a single fiber type including a single fiber-forming material; (b) a single fiber type including a blend of fiber-forming materials; (c) a blend of various types of fibers, each type of fiber including a single fiber-forming material; (d) a blend of various types of fibers, each type of fiber including a blend of fiber-forming materials; or (e) a blend of various types of fibers, each type of fiber including a single fiber-forming material or a blend of fiber-forming materials.

[0213]

[0214]

[0215] In an embodiment, the first plurality of fibers includes a water-soluble polyvinyl alcohol fiber-forming material. In an embodiment, the second plurality of fibers includes a water-soluble polyvinyl alcohol fiber-forming material. In an embodiment, the first plurality of fibers and the second plurality of fibers include a water-soluble polyvinyl alcohol fiber-forming material. In an embodiment including a third layer of nonwoven fabric having a third plurality of fibers, the third plurality of fibers may include a water-soluble polyvinyl alcohol fiber-forming material. In an embodiment, the polyvinyl alcohol fiber-forming material may be present in one or more fiber types in the plurality of fibers. The water-soluble polyvinyl alcohol fiber-forming material of any one of the first plurality, the second plurality, or the third plurality of fibers can be any water-soluble polyvinyl alcohol fiber-forming material disclosed herein. In an embodiment where two or more of the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers include a polyvinyl alcohol fiber-forming material, the polyvinyl alcohol in the various pluralities of fibers can be the same or different, the polyvinyl alcohol in the various pluralities of fibers can be a part of a separate fiber-forming material or a blend of fiber-forming materials, and if the various pluralities of fibers include different water-soluble polyvinyl alcohol fiber-forming materials, then the diameter, length, toughness, shape, rigidity, elasticity, solubility, melting point, glass transition temperature (T g )、fiber-forming material, color, or a combination thereof may be different. In an embodiment, the water-soluble polyvinyl alcohol fiber-forming material includes a polyvinyl alcohol homopolymer, a polyvinyl alcohol copolymer, or a combination thereof. In an embodiment, the polyvinyl alcohol includes a copolymer and the copolymer can be an anion-modified polyvinyl alcohol. In an embodiment, the polyvinyl alcohol includes an anion-modified polyvinyl alcohol and the anion-modified polyvinyl alcohol includes (alkyl) acrylate-modified polyvinyl alcohol, maleate-modified polyvinyl alcohol, sulfonate-modified polyvinyl alcohol, or a combination thereof.

[0216] In an embodiment, the fibers in the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers may include a water-soluble fiber-forming material other than the polyvinyl alcohol fiber-forming material. In an embodiment, the fibers in the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers may include a blend of water-soluble fiber-forming materials, the blend including a polyvinyl alcohol fiber-forming material and a water-soluble fiber-forming material other than the polyvinyl alcohol fiber-forming material. In an embodiment, the water-soluble fiber-forming material other than the polyvinyl alcohol fiber-forming material may include polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, cellulose amide, or a combination of the foregoing. In an embodiment, the first plurality of fibers includes a water-soluble fiber-forming material selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, cellulose amide, and a combination of the foregoing. In an embodiment, the second plurality of fibers includes a water-soluble fiber-forming material selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, cellulose amide, and a combination of the foregoing. In an embodiment, the third plurality of fibers includes a water-soluble fiber-forming material selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, cellulose amide, and a combination of the foregoing.

[0217] In an embodiment, the fibers in the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers may include the water-insoluble fiber-forming materials disclosed herein. In an embodiment, the water-insoluble fiber-forming materials may include cellulose, cotton, hemp, jute, flax, ramie, sisal, bagasse, banana fiber, flower bark, silk, tendon, catgut, wool, seaweed fiber, mohair, angora wool, cashmere, collagen, actin, nylon, polyester, rayon, bamboo fiber, modal fiber, diacetate fiber, triacetate fiber, polypropylene, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyamide, thermoplastic polyurethane, elastic polypropylene, rayon, or a combination thereof. In an embodiment, the water-insoluble fiber-forming material includes cellulose. In an embodiment, the water-insoluble fiber-forming materials include cellulose, cotton, hemp, jute, flax, ramie, sisal, bagasse, banana fiber, flower bark, silk, tendon, catgut, wool, seaweed fiber, mohair, angora wool, cashmere, collagen, actin, nylon, polyester, rayon, bamboo fiber, modal fiber, diacetate fiber, triacetate fiber, polypropylene, polycarbonate, polybutylene terephthalate, polyethylene terephthalate, polyamide, thermoplastic polyurethane, elastic polypropylene, rayon, or a combination thereof.

[0218] For the first, second, and third pluralities of fibers, and for any additional pluralities of fibers provided in the composite material, such as when the composite article includes additional nonwoven layers (i.e., fourth layer, fifth layer, etc.), consider the following embodiments:

[0219]

[0220] In an embodiment, the first plurality of fibers includes a single type of fiber. In an optimization of the foregoing embodiment, the single type of fiber includes the sole fiber-forming material selected from water-soluble polyvinyl alcohol fiber-forming materials, water-soluble fiber-forming materials other than polyvinyl alcohol, and water-insoluble fiber-forming materials. In another optimization, the single type of fiber includes a blend of fiber-forming materials that includes two or more of the following: water-soluble polyvinyl alcohol fiber-forming materials, water-soluble fiber-forming materials other than polyvinyl alcohol, water-insoluble fiber-forming materials, and combinations thereof. In an embodiment, the first plurality of fibers includes a blend of fibers. In an embodiment, the first plurality of fibers includes a single fiber type that includes fiber-forming materials selected from the group consisting of polyvinyl alcohol homopolymers, polyvinyl alcohol copolymers, and combinations thereof.

[0221] In an embodiment, the second plurality of fibers includes a single type of fiber. In an optimization of the foregoing embodiment, the single type of fiber includes a sole fiber-forming material selected from a water-soluble polyvinyl alcohol fiber-forming material, a water-soluble fiber-forming material other than polyvinyl alcohol, and a water-insoluble fiber-forming material. In another optimization, the single type of fiber includes a blend of fiber-forming materials that includes two or more of the following: a water-soluble polyvinyl alcohol fiber-forming material, a water-soluble fiber-forming material other than polyvinyl alcohol, a water-insoluble fiber-forming material, and combinations thereof. In an embodiment, the second plurality of fibers includes a blend of fibers. In an embodiment, the second plurality of fibers includes a single fiber type that includes a water-soluble fiber-forming material. In an optimization of the foregoing embodiment, the water-soluble fiber-forming material includes a water-soluble polyvinyl alcohol fiber-forming material, a water-soluble fiber-forming material other than polyvinyl alcohol, or combinations thereof. In an embodiment, the second plurality of fibers includes a single fiber type, and the single fiber type includes a water-insoluble fiber-forming material. In an embodiment, the second plurality of fibers includes a blend of fiber types, and at least one of the blend of fiber types includes a water-soluble fiber-forming material.

[0222] In an embodiment, the third plurality of fibers includes a single type of fiber. In an optimization of the foregoing embodiment, the single type of fiber includes a sole fiber-forming material selected from a water-soluble polyvinyl alcohol fiber-forming material, a water-soluble fiber-forming material other than polyvinyl alcohol, and a water-insoluble fiber-forming material. In another optimization, the single type of fiber includes a blend of fiber-forming materials that includes two or more of the following: a water-soluble polyvinyl alcohol fiber-forming material, a water-soluble fiber-forming material other than polyvinyl alcohol, a water-insoluble fiber-forming material, and combinations thereof. In an embodiment, the third plurality of fibers includes a blend of fibers. In an embodiment, the third plurality of fibers includes a single fiber type that includes a fiber-forming material selected from the group consisting of polyvinyl alcohol homopolymers, polyvinyl alcohol copolymers, and combinations thereof. In an embodiment, the third plurality of fibers includes a blend of fiber types. In an embodiment, the third plurality of fibers is the same as the first plurality of fibers.

[0223] In an embodiment, the first plurality of fibers, the second plurality of fibers, the third plurality of fibers, or combinations thereof include a natural fiber-forming material, a plant-based fiber-forming material, a bio-based fiber-forming material, a biodegradable fiber-forming material, a compostable fiber-forming material, or combinations thereof.

[0224] In an embodiment, the tenacity ratio (MD:CD) of the first nonwoven fabric is from about 0.5 to about 1.5. In an embodiment, the MD:CD of the first nonwoven fabric is from about 0.8 to about 1.25. In an embodiment, the MD:CD of the first nonwoven fabric is from about 0.9 to about 1.1. In an embodiment, the tenacity ratio (MD:CD) of the second nonwoven fabric is from about 0.5 to about 1.5. In an embodiment, the MD:CD of the second nonwoven fabric is from about 0.8 to about 1.25. In an embodiment, the MD:CD of the second nonwoven fabric is from about 0.9 to about 1.1. In an embodiment, the tenacity ratio (MD:CD) of the third nonwoven fabric is from about 0.5 to about 1.5. In an embodiment, the MD:CD of the third nonwoven fabric is from about 0.8 to about 1.25. In an embodiment, the MD:CD of the third nonwoven fabric is from about 0.9 to about 1.1. In an embodiment, the tenacity ratio (MD:CD) of the nonwoven composite article is in the range of from about 0.5 to about 1.5, from about 0.8 to about 1.25, from about 0.9 to about 1.1, or from about 0.95 to about 1.05. In an embodiment, the MD:CD of the nonwoven composite article is from about 0.8 to about 1.5. In an embodiment, the MD:CD of the nonwoven composite article is from about 0.9 to about 1.1. The MD:CD of the nonwoven composite article is related to the MD:CD ratio of each individual nonwoven fabric layer present in the composite article. Without wishing to be bound by theory, it is believed that the MD:CD of the composite article cannot be determined by considering the MD and CD of each nonwoven fabric layer individually, but rather the MD and CD of the nonwoven composite article must be measured. Without wishing to be bound by theory, it is believed that as the tenacity ratio MD:CD of the nonwoven composite article approaches 1, the durability of the composite article increases, providing excellent resistance to rupture of the nonwoven fabric when stress is applied to the nonwoven fabric during use. Further, without wishing to be bound by theory, it is believed that compared to a composite article that is the same except for including all carded layers, a composite article including at least one meltblown nonwoven fabric will have an MD:CD ratio that is closer to 1:1.

[0225] In an embodiment, the first plurality of fibers, the second plurality of fibers, the third plurality of fibers, or a combination thereof includes bicomponent fibers. In an embodiment, the first plurality of fibers includes bicomponent fibers. In an embodiment, the second plurality of fibers includes bicomponent fibers. In an embodiment, the third plurality of fibers includes bicomponent fibers. In an embodiment, the first and second pluralities of fibers comprise bicomponent fibers. In an embodiment, the first and third pluralities of fibers comprise bicomponent fibers. In an embodiment, the second and third pluralities of fibers comprise bicomponent fibers. In an embodiment, the first, second, and third pluralities of fibers comprise bicomponent fibers. In embodiments where the first, second, and / or third pluralities of fibers comprise bicomponent fibers, the bicomponent fibers can include a core of a fiber-forming material surrounded by a sheath of a fiber-forming material, wherein for a given water temperature, the solubility of the sheath fiber-forming material in water is higher than that of the core fiber-forming material.

[0226] In embodiments, the first plurality of fibers, the second plurality of fibers, the third plurality of fibers, or combinations thereof include a plasticizer, a surfactant, or combinations thereof. In embodiments, the nonwoven composite article of the present disclosure includes an active agent, an absorbent material, or combinations thereof. In an optimization of the foregoing embodiments, the first plurality of fibers, the second plurality of fibers, the third plurality of fibers, or combinations thereof include an active agent, an absorbent material, or combinations thereof. In embodiments, the nonwoven composite article of the present disclosure includes an active agent that includes an enzyme, an oil, a fragrance, a colorant, an odor absorber, an aroma agent, an insecticide, a fertilizer, an oxidizer, an activator, an acid catalyst, a metal catalyst, an ion scavenger, a detergent, a disinfectant, a surfactant, a bleaching agent, a bleaching component, a fabric softener, or combinations thereof. In embodiments, the nonwoven composite article of the present disclosure includes an active agent that includes an enzyme, an oil, a colorant, an odor absorber, an aroma agent, an insecticide, an oxidizer, an ion scavenger, a detergent, a disinfectant, a surfactant, a bleaching agent, a bleaching component, a fabric softener, or combinations thereof. In embodiments, the nonwoven composite article of the present disclosure includes an active agent that includes an oil, a colorant, an odor absorber, an aroma agent, an ion scavenger, a disinfectant, or combinations thereof. In embodiments in which the nonwoven composite article includes a perfume, the perfume may be encapsulated.

[0227] The nonwoven layer of the composite article can generally be prepared using any of the methods described herein. In some embodiments, the first layer of the first nonwoven can be a carded layer. In embodiments, the second layer of the second nonwoven can be a meltblown layer. In embodiments, the first layer includes a carded layer and the second layer includes a meltblown layer. In embodiments, the first layer can be a carded layer and the second layer can be a spunbond layer. In embodiments, the first layer can be a carded layer and the second layer can be an airlaid layer. In embodiments, the first layer can be a carded layer that includes fibers comprising a polyvinyl alcohol fiber-forming material, and the second layer can be a meltblown layer that includes fibers comprising a low molecular weight polyvinyl alcohol homopolymer having a viscosity of about 5 cP or less. In embodiments, the first layer can be a carded layer that includes fibers comprising a polyvinyl alcohol fiber-forming material, and the second layer can be an airlaid layer that includes cellulose fibers. In embodiments, the third layer can be a carded layer or a meltblown layer. In embodiments, the third layer can be a carded layer. In embodiments, the third layer can be a meltblown layer. In embodiments, the first layer can be a carded layer, the second layer can be a meltblown layer, and the third layer can be a carded layer. In embodiments, the first layer can be a carded layer, the second layer can be an airlaid layer, and the third layer can be a meltblown layer.

[0228] The basis weight of the nonwoven composite article of the present disclosure is not particularly limited and can be from about 5 g / m 2 to about 150 g / m 2 、about 5 g / m2 to about 125 g / m 2 、about 5 g / m 2 to about 100 g / m 2 、about 5 g / m 2 to about 70 g / m 2 、about 5 g / m 2 to about 50 g / m 2 、about 5 g / m 2 to about 30 g / m 2 range. In an embodiment, the basis weight of the nonwoven composite article of the present disclosure can be about 5 g / m 2 to about 50 g / m 2 . In an embodiment, the basis weight of the nonwoven composite article of the present disclosure can be about 50 g / m 2 to about 150 g / m 2 . In an embodiment, the basis weight of the first layer of nonwoven fabric can be about 30 g / m 2 to about 70 g / m 2 , and the basis weight of the nonwoven composite article can be about 60 g / m 2 to about 150 g / m 2 . In an embodiment, the basis weight of the first layer of nonwoven fabric can be about 5 g / m 2 to about 15 g / m 2 . In an embodiment, the basis weight of the first layer of nonwoven fabric can be about 5 g / m 2 to about 15 g / m 2 , and the basis weight of the nonwoven composite article can be in the range of about 15 g / m 2 to about 50 g / m 2 . In an embodiment, the basis weight of the third layer of nonwoven fabric can be about 5 g / m 2 to about 15 g / m 2 . In an embodiment, the basis weight of the first layer of nonwoven fabric can be about 5 g / m 2 to about 15 g / m 2 , and the basis weight of the third layer of nonwoven fabric can be about 5 g / m 2 to about 15 g / m 2. In an embodiment, the second nonwoven fabric can be included in the composite article in an amount of from about 2.5 wt.% to about 10 wt.%, based on the total weight of the composite article. In an embodiment, the second nonwoven fabric can be included in the composite article in an amount of from about 2.5 wt.% to about 10 wt.%, based on the total weight of the composite article, and the first nonwoven fabric can be included in the composite article in an amount of from about 90 wt.% to about 97.5 wt.%, based on the total weight of the composite article. In an embodiment, the second nonwoven fabric can be included in the composite article in an amount of from about 2.5 wt.% to about 10 wt.%, based on the total weight of the composite article, and the first nonwoven fabric and the third nonwoven fabric together can be included in an amount of from about 90 wt.% to about 97.5 wt.%. In an embodiment, the third nonwoven fabric can be included in the composite article in an amount of from about 2.5 wt.% to about 10 wt.%, based on the total weight of the composite article, and the first nonwoven fabric and the second nonwoven fabric together can be included in an amount of from about 45 wt.% to about 48 wt.%.

[0229] In an embodiment, the fiber diameters of the first plurality of fibers can be substantially uniform. In an embodiment, the fiber diameters of the second plurality of fibers can be substantially uniform. In an embodiment, the fiber diameters of the third plurality of fibers can be substantially uniform. In an embodiment, the fiber diameters of the first plurality of fibers and the third plurality of fibers can be substantially uniform. In an embodiment, the fiber diameters of each of the first plurality of fibers, the second plurality of fibers, and the third plurality of fibers can be substantially uniform.

[0230] Generally, the tenacity of the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers can be from 3 cN / dtex to about 10 cN / dtex, optionally from about 3 cN / dtex to about 5 cN / dtex, from about 4 cN / dtex to about 7 cN / dtex, from about 7 cN / dtex to about 10 cN / dtex, from about 4 cN / dtex to about 8 cN / dtex, from about 5 cN / dtex to about 8 cN / dtex, or from about 6 cN / dtex to about 8 cN / dtex. In embodiments, the tenacity of the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers can be from 4 cN / dtex to 8 cN / dtex. In embodiments, the tenacity of the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers can be from about 6 cN / dtex to about 8 cN / dtex. In embodiments, the tenacity of the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers can be from about 3 cN / dtex to about 5 cN / dtex. In embodiments, the tenacity of the first plurality of fibers can be in the range of from about 4 cN / dtex to about 8 cN / dtex. In embodiments where the plurality of fibers comprises a blend of fiber types, the tenacity of the fiber blend is the arithmetic weighted average of the tenacities of each fiber type.

[0231] In embodiments, the nonwoven composite article can have improved modulus, tensile strength, elongation, tenacity, or combinations thereof in the machine direction, cross direction, or both, relative to the same article comprising only the first layer. In embodiments, the nonwoven composite article can have improved modulus, tensile strength, elongation, tenacity, or combinations thereof in the machine direction, relative to the same article comprising only the first layer. In embodiments, the nonwoven composite article can have improved modulus, tensile strength, elongation, or combinations thereof in the cross direction, relative to the same article comprising only the first layer. In embodiments, the nonwoven composite article can have improved modulus, tensile strength, elongation, tenacity, or combinations thereof in the machine direction and cross direction, relative to the same article comprising only the first layer.

[0232] Method of making a composite article

[0233] Generally, the composite article can be made using any process known in the art suitable for combining two or more layers of nonwoven fabric such that at least a portion of the first layer fuses with a portion of the second layer, thereby forming an interface.

[0234] In embodiments, the method of forming the nonwoven composite article of the present disclosure can include the following steps:

[0235] (a) Deposit a second layer comprising a second nonwoven fabric on a first layer comprising a first nonwoven fabric under conditions sufficient to fuse at least a portion of the first nonwoven fabric to at least a portion of the second nonwoven fabric, thereby forming a first interface; and

[0236] (b) Optionally, deposit a third layer comprising a third nonwoven fabric on the second layer comprising the second nonwoven fabric under conditions sufficient to fuse at least a second portion of the second nonwoven fabric to at least a portion of the third nonwoven fabric, thereby forming a second interface.

[0237] In embodiments, steps (a) and (b) may be repeated to include additional nonwoven layers into the composite structure, such as a fourth nonwoven layer, a fifth nonwoven layer, and the like.

[0238] Generally, the conditions sufficient to fuse at least a portion of the first nonwoven fabric to at least a portion of the second nonwoven fabric and / or to fuse at least a second portion of the second nonwoven fabric to at least a portion of the third nonwoven fabric may include thermal fusion and / or solvent fusion as described herein.

[0239] In embodiments, thermal fusion includes bringing a portion of the first nonwoven fabric into contact with a portion of the second nonwoven fabric, bringing a second portion of the second nonwoven fabric into contact with a portion of the third nonwoven fabric, or both, when one of the first nonwoven fabric or the second nonwoven fabric or one of the second nonwoven fabric or the third nonwoven fabric is in a heated state such that one or more portions of the nonwoven fabrics to be fused are in a softened state. In embodiments, thermal fusion includes bringing a portion of the first nonwoven fabric into contact with a portion of the second nonwoven fabric when the second nonwoven fabric is in a heated state. In embodiments, bringing a portion of the first nonwoven fabric into contact with a portion of the second nonwoven fabric when the second nonwoven fabric is in a heated state includes forming the fibers of the second nonwoven fabric in an on-line process and depositing the fibers of the second nonwoven fabric on the first nonwoven fabric such that the fibers of the second nonwoven fabric are deposited after being extruded through a die assembly and then cooled and / or quenched. In embodiments, thermal fusion includes bringing a second portion of the second nonwoven fabric into contact with a portion of the third nonwoven fabric when the second nonwoven fabric is in a heated state. In embodiments, bringing a second portion of the second nonwoven fabric into contact with a portion of the third nonwoven fabric when the second nonwoven fabric is in a heated state includes forming the fibers of the second nonwoven fabric in an on-line process and depositing the fibers of the second nonwoven fabric on the first nonwoven fabric such that the fibers of the second nonwoven fabric are deposited after being extruded through a die assembly and then cooled and / or quenched, and then depositing the third nonwoven fabric on the still heated second layer of the nonwoven fabric and then cooling and / or quenching the second nonwoven fabric.

[0240] In an embodiment, solvent fusion includes applying a solvent to a portion of the first nonwoven fabric, a portion of the second nonwoven fabric, or both, and then depositing the second nonwoven fabric on the first nonwoven fabric, thereby forming a first interface. In an embodiment, solvent fusion includes applying a solvent to a second portion of the second nonwoven fabric, a portion of the third nonwoven fabric, or both, and then depositing the third nonwoven fabric on the second nonwoven fabric, thereby forming a second interface. In an embodiment, solvent fusion includes applying a solvent to a portion of the first nonwoven fabric and then depositing the second nonwoven fabric. In an embodiment, solvent fusion includes applying a solvent to a second portion of the second nonwoven fabric and then depositing the third nonwoven fabric. The solvent for solvent fusion can be any solvent or adhesive solution disclosed herein for solvent fusion and chemical bonding. In an embodiment, a portion of the first nonwoven fabric, a portion of the second nonwoven fabric, a second portion of the second nonwoven fabric, a portion of the third nonwoven fabric, or a combination of the foregoing is at least partially soluble in the solvent. In an embodiment, the solvent includes water, glycerol, or a combination thereof. In an embodiment, solvent fusion further includes applying pressure after depositing the second and / or third nonwoven fabric layers.

[0241] In an embodiment of the foregoing method, the first layer can comprise a carded nonwoven fabric. In an embodiment of the foregoing method, the third layer can comprise a carded nonwoven fabric or a meltblown nonwoven fabric. In an embodiment of the foregoing method, the second layer can include a meltblown nonwoven fabric or an airlaid nonwoven fabric. In an embodiment, the first layer can include a carded nonwoven fabric, the second layer can include a meltblown nonwoven fabric, and the third layer can include a carded nonwoven fabric. In an embodiment, the first layer can include a carded nonwoven fabric, the second layer can include a spunbond nonwoven fabric, and the third layer can include a carded nonwoven fabric. In an embodiment, the second layer can include an airlaid nonwoven fabric. In an embodiment, the first layer can include a carded nonwoven fabric, the second layer can include an airlaid nonwoven fabric, and the third layer can include a meltblown nonwoven fabric. In an embodiment, the first layer can include a carded nonwoven fabric, the second layer can include an airlaid nonwoven fabric, and the third layer can include a spunbond nonwoven fabric. In an embodiment, the nonwoven composite article can include five nonwoven fabric layers, wherein the first layer can include a carded nonwoven fabric, the second layer can include an airlaid nonwoven fabric, the third layer can include a meltblown nonwoven fabric, the fourth layer can include an airlaid nonwoven fabric, and the fifth layer can include a carded nonwoven fabric. In an embodiment, the nonwoven composite article can include five nonwoven fabric layers, wherein the first layer can include a carded nonwoven fabric, the second layer can include an airlaid nonwoven fabric, the third layer can include a spunbond nonwoven fabric, the fourth layer can include an airlaid nonwoven fabric, and the fifth layer can include a carded nonwoven fabric. In an embodiment, the second nonwoven fabric can include a cellulose fiber-forming material.

[0242] Flushable Tissue

[0243] One part of the flushable tissue paper of the present disclosure includes a nonwoven composite article according to the present disclosure.

[0244] As used herein, the term "flushable" refers to a nonwoven fabric, a composite article, or other articles containing a nonwoven fabric or a composite article that are dispersible in an aqueous environment, such as a liquid sewage system, such that discarding the fabric or article does not cause such articles to become stuck inside the pipes of the pipe system or accumulate over time to cause such pipe blockages. Flushable articles have the advantage of being more easily processed in a recycling process, or can simply be flushed in, for example, septic tanks and municipal sewage treatment systems, such that after use, the fabric or article does not need to be landfilled, incinerated, or otherwise disposed of.

[0245] The flushable tissue paper may include a plurality of fibers, wherein the plurality of fibers may include water-soluble fibers and non-water-soluble fibers. The water-soluble fibers of the flushable nonwoven fabric may include any of the water-soluble polymers disclosed herein. In an embodiment, the water-soluble fibers include polyvinyl alcohol polymers. In an optimization of the foregoing embodiment, the water-soluble fibers include PVOH homopolymers. In another optimization of the foregoing embodiment, the water-soluble fibers include PVOH copolymers. In an embodiment, the water-soluble fibers include a blend of polyvinyl alcohol polymers. In an optimization of the foregoing embodiment, the water-soluble fibers include one or more PVOH homopolymers. In another optimization of the foregoing embodiment, the water-soluble fibers include one or more PVOH copolymers. In yet another optimization of the foregoing embodiment, the water-soluble polymer includes one or more PVOH homopolymers and one or more PVOH copolymers.

[0246] In an embodiment, the water-soluble fibers include a blend of water-soluble polymers. In an optimization of the foregoing embodiment, the blend of water-soluble polymers may include polyvinyl alcohol polymers or a blend of polyvinyl alcohol polymers containing polyvinyl alcohol homopolymers, polyvinyl alcohol copolymers, or combinations thereof. In a further optimization, the water-soluble fibers may include a blend of water-soluble polymers that includes polyvinyl alcohol homopolymers and polyvinyl alcohol copolymers.

[0247] In an embodiment, the water-soluble fibers include bicomponent fibers. In the foregoing optimization, the bicomponent fibers include core / sheath type fibers. Without wishing to be bound by theory, it is believed that the bicomponent fibers can provide stability to the flushable tissue paper during storage and use due to the composition of the sheath layer, and provide a waste product that is easily soluble, degradable, or compostable to be disposed of based on the composition of the core.

[0248] In an embodiment, the flushable nonwoven fabric may include a plurality of water-soluble fibers, which include a first water-soluble fiber and a second water-soluble fiber, wherein the first and second water-soluble fibers may differ in diameter, length, toughness, shape, stiffness, elasticity, solubility, melting point, glass transition temperature (T g ), water-soluble polymer, color, or a combination thereof.

[0249] As previously described, the water-insoluble fibers generally include fibers made of any material that does not dissolve at a temperature of 80 °C or lower within 300 seconds or less, as measured by MSTM-205. Suitable water-insoluble fiber materials include (but are not limited to) cotton, polyester, polyethylene (such as high-density polyethylene and low-density polyethylene), polypropylene, wood pulp, staple pulp, abaca, rayon, polylactic acid, nylon 6, insoluble cellulose, insoluble starch, hemp, jute, flax, ramie, sisal, bagasse, banana fiber, flower bark, silk, tendon, catgut, wool, seaweed fiber, mohair, angora wool, cashmere, collagen, actin, nylon, polyester, rayon, bamboo fiber, modal fiber, diacetate fiber, triacetate fiber, and combinations thereof.

[0250] The amount of water-soluble fibers in the flushable nonwoven fabric may be in the range of about at least about 20, 25, 30, 40, 50, or 60 wt% and / or at most about 90, 85, 80, 75, 70, 60, 50, or 40 wt% based on the total weight of the flushable nonwoven fabric, for example, about 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90 wt% based on the total weight of the flushable nonwoven fabric.

[0251] The amount of water-insoluble fibers in the flushable nonwoven fabric may be in the range of about at least about 5, 10, 15, 20, 40, 50, or 60 wt% and / or at most about 75, 70, 60, 50, 40, 30, or 25 wt% based on the total weight of the flushable nonwoven fabric, for example, about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75 wt% based on the total weight of the flushable nonwoven fabric.

[0252] The ratio of water-insoluble fibers to water-soluble fibers in the flushable nonwoven fabric may be in the range of about 1:18 to about 4:1, about 1:10 to about 3:1, about 1:5 to about 2:1, or about 1:2 to about 2:1, for example, about 1:18, 1:16, 1:14, 1:12, 1:10, 1:5, 1:3, 1:2, 1:1, 2:1, 3:1, or 4:1.

[0253] Without wishing to be bound by theory, for a nonwoven fabric containing only polyvinyl alcohol fibers, as the rinsing ability increases, the mechanical stability decreases. Accordingly, the inventors have found that by incorporating non-water-soluble fibers into the nonwoven fabric, the rinsing ability can still be increased without compromising the mechanical stability of the fabric.

[0254] For a rinsable nonwoven fabric comprising polyvinyl alcohol, the rinsing ability increases with increasing water solubility, but there is an inverse relationship between water solubility and mechanical stability. Accordingly, the selection of a particular polyvinyl alcohol and any additional water-soluble and / or non-water-soluble fibers may be important for maintaining the mechanical integrity of the fabric while also having a suitable rinsing ability. For example, parameters such as polyvinyl alcohol homopolymers or copolymers like DH and the percentage of modification may affect the rinsing ability and mechanical properties of the fibers.

[0255] The rinsable paper towels of the present disclosure may include a cleaning lotion. The rinsable paper towels of the present disclosure generally include fibers having a surface energy high enough to allow the fibers to be easily wetted by the cleaning lotion during the wetting step of the paper towel manufacturing process. Accordingly, in an embodiment, at least a portion of at least one outer layer of the nonwoven composite article of the rinsable paper towel includes hydrophilic fibers. In an embodiment, at least a portion of each outer layer of the nonwoven composite article for preparing the rinsable paper towel includes hydrophilic fibers.

[0256] Non-limiting examples of applications of the paper towels include cleaning surfaces, cleaning skin, automotive uses, baby care, feminine care, hair cleaning and makeup removal or application, skin conditioners, ointments, sunscreens, insect repellents, medicaments, varnish industries, and institutional cleaning.

[0257] Lotion Composition

[0258] The rinsable paper towels of the present disclosure may contain a lotion composition to wet the substrate to aid in cleaning. In an embodiment where the rinsable paper towel is a personal care paper towel, the lotion composition may further include ingredients such as soothing, softening, or caring for the skin, improving the feel of the lotion, improving the removal of residues from the skin, providing a pleasant fragrance, and / or preventing bacterial growth.

[0259] The pH of the lotion composition can be at or near about 5.5, close to the physiological skin pH. The pH of the low pH lotion composition can be at or near about 3.8 and can be suitable for situations where a tissue is used to remove alkaline residues such as those from fecal matter and to help restore a healthy acidic skin pH of about 5 and / or to render irritants from fecal matter non-irritating, such as by inactivating fecal enzymes. The low pH lotion can also inhibit microbial growth. In embodiments where the pH of the lotion composition is about 4 or lower, the fibers of the first plurality of fibers, the second plurality of fibers, and / or the third plurality of fibers can include a polyvinyl alcohol copolymer. The copolymer can be provided as the sole fiber-forming material in the fibers of a fiber blend or as one component of the fiber-forming material in a blend including a fiber-forming material. In an optimization of the foregoing embodiments, the fibers can include a blend of a polyvinyl alcohol copolymer and a homopolymer. The polyvinyl alcohol copolymer and the homopolymer can be provided in a ratio of about 1:1 to about 4:1. In a further optimization of the foregoing embodiments, the fibers containing the polyvinyl alcohol copolymer can be blended with non-water-soluble fibers.

[0260] The lotion composition can include a superwetting agent, a rheology modifier, an emollient, and / or an emulsifier. The superwetting agent can be present in an amount of about 0.01 wt% to 0.2 wt% relative to the total weight of the lotion composition. The superwetting agent can be selected from the group consisting of: trisiloxane, polyether polydimethylsiloxane, where the polyether functional group is PEG, PPG, or a mixture thereof, and mixtures of the foregoing.

[0261] The rheology modifier can be present in an amount of about 0.01 wt% to 0.5 wt% based on the total weight of the lotion composition. The rheology modifier can be selected from the group consisting of: xanthan gum, modified xanthan gum, and combinations thereof.

[0262] The emollient, if present, can be a thickening emollient. Suitable emollients include (but are not limited to) PEG-10 sunflower glycerides, sunflower oil, palm oil, olive oil, emu oil, babassu oil, evening primrose oil, palm kernel oil, cod liver oil, cottonseed oil, jojoba oil, meadowfoam seed oil, sweet almond oil, canola oil, soybean oil, avocado oil, safflower oil, coconut oil, sesame oil, rice bran oil, grapeseed oil, mineral oil, isopropyl stearate, isostearyl isononanoate, diethylhexyl fumarate, diisostearyl malate, triisocetyl citrate, stearyl stearate, methyl palmitate, methylheptyl isostearate, petrolatum, lanolin oil and lanolin wax, long-chain alcohols such as cetyl alcohol, stearyl alcohol, behenyl alcohol, isostearyl alcohol and 2-hexyldecanol, myristyl alcohol, polydimethylsiloxane fluids of various molecular weights and mixtures thereof, PPG-15 stearyl ether (also known as arlatone E), shea butter, olive butter, sunflower butter, coconut butter, jojoba butter, cocoa butter, squalene and squalane, isoparaffins, polyethylene glycols of various molecular weights, polypropylene glycols of various molecular weights or mixtures thereof.

[0263] The emulsifier, if present, can be a solid at room temperature. Suitable emulsifiers include (but are not limited to) laureth-23, ceteth-2, ceteth-10, ceteth-20, ceteth-21, cetearyl ethoxylate-20, steareth-2, steareth-10, steareth-20, oleth-2, oleth-10, oleth-20, steareth-100, steareth-21, PEG-40 sorbitan tetraoleate, PEG-8 stearate, PEG-40 stearate, PEG-50 stearate, PEG-100 stearate, sorbitan laurate, sorbitan palmitate, sorbitan stearate, sorbitan tristearate, sorbitan oleate, sorbitan trioleate, polysorbate 20, polysorbate 21, polysorbate 40, polysorbate 60, polysorbate 61, polysorbate 65, polysorbate 80, polysorbate 81, polysorbate 85, PEG-40 hydrogenated castor oil, citrate esters, microcrystalline wax, paraffin wax, beeswax, carnauba wax, ozokerite, cetyl alcohol, stearyl alcohol, cetearyl alcohol, myristyl alcohol, behenyl alcohol and mixtures thereof.

[0264] In the examples, the cleansing lotion comprises an aqueous emulsion which comprises an emollient and an emulsifier.

[0265] The cleansing lotion may further comprise a humectant, including (but not limited to) glycerin, propylene glycol, and phospholipids; a fragrance, such as the essential oils and perfumes described herein; a preservative; an enzyme; a colorant; an oil absorbent; an insecticide; a fertilizer; an activator; an acid catalyst; a metal catalyst; an ion scavenger; a detergent; a bactericide; a surfactant; a bleaching agent; a bleaching component; and a fabric softener. In an embodiment, the cleansing lotion comprises a fragrance, a preservative, an enzyme, a colorant, an oil absorbent, an insecticide, an ion scavenger, a detergent, a disinfectant, or a combination thereof.

[0266] Preservatives prevent the growth of microorganisms in the liquid lotion, the flushable tissue, and / or the substrate on which the tissue is used. The preservative can be hydrophobic or hydrophilic. Suitable preservatives include (but not limited to) methylparaben, such as methylparaben, propylparaben, glycine alkyl ester, iodine derivatives, and combinations thereof.

[0267] The lotion loading can be between 150% and 480%. As used herein, "loading" refers to combining the nonwoven composite article with the lotion composition, i.e., loading the lotion composition onto or into the nonwoven composite article, regardless of the method used to combine the nonwoven composite article with the lotion composition, i.e., dipping, spraying, kiss roll coating, etc. "Lotion loading" refers to the amount of lotion loaded onto or into the nonwoven composite article and is expressed as the ratio of the weight of the lotion to the weight of the dry (unloaded) nonwoven composite article, in percentage. It may be necessary for the flushable tissue to be loaded with lotion to such an extent that some lotion can be easily transferred to the substrate (e.g., skin or another surface to be cleaned) during use. The transfer can contribute to cleaning, provide a pleasant sensation to the user (such as a smooth skin feel or a cooling sensation from evaporation), and / or allow the transfer of compounds to provide beneficial functions on the substrate.

[0268] The flushable tissue can be a nonwoven composite article having a high density of interstitial spaces between the fibers constituting the tissue. To maintain sufficient available lotion on the tissue surface for transfer to the substrate, a large amount of the interstitial spaces in the tissue can be filled with lotion. The lotion in the interstitial spaces may not be easily transferred to the substrate, so an excess amount of lotion can be loaded into the tissue, an amount sufficient to signal to the user that the lotion is available for transfer to the substrate, e.g., by providing a sufficient wetting sensation. Advantageously, the nonwoven composite article used in the flushable tissue can have a porosity gradient as described herein, which can contribute to loading the lotion into the tissue.

[0269] Flushable paper towels can be made by wetting a nonwoven composite material article with at least 1 gram of a liquid cleansing agent per gram of dry fibrous composite material. Suitable methods for delivering the cleansing agent to the substrate include, but are not limited to, immersion, spraying, drenching, slot-die coating, and dip coating. After wetting, the wetted composite material article can be folded, stacked, cut to length, and packaged as desired. Flushable paper towels generally have dimensions sufficient to allow for convenient disposal, while being small enough to be easily discarded into the sewage system. The wetted composite material article can be cut or folded to such dimensions during the manufacturing process, or the dimensions can be larger and have members such as perforations to allow the user to separate individual paper towels from the fabric in the desired dimensions.

[0270] Generally, the nonwoven composite material articles of the present disclosure can be used for flushable paper towels. In embodiments, the flushable paper towels of the present disclosure comprise the nonwoven composite material articles of the present disclosure and a cleansing agent. In embodiments, the flushable paper towels of the present disclosure consist of the nonwoven composite material articles of the present disclosure and a cleansing agent.

[0271] Absorbent Article

[0272] The nonwoven fabrics and nonwoven composite material articles of the present disclosure can be used as the liquid collection layer of absorbent articles. Absorbent articles can include bibs, breast pads, nursing pads, cleaning pads (such as floor cleaning pads), diapers, diaper pants, incontinence liners, pads, and other articles (such as adult incontinence diapers, adult incontinence pads, adult incontinence pants, toilet training liners, toilet training pads, toilet training pants, and pet training pads, such as puppy pads), interlabial devices, menstrual pads, pantiliners, sanitary napkins, tampons, spill absorbing mats, spill absorbing pads, spill absorbing rolls, wound dressings, etc. In one aspect, any of the foregoing articles can be disposable articles. The term "disposable" refers to an article designed or intended to be discarded after a single use. That is, a disposable article is not intended to be washed or otherwise restored or reused, and in embodiments, may not be washable, restorable, or reusable.

[0273] As used herein, the term "absorbent article" includes articles that absorb and contain body exudates. The term "absorbent article" is intended to include diapers, incontinence articles, sanitary napkins, etc. The term "incontinence article" is intended to include pads, undergarments (pads held in place by a certain type of suspension system, such as straps, etc.), inserts for absorbent articles, capacity boosters for absorbent articles, underwear, mattress pads, etc., regardless of whether they are worn by adults or other incontinent individuals. At least some of such absorbent articles are intended to absorb body fluids such as menstrual or blood, vaginal discharge, urine, sweat, breast milk, and fecal matter.

[0274] As used herein, "diaper" refers to a device intended to be placed against a wearer's skin to absorb and contain various exudates discharged from the body. Diapers are generally worn by infants and incontinent individuals around the lower torso so as to encircle the wearer's waist and legs. Examples of diapers include infant or adult diapers and pant diapers such as training pants. As used herein, "training pants" refers to a disposable garment designed for infant or adult wearers and having a waist opening and leg openings. The pants can be placed on the wearer in the proper position by inserting the wearer's legs into the leg openings and sliding the pants into position around the wearer's lower torso. The pants can be preformed by any suitable technique, including (but not limited to) using re-fastenable and / or non-re-fastenable joins (e.g., seams, welding, adhesives, sticky joins, fasteners, etc.) to join portions of the article together. The pants can be preformed anywhere along the circumference of the article (e.g., side fastening, front waist fastening).

[0275] Absorbent articles of the present disclosure will generally include a liquid-permeable topsheet, a liquid-impermeable backsheet joined to the topsheet, and a liquid collection layer and an absorbent core between the topsheet and the backsheet. In embodiments where the absorbent article is a wearable article (e.g., an incontinence article, a sanitary napkin, etc.), the article can have a side facing the wearer and a side facing the exterior. Generally, the liquid-permeable topsheet is on the side facing the wearer, and the liquid-impermeable backsheet is on the side of the absorbent article facing the exterior. The absorbent core is generally a sheet-like structure and, when provided as a wearable piece, has a side facing the wearer and a side facing the exterior.

[0276] Generally speaking, the liquid-permeable topsheet can be any liquid-permeable topsheet known in the art. For wearable articles, the topsheet can be fully or partially elastified or can be shortened to provide void space between the topsheet and the absorbent core. Generally speaking, the liquid-impermeable backsheet can be any liquid-impermeable backsheet known in the art. The backsheet prevents the exudates absorbed by the absorbent core and contained within the article form from contacting any substrate that the absorbent article may contact. The backsheet can be liquid-impermeable and include a laminate of a nonwoven fabric and a thin plastic film (such as a thermoplastic film). Suitable backsheet films include those manufactured by Tredegar Industries Inc. of Terre Haute, Ind. and sold under the trade names X15306, X10962, and X10964. Other suitable backsheet materials can include breathable materials that allow vapor to escape from the absorbent article while still preventing liquid from passing through the backsheet. Exemplary breathable materials can include materials such as textiles, nonwovens, and composite materials, such as those manufactured by Mitsui Toatsu Col of Japan under the name ESPOIR NO and by EXXON Chemical Co. of Bay City, Tex. under the name EXXAIRE.

[0277] The absorbent core is disposed between the topsheet and the backsheet. The absorbent core can comprise any absorbent material generally capable of absorbing and retaining liquids such as urine and other body exudates. The absorbent core can include a wide variety of liquid-absorbent materials commonly used in disposable diapers and other absorbent articles, such as superabsorbent polymers, comminuted wood pulp (airfelt), wrinkled cellulose wadding; absorbent foams, absorbent sponges, absorbent gelling materials, or any other known absorbent material or combination of materials. The absorbent core can include a small amount (less than about 10%) of non-liquid-absorbent materials, such as adhesives, waxes, oils, etc.

[0278] Generally speaking, the liquid collection layer includes the nonwoven fabric of the present disclosure, which includes a plurality of fibers comprising a water-soluble polyvinyl alcohol fiber-forming material. The plurality of fibers can include a single fiber type or a blend of fiber types, and the fibers can include the sole polyvinyl alcohol fiber-forming material or a blend of fiber-forming materials including the polyvinyl alcohol fiber-forming material.

[0279] In an embodiment, the liquid collection layer may be disposed between the absorbent core and the top sheet. In a wearable embodiment, the liquid collection layer may be disposed on a side of the absorbent core facing the wearer. In an embodiment, the liquid collection layer may be disposed between the absorbent core and the back sheet. In a wearable embodiment, the liquid collection layer may be disposed on a side of the absorbent core facing the exterior. In an embodiment, the liquid collection layer wraps the absorbent core. The liquid collection layer may be a single sheet that wraps the absorbent core or may be provided as two separate layers joined together. Without wishing to be bound by theory, it is believed that by including the liquid collection layer between the absorbent core and the back sheet or on a side of the absorbent core facing the exterior, leakage of liquid from the absorbent article is advantageously prevented by providing additional liquid collection material to capture any liquid overflow from the top sheet side and / or the side facing the wearer.

[0280] Generally, the liquid collection layer may be in direct contact with the absorbent core, a space may be included between the absorbent core and the liquid collection layer, or an intervening layer may be included between the absorbent core and the liquid collection layer. In an embodiment, the liquid collection layer is in contact with the absorbent core. In an embodiment, the absorbent article includes an intervening layer disposed between the collection layer and the absorbent core. In an embodiment, the liquid collection layer is in contact with the absorbent core on the top sheet side / side facing the wearer, and the intervening layer is disposed between the collection layer and the absorbent core on the back sheet side / side facing the exterior. In an embodiment, the liquid collection layer is in contact with the absorbent core on the back sheet side / side facing the exterior, and the intervening layer is disposed between the collection layer and the absorbent core on the top sheet side / side facing the wearer. The intervening layer may be, for example, a second liquid-permeable layer or a liquid collection layer, which is included to help facilitate the diffusion of liquid from the deposition point to cover the entire area of the absorbent core.

[0281] In an embodiment, the absorbent article includes an absorbent core and a liquid collection layer, wherein the liquid collection layer includes a nonwoven fabric that includes a plurality of fibers comprising a water-soluble polyvinyl alcohol fiber-forming material, and the liquid collection layer includes a nonwoven composite article that includes a first nonwoven fabric layer comprising a first plurality of fibers, a second nonwoven fabric layer comprising a second plurality of fibers, and an optional third nonwoven fabric layer, wherein the nonwoven fabric layer, the second nonwoven fabric layer, and / or the third nonwoven fabric layer may be a nonwoven fabric that includes a water-soluble polyvinyl alcohol fiber-forming material. In an embodiment, the wearable absorbent article includes an absorbent core having a side facing the wearer and a side facing the exterior and a liquid collection layer, wherein the liquid collection layer includes a nonwoven fabric that includes a plurality of fibers comprising a water-soluble polyvinyl alcohol fiber-forming material, and the liquid collection layer includes a nonwoven composite article that includes a first nonwoven fabric layer comprising a first plurality of fibers, a second nonwoven fabric layer comprising a second plurality of fibers, and an optional third nonwoven fabric layer, wherein the nonwoven fabric layer, the second nonwoven fabric layer, and / or the third nonwoven fabric layer may be a nonwoven fabric that includes a water-soluble polyvinyl alcohol fiber-forming material.

[0282] In an embodiment, the absorbent article includes a liquid collection layer, which is the nonwoven composite article of the present disclosure. In an embodiment, the wearable absorbent article includes a liquid collection layer, which is the nonwoven composite article of the present disclosure.

[0283] In an embodiment, the liquid collection layer can be a single-layer nonwoven fabric as disclosed herein, and the nonwoven fabric layer includes a water-soluble polyvinyl alcohol fiber forming material. In an embodiment, the nonwoven composite article of the present disclosure can be used for the liquid collection layer. In an embodiment, the liquid collection layer includes the nonwoven composite article of the present disclosure. In an embodiment, the liquid collection layer consists of the nonwoven composite article of the present disclosure.

[0284] Nonwoven article containing liquid

[0285] The nonwoven fabric of the present disclosure can be used for a nonwoven article containing liquid. The nonwoven article containing liquid can be a single unit dose article for precise administration of a liquid including an active agent. The liquid including the active agent can include (but is not limited to) liquid household care compositions such as laundry detergents, cleaning compositions, fabric softeners or dishwashing detergents, liquid personal care compositions (such as shampoos, body washes or shaving creams) or non-household, non-personal care compositions (such as liquid agricultural products such as fertilizers and pesticides). The liquid generally can include a non-aqueous liquid that will not dissolve the nonwoven article. Suitable liquids include (but are not limited to) 1,2-propanediol, ethanol, glycerol, propylene glycol, dipropylene glycol, methyl propylene glycol and mixtures thereof. Other lower alcohols, low molecular weight polyols, C1-C4 alkanolamines such as monoethanolamine and triethanolamine can also be used. As used herein, "low molecular weight polyol" is a molecule having more than two hydroxyl groups, and its molecular weight is in the range of 50 g / mol to 1000 g / mol, 50 g / mol to 800 g / mol or 50 g / mol to 600 g / mol. Based on the total weight of the liquid and the active agent, the liquid can be present at a level of about 0.1% to about 98%, about 1% to about 75% or about 5% to about 50%, for example about 10%, about 25%, about 35%, about 40%, about 45%, about 48% or about 50%. Typically, the liquid contains less than 50% water, less than 25% water, less than 20% water, less than 10% water, less than 5% water or about 0.001% to about 20% water or about 0.001% to about 10% water.

[0286] The active agent in the liquid can include (but is not limited to) one or more of the following groups: enzymes, oils, fragrances, colorants, odor absorbers, aromatics, pesticides, fertilizers, oxidants, activators, acid catalysts, metal catalysts, ion scavengers, detergents, disinfectants, surfactants, bleaches, bleach components and fabric softeners. In an embodiment, the active agent contains one or more enzymes and one or more surfactants.

[0287] Advantageously, the nonwoven fabric of the present disclosure can absorb and / or adsorb a liquid composition into and onto the fiber network to provide a sufficient amount of active agent for a unit dose. The nonwoven fabric having the liquid composition adsorbed / adsorbed thereon can be wrapped or otherwise enclosed in a second nonwoven fabric to provide a barrier between the active agent and the consumer's hand. Thus, the liquid-containing nonwoven article of the present disclosure can be advantageously disposed of by the consumer without contaminating the consumer's hand or other surfaces. Compared to a single unit dose sachet made of a film for liquid laundry detergents, the liquid-containing nonwoven article of the present disclosure can dissolve faster and more completely than the film because of the increased surface area provided by the fibers of the nonwoven fabric.

[0288] Generally, the liquid-containing nonwoven fabric includes a core nonwoven fabric that includes a first plurality of fibers comprising a first polyvinyl alcohol fiber-forming material, wherein the core nonwoven fabric includes a liquid comprising an active agent; and an outer nonwoven fabric that includes a second plurality of fibers comprising a second polyvinyl alcohol fiber-forming material, wherein the core nonwoven fabric is enclosed by the outer nonwoven fabric. In an embodiment, the outer nonwoven fabric wraps the core nonwoven fabric. As Figure 4A shown, the nonwoven fabric can have a machine direction 301 and a cross direction 300. The nonwoven fabric can be wrapped around the core nonwoven fabric 302, for example, by folding the nonwoven fabric around an axis, such as along the machine direction ( Figure 4B ). In an embodiment, the outer nonwoven fabric can have the form of a sleeve or an envelope, and the core nonwoven fabric can be provided to the sleeve or envelope. The sleeve or envelope can be prepared from a single nonwoven fabric, for example, by folding the fabric in half and sealing the long edges to provide a sleeve structure with two openings through which the core nonwoven fabric can be inserted, or by folding the fabric in half and sealing two of the three edges to form an envelope or pocket structure with one opening through which the core nonwoven fabric can be inserted. The sleeve or envelope can alternatively be prepared from two nonwoven fabrics that are stacked and sealed along two opposite edges (to form a sleeve) or along three edges (to form a pocket or envelope). In an embodiment, the core nonwoven fabric and the outer nonwoven fabric have the same length in at least one dimension. For example, in embodiments where the outer nonwoven fabric wraps the core nonwoven fabric and in embodiments where the outer nonwoven fabric is provided as a sleeve, the core nonwoven fabric and the outer nonwoven fabric can have the same length. In contrast, in embodiments where the outer nonwoven fabric is provided as an envelope or pocket, the core nonwoven fabric will necessarily be shorter than the envelope or pocket because three sides of the envelope or pocket are sealed before the core nonwoven fabric is introduced.

[0289] Generally, the core nonwoven fabric contains liquid, and the liquid contains an active agent. Before the core nonwoven fabric is exposed to the liquid, the dry basis weight of the core nonwoven fabric can be in the range of about 15 gsm to about 200 gsm, about 20 gsm to about 175 gsm, about 25 gsm to about 150 gsm, or about 30 gsm to about 120 gsm. The core nonwoven fabric can be saturated with the liquid. In an embodiment, the weight of the core nonwoven fabric containing the liquid is two to ten times the weight of the core nonwoven fabric before the addition of the liquid. In an embodiment, the core nonwoven fabric contains about 5 g to about 30 g of liquid, about 5 g to about 25 g of liquid, about 8 g to about 20 g of liquid, about 8 g to about 19 g of liquid, about 10 g to about 19 g of liquid, or about 12 g to about 18 g of liquid. In an embodiment, the liquid weight of the core nonwoven fabric containing the liquid is about 30 gsm to about 2000 gsm, about 40 gsm to about 1750 gsm, about 50 gsm to about 1500 gsm, about 60 gsm to about 1200 gsm, about 100 gsm to about 1000 gsm, about 200 gsm to about 800 gsm, or about 300 gsm to about 600 gsm. That is, the amount of liquid per square meter of the core nonwoven fabric is about 30 g to about 2000 g, about 40 g to about 1750 g, about 50 g to about 1500 g, about 60 g to about 1200 g, about 100 g to about 1000 g, about 200 g to about 800 g, or about 300 g to about 600 g.

[0290] Generally, the core nonwoven fabric can comprise a single layer of nonwoven fabric or can comprise multiple layers of nonwoven fabric (such as discrete layers or stacked by folding), optionally laminated or bonded together. In an embodiment, the core nonwoven fabric, whether a single layer or multiple layers of nonwoven fabric, can be folded upon itself to provide a thicker core for the nonwoven article containing the liquid. The number of times the core nonwoven fabric can be folded is not particularly limited and will depend on the desired thickness of the nonwoven article containing the liquid. In an embodiment, the total thickness of the nonwoven article containing the liquid (including both the outer nonwoven fabric and the core nonwoven fabric) can be about 2 mm to about 50 mm, about 3 mm to about 45 mm, about 4 mm to about 40 mm, about 5 mm to about 35 mm, about 5 mm to about 30 mm, or about 5 mm to about 25 mm.

[0291] Generally, the outer nonwoven fabric can comprise a single layer of nonwoven fabric or can comprise multiple layers of nonwoven fabric (e.g., discrete layers or stacked by folding), optionally laminated or adhered together. In embodiments, the basis weight of the outer nonwoven fabric can be from about 15 gsm to about 400 gsm, from about 20 gsm to about 300 gsm, from about 25 gsm to about 250 gsm, from about 30 gsm to about 210 gsm, or from about 30 gsm to about 140 gsm. In embodiments, the thickness of the outer nonwoven fabric can be from about 0.5 mm to about 6.0 mm, from about 0.75 mm to about 4.5 mm, or from about 1.0 mm to about 3.0 mm. Advantageously, the basis weight and thickness of the outer nonwoven fabric can be selected to provide a barrier between the active agent and the environment so that the active agent does not contaminate the secondary packaging, the surface, or the consumer's hand. The outer nonwoven fabric also advantageously provides a surface on which a trademark, printing, or embossing can be applied. In embodiments, markings such as logos or instructions can be printed on the outer nonwoven fabric such that the markings are visible to the consumer. In embodiments, the outer nonwoven fabric can be embossed with a pattern. The outer nonwoven fabric can be printed, embossed, or otherwise marked before and / or after forming the nonwoven article containing the liquid.

[0292] Generally, at least a portion of the core nonwoven fabric can be in contact with at least a portion of the outer nonwoven fabric. In embodiments, the portion of the core nonwoven fabric in contact with the portion of the outer nonwoven fabric can be an edge or a perimeter of the core nonwoven fabric, and the portion of the outer nonwoven fabric in contact with the portion of the core nonwoven fabric can be an edge or a perimeter. In embodiments, the portion of the core nonwoven fabric in contact with the portion of the outer nonwoven fabric can be sealed or otherwise adhered to the outer nonwoven fabric. In embodiments, the core nonwoven fabric and the outer nonwoven fabric can be sealed at at least one edge, at least two edges, or at least three edges. In embodiments, the portion of the core nonwoven fabric in contact with the portion of the outer nonwoven fabric can be a portion of a face of the core nonwoven fabric, and the portion of the outer nonwoven fabric in contact with the core nonwoven fabric can be a portion of a face of the outer nonwoven fabric. In embodiments, the core nonwoven fabric can fit tightly within the outer nonwoven fabric such that the core nonwoven fabric substantially fills the internal volume formed by the outer nonwoven fabric. As used herein, and unless otherwise specified, the core nonwoven fabric “substantially fills” means that at least 70% of the internal volume formed by the outer nonwoven fabric is occupied by the core nonwoven fabric. In embodiments, the core nonwoven fabric occupies at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, or at least 98% of the internal volume formed by the outer nonwoven fabric.

[0293] Generally, the shape and size of the nonwoven article containing a liquid are not particularly limited. In an embodiment, the size and shape of the nonwoven article containing a liquid are selected such that the article containing a liquid fits into the consumer's palm. In an embodiment, the maximum length in any dimension is about 7 inches (17.78 cm), about 6 inches (15.24 cm), about 5 inches (12.70 cm), or about 4 inches (10.16 cm). In an embodiment, the maximum length in any dimension is at least about 0.5 inches (1.27 cm), at least about 1 inch (2.54 cm), at least about 1.5 inches (3.81 cm), or at least about 2 inches (5.08 cm). In an embodiment, the maximum length in any dimension is from about 2 inches (5.08 cm) to about 4 inches (10.16 cm). In an embodiment, the nonwoven article containing a liquid has a shape selected from the group consisting of quadrilateral, triangle, circle, star, heart, octagon, pentagon, hexagon, heptagon, ellipse, crescent, semi - circle, cross, cloverleaf, four - leaf clover, teardrop, pentagram, hexagram, octagram, crown, snowflake, shield, cloud, arrow, and combinations of the foregoing.

[0294] Generally, the nonwoven article containing a liquid may include fibers comprising any of the fiber - forming materials disclosed herein. In an embodiment, the core nonwoven fabric comprises fibers comprising a first polyvinyl alcohol fiber - forming material selected from polyvinyl alcohol homopolymers, polyvinyl alcohol copolymers, and combinations of the foregoing. In an embodiment, the first polyvinyl alcohol comprises a polyvinyl alcohol copolymer comprising an anion - modified polyvinyl alcohol. In an embodiment, the anion - modified polyvinyl alcohol comprises (alkyl) acrylate - modified polyvinyl alcohol, maleate - modified polyvinyl alcohol, sulfonate - modified polyvinyl alcohol, or combinations thereof. In an embodiment, the first polyvinyl alcohol comprises a polyvinyl alcohol homopolymer.

[0295] In an embodiment, the outer nonwoven fabric comprises fibers comprising a second polyvinyl alcohol fiber - forming material selected from polyvinyl alcohol homopolymers, polyvinyl alcohol copolymers, and combinations of the foregoing. In an embodiment, the second polyvinyl alcohol comprises a polyvinyl alcohol copolymer comprising an anion - modified polyvinyl alcohol. In an embodiment, the anion - modified polyvinyl alcohol comprises (alkyl) acrylate - modified polyvinyl alcohol, maleate - modified polyvinyl alcohol, sulfonate - modified polyvinyl alcohol, or combinations thereof. In an embodiment, the second polyvinyl alcohol comprises a polyvinyl alcohol homopolymer.

[0296] In an embodiment, the core nonwoven fabric comprises a first plurality of fibers that include a first polyvinyl alcohol fiber-forming material, and the first plurality of fibers further includes one or more fiber-forming materials selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, and cellulose amide. In an embodiment, the outer nonwoven fabric comprises a second plurality of fibers that include a second polyvinyl alcohol fiber-forming material, and the second plurality of fibers further includes one or more fiber-forming materials selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, and cellulose amide.

[0297] Generally, the first polyvinyl alcohol of the core nonwoven fabric and the second polyvinyl alcohol of the outer nonwoven fabric can be the same or different. In embodiments where the first and second polyvinyl alcohols are different, the first polyvinyl alcohol fiber-forming material and the second polyvinyl alcohol fiber-forming material can differ in terms of viscosity, degree of hydrolysis, degree of copolymerization, type of copolymer modification, or a combination thereof.

[0298] Generally, the core nonwoven fabric before adding the liquid can be the same as or different from the outer nonwoven fabric. Advantageously, the nonwoven article containing the liquid can provide a consumer product containing a liquid composition that has a comfortable cloth-like feel upon disposal, in contrast to currently commercially available pouches made of water-soluble polymeric films that have an unpleasant rubbery or plastic-like feel when disposed of by the consumer. As determined using the softness rating method disclosed herein, the softness rating of the nonwoven article containing the liquid can be from 1 to 5.

[0299] A nonwoven article containing a liquid can be prepared by contacting the core nonwoven fabric with a liquid containing an active agent, encapsulating the core nonwoven fabric with the outer nonwoven fabric, and sealing the outer nonwoven fabric to enclose the core nonwoven fabric.

[0300] In an embodiment, the method of preparing a nonwoven article containing a liquid further comprises folding the core nonwoven fabric itself 2 to 50 times, 3 to 45 times, 4 to 40 times, 5 to 35 times, or 6 to 30 times. As Figure 6 and 7 shown, folding the core nonwoven fabric itself provides a thicker nonwoven core. The method of folding is not particularly limited and can be accordion-style ( Figure 6 ) or continuous folding in the same direction ( Figure 7 ). After folding, the layers can optionally be bonded together using any bonding method known in the art.

[0301] Generally, contacting the core nonwoven fabric with a liquid containing an active agent can be carried out using any method known in the art for applying a liquid composition to a substrate. Methods for contacting include, but are not limited to, one or more of the following: gravure coating, dip coating, slot die coating, wire coating, overflow coating, spraying, and immersing the core nonwoven fabric in a bath of liquid containing an active agent. In an embodiment, folding occurs after contacting, and the contacting includes one or more of gravure coating, dip coating, slot die coating, wire coating, overflow coating, and spraying. In an embodiment, folding occurs before contacting, and the contacting includes immersing the core nonwoven fabric in a bath of liquid containing an active agent.

[0302] In an embodiment, the method further includes preparing an outer nonwoven fabric by laminating, stacking, folding, or laminating multiple nonwoven fabrics. One or more nonwoven fabrics can be superimposed and optionally bonded and laminated together.

[0303] Generally, encapsulating the core nonwoven fabric with an outer nonwoven fabric can include any process in which the outer nonwoven fabric forms an internal space and the core nonwoven fabric is disposed in the internal space. In an embodiment, encapsulating the core nonwoven fabric with an outer nonwoven fabric includes wrapping the core nonwoven fabric with the outer nonwoven fabric, inserting the core nonwoven fabric into an envelope containing the outer nonwoven fabric, or inserting the core nonwoven fabric into a sleeve containing the outer nonwoven fabric. In an embodiment, the encapsulation includes horizontal flow wrapping. The outer nonwoven fabrics can then be sealed together along the processing direction to manufacture a tube surrounding the core nonwoven fabric containing the liquid with the active agent.

[0304] As shown in Figure 4, the outer nonwoven fabric can have a machine direction (301) and a cross direction (300), and the core nonwoven fabric (302) can be encapsulated by wrapping the core nonwoven fabric with the outer nonwoven fabric. As shown in Figure 5, the sealing can include sealing the outer nonwoven fabric (303) at two or more points along the machine direction. The sealing can further include sealing the outer nonwoven fabric along at least one of the lateral edges (304). The sealing can include any sealing method known in the art, such as heat sealing, solvent welding, and adhesive sealing. Typically, only the areas forming the sealed portions are treated with heat or solvent. Heat or solvent can be applied by any method. If a solvent or wet sealing or welding is used, it may be preferred to also apply heat. Preferred wet or solvent sealing / welding methods include selectively applying the solvent, for example, by spraying or printing the solvent onto the areas to be sealed, and then applying pressure to these areas to form the sealed portions. For example, a sealing roll and a sealing belt (optionally also providing heat) can be used. The solvent for solvent sealing / welding can include any suitable solvent, such as a polar solvent including water and / or glycerol. Without wishing to be bound by theory, it is believed that solution sealing will result in a lower crystallinity of the nonwoven fibers, which in turn helps to leave less residue after dissolving the nonwoven article containing the liquid.

[0305] The nonwoven article containing the liquid can be prepared by an on-line process. As Figure 5B shown, the method for preparing the nonwoven article containing the liquid can further include cutting the nonwoven article (305) along the sealed portion (303) in the machine direction in the cross direction to provide a unit dose having a flange (307). A die-cutting system can be used to separate individual doses ( Figure 5B (306)). The incisions are provided between the unit dose sealed portions such that a flange will be produced around each unit dose. In an embodiment, the flange can be at least 1 mm and not more than 10 mm, such as about 1.5 mm to about 9 mm, about 2 mm to about 7.5 mm, or about 2.5 mm to about 5 mm. The individual unit doses can then be collected, weighed, and divided for placement into secondary packaging.

[0306] Dissolution and Disintegration Test (MSTM 205)

[0307] According to the MonoSol Test Method 205 (MSTM 205), a method known in the art, a nonwoven fabric, a water-soluble film, or a composite material structure can be characterized or tested for dissolution time and disintegration time by the dissolution time and the disintegration time. See, for example, U.S. Patent No. 7,022,656. The description provided below refers to the nonwoven fabric, and it is equally applicable to the water-soluble film or the composite material structure.

[0308] Equipment and Materials:

[0309] 600mL beaker

[0310] Magnetic stirrer (Labline model 1250 or equivalent)

[0311] Magnetic stirring bar (5cm)

[0312] Thermometer (0 to 100℃±1℃)

[0313] Template, stainless steel (3.8cm×3.2cm)

[0314] Timer (0-300 seconds, accurate to the nearest second)

[0315] Polaroid 35mm slider mount (or equivalent)

[0316] Monoso 35mm Slider Mount Standoff (or equivalent)

[0317] Distilled water

[0318] For each nonwoven fabric to be tested, three test specimens are cut from the nonwoven fabric sample as 3.8 cm x 3.2 cm specimens. The specimens should be cut from areas of the fabric that are evenly spaced in the cross-machine direction of the fabric. Each test specimen is then analyzed using the following procedure.

[0319] Each specimen was snapped into a separate 35 mm slide mount.

[0320] Fill the beaker with 500 mL of distilled water. Measure the water temperature with a thermometer and heat or cool the water as necessary to maintain the temperature at the temperature at which dissolution is determined, for example 20°C (about 68°F).

[0321] Mark the height of the water column. Place the electromagnetic stirrer on the base of the stand. Place the beaker on the electromagnetic stirrer, add the electromagnetic stir bar to the beaker, turn on the stirrer, and adjust the stirring speed until a vortex is created that is approximately one fifth the height of the water column. Mark the depth of the vortex.

[0322] Fasten the 35 mm slider mount into the alligator clamp of the 35 mm slider mount holder so that the long end of the slider mount is parallel to the surface of the water. The depth adjuster of the holder should be set so that when dropped, the end of the clamp will be 0.6 cm below the surface of the water. One of the short sides of the slider mount should be against the side of the beaker while the other is positioned just above the center of the stir bar so that the nonwoven surface is perpendicular to the water flow.

[0323] In one operation, lower the clamped slider and fixture into the water and start the timer. Disintegration occurs when the nonwoven fabric breaks apart. When all visible nonwoven fabric has been released from the slider mount, lift the slider out of the water while continuing to monitor for undissolved nonwoven fabric fragments in the solution. Dissolution occurs when all nonwoven fabric fragments are no longer visible and the solution becomes clear.

[0324] Results shall include the following: complete sample identification; individual and average disintegration and dissolution times; and the water temperature of the test sample.

[0325] Method for determining the solubility of single fibers

[0326] The solubility of a single fiber can be characterized by the water break temperature. The fiber break temperature can be determined as follows. Place a load of 2 mg / dtex on a fiber with a fixed length of 100 mm. The water temperature starts at 1.5 °C and then increases in 1.5 °C increments every 2 minutes until the fiber breaks. The temperature at which the fiber breaks is designated as the water break temperature.

[0327] The solubility of a single fiber can also be characterized by the temperature of complete dissolution. The temperature of complete dissolution can be determined as follows. Add 0.2 g of fibers with a fixed length of 2 mm to 100 mL of water. The water temperature starts at 1.5 °C and then increases in 1.5 °C increments every 2 minutes until the fibers are completely dissolved. Stir the sample at each temperature. The temperature at which the fibers are completely dissolved is designated as the temperature of complete dissolution.

[0328] Diameter test method

[0329] The diameter of discrete fibers or fibers within a nonwoven fabric is determined by using a scanning electron microscope (SEM) or an optical microscope and image analysis software. Select a magnification of 200 to 10,000 times such that the fibers are appropriately magnified for measurement. When using an SEM, sputter coat the sample with a gold or palladium compound to avoid charging and vibration of the fibers in the electron beam. Use a manual procedure for determining fiber diameter from the images (on the monitor screen) taken with an SEM or an optical microscope. Using the mouse and cursor tools, seek the edge of a randomly selected fiber and then measure across its width (i.e., perpendicular to the fiber direction at that point) to the other edge of the fiber. A scaled and calibrated image analysis tool provides a scaled reading to obtain the actual reading in micrometers. For fibers within a nonwoven fabric, randomly select several fibers in a sample of the nonwoven fabric using an SEM or an optical microscope. Cut and test at least two portions of the nonwoven fabric material in this manner. Conduct at least 100 such measurements in total and then record all the data for statistical analysis. The recorded data is used to calculate the mean (average) of the fibers, the standard deviation of the fibers, and the median fiber diameter.

[0330] Tensile strength, modulus, and elongation testing

[0331] The following analysis is for the characterization of the following nonwoven fabrics, water-soluble films, or composite material structures, or for testing the same: Tensile strength as measured by the Tensile Strength (TS) test, modulus (or tensile stress) as measured by the Modulus (MOD) test, and elongation as measured by the elongation test. The description provided below refers to nonwoven fabrics, and the same applies to water-soluble films or composite material structures. The procedure involves determining the tensile strength in accordance with ASTM D 882 ("Standard Test Method for Tensile Properties of Thin Plastic Sheeting") or an equivalent method and determining the modulus at 10% elongation. The collection of nonwoven fabric data is performed using an INSTRON tensile testing device (Model 5544 tensile tester or equivalent). For each measurement, at least three test specimens are tested along the machine direction (MD) (if applicable), and each test specimen is cut using a reliable cutting tool to ensure dimensional stability and reproducibility. The tests are conducted in a standard laboratory atmosphere of 23°C ± 2.0°C and 35% ± 5% relative humidity. For the determination of tensile strength or modulus, nonwoven fabric samples 1 inch wide (2.54 cm) are prepared. Subsequently, the samples are transferred to the INSTRON tensile testing machine for continued testing while minimizing exposure to a 35% relative humidity environment. A tensile testing machine equipped with a 500 N load cell and calibrated in accordance with the manufacturer's instructions is prepared. The appropriate grips and faces are assembled (INSTRON grips, with a Model 2702-032 face, which is coated with rubber and 25 mm wide, or equivalent). The samples are mounted in the tensile testing machine and analyzed to determine the 100% modulus (i.e., the stress required to achieve 100% film elongation), the tensile strength (i.e., the stress required to break the film), and the elongation % (the length of the sample at break relative to the initial sample length). Generally, the higher the elongation % of the sample, the better the processability characteristics of the nonwoven fabric (e.g., increased formability of bags or pouches).

[0332] Determination of Basis Weight

[0333] The basis weight is determined in accordance with ASTM D3776 / D3776M-09a (2017). Briefly, a sample with a cut area of at least 130 cm 2 is cut, or multiple smaller die-cut samples are taken from different locations in the sample and the total area is at least 130 cm 2 . The samples are weighed on a top-loading analytical balance with a resolution of ±0.001 g to determine the mass. A draft shield is used to protect the balance from air currents and other interferences. The fabric samples can be weighed together. The mass is calculated in ounces per square yard, ounces per linear yard, linear yards per pound, or grams per square meter, to three significant figures.

[0334] Determination of Moisture Permeation Rate

[0335] Determine the moisture vapor transmission rate (MVTR) according to MSTM - 136. MVTR defines how much moisture passes through a sample of non - woven fabric, film, or composite material per day. The description provided below refers to non - woven fabric, and it is equally applicable to water - soluble films or composite structures.

[0336] Equipment and Materials:

[0337] Permatran - W Model 3 / 34 (or equivalent)

[0338] Nitrogen compressed gas cylinder (99.7% or above)

[0339] Regulator - three - way (part number 027 - 343)

[0340] Main line supply regulator

[0341] HPLC - grade water (or equivalent)

[0342] 10 cc syringe with Luerlok tip (part number 800 - 020)

[0343] Powder - free gloves

[0344] High - vacuum grease (part number 930 - 022)

[0345] (2) Test unit

[0346] Cutting template

[0347] Cutting board

[0348] Razor blade with handle

[0349] Cut - resistant gloves

[0350] Preparation of Permatran W - 3 / 34: Ensure that the nitrogen pressure level is higher than 300 psi, the pressure reading on the carrier gas regulator - three - way is 29 psi (not exceeding 32 psi), and the main line supply regulator pressure is set to 35 psi. Open the door on the instrument panel to access the humidifier to check the water level. If the water level is low, fill the syringe with HPLC - grade water and insert the Luer fitting on the syringe into the "fill port" of the reservoir. Open the "injection valve" by turning it counter - clockwise 2 - 3 turns, then push the plunger on the syringe to force the water into the reservoir. Close the "injection valve" and remove the syringe. Note: Do not allow the water level to exceed the line adjacent to the reservoir mark.

[0351] Preparing and Testing Samples: For each nonwoven fabric to be tested, obtain a sample fabric and lay it flat on a cutting board. Place the template on top of the fabric and cut out the sample with a razor blade having a handle. Ensure that cut-resistant gloves are worn while cutting out the sample. Set the sample aside. Apply grease around the sealing surface of the top component of the test unit with high-vacuum grease. Mount the nonwoven fabric sample on top of the top component of the test unit. Note: Orientation may be important. If it is a homogeneous material, then the orientation is not critical. If it is a multi-layer and laminated material, then place the multi-layer film or laminate such that the barrier coating or laminate is upward, towards the top of the unit. For example, a single-sided wax-coated PVOH fabric should be mounted with the wax side up, placing the wax towards the carrier gas (nitrogen). Place the top component of the test unit on top of the bottom component of the test unit. Ensure that the test unit is held together with a good seal. Press the unit load / unload button to open the unit tray. Grasp the front and back edges of the test unit and lower it straight down. Close the unit tray completely by gently pushing it straight towards the plate. Press the unit load / unload button to clamp the unit. Note: You should hear a click. Repeat for the second sample.

[0352] After loading the sample and the instrument is ready, the test parameters must be set. Note: There are two types of test parameters, unit parameters and instrument parameters. Unit parameters are specific to each unit, while instrument parameters are common to all units. Touch the "Test Button" on the touch screen. Select "Tab A" under "Auto Test". Touch the "Unit Tab". Fill in the following by touching each bubble: ID, Area (cm²), Thickness (mils). Note: The area of the template is 50 cm 2 . Repeat for "Tab B". Touch the "Instrument Tab". Fill in the following by touching each bubble: Unit Temperature (°C) and Test Gas RH (%). Note: Ensure that 100% RH is set to off. The unit temperature can be set from a minimum of 10 °C to a maximum of 40 °C. The test gas RH can be set from a minimum of 5% to 90%. If 100% RH is required, then a different method is needed. Repeat for "Tab B". Once the test parameters are set, select "Start Selected" or "Start All" depending on the number of samples. Note: The indicator light for each unit on the front panel will be green, indicating the start of the test.

[0353] Surface Resistivity Measurement

[0354] The surface resistivity of nonwoven fabrics and films can be measured according to ASTM D257.

[0355] Softness Grade

[0356] The feel of the nonwoven fabrics, nonwoven articles containing liquids, or nonwoven composite articles of the present disclosure is related to the softness of a sample and can be evaluated using relative testing methods. A tester performing the softness evaluation uses a clean hand to feel the sample in any manner or method of their choosing to determine the softness grade of the nonwoven fabrics and articles of the present disclosure compared to the following: a control material comprising a nonwoven fabric composed of fibers consisting of a polyvinyl alcohol homopolymer with a degree of hydrolysis of 88%, the fibers having a 2.2 dtex / 51 mm cut, with a softness grade of 1 (softest); and a control material comprising a nonwoven fabric composed of fibers consisting of 75% polyvinyl alcohol homopolymer with a degree of hydrolysis of 88% (the fibers having a 2.2 / 51 mm cut) and 25% 22 dtex / 38 mm PET fibers, with a softness grade of 5 (roughest / coarsest). The hand panel can be studied blindly such that the assessors are not swayed by their perception of the sample name. The grade of the sample can be from 1 to 5.

[0357] Horizontal wicking test

[0358] The horizontal wicking of nonwoven fabrics is tested as disclosed herein. The test is completed with the fan off in a fume hood. The liquid to be tested is exposed to the atmosphere for a time suitable for the liquid to equilibrate to the room conditions. The nonwoven strip is cut such that the processing direction is parallel to the direction of liquid movement. A glass Petri dish is used as a reservoir and filled with liquid to the highest water level possible to test wicking. The lid of the Petri dish is placed adjacent to the Petri dish to support the nonwoven fabric. A long tail clip is placed on the Petri dish lid to support the end of the nonwoven strip such that it does not adhere to the glass. Figure 8 The sample setup is shown. A video of the liquid passing through the nonwoven fabric is taken and a ruler can be seen. The distance the liquid travels in mm is recorded at different time points. The distance over time is plotted to obtain the wicking rate. Horizontal wicking occurs in three stages, a wetting delay, a Washburn period (linear flux of the solution through the substrate), and a falling period. The data for the Washburn slope, wicking rate, and absorption rate are taken at 30 seconds into the trial, which is fully within the Washburn period. The rate v 芯吸 Is determined according to the following equation:

[0359] Lucas-Washburn Equation:

[0360]

[0361]

[0362] Absorption capacity and rate

[0363] Test the absorption capacity and rate of the nonwoven fabric as disclosed herein. For the liquid absorption capacity (LAC%), immerse the test sample (one at a time) in the test liquid at a depth of 20 mm for 60 seconds. Drain the test sample vertically for 120 seconds. Subsequently, calculate the LAC% according to the following equation:

[0364] Absorption rate (volume rate of capillary rise per unit area) By multiplying the capillary rise rate v obtained from the horizontal capillary rise test 芯吸 by the void fraction φ of the nonwoven fabric sample:

[0365]

[0366] The void fraction can be determined by immersing a dry, weighed nonwoven fabric sample into a disk containing water of a known volume. Immerse the nonwoven fabric for 15 seconds and drain it on a petri dish for 30 seconds. Measure the amount of water (volume) lost from the petri dish and calculate the void fraction according to the following equation:

[0367] Examples

[0368] The nonwoven fabrics of the examples are prepared from one or more fibers selected from the group consisting of: Fiber D, Fiber E, Fiber F, and Fiber G, which are described below.

[0369] Fiber D is a commercially available PVOH staple fiber product that includes a PVOH homopolymer having a degree of hydrolysis (DH) of 88% and a fineness of 1.7 - 2.2 dtex. Fiber D will dissolve in water at a temperature of 20°C under the following conditions: Place 10 g of the fiber into a 500 cc container, and then add distilled water at 30 times the weight of the fiber sample. Stir the water gently, and it is observed that the sample completely dissolves within a few minutes, typically within 15 minutes.

[0370] Fiber E is a commercially available PVOH staple fiber product that includes a PVOH homopolymer having a degree of hydrolysis (DH) of 96% and a fineness of 1.4 - 2.2. Fiber E will dissolve in water at a temperature of 40°C under the following conditions: Place 10 g of the fiber into a 500 cc container, and then add distilled water at 30 times the weight of the fiber sample. Stir the water gently, and it is observed that the sample completely dissolves within a few minutes, typically within 15 minutes.

[0371] Fiber F is a commercially available PVOH staple fiber product that includes a PVOH homopolymer having a degree of hydrolysis (DH) of 98% and a fineness of 1.4 - 2.2. Fiber F will dissolve in water at a temperature of 70°C under the following conditions: 10 g of the fiber is placed in a 500 cc container, followed by distilled water at 30 times the weight of the fiber sample. The water is stirred gently, and it is observed that the sample completely dissolves within a few minutes, typically within 15 minutes.

[0372] Fiber G is a commercially available PVOH staple fiber product that includes a PVOH homopolymer having a degree of hydrolysis (DH) of 99+% and a fineness of 1.7 dtex. Fiber G will dissolve in water at a temperature of 95°C under the following conditions: 10 g of the fiber is placed in a 500 cc container, followed by distilled water at 30 times the weight of the fiber sample. The water is stirred gently, and it is observed that the sample completely dissolves within a few minutes, typically within 15 minutes.

[0373] Example 1

[0374] Various nonwoven fabrics are prepared using fibers comprising a single PVOH fiber-forming material. The fibers are composed of PVOH homopolymers having different degrees of hydrolysis. Specifically, fibers D, E, F, and G with DH values of 88%, 96%, 98%, and 99% respectively are used alone or blended 50 / 50 (by weight) to provide nonwoven fabrics with average DH values of 88% (fiber D), 92% (D / E fiber), 93% (D / F fiber), 93.5% (D / G fiber), 96% (E fiber), 97% (E / F fiber), 97.5% (E / G fiber), 98% (F fiber), 98.5% (F / G fiber), and 99+% (G fiber). The fibers are calender bonded to form nonwoven fabrics. The nonwoven fabric with an average DH of 88% is calendered at 40 psi, a speed of 2 FPM (feet per minute), and a temperature of 140°C. Depending on the DH of the fibers as needed, the remaining nonwoven fabrics are calendered at 40 psi and a temperature between 140°C and 190°C at a rate of 1 - 2 FPM to achieve the same degree of bonding as the nonwoven fabric with an average DH of 88%. The degree of bonding of two nonwoven fabrics is considered the same when the tensile strength of the fabrics is the same (±5%) as measured by the tensile strength test disclosed herein. The horizontal wicking and absorption capacity and rate of the resulting nonwoven fabrics are tested according to the methods provided herein.

[0375] The liquids tested with the various nonwoven fabrics are DI water, hexane, synthetic blood, and synthetic urine. Synthetic blood is a 94% water mixture of hemoglobin, amino acids, proteins, and other harmless components. Synthetic urine is a 97% water mixture of urea, magnesium sulfate heptahydrate, calcium chloride dihydrate, and sodium chloride.

[0376] As shown in Figure 9, for water and synthetic urine, as the average DH of the nonwoven fabric increases, the Washburn slope, wicking rate, and absorption rate increase; for synthetic blood, as the average DH increases, the Washburn slope and wicking rate increase and the absorption rate remains; and for hexane, as the DH of the nonwoven fabric increases, each of the Washburn slope, wicking rate, and absorption rate decreases.

[0377] As Figure 10 shown, for liquid absorption capacity, when provided as blends, high DH fibers have a greater effect on capacity than low DH fibers, rather than exhibiting a mixing rule effect on absorption capacity. Nonwovens containing only cotton ball material were also tested for comparison.

[0378] Example 2

[0379] Various multilayer nonwovens were prepared using nonwovens comprising fibers containing a single PVOH fiber forming material. The fibers were composed of PVOH homopolymers having different degrees of hydrolysis. Specifically, fibers D, E, F, and G with DHs of 88%, 96%, 98%, and 99+% respectively were used alone or in blends. The fibers of the first layer were carded and the fiber layer of the second layer was laminated on top of the fibers of the first layer. The two layers were simultaneously bonded into a nonwoven and a multilayer nonwoven article using a calender. The nonwoven with an average DH of 88% was calendered at a temperature of 40 psi, 2 FPM, and 140 °C. Depending on the DH of the fibers as needed, the remaining nonwovens were calendered at 40 psi and a temperature between 140 °C and 190 °C at 1 - 2 FPM to achieve the same degree of bonding as the nonwoven with an average DH of 88%. When the tensile strength of the fabric is the same (±5%) as measured by the tensile strength test disclosed herein, the degree of bonding of the two nonwovens is considered the same. Articles were prepared by combining two nonwovens having the same composition and basis weight, with average DHs of 92% (50 / 50 D / E fiber nonwoven), 93% (50 / 50 D / F fiber nonwoven), 93.5% (50 / 50 D / G fiber nonwoven), 94% (25 / 75 D / E fiber nonwoven), 95.2% (10 / 90 D / E fiber nonwoven), 96% (E fiber nonwoven), 97% (50 / 50 E / F fiber nonwoven), and 97.5% (50 / 50 E / G fiber nonwoven).

[0380] All multilayer articles were tested for horizontal wicking and absorption capacity and rate according to the methods provided herein.

[0381] The liquids tested with various nonwovens were DI water, hexane, synthetic blood, and synthetic urine. Synthetic blood is a 94% water mixture of hemoglobin, amino acids, proteins, and other harmless components. Synthetic urine is a 97% water mixture of urea, magnesium sulfate heptahydrate, calcium chloride dihydrate, and sodium chloride.

[0382] As shown in Figure 11, for all liquids except hexane, as the average DH of the multi-layer article increases, the Washburn slope, wicking rate, and absorption rate increase. For hexane, as the DH of the multi-layer article increases, the Washburn slope, wicking rate, and absorption rate remain relatively stable and increase slightly.

[0383] As Figure 12 shown, for liquid absorption capacity, when provided as a blend, the high DH layer has a greater effect on capacity than the low DH fibers, rather than exhibiting a mixing rule effect on absorption capacity. Nonwovens containing only cotton ball material were also tested for comparison.

[0384] Example 3

[0385] Various multi-layer nonwovens were prepared using nonwovens with fibers comprising a single PVOH fiber-forming material. The fibers were composed of PVOH homopolymers with different degrees of hydrolysis. Specifically, fibers D, E, F, and G with DHs of 88%, 96%, 98%, and 99+% respectively were used alone. The fibers of the first layer were carded and the fiber layer of the second layer was laminated on top of the fibers of the first layer. The two layers were simultaneously bonded into a nonwoven and a multi-layer nonwoven article using a calender. The nonwoven was calendered at a temperature of 40 psi, 2 FPM, and 150 °C. Some single-layer articles were also prepared using air-through bonding. The air-through bonding was carried out at 180 °C at a speed of 6:50. The air-through bonded nonwoven included PVOH fibers with a DH of 96% and up to 5 wt% polyethylene terephthalate (PET) fibers to assist in bonding. For multi-layer articles, the DH was considered the average DH of the two layers. Articles were prepared by combining two nonwovens with different compositions but the same basis weight, with average DHs of 92% (D fiber nonwoven / E fiber nonwoven), 93% (D fiber nonwoven / F fiber nonwoven), 93.5% (D fiber nonwoven / G fiber nonwoven), 97% (E fiber nonwoven / F fiber nonwoven), and 97.5% (E fiber nonwoven / G fiber nonwoven).

[0386] The horizontal wicking and absorption capacity and rate of multi-layer articles containing two different nonwovens were tested according to the method provided herein. Multiple tests were run with the multi-layer article in a first orientation with the higher DH side up and a second orientation with the lower DH side up. No discernible difference in wicking rate was found between the two orientations.

[0387] The liquids tested with various nonwovens were DI water, hexane, synthetic blood, and synthetic urine. The synthetic blood was a 94% water mixture of hemoglobin, amino acids, proteins, and other innocuous components. The synthetic urine was a 97% water mixture of urea, magnesium sulfate heptahydrate, calcium chloride dihydrate, and sodium chloride.

[0388] The articles exhibited the same trend as in Example 1, where the Washburn slope increased with increasing average DH.

[0389] As shown in Figure 13, for all liquids except hexane, the Washburn slope, capillary rise rate, and absorption rate increased with increasing average DH of the multilayer articles. For hexane, the Washburn slope, capillary rise rate, and absorption rate remained relatively stable and increased slightly with increasing DH of the multilayer articles. The data in Figure 13 were collected for calender-bonded articles with the nonwoven in the orientation where the higher DH side was upward and the lower DH side was exposed to the liquid.

[0390] As Figure 14 shown, the performance of the nonwoven depends on the average DH of the article and the type of bonding. The air-through bonded nonwovens exhibited higher LAC% values relative to their calender-bonded counterparts. This trend indicates that at a higher degree of bonding, such as calender bonding (which has higher temperature, pressure, and longer dwell time than the air-through process), the LAC of the article decreases. Figure 14 The labels on the x-axis refer to the following nonwovens of the present disclosure: "E blend" is a single-layer nonwoven composed of E fibers (from Example 1), "E blend, 1.75% PET" is a single-layer nonwoven including E fibers and 1.75 wt.% PET fibers, "E blend, 2.5% PET" is a single-layer nonwoven including E fibers and 2.5 wt.% PET fibers, "E blend, 5% PET" is a single-layer nonwoven including E fibers and 5 wt.% PET fibers, "E multilayer" is a double-layer nonwoven where each layer is composed of E fibers (from Example 2), "E / F blend" is a double-layer nonwoven article where one layer is composed of E fibers and one layer is composed of F fibers, and "E / G blend" is a double-layer nonwoven article where one layer is composed of E fibers and one layer is composed of G fibers. Nonwovens containing only cotton ball material were also tested for comparison.

[0391] Example 4

[0392] The single-layer nonwoven fabric is prepared from a mixture of polyvinyl alcohol fibers (Fiber E) and polylactic acid (PLA) fibers or cotton fibers. In the nonwoven fabric, the polyvinyl alcohol fibers account for 50 wt.% of the total fiber weight and the other 50 wt.% is PLA fibers or cotton fibers. The polyvinyl alcohol fibers and the PLA fibers or cotton fibers are carded together and calendared at 40 psi and 140 °C. The basis weight of the resulting nonwoven fabric is about 50 gsm.

[0393] Thus, Example 4 demonstrates the preparation of a heterogeneous nonwoven fabric comprising water-soluble fibers and water-insoluble fibers.

[0394] The foregoing description is given for clarity of understanding only and should not be construed as imposing unnecessary limitations, as modifications within the scope of the present disclosure may be apparent to those of ordinary skill in the art.

[0395] All patents, publications, and references cited herein are hereby incorporated by reference. In the event of any conflict between the present disclosure and the incorporated patents, publications, and references, the present disclosure shall prevail.

Claims

1. A nonwoven composite article, comprising: A first layer comprising a first nonwoven fabric, the first nonwoven fabric comprising a first plurality of fibers having a first diameter; A second layer comprising a second nonwoven fabric, the second nonwoven fabric comprising a second plurality of fibers having a second diameter; and A first interface comprising a portion of the first nonwoven fabric and a portion of the second nonwoven fabric, wherein the portion of the first nonwoven fabric is fused with the portion of the second nonwoven fabric, wherein the second diameter is less than the first diameter, and the first plurality of fibers, the second plurality of fibers, or both comprise a water-soluble polyvinyl alcohol fiber-forming material, wherein the portion of the first nonwoven fabric forming the first interface is fused with the portion of the second nonwoven fabric by a solvent, and wherein the solvent comprises one or more selected from the group consisting of water, ethanol, methanol, DMSO, and glycerol.

2. The nonwoven composite article according to claim 1, wherein the first nonwoven fabric has a first porosity, and the second nonwoven fabric has a second porosity different from the first porosity.

3. The nonwoven composite article according to claim 1, wherein the nonwoven composite article further comprises a third layer comprising a third nonwoven fabric, the third nonwoven fabric comprising a third plurality of fibers.

4. The nonwoven composite article according to claim 3, wherein the second layer is disposed between the first layer and the third layer, the nonwoven composite article comprises a second interface, the second interface comprising at least a second portion of the second nonwoven fabric and at least a portion of the third nonwoven fabric, wherein the at least second portion of the second nonwoven fabric is fused with the portion of the third nonwoven fabric.

5. The nonwoven composite article according to claim 3, wherein the first nonwoven fabric, the second nonwoven fabric, and the third nonwoven fabric each comprise a plurality of pores and the size of the pores of the third nonwoven fabric is different from the pores of the second nonwoven fabric and the pores of the first nonwoven fabric.

6. The nonwoven composite article according to claim 5, wherein the pores of the first nonwoven fabric are larger than the pores of the second nonwoven fabric and the pores of the second nonwoven fabric are larger than the pores of the third nonwoven fabric.

7. The nonwoven composite article according to claim 4, wherein the portion of the second nonwoven fabric forming the second interface is fused with the portion of the third nonwoven fabric by heat fusion or solvent fusion.

8. The nonwoven composite article according to claim 1, wherein the first plurality of fibers comprises the water-soluble polyvinyl alcohol fiber-forming material.

9. The nonwoven composite article according to claim 1, wherein the second plurality of fibers comprises the water-soluble polyvinyl alcohol fiber-forming material.

10. The nonwoven composite article according to claim 3, wherein the third plurality of fibers comprises a water-soluble polyvinyl alcohol fiber-forming material.

11. The nonwoven composite article according to claim 1, wherein the water-soluble polyvinyl alcohol fiber-forming material comprises one or more selected from the group consisting of polyvinyl alcohol homopolymers and polyvinyl alcohol copolymers.

12. The nonwoven composite article according to claim 11, wherein the polyvinyl alcohol copolymer comprises an anion-modified polyvinyl alcohol.

13. The nonwoven composite article according to claim 12, wherein the anion-modified polyvinyl alcohol comprises one or more selected from the group consisting of (alkyl) acrylate-modified polyvinyl alcohol, maleate-modified polyvinyl alcohol, and sulfonate-modified polyvinyl alcohol.

14. The nonwoven composite article according to claim 1, wherein the first plurality of fibers comprises one or more water-soluble fiber-forming materials selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, and cellulose amide.

15. The nonwoven composite article according to claim 1, wherein the second plurality of fibers comprises one or more water-soluble fiber-forming materials selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, and cellulose amide.

16. The nonwoven composite article according to claim 3, wherein the third plurality of fibers comprises one or more water-soluble fiber-forming materials selected from the group consisting of polyacrylate, polyvinylpyrrolidone, polyethyleneimine, guar gum, gum arabic, xanthan gum, carrageenan, water-soluble starch, water-soluble cellulose, cellulose ether, cellulose ester, and cellulose amide.

17. The nonwoven composite article according to claim 1, wherein the first plurality of fibers comprises a water-insoluble fiber-forming material.

18. The nonwoven composite article according to claim 1, wherein the second plurality of fibers comprises a water-insoluble fiber-forming material.

19. The nonwoven composite article according to claim 3, wherein the third plurality of fibers comprises a water-insoluble fiber-forming material.

20. The non-woven composite article according to claim 17, wherein the water-insoluble fiber-forming material comprises one or more selected from the group consisting of cotton, hemp, jute, flax, ramie, sisal, bagasse, banana fiber, flower bark, silk, tendon, catgut, wool, seaweed fiber, cashmere, collagen, actin, nylon, polyester, rayon, bamboo fiber, diacetate fiber, triacetate fiber, polypropylene, polycarbonate, thermoplastic polyurethane, and rayon.

21. The non-woven composite article according to claim 17, wherein the water-insoluble fiber-forming material comprises one or more selected from the group consisting of mohair, modal fiber, elastic polypropylene, polybutylene terephthalate, and polyethylene terephthalate.

22. The non-woven composite article according to claim 1, wherein the first plurality of fibers comprises a blend of fiber-forming materials.

23. The non-woven composite article according to claim 1, wherein the second plurality of fibers comprises a blend of fiber-forming materials.

24. The non-woven composite article according to claim 3, wherein the third plurality of fibers comprises a blend of fiber-forming materials.

25. The non-woven composite article according to claim 3, wherein one or more of the first plurality of fibers, the second plurality of fibers, and the third plurality of fibers comprise one or more fiber-forming materials selected from the group consisting of bio-based fiber-forming materials, biodegradable fiber-forming materials, and compostable fiber-forming materials.

26. The non-woven composite article according to claim 25, wherein the one or more fiber-forming materials are natural fiber-forming materials.

27. The non-woven composite article according to claim 25, wherein the one or more fiber-forming materials are plant-based fiber-forming materials.

28. The non-woven composite article according to claim 1, wherein the first non-woven fabric has a ratio MD:CD of tenacity in the machine direction to tenacity in the cross direction in the range of 0.5 to 1.

5.

29. The non-woven composite article according to claim 1, wherein the second non-woven fabric has a ratio MD:CD of tenacity in the machine direction to tenacity in the cross direction in the range of 0.75 to 1.

5.

30. The non-woven composite article according to claim 3, wherein the third non-woven fabric has a ratio MD:CD of tenacity in the machine direction to tenacity in the cross direction in the range of 0.75 to 1.

5.

31. The nonwoven composite article according to claim 3, wherein one or more of the first plurality of fibers, the second plurality of fibers, and the third plurality of fibers comprise bicomponent fibers.

32. The nonwoven composite article according to claim 31, wherein the bicomponent fibers comprise a core surrounded by a sheath, the core comprising a fiber-forming material having a first water solubility, and the sheath comprising a fiber-forming material having a second water solubility less than the first water solubility.

33. The nonwoven composite article according to claim 3, wherein one or more of the first plurality of fibers, the second plurality of fibers, and the third plurality of fibers further comprise one or both of a plasticizer and a surfactant.

34. The nonwoven composite article according to claim 1, wherein the nonwoven composite further comprises one or both of an active agent and an absorbent material.

35. The nonwoven composite article according to claim 3, wherein one or more of the first plurality of fibers, the second plurality of fibers, and the third plurality of fibers comprise one or both of an active agent and an absorbent material.

36. The nonwoven composite article according to claim 34, wherein the active agent comprises one or more selected from the group consisting of: enzymes, oils, fragrances, colorants, odor absorbers, aromatics, pesticides, fertilizers, oxidants, activators, acid catalysts, metal catalysts, ion scavengers, detergents, disinfectants, surfactants, bleaching agents, bleaching components, and fabric softeners.

37. The nonwoven composite according to claim 36, wherein the aromatic comprises a perfume, and the perfume is encapsulated.

38. The nonwoven composite article according to claim 1, wherein the first layer comprises a carded layer and the second layer comprises a meltblown layer.

39. The nonwoven composite article according to claim 3, wherein the third layer comprises a carded layer.

40. The nonwoven composite article according to claim 1, wherein the first layer comprises a carded layer and the second layer comprises an air-laid layer containing cellulose fibers.

41. The nonwoven composite article according to claim 3, wherein the third layer comprises a meltblown layer.

42. The nonwoven composite article according to claim 40, wherein the first layer has a basis weight of 30 g / m 2 to 70 g / m 2 of the basis weight.

43. The nonwoven composite article according to claim 1, wherein the composite article has a basis weight of 5 g / m 2 to 150 g / m 2The basis weight.

44. The nonwoven composite article according to claim 43, wherein the first layer has a basis weight of 5 g / m 2 to 15 g / m 2 The basis weight.

45. The nonwoven composite article according to claim 3, wherein the third layer has a basis weight of 5 g / m 2 to 15 g / m 2 The basis weight.

46. The nonwoven composite article according to claim 1, wherein the second layer is included in the composite article at 2.5 wt.% to 10 wt.% based on the total weight of the composite article.

47. The nonwoven composite article according to claim 3, wherein the third layer is included in the composite article at 2.5 wt.% to 10 wt.% based on the total weight of the composite article.

48. The nonwoven composite article according to claim 1, wherein the first diameter is 10 microns to 300 microns.

49. The nonwoven composite article according to claim 1, wherein the first diameter of the first plurality of fibers is substantially uniform.

50. The nonwoven composite article according to claim 3, wherein the first plurality of fibers, the second plurality of fibers, the third plurality of fibers, or a combination thereof has a tenacity of 3 cN / dtex to 10 cN / dtex.

51. The nonwoven composite article according to claim 1, wherein the nonwoven composite article has improved modulus, improved tensile strength, improved elongation, improved tenacity, or a combination thereof in the machine direction, the cross-machine direction, or both directions relative to the same nonwoven composite article comprising only the first layer.

52. The nonwoven composite article according to claim 51, wherein the nonwoven composite article has improved modulus, improved tensile strength, improved elongation, improved tenacity, or a combination thereof in both the machine direction and the cross-machine direction relative to the same nonwoven composite article comprising only the first layer.

53. A flushable wet wipe comprising the nonwoven composite article according to claim 1.

54. The flushable wet wipe according to claim 53, further comprising a cleaning lotion comprising an aqueous emulsion including an emollient and an emulsifier.

55. The flushable wet wipe according to claim 54, wherein the cleaning lotion comprises one or more selected from the group consisting of: fragrances, preservatives, enzymes, colorants, oil absorbers, pesticides, ion scavengers, detergents, and disinfectants.

56. A method of forming a nonwoven composite article, the method comprising: forming a first layer comprising a first nonwoven fabric, the first nonwoven fabric comprising a first plurality of fibers having a first diameter; and a first interface comprising a portion of the first nonwoven fabric and a portion of a second nonwoven fabric, wherein the portion of the first nonwoven fabric and the portion of the second nonwoven fabric are solvent-fused together, depositing a second layer comprising the second nonwoven fabric on the first layer under conditions sufficient to fuse a portion of the first nonwoven fabric with a portion of the second nonwoven fabric, the second nonwoven fabric comprising a second plurality of fibers having a second diameter less than the first diameter, thereby forming the first interface, wherein the first plurality of fibers, the second plurality of fibers, or both comprise a water-soluble polyvinyl alcohol fiber-forming material, and wherein the solvent comprises one or more selected from the group consisting of water, ethanol, methanol, DMSO, and glycerol.

57. The method of claim 56, further comprising depositing a third layer comprising the third nonwoven fabric containing a third plurality of fibers on the second layer under conditions sufficient to fuse at least a second portion of the second nonwoven fabric with at least a portion of a third nonwoven fabric, thereby forming a second interface.

58. The method of claim 57, wherein the conditions sufficient to fuse the portion of the first nonwoven fabric with the portion of the second nonwoven fabric, the conditions sufficient to fuse at least the second portion of the second nonwoven fabric with the portion of the third nonwoven fabric, or both comprise thermal fusion or solvent fusion.

59. The method of claim 58, wherein thermal fusion comprises: contacting the portion of the first nonwoven fabric with the portion of the second nonwoven fabric, the second portion of the second nonwoven fabric with the portion of the third nonwoven fabric, or both, while one of the first nonwoven fabric or the second nonwoven fabric, or one of the second nonwoven fabric or the third nonwoven fabric, is in a heated state.

60. The method of claim 59, wherein thermal fusion comprises contacting the second portion of the second nonwoven fabric with the portion of the third nonwoven fabric while the second nonwoven fabric is in a heated state.

61. The method of claim 58, wherein solvent fusion comprises applying a solvent to the portion of the first nonwoven fabric, the portion of the second nonwoven fabric, or both, before depositing the second nonwoven fabric on the first nonwoven fabric.

62. The method according to claim 58, wherein the solvent fusion comprises applying a solvent to the second portion of the second nonwoven fabric, the portion of the third nonwoven fabric, or both, prior to depositing the third nonwoven fabric on the second nonwoven fabric.

63. The method according to claim 58, wherein the solvent fusion comprises applying a solvent to the portion of the first nonwoven fabric prior to depositing the second nonwoven fabric.

64. The method according to claim 58, wherein the solvent fusion comprises applying a solvent to the second portion of the second nonwoven fabric prior to depositing the third nonwoven fabric.

65. The method according to claim 61, wherein the portion of the first nonwoven fabric, the second portion of the second nonwoven fabric, or both are at least partially soluble in the solvent.

66. The method according to claim 56, wherein the first layer comprises a carded nonwoven fabric.

67. The method according to claim 57, wherein the third layer comprises a carded nonwoven fabric.

68. The method according to claim 56, wherein the second layer comprises a meltblown nonwoven fabric.

69. The method according to claim 57, wherein the third layer comprises a meltblown nonwoven fabric.

70. The method according to claim 69, wherein the second layer comprises a nonwoven fabric containing a cellulose fiber-forming material.

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