Absorbent nonwoven material

Abstract

The subject matter of the present disclosure relates to multi-layer nonwoven materials and their use in absorbent articles, for example, as absorbent cores and / or acquisition-distribution layers (ADLs). In particular, the subject matter of the present disclosure relates to layered structures that provide improved liquid acquisition, distribution, storage, and rewet properties while allowing for the use of less synthetic materials, such as superabsorbent polymers (SAPs), than other commercially available materials.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority to U.S. Provisional Patent Application Nos. 62 / 902,038 and 62 / 902,051, both filed September 18, 2019, the contents of each of which are incorporated herein by reference in their entirety.

[0002] The subject matter of this disclosure relates to novel nonwoven materials and their use in absorbent articles, including personal hygiene products such as incontinence, light incontinence, and feminine hygiene products, for example, as absorbent cores and / or collection-distribution layers. Among other things, such structures provide improved liquid acquisition, distribution, storage, and rewet, while allowing for the use of less synthetic materials, such as superabsorbent polymers (SAPs), compared to conventional absorbent cores or absorbent systems that include a separate collection-distribution material. [Background technology]

[0003] Nonwoven structures are important in a wide range of consumer products, such as absorbent articles, including baby diapers, adult incontinence products, light incontinence products, and feminine hygiene products such as panty liners and sanitary napkins. Such absorbent articles may require rapid liquid collection. In some nonwoven articles, an absorbent core is often present to receive and retain bodily fluids. The absorbent core is typically positioned between a liquid-permeable topsheet, whose function is to allow fluid to pass through to the core, and a liquid-impermeable backsheet, whose function is to contain fluid and prevent it from passing through the absorbent article and reaching the clothing of the wearer of the absorbent article. In some nonwoven articles, an acquisition-distribution layer (ADL) can be used in combination with the absorbent core. The ADL can facilitate both the collection of liquid for storage in the absorbent core and the distribution of such liquid.

[0004] In conventional multi-layer absorbent structures having a collection layer, a distribution layer, and a storage layer, the collection layer collects liquid insult and rapidly transports it away from the wearer's skin (in the Z direction) by capillary action. The fluid then encounters the distribution layer, which is typically made of a denser material and transports the liquid away from the wearer's skin (in the Z direction) and laterally across the structure (in both the X and Y directions). Finally, the liquid migrates to the storage layer, which generally contains high-density cellulose fibers and superabsorbent polymer (SAP) particles. The liquid is absorbed into the storage layer and, in particular, the SAP particles contained therein. In other conventional multi-layer absorbent structures having a collection layer and a storage layer, the collection layer collects liquid insult and distributes the liquid away from the wearer's skin. The liquid migrates and is absorbed into the storage layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 5,492,759 [Patent Document 2] U.S. Patent No. 5,601,921 [Patent Document 3] U.S. Patent No. 6,159,335 [Patent Document 4] U.S. Patent No. 4,432,833 [Patent Document 5] U.S. Patent No. 4,425,186 [Patent Document 6] U.S. Patent No. 5,776,308 [Patent Document 7] U.S. Patent No. 4,098,996 [Patent Document 8] U.S. Patent No. 5,547,541 [Patent Document 9] U.S. Patent No. 4,731,269 [Patent Document 10] U.S. Patent No. 5,372,885 [Patent Document 11] U.S. Patent No. 5,456,982 [Patent Document 12] U.S. Patent No. 4,950,541 [Patent Document 13] U.S. Patent No. 5,082,899 [Patent Document 14] U.S. Patent No. 5,126,199 [Patent Document 15] U.S. Patent No. 5,705,565 [Patent Document 16] U.S. Patent No. 2,861,319 [Patent Document 17] U.S. Patent No. 2,931,091 [Patent Document 18] U.S. Patent No. 2,989,798 [Patent Document 19] U.S. Patent No. 3,038,235 [Patent Document 20] U.S. Patent No. 3,081,490 [Patent Document 21] U.S. Patent No. 3,117,362 [Patent Document 22] U.S. Patent No. 3,121,254 [Patent Document 23] U.S. Patent No. 3,188,689 [Patent Document 24] U.S. Patent No. 3,237,245 [Patent Document 25] U.S. Patent No. 3,249,669 [Patent Document 26] U.S. Patent No. 3,457,342 [Patent Document 27] U.S. Patent No. 3,466,703 [Patent Document 28] U.S. Patent No. 3,469,279 [Patent Document 29] U.S. Patent No. 3,500,498 [Patent Document 30] U.S. Patent No. 3,585,685 [Patent Document 31] U.S. Patent No. 3,163,170 [Patent Document 32] U.S. Patent No. 3,692,423 [Patent Document 33] U.S. Patent No. 3,716,317 [Patent Document 34] U.S. Patent No. 3,778,208 [Patent Document 35] U.S. Patent No. 3,787,162 [Patent Document 36] U.S. Patent No. 3,814,561 [Patent Document 37] U.S. Patent No. 3,963,406 [Patent Document 38] U.S. Patent No. 3,992,499 [Patent Document 39] U.S. Patent No. 4,052,146 [Patent Document 40] U.S. Patent No. 4,251,200 [Patent Document 41] U.S. Patent No. 4,350,006 [Patent Document 42] U.S. Patent No. 4,370,114 [Patent Document 43] U.S. Patent No. 4,406,850 [Patent Document 44] U.S. Patent No. 4,445,833 [Patent Document 45] U.S. Patent No. 4,717,325 [Patent Document 46] U.S. Patent No. 4,743,189 [Patent Document 47] U.S. Patent No. 5,162,074 [Patent Document 48] U.S. Patent No. 5,256,050 [Patent Document 49] U.S. Patent No. 5,505,889 [Patent Document 50] U.S. Patent No. 5,582,913 [Patent Document 51] U.S. Patent No. 6,670,035 [Patent Document 52] U.S. Patent No. 2,345,543 [Patent Document 53] U.S. Patent No. 2,926,116 [Patent Document 54] U.S. Patent No. 2,926,154 [Patent Document 55] U.S. Patent No. 3,700,623 [Patent Document 56] U.S. Patent No. 3,772,076 [Patent Document 57] U.S. Patent No. 3,556,932 [Patent Document 58] U.S. Patent No. 5,466,337 [Patent Document 59] U.S. Patent No. 3,556,933 [Patent Document 60] U.S. Patent No. 4,605,702 [Patent Document 61] U.S. Patent No. 4,603,176 [Patent Document 62] U.S. Patent No. 5,935,383 [Patent Document 63] U.S. Patent No. 6,017,417 [Patent Document 64] U.S. Patent No. 5,147,343 [Patent Document 65] U.S. Patent No. 5,378,528 [Patent Document 66] U.S. Patent No. 5,795,439 [Patent Document 67] U.S. Patent No. 5,807,916 [Patent Document 68] U.S. Patent No. 5,849,211 [Patent Document 69] U.S. Patent No. 6,403,857 [Patent Document 70] U.S. Patent No. 2,929,154 [Patent Document 71] U.S. Patent No. 3,224,986 [Patent Document 72] U.S. Patent No. 3,332,909 [Patent Document 73] U.S. Patent No. 4,076,673 [Patent Document 74] U.S. Patent No. 3,972,092 [Non-patent literature]

[0006] [Non-Patent Document 1] Dutkiewicz, T, Nonwoven Structures for Absorption of Body Fluids, (2003) ISBN 2-930159-46-4 (published by Edana - Brussels, Belgium), Section 2.1.3 "Surface Properties and Capillary Tension" [Non-patent document 2] Watson, P. et al., Canadian Pulp Fibre Morphology: Superiority and Considerations for End Use Potential, The Forestry Chronicle, Vol. 85, No. 3, pp. 401-408, May / June 2009 [Non-patent document 3] Horn, R., Morphology of Pulp Fiber from Hardwoods and Influence on Paper Strength, Research Paper FPL 312, Forest Products Laboratory, US Department of Agriculture (1978) and Bleached Eucalyptus Kraft Pulp ECF Technical Sheet (April 2017) (https: / / www.metsafibre.com / en / Documents / Data-sheets / Cenibra-euca-Eucalyptus.pdf) [Non-patent document 4] AJ Stamm, Forest Products Journal 5(6):413 pages, 1955 Summary of the Invention [Problem to be solved by the invention]

[0007] Recently, there has been market and consumer demand for absorbent articles that do not require as much synthetic material, such as SAP, and are more economical. There is also market and consumer demand for thinner absorbent articles. Furthermore, there is a need for improved performance of such nonwoven articles in terms of liquid acquisition, distribution, storage, and rewet properties, while also providing adequate dryness.

[0008] Thus, there remains a need for nonwoven materials that have sufficient absorbent capacity for their intended use, yet are consistent with a desired dryness profile. There also remains a need for economical, thinner absorbent articles that contain reduced amounts of synthetic materials. The subject matter of the present disclosure addresses these and other needs. [Means for solving the problem]

[0009] The presently disclosed subject matter provides absorbent structures having multilayer nonwoven materials that include specific layered structures that advantageously achieve increased liquid acquisition, distribution storage, and rewet performance while allowing for the use of less synthetic materials, such as superabsorbent polymers (SAPs), and a reduced overall basis weight. In some embodiments, the nonwoven materials of the present disclosure include a multilayer absorbent core that includes a layer of bonded fine cellulosic fibers, such as hardwood fibers, and a layer of bonded coarse cellulosic fibers, such as softwood fibers, providing the nonwoven material with improved liquid acquisition, distribution, and rewet performance, advantageously allowing for reduced incorporation of synthetic materials. In some embodiments, the nonwoven materials of the present disclosure include an acquisition-distribution layer (ADL) that has the absorbent properties of a fibrous network of bonded long fibers and a fibrous network of bonded short fibers, which advantageously provide increased liquid storage and distribution performance.

[0010] A multi-layer nonwoven material including at least two layers and an absorbent article including the same are provided. The nonwoven material can include a first layer and a second layer. The first layer can include cellulose fibers and bicomponent fibers. The second layer can be adjacent to the first layer and can include finer cellulose fibers and bicomponent fibers. At least a portion of the first and second layers can be coated with a binder.

[0011] In some embodiments, the nonwoven material may have an Effective Acquisition Time (EAT) of about 40 seconds or less, or about 20 seconds or less. In some embodiments, the nonwoven material may have a wicking distance of at least about 85 mm or at least about 140 mm. In some embodiments, the nonwoven material may have a rewet value of about 0.2 g or less, or about 0.15 g or less. In some embodiments, the nonwoven material may have a retention before breakthrough of at least about 3.0 g.

[0012] In some embodiments, the finely divided cellulose fibers may include eucalyptus pulp.

[0013] In some embodiments, the nonwoven material can further include an intermediate layer disposed between the first and second layers. The first intermediate layer can include a superabsorbent polymer (SAP).

[0014] In some embodiments, the nonwoven material can further include a second intermediate layer disposed between the first layer and the first intermediate layer. The second intermediate layer can include cellulosic fibers and bicomponent fibers.

[0015] A multi-layer nonwoven material including at least four layers and an absorbent article including the same are provided. The nonwoven material can include a first layer, a second layer, a third layer, and a fourth layer. The first layer can include cellulose fibers and synthetic fibers. The second layer can be adjacent to the first layer and can include cellulose fibers and synthetic fibers. The third layer can be adjacent to the second layer and can include a superabsorbent polymer (SAP). The fourth layer can be adjacent to the third layer and can include fine cellulose fibers and synthetic fibers. At least a portion of the first and fourth layers can be coated with a binder.

[0016] In some embodiments, the finely divided cellulose fibers may comprise eucalyptus pulp. In some embodiments, the synthetic products may comprise bicomponent fibers.

[0017] A multi-layer nonwoven material having at least two layers and an absorbent article including the same are provided. The nonwoven material can include a first layer and a second layer. The first layer can include long fibers. The second layer is adjacent to the first layer and can include short fibers. At least a portion of the second layer can be coated with a binder.

[0018] In some embodiments, the nonwoven material can have an Effective Acquisition Time (EAT) of about 15 seconds or less, or about 1 second or less. In some embodiments, the nonwoven material can have a rewet value of about 0.5 g or less, or about 0.05 g or less. In some embodiments, the nonwoven material can have a wicking distance of at least about 140 mm or at least about 180 mm.

[0019] In some embodiments, the long fibers can include synthetic fibers, regenerated cellulose fibers, or combinations thereof. In certain embodiments, the long fibers can include synthetic fibers formed as a carded web. The long fibers can have a length between about 8 mm and about 70 mm. In some embodiments, the short fibers can include synthetic fibers, cellulose fibers, regenerated cellulose fibers, or combinations thereof. The short fibers can have a length between about 1 mm and about 8 mm.

[0020] A multi-layer nonwoven material having at least two layers, including a first layer comprising synthetic fibers formed as a carded web, and an absorbent article comprising the same are provided. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can comprise cellulose fibers. At least a portion of the second layer can be coated with a binder. In some embodiments, the synthetic fibers can have a length between about 8 mm and about 70 mm.

[0021] A multi-layer nonwoven material comprising at least three layers and an absorbent article comprising the same are provided. The nonwoven material can include a first layer, a second layer, and a third layer. The first layer can include synthetic fibers formed as a carded web. The second layer can be adjacent to the first layer and can include cellulose fibers and bicomponent fibers. The third layer can be adjacent to the second layer and can include cellulose fibers and bicomponent fibers. At least a portion of the third layer can be coated with a binder. In some embodiments, the synthetic fibers can have a length between about 8 mm and about 70 mm. In some embodiments, the cellulose fibers of the third layer can include fine cellulose fibers. In certain embodiments, the cellulose fibers of the third layer can include eucalyptus pulp.

[0022] A multi-layer nonwoven material including at least four layers and an absorbent article including the same are provided. The nonwoven material can include a first layer, a second layer, a third layer, and a fourth layer. The first layer can include synthetic fibers formed as a carded web. The second layer can be adjacent to the first layer and can include cellulose fibers and bicomponent fibers. The third layer can be adjacent to the second layer and can include a superabsorbent polymer (SAP). The fourth layer can be adjacent to the third layer and can include cellulose fibers and bicomponent fibers. At least a portion of the fourth layer can be coated with a binder. In some embodiments, the synthetic fibers can have a length between about 8 mm and about 70 mm. In some embodiments, the cellulose fibers of the fourth layer can include fine cellulose fibers. In certain embodiments, the cellulose fibers of the fourth layer can include eucalyptus pulp.

[0023] The foregoing has outlined rather broadly the features and technical advantages of the present application in order that the detailed description that follows may be better understood.

[0024] Additional features and advantages of the present application will be described hereinafter, which form the subject of the claims of the present application. It should be appreciated by those skilled in the art that the conception and specific embodiments disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present application. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the present application as set forth in the appended claims. The novel features believed characteristic of the present application, both as to its organization and method of operation, together with further objects and advantages, will be better understood from the following description. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 1 depicts the results of testing the effective collection time of absorbent structures prepared according to certain non-limiting embodiments (Structures B, C, and D) compared to commercially available absorbent structures according to Example 2. [Figure 2]FIG. 1 depicts rewet test results of absorbent structures prepared according to certain non-limiting embodiments (Structures B, C, and D) compared to commercially available absorbent structures according to Example 2. [Figure 3] FIG. 1 depicts the results of testing the effective collection time of absorbent structures prepared according to certain non-limiting embodiments (Structures C, D, F, H, I, J, and K) compared to commercially available absorbent structures according to Example 2. [Figure 4] FIG. 1 depicts rewet test results of absorbent structures prepared according to certain non-limiting embodiments (Structures C, D, F, H, I, J, and K) compared to commercially available absorbent structures according to Example 2. [Figure 5] FIG. 1 depicts the apparatus used during fluid retention testing for retention before leakage of absorbent structures according to Example 2. [Figure 6A] FIG. 1 depicts liquid retention test results, as retention before leakage, of an absorbent structure prepared according to one non-limiting embodiment (Structure B) compared to a commercially available absorbent structure according to Example 2. [Figure 6B] FIG. 1 depicts liquid retention test results, as retention before leakage, of absorbent structures prepared according to certain non-limiting embodiments (Structures C, H, and I) compared to commercially available absorbent structures according to Example 2. [Figure 6C] FIG. 1 depicts liquid retention test results, as retention before leakage, of absorbent structures prepared according to certain non-limiting embodiments (Structures F, J, and K) compared to commercially available absorbent structures according to Example 2. [Figure 7A] FIG. 1 depicts wicking test results of an absorbent structure prepared according to one non-limiting embodiment (Structure B) compared to a commercially available absorbent structure according to Example 2. [Figure 7B] FIG. 1 depicts wicking test results of absorbent structures prepared according to certain non-limiting embodiments (Structures C, H, and I) compared to commercially available absorbent structures according to Example 2. [Figure 7C]FIG. 1 depicts wicking test results of absorbent structures prepared according to certain non-limiting embodiments (Structures F, J, and K) compared to commercially available absorbent structures according to Example 2. [Figure 8] 1 depicts the results of testing the effective collection time of absorbent structures prepared according to certain non-limiting embodiments compared to commercially available absorbent structures according to Example 4. [Figure 9] FIG. 1 depicts rewet test results of an absorbent structure prepared according to one non-limiting embodiment (Structure 1A) according to Example 4 compared to a commercially available absorbent structure in a feminine sanitary napkin application. [Figure 10] FIG. 1 depicts rewet test results of an absorbent structure prepared according to one non-limiting embodiment (Structure IB) according to Example 2 compared to a commercially available absorbent structure in a diaper application. [Figure 11] FIG. 1 depicts the basis weight of absorbent structures prepared in accordance with certain non-limiting embodiments (Structures 2-4) compared to commercially available absorbent structures according to Example 6. [Figure 12] FIG. 1 depicts the thickness of absorbent structures (Structures 2-4) prepared according to certain non-limiting embodiments before and after 4 bar compression, according to Example 6. [Figure 13] FIG. 1 depicts the results of measuring effective collection time for absorbent structures prepared according to certain non-limiting embodiments (Structures 2-4) compared to commercially available absorbent structures according to Example 6. [Figure 14] FIG. 1 depicts rewet test results of absorbent structures prepared according to certain non-limiting embodiments (Structures 2-4) compared to commercially available absorbent structures according to Example 6. [Figure 15] FIG. 1 depicts wicking test results of absorbent structures prepared according to certain non-limiting embodiments (Structures 2-4) compared to commercially available absorbent structures according to Example 6. DETAILED DESCRIPTION OF THE INVENTION

[0026] The presently disclosed subject matter provides multi-layer nonwoven materials for use in absorbent articles, for example, as absorbent cores and / or acquisition-distribution layers (ADLs). The presently disclosed subject matter also provides methods of making such materials. These and other aspects of the presently disclosed subject matter are discussed in the more detailed description and examples.

[0027] definition The terms used herein have their ordinary meanings in the art, generally within the context of this subject matter and in the specific context in which each term is used. Certain terms are defined below to provide additional guidance in describing the compositions and methods of the presently disclosed subject matter, and how to make and use the same.

[0028] As used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "compound" includes a mixture of compounds.

[0029] The term "about" or "approximately" means within an acceptable error range for a particular value as determined by one of ordinary skill in the art, which depends in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, "about" can mean within 3 or more standard deviations, in accordance with industry practice. Alternatively, "about" can mean within a range of up to 20%, preferably up to 10%, more preferably up to 5%, and more preferably still up to 1% of a given value. Alternatively, particularly with respect to a system or method, the term can mean within an order of magnitude of a value, preferably within 5-fold, and more preferably within 2-fold.

[0030] The term "basis weight" as used herein refers to the amount by mass of a compound over a given area. Examples of units of measure include grams per square meter, identified by the acronym "gsm."

[0031] As used herein, the term "capillary action" refers to the ability of a liquid to flow in a narrow space without the assistance of, or even against, an external force such as gravity. Section 2.1.3 "Surface Properties and Capillary Tension" in the book by Dutkiewicz, T, Nonwoven Structures for Absorption of Body Fluids, (2003) ISBN 2-930159-46-4 (published by Edana - Brussels, Belgium) provides additional disclosure regarding capillary action.

[0032] As used herein, the term "cellulose" or "cellulosic" includes any material having cellulose as the primary component, especially at least 50 weight percent cellulose or a cellulose derivative. Thus, the term includes cotton, ordinary wood pulp, cellulose acetate, rayon, thermochemical wood pulp, chemical wood pulp, debonded chemical wood pulp, milkweed floss, microcrystalline cellulose, microfibrillated cellulose, etc.

[0033] As used herein, the phrase "chemical modification," when used with reference to fibers, means that the fibers are treated with a polyvalent metal-containing compound to produce fibers containing the polyvalent metal-containing compound bound thereto. It is not necessary for the compound to be chemically bound to the fibers, but it is preferred that the compound remain in close association with the fibers by coating, adhesion, precipitation, or any other mechanism so that the compound does not migrate from the fibers during normal handling of the fibers. In particular, the compound can remain associated with the fibers even when wetted or washed with a liquid. For convenience, the association between the fibers and the compound can be referred to as a bond, and the compound can be said to be bound to the fibers.

[0034] As used herein, the terms "fibrous" or "fibrous" refer to particulate materials, such particulate materials having a length to diameter ratio of greater than about 10. Conversely, "non-fibrous" or "non-fibrous" materials are meant to refer to particulate materials, such particulate materials having a length to diameter ratio of less than or equal to about 10.

[0035] As used herein, the term "hybrid" as in "hybrid absorbent structure" or "hybrid absorbent material" refers to a structure comprising a carded nonwoven web (e.g., TABCW) and an absorbent core.

[0036] As used herein, the term "liquid" refers to a substance having a fluid consistency. By way of example and not limitation, liquids can include water, oil, solvents, bodily fluids such as urine or blood.

[0037] As used herein, the terms "long fibers" or "longer fibers" refer to fibers having a length of from about 8 mm to about 70 mm, inclusive of all intervening values. In some embodiments, the long fibers can include synthetic fibers formed as a carded nonwoven web.

[0038] As used herein, "nonwoven" refers to a class of materials, including, but not limited to, textiles or plastics. A nonwoven is a sheet or web structure made of fibers, filaments, fused plastics, or plastic films mechanically, thermally, or chemically bonded together. A nonwoven is a fabric made directly from a web of fibers, without the yarn preparation required for weaving or knitting. In a nonwoven, the collection of fibers is held together by one or more of the following: (1) mechanical interlocking in a random web or mat; (2) fusion of the fibers, as in the case of thermoplastic fibers; or (3) bonding by a bonding medium such as a natural or synthetic resin.

[0039] As used herein, the terms "short fibers" or "shorter fibers" refer to fibers having a length of from about 1 mm to about 8 mm, inclusive of all intervening values.

[0040] As used herein, the term "weight percent" is meant to refer to either (i) the amount by weight of a component / ingredient in a material as a weight percentage of a material layer; or (ii) the amount by weight of a component / ingredient in a material as a weight percentage of the final nonwoven material or product.

[0041] fiber The nonwoven material of the presently disclosed subject matter comprises fibers. In some embodiments, the fibers can comprise long fibers, short fibers, or a mixture thereof. The fibers can be natural fibers, synthetic fibers, or a mixture thereof. In some embodiments, the fibers can be cellulosic fibers, one or more synthetic fibers, or a mixture thereof.

[0042] cellulose fiber Any naturally occurring cellulose fiber known in the art, including those derived from wood pulp or regenerated cellulose, can be used in the cellulosic layer. In some embodiments, the cellulose fibers include, but are not limited to, digested fibers such as kraft fibers, prehydrolyzed kraft fibers, soda fibers, sulfite fibers, chemithermomechanical fibers, and thermomechanically treated fibers derived from softwoods, hardwoods, or cotton linters. Regenerated cellulose can be prepared by dissolving cellulose into monomers to regenerate a continuous cellulose polymer. The resulting polymer can be 100% cellulose and can be made into longer fibers for use in textiles, etc. In other embodiments, the cellulose fibers include, but are not limited to, kraft digested fibers, including prehydrolyzed kraft digested fibers. Non-limiting examples of cellulose fibers suitable for use in the present subject matter are cellulose fibers derived from softwoods, such as pine, fir, and spruce. Other suitable cellulose fibers include, but are not limited to, those derived from esparto grass, bagasse, kemp, flax, hemp, kenaf, and other woody and cellulosic fiber sources. Suitable cellulose fibers include, but are not limited to, bleached kraft southern pine fibers sold under the trademark FOLEY FLUFFS® (Buckeye Technologies Inc., Memphis, Tenn.). Additionally, fibers sold under the trademark CELLU TISSUE® (e.g., Grade 3024) (Clearwater Paper Corporation, Spokane, Wash.) find use in certain embodiments of the presently disclosed subject matter.

[0043] Nonwoven materials of the presently disclosed subject matter can also include commercially available bright fluff pulps, including, but not limited to, southern softwood kraft (e.g., GP Cellulose's Golden Isles® 4725) or southern softwood fluff pulp (e.g., Treated FOLEY FLUFFS®), northern softwood sulfite pulp (e.g., Weyerhaeuser's T730), or hardwood pulp (e.g., eucalyptus). In some embodiments, the nonwoven material can include eucalyptus fibers (Suzano, untreated). While certain pulps may be preferred based on various factors, any absorbent fluff pulp or mixtures thereof can be used. In some embodiments, wood cellulose, cotton enthalpy pulp, chemically modified cellulose, such as crosslinked cellulose fibers, and highly refined cellulose fibers can be used. Further non-limiting examples of pulps are FOLEY FLUFFS® FFTAS (also known as FFTAS or Buckeye Technologies FFT-AS pulp) and Weyco CF401.

[0044] In some embodiments, fine fibers, such as certain softwood fibers, can be used. Some non-limiting examples of such fine fibers, including pulp coarseness, are provided in Table I below with reference to Watson, P. et al., Canadian Pulp Fibre Morphology: Superiority and Considerations for End Use Potential, The Forestry Chronicle, Vol. 85, No. 3, pp. 401-408, May / June 2009.

[0045] [Table 1]

[0046] In some embodiments, fine fibers, such as certain hardwood fibers, can be used. Some non-limiting examples of such fine fibers, including pulp coarseness, are provided in Table II, with at least partial reference to Horn, R., Morphology of Pulp Fiber from Hardwoods and Influence on Paper Strength, Research Paper FPL 312, Forest Products Laboratory, US Department of Agriculture (1978) and Bleached Eucalyptus Kraft Pulp ECF Technical Sheet (April 2017) (available at: https: / / www.metsafibre.com / en / Documents / Data-sheets / Cenibra-euca-Eucalyptus.pdf). In certain embodiments, eucalyptus pulp can be used.

[0047] [Table 2]

[0048] Other suitable types of cellulose fibers include, but are not limited to, chemically modified cellulose fibers. In certain embodiments, the modified cellulose fibers are crosslinked cellulose fibers. U.S. Patent Nos. 5,492,759, 5,601,921, and 6,159,335, all of which are incorporated herein by reference in their entireties, relate to chemically treated cellulose fibers useful in practicing the subject matter of the present disclosure. In certain embodiments, the modified cellulose fibers include a polyhydroxy compound. Non-limiting examples of polyhydroxy compounds include glycerin, trimethylolpropane, pentaerythritol, polyvinyl alcohol, partially hydrolyzed polyvinyl acetate, and fully hydrolyzed polyvinyl acetate. In certain embodiments, the fibers are treated with a polyvalent cation-containing compound. In one embodiment, the polyvalent cation-containing compound is present in an amount of about 0.1 weight percent to about 20 weight percent based on the dry weight of the untreated fiber. In certain embodiments, the polyvalent cation-containing compound is a polyvalent metal ion salt. In certain embodiments, the polyvalent cation-containing compound is selected from the group consisting of aluminum, iron, tin, salts thereof, and mixtures thereof. Any polyvalent metal salt, including transition metal salts, may be used. Non-limiting examples of suitable polyvalent metals include beryllium, magnesium, calcium, strontium, barium, titanium, zirconium, vanadium, chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper, zinc, aluminum, and tin. Preferred ions include aluminum, iron, and tin. Preferred metal ions have an oxidation state of +3 or +4. Any salt containing a polyvalent metal ion may be used. Non-limiting examples of suitable inorganic salts of the above metals include chlorides, nitrates, sulfates, borates, bromides, iodides, fluorides, nitrides, perchlorates, phosphates, hydroxides, sulfides, carbonates, bicarbonates, oxides, alkoxides, phenoxides, phosphites, and hypophosphites.Non-limiting examples of suitable organic salts of the above metals include formate, acetate, butyrate, hexanoate, adipate, citrate, lactate, oxalate, propionate, salicylate, glycinate, tartrate, glycolate, sulfonate, phosphonate, glutamate, octanoate, benzoate, gluconate, maleate, succinate, and 4,5-dihydroxy-benzene-1,3-disulfonate. In addition to polyvalent metal salts, other compounds such as complexes of the above salts can be used, including, but not limited to, amines, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DIPA), nitrilotriacetic acid (NTA), 2,4-pentanedione, and ammonia.

[0049] In one embodiment, the cellulose pulp fibers are chemically modified cellulose pulp fibers that have been softened or plasticized to make them inherently more compressible than unmodified pulp fibers. The same pressure applied to a plasticized pulp web results in a higher density than when applied to an unmodified pulp web. Furthermore, a densified web of plasticized cellulose fibers is inherently softer than a web of similar density made of unmodified fibers of the same wood type. Softwood pulp may be made more compressible using cationic surfactants as debonders to break down intrafiber associations. The use of one or more debonders facilitates the disintegration of the pulp sheet into fluff during the airlaid process. Examples of debonders include, but are not limited to, those disclosed in U.S. Pat. Nos. 4,432,833, 4,425,186, and 5,776,308, all of which are incorporated herein by reference in their entireties. One example of a debonder-treated cellulose pulp is FFLE+. Plasticizers for cellulose, which can be added to the pulp slurry before the formation of a wet-laid sheet, can also be used to soften the pulp, but they work by a different mechanism than debonders. Plasticizers act on the cellulose molecules within the fiber, making the amorphous regions flexible or soft. The resulting fibers are characterized as soft. Because plasticized fibers lack stiffness, this ground pulp is easier to densify compared to fibers that are not treated with a plasticizer. Plasticizers include, but are not limited to, polyhydric alcohols such as glycerol, low molecular weight polyglycols such as polyethylene glycol, and polyhydroxy compounds. These and other plasticizers are described and exemplified in U.S. Pat. Nos. 4,098,996, 5,547,541, and 4,731,269, all of which are incorporated herein by reference in their entireties. Ammonia, urea, and alkylamines are also known to plasticize wood products that primarily contain cellulose (AJ Stamm, Forest Products Journal 5(6):413, 1955, incorporated herein by reference in its entirety).

[0050] In certain embodiments of the presently disclosed subject matter, the following celluloses are used: GP 4723, fully treated pulp, (Leaf River) (available from Georgia-Pacific); GP4725, semi-treated pulp (available from Georgia-Pacific); Tencel (available from Lenzing); cellulose flax fiber; Danufil (available from Kelheim); Viloft (available from Kelheim); GP4865, semi-treated pulp with odor control (available from Georgia-Pacific); Grade 3024 Cellu Tissue (available from Clearwater); Browny Industrial Flax 500 (available from Georgia-Pacific).

[0051] The nonwoven material of the present disclosure can comprise cellulose fibers. In some embodiments, one or more layers of the nonwoven material can comprise cellulose fibers having a density of about 5 gsm to about 150 gsm, about 5 gsm to about 100 gsm, or about 10 gsm to about 50 gsm. In specific embodiments, one or more layers can comprise cellulose fibers having a density of about 18 gsm, about 25 gsm, about 54 gsm, about 62 gsm, about 69 gsm, or about 70 gsm.

[0052] Synthetic fibers In addition to the use of cellulosic fibers, the presently disclosed subject matter also contemplates the use of synthetic fibers. In one embodiment, the synthetic fibers include bicomponent and / or monocomponent fibers. Bicomponent fibers having a core and a sheath are known in the art. Many types, particularly those manufactured for use in airlaid techniques, are used in the fabrication of nonwoven materials. Various bicomponent fibers suitable for use in the presently disclosed subject matter are disclosed in U.S. Pat. Nos. 5,372,885 and 5,456,982, both of which are incorporated herein by reference in their entireties. Examples of bicomponent fiber manufacturers include, but are not limited to, Trevira (Bobingen, Germany), Fiber Innovation Technologies (Johnson City, TN), and ES Fiber Visions (Athens, GA).

[0053] Bicomponent fibers can incorporate a variety of polymers as their core and sheath components. Bicomponent fibers with a PE (polyethylene) or modified PE sheath typically have a PET (polyethylene terephthalate) or PP (polypropylene) core. In one embodiment, the bicomponent fiber has a core made from polyester and a sheath made from polyethylene. In another embodiment, the bicomponent fiber has a core made from polypropylene and a sheath made from polyethylene.

[0054] The denier of the bicomponent fiber preferably ranges from about 1.0 dpf to about 4.0 dpf, more preferably from about 1.5 dpf to about 2.5 dpf. The length of the bicomponent fiber may be from about 3 mm to about 36 mm, preferably from about 3 mm to about 12 mm, more preferably from about 3 mm to about 10 mm. In certain embodiments, the length of the bicomponent fiber is from about 4 mm to about 8 mm, or about 6 mm. In certain embodiments, the bicomponent fiber is Trevira T255, which comprises a polyester core and a maleic anhydride-modified polyethylene sheath. T255 is manufactured in various denier, cut lengths, and core-sheath configurations, with a preferred configuration having a denier of about 1.7 dpf to 2.0 dpf, a cut length of about 4 mm to 12 mm, and a concentric core-sheath configuration. In certain embodiments, the bicomponent fiber is Trevira 1661, T255, with a 2.0 dpf and 6 mm length. In an alternative embodiment, the bicomponent fiber is Trevira 1663, T255, 2.0 dpf and 3 mm long.

[0055] Bicomponent fibers are typically commercially produced by melt spinning. In this procedure, each molten polymer is extruded through a die, e.g., a spinneret, and then pulled to remove it from the face of the spinneret. This is followed by solidification of the polymer by heat transfer to a surrounding fluid medium, e.g., quenched air, and then winding of the solid filaments. Non-limiting examples of further steps after melt spinning include hot or cold drawing, heat treatment, crimping, and cutting. This overall fabrication process is generally carried out as a discontinuous two-step process, first involving spinning of filaments and their converging into a tow containing multiple filaments. During the spinning step, some stretching of the filaments does occur as the molten polymer is pulled away from the face of the spinneret, which may also be called drawdown. This is followed by a second step in which the spun fiber is drawn or stretched to increase molecular alignment and crystallinity, imparting enhanced strength and other physical properties to the individual filaments. Subsequent steps can include, but are not limited to, heat setting, crimping, and cutting the filaments into fibers. The drawing or stretching step can involve stretching the core of a bicomponent fiber, the sheath of a bicomponent fiber, or both the core and sheath of a bicomponent fiber, depending on the materials comprised by the core and sheath and the conditions used during the drawing or stretching process.

[0056] Bicomponent fibers can also be formed in a continuous process, where spinning and drawing are performed in a continuous process. During the fiber fabrication process, it may be desirable to add various materials to the fiber after the melt-spinning step at various subsequent steps in the process. These materials may be referred to as "finishes" and include, but are not limited to, active agents such as lubricants and antistatic agents. Finishes are typically applied via aqueous-based solutions or emulsions. Finishes can impart desirable properties for both the fabrication of the bicomponent fiber and the user of the fiber, for example, in airlaid or wetlaid processes.

[0057] Numerous other processes are involved before, during, and after the spinning and drawing steps, as seen in U.S. Pat. No. 4,950,541, U.S. Pat. No. 5,082,899, U.S. Pat. No. 5,126,199, U.S. Pat. No. 5,372,885, U.S. Pat. No. 5,456,982, U.S. Pat. No. 5,705,565, U.S. Pat. No. 2,861,319, U.S. Pat. No. 2,931,091, U.S. Pat. No. 2,989,798, U.S. Pat. No. 3,038, 235, U.S. Patent No. 3,081,490, U.S. Patent No. 3,117,362, U.S. Patent No. 3,121,254, U.S. Patent No. 3,188,689, U.S. Patent No. 3,237,245, U.S. Patent No. 3,249,669, U.S. Patent No. 3,457,342, U.S. Patent No. 3,466,703, U.S. Patent No. 3,469,279, U.S. Patent No. 3,500,498, U.S. Patent No. 3,585,685, U.S. Patent No. Nos. 3,163,170, 3,692,423, 3,716,317, 3,778,208, 3,787,162, 3,814,561, 3,963,406, 3,992,499, 4,052,146, 4,251,200, 4,350,006, and 4,370,114. Nos. 4,406,850, 4,445,833, 4,717,325, 4,743,189, 5,162,074, 5,256,050, 5,505,889, 5,582,913, and 6,670,035, all of which are incorporated herein by reference in their entireties.

[0058] The subject matter of the present disclosure can also include, but is not limited to, articles containing partially drawn bicomponent fibers with varying degrees of stretch or elongation, highly drawn bicomponent fibers, and mixtures thereof. These can include, but are not limited to, highly drawn polyester core bicomponent fibers with various sheath materials, specifically including a polyethylene sheath, such as Trevira T255 (Bobingen, Germany), or highly drawn polypropylene core bicomponent fibers with various sheath materials, specifically including a polyethylene sheath, such as ES FiberVisions AL-Adhesion-C (Varde, Denmark). Additionally, Trevira T265 bicomponent fibers (Bobingen, Germany) can be used, which have a partially drawn core with a core made of polybutylene terephthalate (PBT) and a sheath made of polyethylene. The use of both partially drawn and highly drawn bicomponent fibers in the same structure can be exploited to meet specific physical and performance properties based on how they are incorporated into the structure.

[0059] The bicomponent fibers of the presently disclosed subject matter are not limited in scope to any particular polymer for either the core or sheath, as any partially drawn core bicomponent fiber can provide enhanced performance in terms of elongation and strength. The extent to which partially drawn bicomponent fibers are drawn is not limited in scope, as different degrees of drawing result in different enhancements in performance. The scope of partially drawn bicomponent fibers encompasses fibers with various core-sheath configurations, including, but not limited to, concentric, eccentric, side-by-side, islands-in-the-sea, pie-split, and other variations. The relative weight percentages of the core and sheath components of the total fiber can vary. Additionally, the scope of the present subject matter extends to the use of partially drawn homopolymers such as polyester, polypropylene, nylon, and other melt-spinnable polymers. The scope of the present subject matter also extends to multicomponent fibers that may have three or more polymers as part of the fiber structure.

[0060] The nonwoven material of the present disclosure can comprise bicomponent fibers. In some embodiments, one or more layers of the nonwoven material can comprise bicomponent fibers having a thickness of about 1 gsm to about 40 gsm, about 5 gsm to about 30 gsm, or about 10 gsm to about 25 gsm. In certain embodiments, one or more layers of the nonwoven material can comprise bicomponent fibers having a thickness of about 8 gsm, about 12 gsm, about 21 gsm, about 25 gsm, or about 27 gsm. In alternative embodiments, the bicomponent layer comprises bicomponent fibers having a thickness of about 10 gsm to about 50 gsm, about 12 gsm to about 40 gsm, or about 20 gsm to about 30 gsm.

[0061] In certain embodiments, the bicomponent fibers are low dtex staple bicomponent fibers ranging from about 0.5 dtex to about 20 dtex. In some embodiments, the dtex value may range from about 1.3 dtex to about 15 dtex, or from about 1.5 dtex to about 10 dtex, or from about 1.7 dtex to about 6.7 dtex, or from about 2.2 dtex to about 5.7 dtex. In some embodiments, the dtex value is about 1.3 dtex, 1.5 dtex, 1.7 dtex, 2.2 dtex, 3.3 dtex, 5.7 dtex, 6.7 dtex, or 10 dtex.

[0062] Other synthetic fibers suitable for use in various embodiments as fibers or as bicomponent binder fibers include, by way of example and not limitation, acrylics, polyamides (including but not limited to nylon 6, nylon 6 / 6, nylon 12, polyaspartic acid, polyglutamic acid), polyamines, polyimides, polyacrylic acids (including but not limited to polyacrylamide, polyacrylonitrile, esters of methacrylic acid and acrylic acid), polycarbonates (including but not limited to polybisphenol A carbonate, polypropylene carbonate), polydienes (including but not limited to polybutadiene, polyisoprene, polynorbornene), polyepoxides, polyesters (including but not limited to polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polycaprolactone, polyglycolide, polylactide, polyhydroxybutyrate, polyhydroxyvalerate, polyethylene adipate, polybutylene adipate, polypropylene succinate), polyethers (polyethylene glycol (polyethylene oxide) , polybutylene glycol, polypropylene oxide, polyoxymethylene (paraformaldehyde), polytetramethylene ether (polytetrahydrofuran), polyepichlorohydrin), polyfluorocarbons, formaldehyde polymers (including but not limited to urea-formaldehyde, melamine-formaldehyde, phenol formaldehyde), natural polymers (including but not limited to cellulosics, chitosan, lignin, waxes), polyolefins (polyethylene, polypropylene, polybutene, Polyethylenes (including but not limited to, polyethylene, polybutene, polyoctene), polyphenylenes (including but not limited to, polyphenylene oxide, polyphenylene sulfide, polyphenylene ether sulfone), silicon-containing polymers (including but not limited to, polydimethylsiloxane, polycarbomethylsilane), polyurethanes, polyvinyls (including but not limited to, polyvinyl butyral, polyvinyl alcohol, esters and ethers of polyvinyl alcohol, polyvinyl acetate, polystyrene, polymethylstyrene, polyvinyl chloride, polyvinylpyrrolidone,These include, but are not limited to, fibers made from a variety of polymers, including but not limited to, polymethyl vinyl ether, polyethyl vinyl ether, polyvinyl methyl ketone), polyacetals, polyarylates, and copolymers (including but not limited to polyethylene-co-vinyl acetate, polyethylene-co-acrylic acid, polybutylene terephthalate-co-polyethylene terephthalate, polylauryllactam-block-polytetrahydrofuran), polybutylene succinate, and polylactic acid-based polymers.

[0063] In specific embodiments, the synthetic fiber layer comprises high dtex staple fibers ranging from about 2 to about 20 dtex. In some embodiments, the dtex value may range from about 2 dtex to about 15 dtex, or from about 2 dtex to about 10 dtex. In certain embodiments, the fibers may have a dtex value of about 6.7 dtex.

[0064] In other specific embodiments, the synthetic layer comprises synthetic filaments. The synthetic filaments can be formed by a spinning and / or extrusion process. For example, such processes can be similar to those described above with respect to the melt-spinning process. The synthetic filaments can comprise one or more continuous strands. In some embodiments, the synthetic filaments can comprise polypropylene.

[0065] Short Fiber In some embodiments, the nonwoven material of the present disclosure can include at least one layer comprising staple fibers. Staple fibers can provide the nonwoven material with enhanced capillary action and increased liquid distribution. Staple fibers suitable for use in the nonwoven material of the present disclosure can include the cellulose fibers, regenerated cellulose fibers, synthetic fibers, and combinations thereof disclosed herein. Staple fibers can include fibers having a length of about 1 mm to about 8 mm, about 2 mm to about 8 mm, about 3 mm to about 6 mm, or about 5 mm to about 6 mm. In certain embodiments, the staple fibers can include fibers having a length of about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, or about 8 mm.

[0066] The nonwoven material of the present disclosure can comprise staple fibers. In some embodiments, one or more layers of the nonwoven material can comprise staple fibers between about 5 gsm and about 150 gsm, between about 5 gsm and about 100 gsm, or between about 10 gsm and about 50 gsm. In specific embodiments, one or more layers can comprise about 15 gsm, about 30 gsm, about 75 gsm, or about 100 gsm staple fibers.

[0067] Long Fiber In some embodiments, the nonwoven material of the present disclosure can include at least one layer comprising long fibers. Long fibers can provide increased liquid collection in a relatively short period of time. Long fibers suitable for use in the nonwoven material of the present disclosure can include regenerated cellulose fibers, synthetic fibers, and combinations thereof, as disclosed herein. The long fibers can include fibers having a length of about 8 mm to about 70 mm, about 10 mm to about 60 mm, about 15 mm to about 50 mm, or about 20 mm to about 40 mm. In certain embodiments, the long fibers can include fibers having a length of about 8 mm, about 10 mm, about 30 mm, about 50 mm, about 55 mm, about 60 mm, about 65 mm, or about 70 mm.

[0068] The nonwoven material of the present disclosure can comprise long fibers. In some embodiments, one or more layers of the nonwoven material can comprise long fibers having a diameter of about 10 gsm to about 150 gsm, about 10 gsm to about 100 gsm, about 20 gsm to about 60 gsm, about 25 gsm to about 50 gsm, or about 30 gsm to about 35 gsm. In certain embodiments, the nonwoven material can comprise long fibers having a diameter of about 10 gsm, about 20 gsm, about 25 gsm, about 30 gsm, about 34 gsm, about 40 gsm, about 45 gsm, about 50 gsm, about 75 gsm, about 100 gsm, about 120 gsm, or about 150 gsm.

[0069] Card Web In some embodiments, the nonwoven material of the present disclosure can include a carded web containing fibers. Such carded webs can include longer fibers, which may be synthetic fibers. The term "longer fibers," as used herein, refers to fibers whose length is between about 8 mm and about 70 mm. An example of a carded web suitable for use in the present disclosure includes carded nonwoven web (TABCW) (product code STACT8H34) (Shalag Nonwovens, Oxford, NC). Carded webs containing longer fibers are generally more resilient than conventional airlaid webs; however, nonwoven materials containing longer fibers generally do not have acceptable liquid distribution and storage properties.

[0070] In some embodiments, the nonwoven material can include at least one layer comprising synthetic fibers formed as a carded web in an amount of about 10 gsm to about 150 gsm, about 10 gsm to about 100 gsm, about 20 gsm to about 60 gsm, about 25 gsm to about 50 gsm, or about 30 gsm to about 35 gsm. In certain embodiments, the nonwoven material can include at least one layer comprising synthetic fibers formed as a carded web in an amount of about 10 gsm, about 20 gsm, about 25 gsm, about 30 gsm, about 34 gsm, about 40 gsm, about 45 gsm, about 50 gsm, about 75 gsm, about 100 gsm, about 120 gsm, or about 150 gsm.

[0071] Binder In some embodiments, the nonwoven materials described herein may include a binder. Suitable binders include, but are not limited to, liquid binders and powder binders. Non-limiting examples of liquid binders include emulsions, solutions, or suspensions of binders. Non-limiting examples of binders include polyethylene powder, copolymer binders, vinyl acetate ethylene binders, styrene-butadiene binders, urethanes, urethane-based binders, acrylic binders, thermoplastic binders, natural polymer-based binders, and mixtures thereof.

[0072] Suitable binders include copolymers, vinyl acetate ethylene ("VAE") copolymers, which may have stabilizers such as Wacker Vinnapas 192, Wacker Vinnapas EF 539, Wacker Vinnapas EP907, Wacker Vinnapas EP129, Celanese Duroset E130, Celanese Dur-O-Set Elite 130 25-1813, and Celanese Dur-O-Set TX-849, Celanese 75-524A, polyvinyl alcohol-polyvinyl acetate blends such as Wacker Vinac 911, vinyl acetate homopolymers, polyvinylamines such as BASF Luredur, acrylic resins, cationic acrylamides, polyacrylamides such as Bercon Berstrength 5040 and Bercon Berstrength 5150, hydroxyethyl cellulose, National Starch CATO R™ Examples of binders include, but are not limited to, starch, guar gum, styrene-butadiene, urethane, urethane-based binders, thermoplastic binders, acrylic binders, such as National Starch CATO R™ 232, National Starch CATO R™ 255, National Starch Optibond, National Starch Optipro, or National Starch OptiPLUS, and carboxymethylcellulose, such as Hercules Aqualon CMC. In some embodiments, the binder is a natural polymer binder. Non-limiting examples of natural polymer binders include polymers derived from starch, cellulose, chitin, and other polysaccharides.

[0073] In some embodiments, the binder is water-soluble. In one embodiment, the binder is a vinyl acetate ethylene copolymer. One non-limiting example of such a copolymer is EP907 (Wacker Chemicals, Munich, Germany). Vinnapas EP907 can be applied at a level of about 10% solids incorporating about 0.75% by weight of Aerosol OT (Cytec Industries, West Paterson, NJ), an anionic surfactant. Other classes of liquid binders, such as styrene-butadiene and acrylic binders, can also be used. In some embodiments, Vinnapas 192 can be applied at a level of about 15% incorporating about 0.08% by weight of Aerosol OT 75 (Cytec Industries, West Paterson, NJ).

[0074] In some embodiments, the binder is not water-soluble. Examples of these binders include, but are not limited to, Vinnapas 124 and 192 (Wacker), which may have opacifiers and whiteners, including, but not limited to, titanium dioxide dispersed in the emulsion. Other binders include, but are not limited to, Celanese Emulsions (Bridgewater, NJ) Elite 22 and Elite 33.

[0075] In some embodiments, the binder is a thermoplastic binder. Such thermoplastic binders include, but are not limited to, any thermoplastic polymer that can be melted at a temperature that does not significantly damage the cellulose fibers. Preferably, the melting point of the thermoplastic binder is less than about 175°C. Examples of suitable thermoplastic materials include, but are not limited to, thermoplastic binders and suspensions of thermoplastic powders. In certain embodiments, the thermoplastic binder may be, for example, polyethylene, polypropylene, polyvinyl chloride, and / or polyvinylidene chloride.

[0076] In certain embodiments, the vinyl acetate ethylene binder is non-crosslinkable. In one embodiment, the vinyl acetate ethylene binder is crosslinkable. In some embodiments, the binder is WD4047 urethane-based binder solution supplied by HB Fuller. In one embodiment, the binder is Michem Prime 4983-45N dispersion of ethylene acrylic acid ("EAA") supplied by Michelman. In some embodiments, the binder is Dur-O-Set Elite 22LV emulsion, a VAE binder supplied by Celanese Emulsions, Inc. (Bridgewater, NJ). As noted above, in certain embodiments, the binder is crosslinkable. It is understood that crosslinkable binders are also known as permanent wet strength binders. Permanent wet strength binders include, but are not limited to, Kymene® (Hercules Inc., Wilmington, Del.), Parez® (American Cyanamid Company, Wayne, NJ), Wacker Vinnapas or AF192 (Wacker Chemie AG, Munich, Germany), and the like. Various permanent wet strength agents are described in U.S. Pat. Nos. 2,345,543, 2,926,116, and 2,926,154, the disclosures of which are incorporated herein by reference in their entireties. Other permanent wet strength binders include, but are not limited to, polyamine-epichlorohydrin, polyamide-epichlorohydrin, or polyamide-amine-epichlorohydrin resins, collectively referred to as "PAE resins." Non-limiting exemplary permanent wet strength binders include Kymene 557H or Kymene 557LX (Hercules Inc., Wilmington, Del.), and are described in U.S. Pat. Nos. 3,700,623 and 3,772,076, which are incorporated herein by reference in their entireties.

[0077] Alternatively, in some embodiments, the binder is a temporary wet strength binder, including, but not limited to, Hercobond® (Hercules Inc., Wilmington, Del.), Parez® 750 (American Cyanamid Company, Wayne, NJ), Parez® 745 (American Cyanamid Company, Wayne, NJ), and the like. Other suitable temporary wet strength binders include, but are not limited to, dialdehyde starch, polyethyleneimine, mannogalactan gum, glyoxal, and dialdehyde mannogalactan. Other suitable temporary wet strength agents are described in U.S. Pat. No. 3,556,932, U.S. Pat. No. 5,466,337, U.S. Pat. No. 3,556,933, U.S. Pat. No. 4,605,702, U.S. Pat. No. 4,603,176, U.S. Pat. No. 5,935,383, and U.S. Pat. No. 6,017,417, all of which are incorporated herein by reference in their entireties.

[0078] In some embodiments, the binder can be applied as an emulsion in an amount ranging from about 1 gsm to about 10 gsm, about 1 gsm to about 8 gsm, about 1 gsm to about 5 gsm, about 1 gsm to about 4 gsm, about 5 gsm to about 10 gsm, about 2 gsm to about 5 gsm, or about 2 gsm to about 3 gsm. In certain embodiments, the binder can be applied as an emulsion in an amount of about 1 gsm, about 2 gsm, about 3 gsm, about 4 gsm, or about 5 gsm. The binder can be applied to one side of the fibrous layer, preferably the exterior-facing layer. Alternatively, the binder can be applied to both sides of the layer in equal or disproportionate amounts. In some embodiments, the binder can be applied to at least one outer surface of the nonwoven material.

[0079] Other additives The materials of the presently disclosed subject matter can also contain other additives. For example, the materials can include superabsorbent polymers (SAPs). Types of superabsorbent polymers that may be used in the presently disclosed subject matter include, but are not limited to, SAPs in particulate form, such as powders, irregular granules, spherical particles, staple fibers, and other elongated particles. In some embodiments, the materials can include superabsorbent fiber (SAF; manufactured by Technical Absorbents Limited, 9 dtex, 5.8 mm). U.S. Patent Nos. 5,147,343, 5,378,528, 5,795,439, 5,807,916, 5,849,211, and 6,403,857, all of which are hereby incorporated by reference in their entireties, describe various superabsorbent polymers and methods of making them. One example of a superabsorbent polymer-forming system is a crosslinked acrylic copolymer of a metal salt of acrylic acid with other monomers, such as acrylamide or 2-acrylamido-2-methylpropanesulfonic acid. Many conventional granular superabsorbent polymers are based on poly(acrylic acid) crosslinked during polymerization with any of several multifunctional comonomer crosslinkers known in the art. Examples of multifunctional crosslinkers are described in U.S. Pat. Nos. 2,929,154, 3,224,986, 3,332,909, and 4,076,673, which are incorporated herein by reference in their entireties. For example, crosslinked carboxylated polyelectrolytes can be used to form superabsorbent polymers. Other water-soluble polyelectrolyte polymers are known to be useful for preparing superabsorbents by crosslinking, including carboxymethyl starch, carboxymethyl cellulose, chitosan salts, gelatin salts, and the like. However, they are not generally used on a commercial scale to enhance the absorbency of disposable absorbent articles, primarily due to their relatively high cost.Superabsorbent polymer granules useful in the practice of the present subject matter are commercially available from several manufacturers, such as BASF, Dow Chemical (Midland, Mich.), Stockhausen (Greensboro, NC), Chemdal (Arlington Heights, Ill.), and Evonik (Essen, Germany). Non-limiting examples of SAPs include surface-crosslinked acrylic acid-based powders such as Stockhausen 9350 or SX70, BASF Hysorb Fem 33, BASF HySorb FEM 33N, or Evonik Favor SXM 7900.

[0080] In certain embodiments, the SAP may be starch-based. For example, the SAP may include K-Boost (XGF-450, manufactured by Como Cascades EEC, Beavertown, OR) or K-Boost (XGF-463, manufactured by Como Cascades EEC, Beavertown, OR). Such starch-based SAPs may be biodegradable. In some embodiments, the SAP may include a high-capacity SAP, a high-speed SAP, or a combination thereof. A specific example of a high-capacity SAP includes K-Boost (XGF-450, manufactured by Como Cascades LLC, Beavertown, OR). A specific example of a high-speed SAP includes K-Boost (XGF-463, manufactured by Como Cascades EEC, Beavertown, OR).

[0081] In some embodiments, SAP may be used in a layer in an amount ranging from about 5% to about 50% based on the total weight of the structure. In some embodiments, the SAP content is between about 0% and about 30%, about 0% and about 15%, about 5% and about 25%, about 5% and about 15%, or about 10% and about 20% based on the total weight of the structure. In specific embodiments, the SAP content is about 0%, about 2%, about 5%, about 8%, about 10%, about 15%, about 20%, about 25%, or about 30% based on the total weight of the structure. In some embodiments, the amount of SAP in a layer may range from about 5 gsm to about 50 gsm, about 5 gsm to about 25 gsm, about 10 gsm to about 50 gsm, about 12 gsm to about 40 gsm, or about 15 gsm to about 25 gsm. In specific embodiments, SAP may be used in a layer in an amount of about 10 gsm or about 20 gsm.

[0082] nonwoven material The presently disclosed subject matter provides improved nonwoven materials that offer several advantages over various commercially available materials. Compared to conventional materials containing higher amounts of synthetic materials, such as superabsorbent polymers (SAPs), the presently disclosed materials have achieved improved overall absorbency in terms of liquid acquisition, distribution, and rewet. Thus, advantageously, nonwoven materials of the present disclosure containing lower amounts of synthetic additives provide increased absorbency. In some embodiments, the presently disclosed materials have the ability to significantly reduce absorbent materials and achieve comparable or improved overall absorbency. Absorbency is measured by increased fluid acquisition or improved dryness characteristics, while maintaining a lower basis weight relative to commercially available products. Furthermore, the presently disclosed nonwoven materials utilize reduced amounts of synthetic materials, such as SAPs, compared to various commercially available materials.

[0083] Nonwoven materials of the present disclosure containing various components can be used in absorbent systems. In some embodiments, the nonwoven materials of the present disclosure can be used as absorbent cores in absorbent systems, such as personal care products, such as light incontinence products, and feminine hygiene products, such as panty liners. Such absorbent cores can have specific multilayer structures including a layer of bound fine cellulosic fibers, such as hardwood fibers, e.g., eucalyptus fibers. The structures can further include a layer of bound coarse cellulosic fibers, such as softwood fibers. In some cases, the structures can further include superabsorbent polymers (SAPs). When combined with a conventional acquisition-distribution layer (ADL), such as a carded layer, such nonwoven materials can exhibit improved performance in terms of liquid acquisition, distribution, and rewet compared to conventional absorbent cores with higher SAP content. In some embodiments, the nonwoven materials of the present disclosure can be used as acquisition-distribution layers (ADLs) in absorbent systems, such as personal care products, such as feminine hygiene products and light incontinence products. Conventional airlaid nonwovens containing bonded short fibers (i.e., between about 1 mm and about 8 mm) generally lack sufficiently high liquid acquisition rate characteristics and do not provide sufficient dryness compared to other nonwovens, such as carded materials that use longer synthetic fibers (i.e., between about 8 mm and about 70 mm). However, as noted above, carded webs with longer fibers are generally more resilient than conventional airlaid webs, and nonwovens containing longer fibers generally do not have acceptable liquid distribution and storage properties. In some embodiments, the nonwoven materials of the present disclosure provide the absorbent characteristics of a fibrous network of bonded long fibers, with either bonded short fibers or a network of bonded short fibers containing superabsorbent polymer embedded in powder (SAP) or fiber (SAF) form. Such nonwoven materials surprisingly and advantageously exhibit increased liquid storage and distribution capabilities. In some embodiments, the nonwoven materials of the present disclosure provide a monolithic, multi-layer hybrid liquid acquisition and distribution (ADL) material with increased fluid wicking and rewet performance compared to conventional airlaids. Such structures combine a bonded carded web with one or more layers of an airlaid web in a specific configuration and fiber content. Another aspect of the present disclosure is the development of a one-piece multi-functional hybrid absorbent fabric with improved liquid acquisition, distribution, storage, and rewet properties. In addition to a layer of longer bonded fibers that provides faster fluid uptake and increased rewet performance, the structures of the present disclosure can also include a liquid storage layer and a distribution layer. The storage layer can optionally include SAP and / or SAF, and the distribution layer can include bonded fine cellulosic fibers, such as hardwood fibers, e.g., eucalyptus fibers. Such nonwoven materials surprisingly and advantageously provide increased liquid acquisition, distribution, storage, and rewet properties, while allowing for reduced basis weights of the absorbent system and the use of less synthetic materials, such as SAP, relative to conventional multi-component absorbent systems that include separate, conventional acquisition-distribution layer (ADL) materials and liquid storage-absorbent components.

[0084] The presently disclosed subject matter provides a nonwoven material. In some embodiments, the nonwoven material comprises at least two layers, at least three layers, or at least four layers.

[0085] In some embodiments, the nonwoven material can include at least two layers, each layer having a specific fibrous content. In certain embodiments, the nonwoven material can be a two-layer nonwoven structure. The nonwoven material can include a first layer including cellulose fibers and synthetic fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can include cellulose fibers and synthetic fibers. The first and second layers can be bonded at least a portion of their outer surfaces using a binder. In some embodiments, the synthetic fibers can include bicomponent fibers. In some embodiments, the cellulose fibers of the second layer can include fine cellulose fibers. In certain embodiments, the cellulose fibers of the second layer can include eucalyptus pulp.

[0086] In some embodiments, the nonwoven material can include a first layer comprising long fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can include short fibers. The second layer can be bonded on at least a portion of its outer surface using a binder. In some embodiments, the long fibers can include synthetic fibers. In certain embodiments, the long fibers can include synthetic fibers formed as a carded web. In some embodiments, the short fibers can include cellulose fibers.

[0087] In some embodiments, the nonwoven material can include at least three layers, each layer having a specific fibrous content. In certain embodiments, the nonwoven material can be a three-layer nonwoven structure. The nonwoven material can include a first layer including cellulose fibers and synthetic fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can include a superabsorbent polymer (SAP). The nonwoven material can further include a third layer adjacent to the second layer. The third layer can include cellulose fibers and synthetic fibers. The first and third layers can be bonded at least a portion of their outer surfaces using a binder. In some embodiments, the synthetic fibers can include bicomponent fibers. In some embodiments, the cellulose fibers of the third layer can include fine cellulose fibers. In certain embodiments, the cellulose fibers of the third layer can include eucalyptus pulp.

[0088] In some embodiments, the nonwoven material may include a first layer comprising long fibers. The nonwoven material may further include a second layer adjacent to the first layer. The second layer may comprise short fibers. The nonwoven material may further include a third layer adjacent to the second layer. The third layer may comprise short fibers. The third layer may be bonded over at least a portion of its outer surface using a binder. In some embodiments, the long fibers may comprise synthetic fibers. In certain embodiments, the long fibers may comprise synthetic fibers formed as a carded web. In some embodiments, the short fibers of the second and third layers may comprise a blend of short fibers. For example, but not by way of limitation, the short fibers of the second and third layers may comprise synthetic fibers and cellulose fibers. In some embodiments, the synthetic fibers of the second and third layers may comprise bicomponent fibers. In some embodiments, the cellulose fibers of the third layer may comprise eucalyptus pulp.

[0089] In some embodiments, the nonwoven material can include at least four layers, each layer comprising a specific fiber content. In certain embodiments, the nonwoven material can be a four-layer nonwoven structure. The nonwoven material can include a first layer comprising cellulose fibers and synthetic fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can comprise cellulose fibers and synthetic fibers. The nonwoven material can further include a third layer adjacent to the second layer. The third layer can comprise a superabsorbent polymer (SAP). The nonwoven material can further include a fourth layer adjacent to the third layer. The fourth layer can comprise cellulose fibers and synthetic fibers. The first and fourth layers can be bonded at least in part to their outer surfaces using a binder. In some embodiments, the synthetic fibers can comprise bicomponent fibers. In some embodiments, the cellulose fibers of the fourth layer can comprise fine cellulose fibers. In certain embodiments, the cellulose fibers of the fourth layer can comprise eucalyptus pulp.

[0090] In some embodiments, the nonwoven material may include a first layer comprising long fibers. The nonwoven material may further include a second layer adjacent to the first layer. The second layer may comprise short fibers. The nonwoven material may further include a third layer adjacent to the second layer. The third layer may comprise an additional additive, such as a superabsorbent polymer (SAP). The nonwoven material may further include a fourth layer adjacent to the third layer. The fourth layer may comprise short fibers. The fourth layer may be bonded over at least a portion of its outer surface using a binder. In some embodiments, the long fibers of the first layer may comprise synthetic fibers. In certain embodiments, the long fibers of the first layer may comprise synthetic fibers formed as a carded web. In some embodiments, the short fibers of the second and fourth layers may comprise a blend of short fibers. For example, but not by way of limitation, the short fibers of the second and fourth layers may comprise synthetic fibers and cellulosic fibers. In some embodiments, the synthetic fibers of the second and fourth layers may comprise bicomponent fibers. In some embodiments, the cellulosic fibers of the fourth layer may include eucalyptus pulp.

[0091] The nonwoven material of the present disclosure can include at least two layers, at least three layers, or at least four layers, each layer containing a specific fiber content. In some embodiments, the first layer can include a blend of cellulosic and synthetic fibers. In some embodiments, the synthetic fibers in the first layer can include bicomponent fibers. The cellulosic fibers can be present in the first layer in an amount of about 20 gsm to about 70 gsm, about 30 gsm to about 60 gsm, or about 40 gsm to about 50 gsm. In certain embodiments, the first layer can include about 25 gsm, about 30 gsm, about 40 gsm, about 54 gsm, about 62 gsm, or about 70 gsm cellulosic fibers. The synthetic fibers can be present in the first layer in an amount of about 15 gsm to about 40 gsm, about 20 gsm to about 35 gsm, or about 25 gsm to about 35 gsm. In certain embodiments, the first layer can include about 12 gsm, about 21 gsm, about 25 gsm, or about 30 gsm synthetic fibers.

[0092] In some embodiments, the first layer can comprise long fibers in an amount of about 20 gsm to about 60 gsm, about 25 gsm to about 50 gsm, or about 30 gsm to about 35 gsm. In certain embodiments, the first layer can comprise long fibers in an amount of about 20 gsm, about 25 gsm, about 30 gsm, about 34 gsm, about 40 gsm, about 45 gsm, or about 50 gsm. In some embodiments, the first layer can comprise synthetic fibers formed as a carded web in an amount of about 20 gsm to about 60 gsm, about 25 gsm to about 50 gsm, or about 30 gsm to about 35 gsm. In certain embodiments, the first layer can comprise synthetic fibers formed as a carded web in an amount of about 20 gsm, about 25 gsm, about 30 gsm, about 34 gsm, about 40 gsm, about 45 gsm, or about 50 gsm.

[0093] In some embodiments, the nonwoven material can include a second layer. The second layer can include a blend of cellulose fibers and synthetic fibers. In some embodiments, the synthetic fibers of the second layer can include bicomponent fibers. In certain embodiments, the cellulose fibers of the second layer can include fine cellulose fibers, such as eucalyptus pulp. The cellulose fibers can be present in the second layer in an amount of about 5 gsm to about 70 gsm, about 10 gsm to about 65 gsm, or about 15 gsm to about 50 gsm. In certain embodiments, the second layer can include cellulose fibers of about 20 gsm, about 25 gsm, about 50 gsm, about 62 gsm, or about 65 gsm. The synthetic fibers can be present in the second layer in an amount of about 15 gsm to about 40 gsm, about 20 gsm to about 35 gsm, or about 25 gsm to about 35 gsm. In certain embodiments, the second layer can include synthetic fibers of about 8 gsm, about 12 gsm, about 20 gsm, or about 25 gsm. In alternative embodiments, the second layer can include a superabsorbent polymer (SAP). For example, and without limitation, the second layer can include about 5 gsm to about 30 gsm, about 15 gsm to about 25 gsm, or about 10 gsm to about 20 gsm of superabsorbent polymer (SAP). In certain embodiments, the second layer can include about 10 gsm or about 20 gsm of superabsorbent polymer (SAP).

[0094] In some embodiments, the second layer can comprise staple fibers. In certain embodiments, the second layer can comprise cellulosic fibers. In alternative embodiments, the second layer can comprise a blend of cellulosic fibers and synthetic fibers, such as bicomponent fibers. In some embodiments, the second layer can comprise staple fibers of about 5 gsm to about 100 gsm, about 10 gsm to about 80 gsm, or about 15 gsm to about 75 gsm. In certain embodiments, the second layer can comprise staple fibers of about 16 gsm, about 18 gsm, about 75 gsm, about 85 gsm, or about 95 gsm. The cellulosic fibers can be present in the second layer in an amount of about 5 gsm to about 70 gsm, about 10 gsm to about 65 gsm, or about 15 gsm to about 50 gsm. In certain embodiments, the second layer can comprise cellulosic fibers of about 18 gsm, about 25 gsm, about 50 gsm, about 54 gsm, about 62 gsm, or about 69 gsm. The synthetic fibers can be present in the second layer in an amount of about 15 gsm to about 40 gsm, about 20 gsm to about 35 gsm, or about 25 gsm to about 35 gsm. In certain embodiments, the second layer can include about 8 gsm, about 12 gsm, about 21 gsm, about 23 gsm, about 25 gsm, or about 26 gsm synthetic fibers.

[0095] In some embodiments, the nonwoven material can include a third layer. The third layer can include a superabsorbent polymer (SAP). Alternatively, in some embodiments, the third layer can include a blend of cellulose fibers and synthetic fibers. In certain embodiments, the cellulose fibers of the third layer can include fine cellulose fibers, such as eucalyptus pulp. In some embodiments, the synthetic fibers of the third layer can include bicomponent fibers. The cellulose fibers can be present in the third layer in an amount of about 5 gsm to about 70 gsm, about 10 gsm to about 65 gsm, or about 15 gsm to about 50 gsm. In certain embodiments, the third layer can include about 25 gsm, about 35 gsm, about 50 gsm, or about 62 gsm cellulose fibers. The synthetic fibers can be present in the third layer in an amount of about 15 gsm to about 40 gsm, about 20 gsm to about 35 gsm, or about 25 gsm to about 35 gsm. In certain embodiments, the third layer can include synthetic fibers of about 8 gsm, about 12 gsm, about 21 gsm, about 23 gsm, about 25 gsm, or about 26 gsm. In alternative embodiments, the third layer can include a superabsorbent polymer (SAP). For example, and not by way of limitation, the third layer can include about 5 gsm to about 30 gsm, about 15 gsm to about 25 gsm, or about 10 gsm to about 20 gsm of superabsorbent polymer (SAP). In some embodiments, the third layer can include about 10 gsm or about 20 gsm of superabsorbent polymer (SAP).

[0096] In some embodiments, the nonwoven material may include a third layer. The third layer may include staple fibers. In some embodiments, the third layer may include a blend of cellulose fibers and synthetic fibers, such as bicomponent fibers. In certain embodiments, the cellulose fibers of the third layer may include fine cellulose fibers, such as eucalyptus pulp. In some embodiments, the third layer may include staple fibers of about 5 gsm to about 100 gsm, about 10 gsm to about 80 gsm, or about 15 gsm to about 75 gsm. In certain embodiments, the third layer may include staple fibers of about 50 gsm, about 55 gsm, about 70 gsm, or about 75 gsm. The cellulose fibers may be present in the third layer in an amount of about 5 gsm to about 70 gsm, about 10 gsm to about 65 gsm, or about 15 gsm to about 50 gsm. In certain embodiments, the third layer may include cellulose fibers of about 25 gsm, about 35 gsm, about 50 gsm, or about 62 gsm. The synthetic fibers can be present in the third layer in an amount of about 15 gsm to about 40 gsm, about 20 gsm to about 35 gsm, or about 25 gsm to about 35 gsm. In certain embodiments, the third layer can include about 8 gsm, about 12 gsm, about 21 gsm, about 23 gsm, about 25 gsm, or about 26 gsm of synthetic fibers. In certain embodiments, the third layer can include a superabsorbent polymer (SAP). For example, and not by way of limitation, the third layer can include about 5 gsm to about 30 gsm, about 15 gsm to about 25 gsm, or about 10 gsm to about 20 gsm of superabsorbent polymer (SAP). In some embodiments, the third layer can include about 10 gsm or about 20 gsm of superabsorbent polymer (SAP).

[0097] In some embodiments, the nonwoven material can include a fourth layer. The fourth layer can include a blend of cellulose fibers and synthetic fibers. In certain embodiments, the cellulose fibers of the fourth layer can include fine cellulose fibers, such as eucalyptus pulp. In some embodiments, the synthetic fibers of the fourth layer can include bicomponent fibers. The cellulose fibers can be present in the fourth layer in an amount of about 5 gsm to about 70 gsm, about 10 gsm to about 65 gsm, or about 15 gsm to about 50 gsm. In certain embodiments, the fourth layer can include cellulose fibers of about 25 gsm, about 35 gsm, about 50 gsm, or 62 gsm. The synthetic fibers can be present in the fourth layer in an amount of about 15 gsm to about 40 gsm, about 20 gsm to about 35 gsm, or about 25 gsm to about 35 gsm. In certain embodiments, the fourth layer can include synthetic fibers of about 8 gsm, about 15 gsm, about 20 gsm, or about 25 gsm.

[0098] In some embodiments, the nonwoven material can include a fourth layer. The fourth layer can include staple fibers. In some embodiments, the fourth layer can include a blend of cellulose fibers and synthetic fibers, such as bicomponent fibers. In certain embodiments, the cellulose fibers of the fourth layer can include fine cellulose fibers, such as eucalyptus pulp. In some embodiments, the fourth layer can include staple fibers of about 5 gsm to about 100 gsm, about 10 gsm to about 80 gsm, or about 15 gsm to about 75 gsm. In certain embodiments, the fourth layer can include staple fibers of about 50 gsm, about 55 gsm, about 70 gsm, or about 75 gsm. The cellulose fibers can be present in the fourth layer in an amount of about 5 gsm to about 70 gsm, about 10 gsm to about 65 gsm, or about 15 gsm to about 50 gsm. In certain embodiments, the third layer can include cellulose fibers of about 25 gsm, about 35 gsm, about 50 gsm, or 62 gsm. The synthetic fibers can be present in the fourth layer in an amount of about 15 gsm to about 40 gsm, about 20 gsm to about 35 gsm, or about 25 gsm to about 35 gsm. In certain embodiments, the fourth layer can include about 8 gsm, about 12 gsm, about 21 gsm, about 23 gsm, about 25 gsm, or about 26 gsm synthetic fibers.

[0099] In some embodiments, at least one outer surface of the nonwoven material can be coated with a binder. The binder can be applied as an emulsion in an amount ranging from about 1 gsm to about 10 gsm, from about 1 gsm to about 8 gsm, from about 1 gsm to about 5 gsm, from about 1 gsm to about 4 gsm, from about 5 gsm to about 10 gsm, from about 2 gsm to about 5 gsm, or from about 2 gsm to about 3 gsm. In certain embodiments, the binder can be applied as an emulsion in an amount of about 1 gsm, about 2 gsm, about 3 gsm, about 4 gsm, or about 5 gsm.

[0100] Absorbent core and collection / distribution layer In another aspect, the presently disclosed subject matter provides an absorbent core comprising multiple layer nonwoven materials, e.g., at least one layer adjacent to an acquisition-distribution layer. In one aspect, the presently disclosed subject matter provides multiple layer nonwoven materials, e.g., an acquisition-distribution layer (ADL) comprising at least one layer adjacent to an absorbent core. Such nonwoven materials of the present disclosure, including a variety of other materials, can be used to provide absorbent systems. Hybrid systems of the present disclosure can include an acquisition-distribution layer bonded to the core, thus providing both the acquisition layer and the core in a single, structured hybrid system.

[0101] The nonwoven materials of the present disclosure as absorbent cores in absorbent systems that include a collection-distribution layer, such as a carded layer, also offer improved performance in terms of liquid acquisition, distribution, and rewet compared to conventional absorbent cores with higher SAP content. In some embodiments, the nonwoven materials of the present disclosure can be used in absorbent systems that include a topsheet. In some embodiments, the nonwoven materials of the present disclosure as absorbent cores can have a total basis weight of greater than about 100 gsm, between about 100 gsm and about 500 gsm, or between about 150 gsm and about 300 gsm.

[0102] The nonwoven materials of the present disclosure as acquisition-distribution layers in absorbent systems including an absorbent core provide hybrid absorbent structures with improved liquid acquisition, distribution, and storage in a single, unitary structure. In some embodiments, the absorbent system can have a total basis weight of about 200 gsm to about 250 gsm, about 210 gsm to about 225 gsm, or about 200 gsm to about 220 gsm. In specific embodiments, the absorbent system can have a total basis weight of about 214 gsm, about 218 gsm, or about 221 gsm.

[0103] Characteristics of nonwoven materials The nonwoven materials of the present disclosure can have improved liquid collection properties. Those skilled in the art recognize that the absorption characteristics of nonwoven materials can vary. For example, the observed absorption characteristics can vary based on the amount of fluid and the surface area of ​​the nonwoven material. Furthermore, when the nonwoven material includes an absorbent core and / or collection-distribution layer, the material can have improved fluid collection properties. Furthermore, the nonwoven materials of the present disclosure can quickly absorb fluids. The use of bicomponent fibers in the nonwoven materials of the present disclosure can provide shorter collection times. Furthermore, the use of fine cellulose fibers, such as eucalyptus pulp, in the bottom layer of the nonwoven material can improve liquid distribution. Such fine cellulose fibers can also provide increased fluid retention and, therefore, reduced rewet.

[0104] In some embodiments, such nonwoven materials can absorb fluid in less than about 60 seconds, less than about 45 seconds, less than about 40 seconds, less than about 30 seconds, less than about 15 seconds, less than about 8 seconds, or less than about 1 second. In certain embodiments, the nonwoven materials can absorb fluid in about 0.8 seconds, about 1 second, about 1.2 seconds, about 1.4 seconds, about 2.7 seconds, about 3.2 seconds, about 4.9 seconds, about 7.1 seconds, about 8 seconds, or about 15 seconds. The time it takes for a material to absorb a fluid can be referred to as the "acquisition time." By way of example and not limitation, acquisition time can be measured using the procedures described in Examples 2, 4, and 6 below. Furthermore, the nonwoven materials of the present disclosure can acquire and retain more liquid before breakthrough occurs. In some embodiments, the nonwoven materials can acquire and retain at least about 4.0 g, at least about 3.5 g, or at least 3.0 g of liquid before breakthrough occurs.

[0105] Furthermore, the nonwoven materials of the present disclosure can have improved dryness characteristics and exhibit improved fluid retention. For example, after absorbing fluid, the nonwoven material can be squeezed to measure the amount of fluid released. In some embodiments, a rewet test or humidity sensation test can be used to squeeze the nonwoven material and measure the amount of fluid released, as described in the various examples below. In some embodiments, less than about 3 g, less than about 2 g, less than about 1.5 g, less than about 1 g, less than about 0.5 g, less than about 0.20 g, less than about 0.15 g, less than about 0.12 g, less than about 0.10 g, less than about 0.08 g, or less than about 0.06 g is released. In certain embodiments, less than about 2.8 g, less than about 0.11 g, or less than about 0.05 g is released. The nonwoven materials of the present disclosure contain no or relatively low amounts of SAP, and have improved rewet performance, even at lower basis weights compared to conventional products.

[0106] The nonwoven materials of the present disclosure can have improved liquid distribution properties. In some embodiments, the nonwoven materials can provide a longer wicking distance compared to conventional products, providing a drier feel and increased comfort to the end user in terms of dryness. Longer wicking distances can provide increased utilization of absorbent materials, for example, in personal hygiene products during use. In some embodiments, the nonwoven materials of the present disclosure can have a wicking distance of about 80 mm to about 200 mm, about 80 mm to about 160 mm, about 90 mm to about 150 mm, or about 100 mm to about 125 mm. In specific embodiments, the nonwoven materials of the present disclosure can have a wicking distance of at least about 80 mm, at least about 85 mm, at least about 100 mm, at least about 125 mm, at least about 140 mm, at least about 148 mm, at least about 180 mm, or at least about 190 mm.

[0107] In some embodiments of the presently disclosed subject matter, at least a portion of at least one outer layer is coated with a binder. In certain embodiments of the presently disclosed subject matter, at least a portion of each outer layer is coated with a binder. In certain embodiments, the first and third layers are coated with binder in an amount ranging from about 1 gsm to about 10 gsm, from about 1 gsm to about 8 gsm, from about 1 gsm to about 5 gsm, from about 1 gsm to about 4 gsm, from about 5 gsm to about 10 gsm, from about 2 gsm to about 5 gsm, or from about 2 gsm to about 3 gsm.

[0108] In some embodiments of the nonwoven material, the basis weight of the overall structure ranges from about 5 gsm to about 600 gsm, or from about 5 gsm to about 400 gsm, or from about 10 gsm to about 400 gsm, or from about 20 gsm to about 300 gsm, or from about 10 gsm to about 200 gsm, or from about 20 gsm to about 200 gsm, or from about 30 gsm to about 200 gsm, or from about 40 gsm to about 200 gsm. In some embodiments where an absorbent core is present, the basis weight of the overall structure may range from about 10 gsm to about 1000 gsm, or from about 50 gsm to about 800 gsm, or from about 100 gsm to about 600 gsm.

[0109] The caliper of a nonwoven material refers to the caliper of the entire nonwoven material, including all layers. In some embodiments, the caliper of the material ranges from about 0.5 mm to about 8.0 mm, or from about 0.5 mm to about 4 mm, or from about 0.5 mm to about 3.0 mm, or from about 0.5 mm to about 2.0 mm, or from about 0.7 mm to about 1.5 mm.

[0110] Method for producing nonwoven materials A variety of methods can be used to assemble the materials used in the practice of the presently disclosed subject matter to produce the material, including, but not limited to, traditional dry forming methods such as air-laying and carding, or other forming techniques such as spunlace or airlace. Preferably, the material can be prepared by an airlaid process, which includes, but is not limited to, the use of one or more forming heads that deposit raw materials of different compositions in a selected order in a manufacturing process that produces a product having distinct layers. This allows for great versatility in the variety of products that can be produced.

[0111] In one embodiment, the material is prepared as a continuous airlaid web. Airlaid webs are typically prepared by disintegrating or defibering a sheet of cellulose pulp, typically with a hammer mill, to produce individualized fibers. Rather than a pulp sheet of virgin fibers, recycled airlaid edge trimmings, as well as off-spec transitional material resulting from grade changes and other airlaid manufacturing waste, can be fed to the hammer mill or other disintegrator. This ability to recycle manufacturing waste contributes to improved economics for the overall process. The individualized fibers, whether from virgin or recycled sources, are then pneumatically conveyed to the forming head of an airlaid web former. Several manufacturers produce airlaid web formers suitable for use in the presently disclosed subject matter, including Dan-Web Forming of Aarhus, Denmark; M&J Fibretech A / S of Horsens, Denmark; Rando Machine Corporation, Macedon, NY (described in U.S. Pat. No. 3,972,092); Margasa Textile Machinery of Cerdanyola del Valles, Spain; and DOA International of Weis, Austria. While these formers differ in the manner in which they open and air-transport the fibers onto the forming wire, they are all capable of producing webs of the presently disclosed subject matter. Dan-Web forming heads include rotating or oscillating perforated drums that help maintain fiber separation until the fibers are pulled by vacuum onto a foraminous forming conveyor or forming wire. In M&J machines, the forming head is essentially a rotary oscillator above a screen. The rotary oscillator may include a series or group of rotating propellers or fan blades. Other fibers, such as synthetic thermoplastic fibers, are opened, metered, and mixed in a fiber dosing system, such as a textile feeder supplied by Laroche SA of Cours-La Ville, France. In certain embodiments, such airlaid machines can be equipped with customized forming heads, or heads capable of layer individualizing filaments.From the textile feeder, the fibers are pneumatically conveyed to the forming head of the airlaid machine, where they are further mixed with comminuted cellulose pulp fibers from the hammer mill and deposited onto a continuously moving forming wire. If defined layers are desired, a separate forming head may be used for each type of fiber. Alternatively, or in addition, one or more layers may be prefabricated before being combined with additional layers, if any.

[0112] The airlaid web is transferred from the forming wire to a calender or other densification stage to densify the web, increase its strength, and control web thickness, if necessary. In one embodiment, the fibers of the web are then bonded by passing it through an oven set at a temperature high enough to fuse the included thermoplastic or other binder material. In a further embodiment, secondary bonding from the drying or curing of the latex spray or foam application occurs in the same oven. The oven may be a conventional ventilated oven, be operated as a convection oven, or achieve the necessary heating by infrared or even microwave irradiation. In certain embodiments, the airlaid web can be treated with additional additives before or after heat setting.

[0113] In some embodiments, nonwoven materials of the present disclosure comprising at least one layer comprising long fibers and at least one layer comprising short fibers can be prepared according to various methods. In some embodiments, at least one layer of short fibers can be air-laid onto at least one layer comprising long fibers. In certain embodiments, the long fibers can be formed into a carded web. In this manner, the nonwoven material can have a structure comprising one layer of long fibers bonded to another layer of short fibers. In an alternative embodiment, such nonwoven materials can be prepared by utilizing a forming head (e.g., manufactured by Campen Technology) to lay long fibers onto a layer comprising short fibers.

[0114] Intended Use and End Use The nonwoven material of the presently disclosed subject matter can be used in any application known in the art. For example, the nonwoven material can be used alone or as a component, such as an absorbent core and / or an acquisition-distribution layer (ADL), in a variety of absorbent articles. In some embodiments, the nonwoven material can be used in absorbent articles that absorb and retain bodily fluids. Such absorbent articles include baby diapers, adult incontinence products, light incontinence products, and feminine hygiene products such as panty liners and sanitary napkins.

[0115] In other embodiments, the nonwoven material can be used alone or as a component in other consumer products, such as an absorbent core and / or collection and distribution layer (ADL). For example, the nonwoven material can be used in absorbent cleaning products such as wipes, sheets, towels, etc. For example, the nonwoven material can be used as disposable wipes for cleaning applications, including household, personal, and industrial cleaning applications. The absorbency of the nonwoven material can assist in the removal of dirt and grime in such cleaning applications. In certain embodiments, the nonwoven material can be used as a filtration medium. [Example]

[0116] The following examples are merely illustrative of the subject matter of the present disclosure and should in no way be construed as limiting the scope of the subject matter.

[0117] Example 1 Absorbent structure The present embodiments provide an absorbent structure that can provide improved collection, distribution, and storage functions. The absorbent structure can be used as an absorbent core, for example, as a component of a personal hygiene product.

[0118] Structure B was a nonwoven substrate containing a multi-layer core structure to provide permanent storage for the application of superabsorbent polymer (SAP). Structure B was formed on a Danweb airlaid production line. The first layer contained 25 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully treated pulp, Leaf River) blended with 12 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The next layer contained 25 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully treated pulp, Leaf River) blended with 12 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The next layer contained 20 gsm of SAP (BASF, HySorb Fem 33N) applied on top of the previous layer. The top layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). 5 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was sprayed onto each of the eucalyptus and outer fluff layers. The total basis weight of Structure B was 174 gsm. Structure B contained approximately 11.5% SAP.

[0119] Table 1 shows the composition of Structure B.

[0120] [Table 3]

[0121] Structure C was a nonwoven substrate containing a multi-layer core structure to provide permanent storage for the application of superabsorbent polymer (SAP). Structure C was formed on a Danweb airlaid pilot line. The first layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 30% core, 1.5 dtex, 6 mm) and was deposited on a forming wire. The next layer contained 10 gsm of SAP (Evonik Favor SXM 7900) applied on top of the previous layer. The next layer contained 62 gsm of cellulosic fiber (Georgia-Pacific, GP 4723, fully treated pulp) blended with 25 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The top and bottom layers were sprayed with 4 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The total basis weight of Structure C was 175 gsm. Structure C contained approximately 5.7% SAP.

[0122] Table 2 shows the composition of Structure C.

[0123] [Table 4]

[0124] Structure D was a nonwoven substrate containing a multi-layer core structure to provide permanent storage. Structure D was formed on a Danweb airlaid pilot line. The first layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 30% core, 1.5 dtex, 6 mm) and was deposited on a forming wire. The next layer contained 70 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully treated pulp) blended with 27 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The top and bottom layers were sprayed with 4 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The basis weight of Structure D was 175 gsm. Structure D did not contain SAP.

[0125] Table 3 shows the composition of Structure D.

[0126] [Table 5]

[0127] Structure F was a nonwoven substrate containing a multi-layer core structure to provide permanent storage for the application of superabsorbent polymer (SAP). Structure F was formed on a Danweb airlaid pilot line. The first layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 30% core, 1.5 dtex, 6 mm) and was deposited on a forming wire. The next layer was 20 gsm of SAP (Evonik Favor SXM 7900) applied on top of the previous layer. The next layer contained 54 gsm of cellulosic fiber (Georgia-Pacific, GP 4723, fully treated pulp) blended with 21 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). 5 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was used to spray the top and bottom layers. Structure F had a basis weight of 175 gsm. Structure F contained approximately 11.5% SAP.

[0128] Table 4 shows the composition of Structure F.

[0129] [Table 6]

[0130] Structure H was a nonwoven substrate containing a multi-layer core structure to provide permanent storage for the application of superabsorbent polymer (SAP). Structure H was formed on a Danweb airlaid pilot line. The first layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 30% core, 1.5 dtex, 6 mm) and was deposited on a forming wire. The next layer contained 10 gsm of starch-based SAP 1, K-Boost (XGF-450, Como Cascades LLC, Beavertown, OR) applied on top of the previous layer. The next layer contained 62 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully treated pulp) blended with 25 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The top and bottom layers were sprayed with 4 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). Structure H had a basis weight of 175 gsm. Structure H contained approximately 5.7% SAP.

[0131] Table 5 shows the composition of Structure H.

[0132] [Table 7]

[0133] Structure I was a nonwoven substrate containing a multi-layer core structure to provide permanent storage for the application of superabsorbent polymer (SAP). Structure I was formed on a Danweb airlaid pilot line. The first layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 30% core, 1.5 dtex, 6 mm) and was deposited on a forming wire. The next layer contained 20 gsm of starch-based SAP 1, K-Boost (XGF-450, Como Cascades LLC, Beavertown, OR) applied on top of the previous layer. The next layer contained 54 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully treated pulp) blended with 21 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). 5 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was used to spray the top and bottom layers. Structure I had a basis weight of 175 gsm. Structure I contained approximately 11.5% SAP.

[0134] Table 6 shows the composition of Structure I.

[0135] [Table 8]

[0136] Structure J was a nonwoven substrate containing a multi-layer core structure to provide permanent storage for the application of superabsorbent polymer (SAP). Structure J was formed on a Danweb airlaid pilot line. The first layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 30% core, 1.5 dtex, 6 mm) and was deposited on a forming wire. The next layer contained 10 gsm of starch-based SAP 2, K-Boost (XGF-450, Como Cascades LLC, Beavertown, OR) applied on top of the previous layer. The next layer contained 62 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully treated pulp) blended with 25 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). 4 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was sprayed onto the top and bottom layers. Structure J had a basis weight of 175 gsm. Structure J contained approximately 5.7% SAP.

[0137] Table 7 shows the composition of Structure J.

[0138] [Table 9]

[0139] Structure K was a nonwoven substrate containing a multi-layer core structure to provide permanent storage for the application of superabsorbent polymer (SAP). Structure K was formed on a Danweb airlaid pilot line. The first layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, PE / PET 30% core, 1.5 dtex, 6 mm) and was deposited on a forming wire. The next layer contained 20 gsm of starch-based SAP 2, K-Boost (XGF-450, Como Cascades LLC, Beavertown, OR) applied on top of the previous layer. The next layer contained 54 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully treated pulp) blended with 21 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). 5 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was used to spray the top and bottom layers. Structure K had a basis weight of 175 gsm. Structure K contained approximately 11.5% SAP.

[0140] Table 8 shows the composition of Structure K.

[0141] [Table 10]

[0142] Example 2 Feminine Sanitary Napkin Applications - Effective Collection Time, Rewet, Retention Before Leakage, and Wicking (Structures BD, F, and HK) In feminine sanitary napkin applications, Structures BD, F, and HK were tested as absorbent cores in combination with a commercially available acquisition and distribution layer (Structure G) for effective acquisition time, rewet, retention before leakage, and liquid wicking properties compared to commercially available absorbent cores (Structures A and E).

[0143] Sample preparation Structure A was a control sample of a commercially available absorbent core. Structure A was a 175 gsm commercially available multibond airlaid (MBAL) (175 gsm, Vizorb 3950) containing approximately 20% SAP (Georgia-Pacific, Steinfurt, Germany).

[0144] Structure E was a control sample of an absorbent core taken from a commercial product. Structure E was a 200 gsm hydrogen-bonded airlaid (HBAL) core containing approximately 30% SAP. Structure E was tested at 6.3 x 2.2 inches (smaller than the other samples).

[0145] Structure G was a commercially available collection-distribution layer. Structure G was a 34 gsm carded web (Shalag Nonwovens, TABCW, product code STACT8H34) comprising polyester fibers. Structure G provided the ADL component of the absorbent system being tested. Each composite or article being tested included a top layer and a bottom layer that was Structure G.

[0146] Liquid Collection Time and Rewet Test The liquid collection properties of each sample were measured using a synthetic blood solution. Synthetic blood was obtained from Johnson, Moen & Co., Inc. (Rochester, MN) (Lot# 201141; February 2014). The synthetic blood had a surface tension of 40-44 mN / m (ASTM F23.40-F1670), a viscosity of 3.020-7.700 mPas, and contained various chemicals, including ammonium polyacrylate polymer, azo red dye, and HPLC-distilled water, among other ingredients. The synthetic blood was used "as is" without dilution.

[0147] The test fixture included a 29.2 cm x 19.1 cm x 0.6 cm hard plastic plate with a 1.9 cm inner diameter hole cut in the center. A weighed stainless steel cylinder with a 1.9 cm inner diameter was attached over the hole. The cylinder had a height of 5.1 cm, and the completed fixture had a total height of 5.7 cm and a total mass of 747.3 g.

[0148] The prepared composites or articles (6.5 cm x 20.5 cm or 6.5 cm x 21.5 cm) containing the sample combined with the collection-distribution layer were compressed in a roller press at 4 bar pressure to simulate the stress of the conversion process. 4 mL of synthetic blood was dispensed into the composite or article at a rate of 10 mL / min depending on the test being performed. The collection time was measured from the start of dispense until the synthetic blood was no longer visible in the dispense cylinder. A total of three dispenses were performed, resulting in collection times #1, #2, and #3. The time interval between dispenses was 10 minutes. The resulting collection time results were then used to calculate the effective collection time (EAT). The EAT value was calculated as the difference between the total collection time (TAT) and the dispense time (IT), which was 24 seconds (i.e., the time it took for all the liquid (in this case, 4 mL) to be delivered to the absorbent system being tested).

[0149] After three collection times were measured, the rewet properties of each material were analyzed. After the third collection time, three pre-weighed square plies (10.1 cm x 10.1 cm) of collagen (Coffi Collagen, Viscofan, USA) were placed on top of the composite or article to be tested. A thin Plexiglas plate and weight were placed on top of the collagen plies for one minute. The Plexiglas and weight applied a total pressure of 1.7 kPa. The collagen plies were weighed to determine the rewet results. The results for each test were the average of the three measurements.

[0150] The test results are shown in Figure 1-4.

[0151] Figures 1 and 2 show the effective collection time and rewet for Structures B, C, and D compared to commercial cores (Structures A and E), respectively. Figures 3 and 4 show Structures B, C, and D, which exhibit improved performance over both commercial cores (Structures A and E). Without being bound by theory, it is hypothesized that the bottom layers of Structures B, C, and D have higher capillary pressure than the top layers of these structures, allowing them to efficiently distribute liquid away from the discharge site, thereby leaving sufficient void volume to accommodate more liquid and thus allowing for better utilization of the absorbent core. The high capillary pressure of these layers may also allow liquid to be kept away from the surfaces of the core and acquisition-distribution layer components of absorbent systems, including the experimental cores (Structures B, C, and D). This results in low rewet, as shown in Figure 2.

[0152] As shown in Figure 1, absorbent systems containing the experimental cores (Structures B, C, and D) are able to collect liquid significantly faster than absorbent systems containing commercial cores (Structures A and E). This results in a shorter effective collection time, as shown in Figure 1. The results in Figure 1 demonstrate that absorbent systems containing the experimental cores (Structures B, C, and D) with relatively low or no SAP (about 11.5%, about 5.7%, and 0%, respectively) have improved performance compared to commercial control absorbent cores (20% and 30% SAP) with similar or higher total basis weights. Structures B, C, and D contain fewer synthetic components than conventional absorbent cores, making them more economical, yet still exhibit improved performance.

[0153] Figures 3 and 4 show the effective collection time and rewet for Structures C, D, F, H, I, J, and K, respectively, compared to a commercially available core (Structure A). Figures 3 and 4 demonstrate the improved performance of Structures C, D, F, H, I, J, and K over the commercially available core (Structure A). Without being bound by theory, it is hypothesized that the bottom layers of Structures C, D, F, H, I, J, and K have higher capillary pressure than the top layers of these structures, allowing them to efficiently distribute liquid from the discharge site, thereby leaving sufficient void volume to accommodate more liquid and thus allowing for better utilization of the absorbent core. The higher capillary pressure of these layers may also allow liquid to be kept away from the surfaces of the core and acquisition-distribution layer components of absorbent systems, including the experimental cores (Structures C, D, F, H, I, J, and K). This provides the low rewet shown in Figure 4.

[0154] The results in Figure 3 show that absorbent systems containing the experimental cores (Structures C, D, F, H, I, J, and K) are able to collect liquid significantly faster than absorbent systems containing commercial cores (Structure A). The results in Figure 3 show that absorbent systems containing the experimental cores (Structures C, D, F, H, I, J, and K) with relatively low or no SAP (about 11.5%, about 5.7%, and 0%, respectively) compared to a commercial control absorbent core of similar basis weight (20% SAP). Structures C, D, F, H, I, and J contain fewer synthetic components than conventional absorbent cores, which are more economical, yet demonstrate improved performance.

[0155] Pre-leak retention and wicking distance test Samples were tested for fluid retention and distribution. The liquid collection properties of each structure were measured using a synthetic blood solution to test retention and wicking distance before leakage. Synthetic blood was used from Johnson, Moen & Co., Inc. (Rochester, MN) (Lot #201141; February 2014). The synthetic blood had a surface tension of 40-44 mN / m (ASTM F23.40-F1670), a viscosity of 3.020-7.700 mPas, and contained various chemicals, including ammonium polyacrylate polymer, azo red dye, and HPLC-distilled water, among other ingredients.

[0156] The test apparatus included a mesh net (5 / 8" x 5 / 8" mesh) suspended on a test platform measuring 30.5 cm x 15.2 cm. The mesh net was positioned 12.7 cm lower in the center relative to the level. Synthetic blood was administered using a peristaltic pump at a rate of 10 mL / min and fell 7.6 cm before landing on the test substrate. A drop tray was placed directly below the mesh net, directly below the sample, to catch the synthetic blood, which marked the end point of the test. Figure 5 shows a schematic representation of the test apparatus.

[0157] Samples were cut to a standard 20.3 cm x 6.4 cm size and measured for initial thickness and basis weight. If the sample had a backing and went through the conversion process, the sample was tested directly. For samples without a backing, a 0.7 mm plastic sheet was glued to the back of the sample. The plastic sheet was cut to the same size as the sample (20.3 cm x 6.4 cm). Glue was applied to the back of the sample along two lines approximately 1.3 cm from each long edge. The 0.7 mm plastic sheet was then applied to the back of the sample. The plastic sheet was gently pressed down onto the glue before compression to avoid altering the collection properties.

[0158] Unconverted samples were compressed using a roller press at 4 bar pressure to simulate the pressure of conversion. Once the samples were compressed, thickness measurements were taken and the samples were tested. The peristaltic pump was set to 10 mL / min and a 10 mL graduated cylinder and timer were used to verify output. A drip tray was placed under the mesh net to catch any leakage.

[0159] The sample was placed directly under the mesh net using a backing plate. The long side of the sample was parallel to the long side of the mesh net. The peristaltic pump line was positioned 3 inches above the sample, allowing the synthetic blood to drip directly onto the center of the sample. The peristaltic pump was turned on, and a timer was started as soon as the first drop of synthetic blood landed on the sample. The timer was stopped as soon as the first drop of synthetic blood dripped from the sample into the drip tray. The peristaltic pump was stopped, the time recorded in seconds, and the wicking distance measured. The wicking distance was measured at the bottom of the sample and was a measure of the liquid distribution (mm). Each test result was the result of three measurements.

[0160] The test results are shown in Figures 6A-C and 7A-C.

[0161] Figures 6A-C provide test results for retention before leakage compared to commercial cores. Figure 6A provides the retention before leakage results for Structure B. Figure 6B provides the retention before leakage results for Structures C, H, and I. Figure 6C provides the retention before leakage results for Structures F, J, and K. The data in Figures 6A-C indicate that experimental Structures B, C, D, F, H, I, J, and K performed better than either of the commercial cores (Structures A and E). Without being bound by theory, it is hypothesized that the bottom layers of the experimental structures have higher capillary pressure than the top layers of these structures, allowing them to efficiently distribute liquid from the discharge site, thereby leaving sufficient void volume to accommodate more liquid, thus allowing for better utilization of the absorbent core. The higher capillary pressure of these layers may also allow for liquid retention away from the surface of the core. The results in Figures 6A-C suggest that the experimental cores are able to collect more liquid. The results in Figures 6A-C further suggest that the experimental cores can provide structures capable of retaining more liquid before leakage occurs compared to absorbent systems containing commercially available cores (Structures A and E). Structures B, C, D, F, H, I, and J, which have relatively low amounts of SAP compared to the commercial control absorbent core, performed better, contained fewer synthetic components, and were more economical than conventional absorbent cores. In particular, Structures H, I, J, and K each have a very low content of synthetic components because each of these structures contains a biodegradable starch-based SAP.

[0162] Figures 7A-C provide wicking test results compared to commercial cores (Structures A and E). Figure 7A provides wicking test results for Structure B. Figure 7B provides wicking test results for Structures C, H, and I. Figure 7C provides wicking test results for Structures F, J, and K. The data in Figures 7A-C indicate that experimental Structures B, C, F, H, I, J, and K performed better than either of the commercial cores (Structures A and E). Without being bound by theory, it is hypothesized that the bottom layers of the experimental structures have higher capillary pressure than the top layers of these structures, allowing them to efficiently distribute liquid away from the discharge site, thereby leaving sufficient void volume to accommodate more liquid and thus allowing for better utilization of the absorbent core. The higher capillary pressure in these layers also allows liquid to be retained away from the surface of the core. The results in Figures 7A-C suggest that liquid can be distributed farther from the discharge site in the experimental cores than in systems including commercial cores (Structures A and E).

[0163] Example 3 Hybrid Absorbent Structure This embodiment provides a hybrid absorbent structure that can provide integrated collection, distribution, and storage functions in one unitary structure. The hybrid absorbent structure can be used as a collection-distribution layer, for example, as a component of a personal hygiene product.

[0164] Structure 1A was a one-piece, two-sided hybrid nonwoven material. When used as an acquisition-distribution layer (ADL), the top layer contained a synthetic nonwoven component, and the bottom layer contained cellulosic fibers bonded with a latex binder. Structure 1A was formed using a laboratory pad former. Cellulosic fibers (Georgia-Pacific, GP 4723, fully treated pulp, Leaf River) in an amount of 18.0 gsm were placed on a layer of a 34 gsm through-air bonded carded nonwoven web (Shalag Nonwovens, product code STACT8H34). The cellulosic fiber layer was sprayed with 3.0 gsm (based on its dry weight) of a polymeric binder in the form of an emulsion (Vinnapas 192, Wacker, 15%) containing 0.20 gsm of surfactant (Aerosol OT 75, Cytec Industries). Structure 1A was cured in an oven (145°C, 4 minutes) to bond the cellulose fibers and carded nonwoven together. Structure 1A had a total basis weight of 55 gsm.

[0165] Table 9 shows the composition of Structure 1A.

[0166] [Table 11]

[0167] Structure IB was a one-piece, two-sided hybrid nonwoven material. When used as an acquisition-distribution layer (ADL), the top layer contained a synthetic nonwoven component, and the bottom layer contained cellulosic fibers bonded with a latex binder. A laboratory pad former was used to form Structure IB. Structure IB was formed by placing a 14.0 gsm amount of cellulosic fibers (Georgia-Pacific, GP 4723, fully treated pulp, Leaf River) on a layer of a 34 gsm through-air bonded carded nonwoven web (Shalag Nonwovens, product code STACT8H34). 2.0 gsm (based on its dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192, Wacker, 15%) containing 0.20 gsm of surfactant (Aerosol OT 75, Cytec Industries) was sprayed onto the cellulosic fiber layer. Structure IB was cured in an oven (145°C, 4 minutes) to bond the cellulose fibers and carded nonwoven together. The total basis weight of Structure IB was 50 gsm.

[0168] Table 10 shows the composition of structure IB.

[0169] [Table 12]

[0170] Structure 2 was a multi-layered monolithic structure formed on a Danweb airlaid pilot line. Structure 2 included a directionally layered synthetic fiber layer to enable acquisition and rewet, and a multi-layer core structure to provide permanent liquid storage and distribution. A carded nonwoven fabric (Shalag Nonwovens, product code STACT8H34) was used as the carrier for the airlaid nonwoven structure. The first layer included 69 gsm of cellulosic fiber (Georgia-Pacific, GP 4723, fully treated pulp, Leaf River) blended with 26 gsm of bicomponent fiber (Trevira, 1.7 dtex, 6 mm). The bicomponent fiber included a polyethylene (PE) sheath (30%) and a polyethylene terephthalate (PET) core (70%). The top layer included 62 gsm of eucalyptus pulp (Suzano, untreated) blended with 8 gsm of bicomponent fiber (Trevira, 1.5 dtex, 6 mm). The bicomponent fiber comprised a PE sheath (70%) and a PET core (30%). 5 gsm (based on dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was sprayed onto the eucalyptus layer. The total basis weight of Structure 2 was 200 gsm.

[0171] Table 11 shows the composition of Structure 2.

[0172] [Table 13]

[0173] Structure 3 was a multi-layer monolithic structure formed on a Danweb airlaid pilot line. Structure 3 included a directionally layered synthetic fiber layer to enable acquisition and rewet, and a multi-layer core structure using superabsorbent polymer (SAP) to provide permanent liquid storage and distribution. A carded nonwoven (Shalag Nonwovens, product code STACT8H34) was used as the carrier for the airlaid nonwoven structure. The first layer included 62 gsm of cellulosic fiber (Georgia-Pacific, GP 4723, fully treated pulp, Leaf River) blended with 23 gsm of bicomponent fiber (Trevira, 30% PE / 70% PET core, 1.7 dtex, 6 mm). The next layer included 10 gsm of superabsorbent polymer (SAP) (Evonik, Favor SXM 7900). The top layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, 70% PE / 30% PET core, 1.5 dtex, 6 mm). 5 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was sprayed onto the eucalyptus layer. The total basis weight of Structure 3 was 200 gsm.

[0174] Table 12 shows the composition of Structure 3.

[0175] [Table 14]

[0176] Structure 4 was a multi-layer monolithic structure formed on a Danweb airlaid pilot line. Structure 4 included directionally layered synthetic fiber layers to enable acquisition and rewet, and a multi-layer core structure using superabsorbent polymer (SAP) to provide permanent liquid storage and wicking. A carded nonwoven (Shalag Nonwovens, product code STACT8H34) was used as the carrier for the airlaid nonwoven structure. The first layer included 54 gsm of cellulosic fiber (Georgia-Pacific, GP 4723, fully treated pulp, Leaf River) blended with 21 gsm of bicomponent fiber (Trevira, 30% PE / 70% PET core, 1.7 dtex, 6 mm). The next layer included 20 gsm of superabsorbent polymer (SAP) (Evonik, Favor SXM 7900). The top layer contained 62 gsm of eucalyptus pulp (Suzano, untreated) mixed with 8 gsm of bicomponent fiber (Trevira, 70% PE / 30% PET core, 1.5 dtex, 6 mm). 5 gsm (by dry weight) of polymeric binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was sprayed onto the eucalyptus layer. The total basis weight of Structure 4 was 200 gsm.

[0177] Table 13 shows the composition of Structure 4.

[0178] [Table 15]

[0179] Example 4 Feminine Sanitary Napkin Applications - Liquid Collection Time and Rewet Test (Structure 1A) In a feminine sanitary napkin application, Structure 1A was tested for liquid acquisition and rewet properties as an acquisition-distribution layer in an absorbent system containing a commercially available absorbent core, compared to the commercially available absorbent system.

[0180] Sample preparation To obtain the absorbent system, Structure 1A (20.3 cm x 6.4 cm) was placed on a 175 gsm commercially available core (Vizorb 3950, Georgia Pacific, Steinfurt) (20.3 cm x 6.4 cm). The resulting absorbent system was roller-compressed at 4 bar pressure. Control 1 was a commercially available 60 gsm latex-bonded airlaid (LBAL). Control 2 was a commercially available 95 gsm multiply-bonded airlaid (MBAL). Control 3 was a commercially available 34 gsm carded nonwoven (Shalag Nonwovens, product code STACT8H34). Controls 1, 2, and 3 were each separately placed on a 175 gsm commercially available core (Vizorb 3950, Georgia Pacific, Steinfurt) (20.3 cm x 6.4 cm) to obtain the absorbent system. Each control was tested as a collection-distribution layer and placed on a 175 gsm commercial core (Vizorb 3950, Georgia-Pacific, Steinfurt) (20.3 cm x 6.4 cm) to obtain an absorbent system. The resulting absorbent system was roller-compressed at a pressure of 4 bar.

[0181] Liquid Collection Time and Rewet Test The liquid collection time and rewet of absorbent systems containing Control 1, Control 2, and Control 3 were evaluated in the same manner as the absorbent system containing Construct 1A. The test device included a Plexiglas plate with an attached stainless steel cylinder (748 g, 2.2 cm inner diameter) placed on top of the absorbent system under test. Seven mL of synthetic blood (Johnson, Moen & Co., Inc., ASTM F1670 synthetic blood, viscosity 5.56 mPa / s, surface tension 40-44 mN / m) was delivered to the top side of the absorbent system at a rate of 10 mL / min using a mini-pump (Fisher Scientific). The mini-pump and timer were simultaneously activated and allowed to pump into the absorbent system for 42 seconds. Total collection time #1 (TAT#1) was measured from the time synthetic blood administration began until no synthetic blood was observed inside the stainless steel cylinder. The sum of the three total collection times (TAT #1, TAT #2, and TAT #3) was measured, including a 10-minute gap between the start of the previous inspiratory session and the start of the next inspiratory session. The absorbent system was allowed to rest for an additional 10 minutes after the third inspiratory session. Four pieces of Coffi collagen sheets (Viscofan, 17.8 cm x 10 cm) were then placed on top of the test device. A thin Plexiglas plate and weight were placed on top of the Coffi sheets for one minute. The Plexiglas plate and weight applied a total of 0.86 kPa over an area of ​​20.3 cm x 6.4 cm. The Coffi collagen sheets were then weighed to determine rewet. Rewet was the difference between the mass of the Coffi collagen sheet before and after testing. Collection time and rewet results were the average of three measurements.

[0182] Figures 8 and 9 and Tables 14 and 15 provide the test results.

[0183] Figure 8 is a graphical depiction of the average effective collection time (EAT) measurements. The EAT value was calculated as the difference between the total collection time (TAT) and the delivery time (IT), which was 42 seconds (i.e., the time it took for all of the liquid (7 mL) in the stainless steel cylinder to reach the absorbent system being tested). The effective collection time (EAT) was calculated as the delivery time (IT) minus the total collection time (TAT). The delivery time is how long the pump was operated to deliver the synthetic blood. (EAT)=(TAT)-(IT)

[0184] As shown in Figure 8 and Table 14, the absorbent system containing Structure 1A as the collection-distribution layer had higher liquid collection performance than all of the control collection-distribution commercially available nonwoven materials.

[0185] [Table 16]

[0186] Figure 9 is a graphical depiction of the results of the rewet test. As shown in Figure 9 and Table 15, the absorbent system containing Structure 1A as the collection-distribution layer can provide more comfort to the end user in terms of dryness than all the control collection-distribution commercial nonwoven materials. Overall, the absorbent system containing Structure 1 had the lowest rewet at 0.11 g.

[0187] [Table 17]

[0188] Example 5 Diaper use - Rewetting test (Structure IB) Construction IB was tested for rewet properties in comparison to a commercial diaper product as an acquisition-distribution layer in a diaper application.

[0189] Sample preparation A commercially available diaper containing a 50 gsm carded nonwoven acquisition-distribution layer was used as a control diaper and tested for rewet. The elastic band around the entire control diaper was removed. The original 50 gsm carded nonwoven acquisition-distribution layer remained inside the diaper. The control diaper was subjected to compression during its manufacturing process, so it was tested without further compression.

[0190] The same commercially available diaper was disassembled. The original 50 gsm carded nonwoven acquisition-distribution layer was removed and replaced with Structure IB (19.0 cm x 8.0 cm). The nonwoven topsheet of the diaper was placed back on top of the diaper. The diaper was then compressed using a roller press at 4 bar pressure.

[0191] Rewetting test The rewet of the diapers containing Structure IB as the collection-distribution layer was evaluated in the same manner as the control diapers. A test fixture was placed on top of the diaper. The test fixture applied approximately 2.8 kPa (1.2 psi) to the diaper. The test fixture included an attached saline delivery cylinder (inner diameter 3.8 cm). The saline delivery cylinder was placed approximately 2 inches from the edge of the collection-distribution layer corresponding to the front of the diaper. 75 mL of 0.9% sodium chloride (NaCl) solution was dispensed into the control diaper by operating the pump, which delivered the solution at a rate of 7 mL / sec for 10.7 seconds. Once the liquid was completely absorbed, a 20-minute timer was started. At 20 minutes, a second 75 mL aliquot of 0.9% sodium chloride (NaCl) solution was used to dispense the product. Once the liquid was completely absorbed, a 20-minute timer was started. At 20 minutes, the test fixture was removed. Eight pieces of Curity (10 cm x 10 cm nonwoven fabric, All Purpose Sponges, Covidien) were spread to increase the coverage area to 20 cm x 10 cm. The eight pieces of Curity were placed on top of the wet diaper to completely cover the 19.0 cm x 8.0 cm collection-distribution layer. The foam-discharge cylinder-weight was placed back on top of the diaper, with the discharge cylinder at the end of the diaper opposite the discharged area. A five-minute timer was started. At five minutes, the Curity was weighed and the rewet value was calculated. The final rewet result was the average of the results of the three tests.

[0192] The test results are provided in Figure 10. Figure 10 provides rewet measurements of the control diaper and the diaper including Structure IB as the collection-distribution layer. The control diaper had a rewet of 4.18 g, while the diaper including Structure IB had a lower rewet value of 2.86 g. The diaper including Structure IB as the collection-distribution layer can provide a drier feel than the diaper including the original carded nonwoven collection-distribution layer.

[0193] Example 6 Feminine Sanitary Napkin Applications - Liquid Collection Time, Rewet and Wicking Tests (Structures 2-4) Constructions 2-4 were tested for liquid acquisition, rewet and wicking properties in comparison to the absorbent system of a commercially available feminine sanitary napkin (Control AD).

[0194] Sample characteristics Control A was a commercially available sanitary napkin (Sannap A). ​​The absorbent system had a total basis weight of 325 gsm. The acquisition-distribution layer included a TABCW layer having a basis weight of approximately 46 gsm and an airlaid sheet having a basis weight of approximately 77 gsm. The core was a hydrogen-bonded airlaid sheet containing approximately 30% SAP material. The core had a basis weight of approximately 200 gsm.

[0195] Control B was a commercially available sanitary napkin (Sannap B). The absorbent system had a total basis weight of about 206 gsm. The acquisition-distribution layer was an airlaid sheet having a basis weight of about 97 gsm. The core was an airlaid sheet containing greater than about 10% SAP material. The core had a basis weight of about 109 gsm.

[0196] Control C was a commercially available sanitary napkin (Sannap C). The absorbent system had a total basis weight of about 241 gsm. The acquisition-distribution layer was an airlaid sheet having a basis weight of about 102 gsm. The core was an airlaid sheet containing greater than about 10% SAP material. The core had a basis weight of about 139 gsm.

[0197] Control D was a commercially available sanitary napkin (Sannap D). The absorbent system had a total basis weight of about 215 gsm. The spunbond acquisition-distribution layer had a basis weight of about 57 gsm. The core was an airlaid sheet containing greater than about 10% SAP material. The core had a basis weight of about 158 ​​gsm.

[0198] Figure 11 is a graphical depiction of the basis weights of Constructions 2-4 compared to the commercially available sanitary napkins tested (Controls A and D). Constructions 2 and 3 had lower basis weights than Controls A and C. Construction 4 had lower basis weights than Controls A, C, and D.

[0199] Liquid Collection Time and Rewet Test The liquid acquisition time and rewet of Structures 2-4 were evaluated in the same manner as the commercial sanitary napkins being tested (Control AD). The absorbent systems (6.5 cm x 20.5 cm or 6.5 cm x 21.5 cm) were roller compressed at 4 bar pressure. Figure 12 and Table 16 provide the thickness of Structure 2-4 before and after 4 bar compression.

[0200] [Table 18]

[0201] The test fixture included a Plexiglas plate with a cylinder (748 g, 2.2 cm inner diameter) placed on top of the absorbent system. Four mL of synthetic blood (Johnson, Moen & Co., Inc., ASTM F1670 synthetic blood, viscosity 5.56 mPa / s, surface tension 40-44 mN / m) was dispensed into the absorbent system using a mini-pump (Fisher Scientific) at a rate of 10 mL / min. The mini-pump and timer were activated simultaneously, and the absorbent system was dispensed for 24 seconds. Total collection time #1 (TAT#1) was measured from the moment the synthetic blood administration began until no synthetic blood was visible inside the stainless steel cylinder. The sum of the three total collection times (TAT#1, TAT#2, and TAT#3) was measured, including a 10-minute gap between the start of each dispense and the start of the next. After the third dispense, the absorbent system was allowed to rest for an additional 10 minutes. Four pieces of Coffi collagen sheets (Viscofan, USA) (10 cm x 10 cm) were then placed on the test fixture. A thin Plexiglas plate and weight were placed on top of the Coffi sheets for 1 minute. The Plexiglas plate and weight applied a total of 0.86 kPa over an area of ​​20 cm x 6.4 cm. The Coffi sheets were then weighed to determine rewet. Collection times and rewet results were the average of three measurements.

[0202] Figures 13 and 14 and Tables 17 and 18 provide the test results.

[0203] Figure 13 graphically illustrates the effective acquisition time (EAT) obtained for each of the experimental multi-functional integrated structures tested (Structures 2-4) and for the control commercial sanitary napkin (Control AD) as shown in Table 17. The EAT value was the difference between the total acquisition time (TAT) and the delivery time (IT). Each delivery volume was 4 mL, and the liquid was delivered at a rate of 10 mL / min. Thus, the duration of the IT was 24 seconds, and EAT = TAT - 24 seconds. As shown in Figure 13 and Table 17, although the basis weight of Structures 2-4 was lower than that of the absorbent system in the commercial product (Control AD), the liquid acquisition performance of all experimental structures was higher than that of the commercial sanitary napkin containing the original absorbent material.

[0204] [Table 19]

[0205] Figure 14 graphically illustrates the rewet results obtained for each of the experimental multi-functional integrated structures tested and for the control commercial sanitary napkin, as shown in Table 18. As shown in Figure 14 and Table 18, although the basis weight of Structures 2-4 was lower than the basis weight of the absorbent system contained in the commercial product (Control AD), and Structures 2-4 contained no SAP or a relatively small amount of SAP, all of the rewet of Structures 2-4 provided improved performance (e.g., lower rewet values) than the commercial sanitary napkin containing the original absorbent material.

[0206] [Table 20]

[0207] Suction distance test Each construction was further tested for wicking and rewet measurements were completed after total collection times #1, #2, and #3. The samples were turned over so that the underside of the core was facing up. A standardized measuring ruler was used to measure the visible stain lengthwise along the construction. Measurements were taken parallel to the long edge of the construction from the outer edge of the stain on one side to the outer edge of the stain on the other side.

[0208] Figure 15 and Table 19 provide the test results.

[0209] As shown in Table 19, Figure 15 graphically illustrates the wicking results obtained for each of the experimental multi-functional integrated structures tested and for the control commercial sanitary napkin. As shown in Figure 15 and Table 19, the measured wicking distances for all of Samples 2-4 were longer than that of the commercial sanitary napkin containing the original absorbent material (Control AD). A longer wicking distance provides better utilization of the absorbent material contained in the personal hygiene product during its use.

[0210] [Table 21]

[0211] In addition to the various embodiments described and claimed, the presently disclosed subject matter is directed to other embodiments having other combinations of the features disclosed and claimed herein. Accordingly, particular features presented herein can be combined with each other in other manners within the scope of the presently disclosed subject matter such that the presently disclosed subject matter includes any suitable combination of the features disclosed herein. The foregoing descriptions of specific embodiments of the presently disclosed subject matter have been presented for purposes of illustration and description and are not intended to be exhaustive or to limit the presently disclosed subject matter to those disclosed embodiments.

[0212] It will be apparent to those skilled in the art that various modifications and variations can be made in the systems and methods of the presently disclosed subject matter without departing from the spirit or scope of the presently disclosed subject matter. Thus, it is intended that the presently disclosed subject matter cover modifications and variations that come within the scope of the appended claims and their equivalents.

[0213] Various patents and patent applications are cited herein, the contents of which are incorporated herein by reference in their entireties.

Claims

1. a first layer comprising cellulose fibers and bicomponent fibers; and a second layer including fine cellulose fibers and bicomponent fibers, the fine cellulose fibers having a pulp fiber coarseness of 4.2 mg / 100 m to 14.08 mg / 100 m; The fine cellulose fibers of the second layer are finer than the cellulose fibers of the first layer, At least a portion of the first layer is coated with a binder and at least a portion of the second layer is coated with a binder; and A multi-layer nonwoven material, wherein the first layer is a top layer of the multi-layer nonwoven material.

2. 10. The multi-layer nonwoven material of claim 1, having an effective collection time of 40 seconds or less.

3. 3. The multi-layer nonwoven material of claim 2, having an effective collection time of 20 seconds or less.

4. 10. The multi-layer nonwoven material of claim 1, having a wicking distance of at least 85 mm.

5. 5. The multi-layer nonwoven material of claim 4, having a wicking distance of at least 140 mm.

6. 10. The multi-layer nonwoven material of claim 1 having a rewet value of 0.20 g or less.

7. 7. The multi-layer nonwoven material of claim 6, having a rewet value of 0.15 g or less.

8. 10. The multi-layer nonwoven material of claim 1, having a retention force before leakage of at least 3.0 g.

9. 10. The multi-layer nonwoven material of claim 1, wherein the fine cellulose fibers comprise eucalyptus pulp.

10. 10. The multi-layer nonwoven material of claim 1, further comprising a first intermediate layer comprising a superabsorbent polymer (SAP) disposed between the first layer and the second layer, the superabsorbent polymer (SAP) having a basis weight in the range of 5 to 10 gsm.

11. 11. The multi-layer nonwoven material of claim 10, further comprising a second intermediate layer comprising cellulosic fibers and bicomponent fibers disposed between the first layer and the first intermediate layer.

12. 10. An absorbent article comprising the multi-layer nonwoven material of claim 1.

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