Absorbent nonwoven materials

Abstract

To provide: multi-layer nonwoven materials and their use in absorbent articles, e.g., as absorbent cores and / or acquisition distribution layers (ADLs); and particularly, layered structures that provide improved liquid acquisition, distribution, storage and rewettability while allowing the use of less synthetic materials, such as superabsorbent polymers (SAP), than other commercially available materials.SOLUTION: A multi-layer nonwoven material comprises: a first layer comprising cellulose fibers and bicomponent fibers; and a second layer adjacent to the first layer and comprising fine cellulose fibers and bicomponent fibers, where at least a portion of the first and second layers are coated with a binder.SELECTED DRAWING: Figure 1

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 on September 18, 2019, the contents of each of which are hereby incorporated by reference in their entirety.

[0002] The subject matter of the present disclosure relates to new non - woven materials, for example, as an absorbent core and / or a collection - distribution layer, and their use in absorbent articles including personal hygiene products such as incontinence, light incontinence, and feminine hygiene products. In particular, such structures enable the use of less synthetic materials such as superabsorbent polymers (SAP) while providing improved liquid collection, distribution, storage, and re - wetting properties compared to conventional absorbent cores or absorbent systems that include separate collection - distribution materials.

Background Art

[0003] Non - woven structures are important in a wide range of consumer products such as absorbent articles including baby diapers, adult incontinence products, light incontinence products, feminine hygiene products such as panty liners, sanitary napkins, etc. Such absorbent articles may require rapid liquid collection. In certain non - woven articles, there is often an absorbent core for receiving and holding body fluids. The absorbent core is typically disposed between a liquid - permeable topsheet whose function is to allow fluid passage to the core and a liquid - impermeable backsheet whose function is to contain the fluid and prevent it from passing through the absorbent article and reaching the clothing of the wearer of the absorbent article. In certain non - woven articles, a collection - 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 a conventional multilayer absorbent structure having a capture layer, a distribution layer, and a storage layer, the capture layer captures liquid insult and quickly conveys it away from the wearer's skin (in the Z direction) by capillary action. Next, the fluid reaches the distribution layer. The distribution layer typically consists of a denser material and moves the liquid away from the wearer's skin (in the Z direction) and also laterally across the structure (in the X-Y direction). Eventually, the liquid moves to the storage layer. The storage layer generally contains high-density cellulose fibers and superabsorbent polymer (SAP) particles. The liquid is absorbed by the storage layer and particularly the SAP particles contained therein. In other conventional multilayer absorbent structures having a capture layer and a storage layer, the capture layer captures liquid discharge and distributes the liquid away from the wearer's skin. The liquid moves and is absorbed into the storage layer.

Prior Art Documents

Patent Documents

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Non-Patent Document

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Summary of the Invention

Problems to be Solved by the Invention

[0007] In recent years, there has been a market and consumer demand for absorbent articles that are more economical and do not require as much synthetic material such as SAP. There is also a market and consumer demand for thinner absorbent articles. Further, there is a need for improving the performance of such nonwoven articles in terms of liquid collection, distribution, storage, and rewetting characteristics while providing an appropriate dry state.

[0008] Thus, there is still a need for nonwoven materials that have sufficient absorbency capacity for their intended use and yet are compatible with the desired dry state profile. There is also still a need for economical and thinner absorbent articles that contain less synthetic material. The subject matter of the present disclosure addresses these and other needs.

Means for Solving the Problems

[0009] The subject matter of the present disclosure provides an absorbent structure having a multilayer nonwoven material that includes a specific layered structure that enables the use and reduced overall basis weight of less synthetic material such as superabsorbent polymer (SAP), and advantageously achieves increased liquid collection, distribution storage, and rewetting. In one aspect, the nonwoven material of the present disclosure includes a multilayer absorbent core that includes a layer of bonded fine cellulose fibers such as hardwood fibers and a layer of bonded coarse cellulose fibers such as softwood fibers, providing improved characteristics with respect to liquid collection, distribution, and rewetting of the nonwoven material and advantageously enabling a reduced incorporation of synthetic material. In one aspect, the nonwoven material of the present disclosure includes a collection and distribution layer (ADL) having the absorbent characteristics 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 multilayer 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 using a binder.

[0011] In certain embodiments, the nonwoven material can have an Effective Acquisition Time (EAT) of about 40 seconds or less or about 20 seconds or less. In certain embodiments, the nonwoven material can have a wicking distance of at least about 85 mm or at least about 140 mm. In certain embodiments, the nonwoven material can have a rewettability value of about 0.2 g or less or about 0.15 g or less. In certain embodiments, the nonwoven material can have a holding capacity before leakage of at least about 3.0 g.

[0012] In certain embodiments, the fine cellulose fibers can include eucalyptus pulp.

[0013] In certain 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 certain 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 cellulose fibers and bicomponent fibers.

[0015] A multilayer nonwoven material comprising at least four layers, and an absorbent article containing 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 is 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 microcrystalline cellulose fibers and synthetic fibers. At least a portion of the first and fourth layers can be coated using a binder.

[0016] In certain embodiments, the microcrystalline cellulose fibers can include eucalyptus pulp. In certain embodiments, the synthetic article can include bicomponent fibers.

[0017] A multilayer nonwoven material having at least two layers, and an absorbent article containing 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 using a binder.

[0018] In certain embodiments, the nonwoven material can have an effective collection time (EAT) of about 15 seconds or less, or about 1 second or less. In certain embodiments, the nonwoven material can have a rewettability value of about 0.5 g or less, or about 0.05 g or less. In certain embodiments, the nonwoven material can have a wicking distance of at least about 140 mm, or at least about 180 mm.

[0019] In certain embodiments, the long fibers can include synthetic fibers, regenerated cellulose fibers, or combinations thereof. In specific embodiments, the long fibers can include synthetic fibers formed as a card web. The long fibers can have a length between about 8 mm and about 70 mm. In certain 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] There is provided a multilayer nonwoven material having at least two layers including a first layer including synthetic fibers formed as a card web, and an absorbent article including the same. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can include cellulose fibers. At least a portion of the second layer can be coated using a binder. In certain embodiments, the synthetic fibers can have a length between about 8 mm and about 70 mm.

[0021] There is provided a multilayer nonwoven material including at least three layers, and an absorbent article including the same. 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 card 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 using a binder. In certain embodiments, the synthetic fibers can have a length between about 8 mm and about 70 mm. In certain embodiments, the cellulose fibers of the third layer can include microcrystalline cellulose fibers. In specific embodiments, the cellulose fibers of the third layer can include eucalyptus pulp.

[0022] A multilayer nonwoven material comprising at least 4 layers and an absorbent article containing 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 card 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 using a binder. In certain embodiments, the synthetic fibers can have a length between about 8 mm and about 70 mm. In certain embodiments, the cellulose fibers of the fourth layer can include microcrystalline cellulose fibers. In certain specific embodiments, the cellulose fibers of the fourth layer can include eucalyptus pulp.

[0023] In the foregoing, the features and technical advantages of the present application have been broadly outlined so that the following detailed description may be better understood.

[0024] Additional features and advantages of the present application, which form the subject matter of the claims of the present application, are described below. It should be recognized by those skilled in the art that the disclosed concepts and specific embodiments can 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 understood by those skilled in the art that such equivalent structures do not depart from the spirit and scope of the present application as set forth in the appended claims. The novel features believed to be characteristic of the present application will be better understood from the following description, together with further objects and advantages, with respect to both the construction and method of operation thereof.

Brief Description of the Drawings

[0025]

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DETAILED DESCRIPTION OF THE INVENTION

[0026] The subject matter of the present disclosure provides a multilayer nonwoven material for use in absorbent articles, for example, as an absorbent core and / or an acquisition distribution layer (ADL). The subject matter of the present disclosure also provides a method of making such a material. These and other aspects of the subject matter of the present disclosure are considered in more detail in the description and examples.

[0027] Definitions As used herein, terms are generally intended to have their ordinary meaning within the context of this subject matter and within the particular context in which each term is used. Certain terms are defined below to provide additional guidance in describing the compositions and methods of the subject matter of the present disclosure, as well as how to make and use them.

[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 mixtures 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 will depend in part on how the value is measured or determined, i.e., the limitations of the measurement system. For example, "about" can mean within three or more standard deviations, per the practice in the art. Alternatively, "about" can mean within up to 20%, preferably up to 10%, more preferably up to 5%, and even more preferably up to 1% of a given value. Alternatively, especially with respect to a system or method, the term can mean within one order of magnitude, preferably within a factor of five, and more preferably within a factor of two of a value.

[0030] As used herein, the term "basis weight" refers to the amount by the mass of a compound over a given area. Examples of units of measurement include grams per square meter, specified 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," of the 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 a main component, particularly any material containing 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, delignified chemical wood pulp, cotton linter, microcrystalline cellulose, microfibrillated cellulose, and the like.

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

[0034] As used herein, the terms "fiber" or "fibrous" refer to a particulate material, and the ratio of the length to the diameter of such particulate material is greater than about 10. Conversely, "non-fiber" or "non-fibrous" material means a particulate material in which the ratio of the length to the diameter of such particulate matter is about 10 or less.

[0035] As used herein, the term "hybrid" in "hybrid absorbent structure" or "hybrid absorbent material" etc. 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 body fluids such as water, oil, solvents, urine or blood.

[0037] As used herein, the terms "long fiber" or "longer fiber" refer to fibers having a length of about 8 mm to about 70 mm, including all intervening values. In certain 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, molten plastics, or plastic films bonded together mechanically, thermally, or chemically. A nonwoven is a fabric made directly from a web of fibers without the need for yarn preparation as in weaving or knitting. In a nonwoven, the aggregate 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 natural or synthetic resins.

[0039] As used herein, the term "short fiber" or "shorter fiber" refers to fibers having a length of from about 1 mm to about 8 mm, including all intervening values.

[0040] As used herein, the term "mass percent" means either (i) the amount by the mass of a component / constituent in a material as a mass percentage of the material layer; or (ii) the amount by the mass of a component / constituent in a material as a mass percentage of the final nonwoven material or product.

[0041] Fiber The nonwoven materials of the subject matter of the present disclosure include fibers. In certain embodiments, the fibers can include long fibers, short fibers, or mixtures thereof. The fibers can be natural fibers, synthetic fibers, or mixtures thereof. In certain embodiments, the fibers can be cellulosic fibers, one or more synthetic fibers, or mixtures thereof.

[0042] Cellulose fiber Any cellulose fiber known in the art can be used in the cellulose layer, including any cellulose fiber of natural origin, such as those derived from wood pulp or regenerated cellulose. In certain 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 thermomechanical treated fibers, derived from softwood, hardwood, or cotton linter. Regenerated cellulose can be prepared by dissolving cellulose into monomers and regenerating continuous cellulose polymers. The resulting polymer can be 100% cellulose and can be made into longer fibers, for example, for use in textiles. 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 softwood, such as pine, spruce, and douglas fir. Other suitable cellulose fibers include, but are not limited to, those derived from esparto grass, bagasse, kemp, linen, hemp, kenaf, and other lignocellulosic 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.). Further, fibers sold under the trademark CELLU TISSUE® (e.g., Grade 3024) (Clearwater Paper Corporation, Spokane, Wash.) are used in certain aspects of the present disclosure.

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

[0044] In certain embodiments, fine fibers such as certain softwood fibers can be used. Certain non-limiting examples of such fine fibers, including the fiber coarseness of the pulp, 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 certain embodiments, fine fibers such as hardwood fibers can be used. Certain non-limiting examples of such fine fibers, including the fiber coarseness of the pulp, are provided in Table II with reference at least in part to Horn, R., Morphology of Pulp Fiber from Hardwoods and Influence on Paper Strength, Research Paper FPL 312, Forest Products Laboratory, U.S. Department of Agriculture (1978) and Bleached Eucalyptus Kraft Pulp ECF Technical Sheet (April 2017) (available from: 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 cross-linked cellulose fibers. U.S. Patent No. 5,492,759, U.S. Patent No. 5,601,921, and U.S. Patent No. 6,159,335, all of which are hereby incorporated by reference in their entirety, relate to chemically treated cellulose fibers useful in the practice of the subject matter of this disclosure. In some embodiments, the modified cellulose fibers include polyhydroxy compounds. Non-limiting examples of polyhydroxy compounds include glycerin, trimethylolpropane, pentaerythritol, polyvinyl alcohol, partially hydrolyzed polyvinyl acetate, and fully hydrolyzed polyvinyl acetate. In some 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 fibers. In certain embodiments, the polyvalent cation-containing compound is a polyvalent metal ion salt. In some 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 containing a transition metal salt can 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 metal 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 the polyvalent metal salts, other compounds such as complexes of the above salts may include, but are not limited to, amines, ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DIPA), nitrilotriacetic acid (NTA), 2,4-pentanedione, and ammonia, and may be used.

[0049] In one embodiment, the cellulose pulp fibers are chemically modified cellulose pulp fibers that have been softened or plasticized to be more compressible than the unmodified pulp fibers. The same pressure applied to the plasticized pulp web results in a higher density than when applied to the unmodified pulp web. Further, the densified web of plasticized cellulose fibers is substantially softer than a web of similar density of unmodified fibers of the same wood type. Softwood pulp may be made more compressible by using a cationic surfactant as a debinder to break the fiber-to-fiber bonding. The use of one or more debinders promotes the disintegration of the pulp sheet into fluff in the airlaid process. Examples of debinders include, but are not limited to, those disclosed in U.S. Patent No. 4,432,833, U.S. Patent No. 4,425,186, and U.S. Patent No. 5,776,308, all of which are incorporated herein by reference in their entirety. An example of a debinder-treated cellulose pulp is FFLE+. Plasticizers for cellulose, which can be added to the pulp slurry prior to the formation of the wet-laid sheet, can also be used to soften the pulp, but they act by a different mechanism than the debinders. Plasticizers act on the cellulose molecules within the fibers to make the amorphous regions flexible or soft. The resulting fibers are characterized as being flexible. Since the plasticized fibers lack rigidity, this ground pulp densifies more easily compared to fibers not treated with plasticizers. 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. Patent No. 4,098,996, U.S. Patent No. 5,547,541, and U.S. Patent No. 4,731,269, all of which are incorporated herein by reference in their entirety. Ammonia, urea, and alkylamines are also known to plasticize wood products that mainly contain cellulose (A. J. Stamm, Forest Products Journal 5(6):413, 1955, which is incorporated herein by reference in its entirety).

[0050] In certain embodiments of the subject matter of the present disclosure, the following celluloses are used: GP 4723, fully processed pulp, (Leaf River), available from Georgia-Pacific; GP4725, semi-processed pulp (available from Georgia-Pacific); Tencel (available from Lenzing); cellulose linen fibers; Danufil (available from Kelheim); Viloft (available from Kelheim); GP4865, semi-processed pulp for odor control (available from Georgia-Pacific); Grade 3024 Cellu Tissue (available from Clearwater); Brawny Industrial Flax 500 (available from Georgia-Pacific).

[0051] The nonwoven materials of the present disclosure can include cellulose fibers. In certain embodiments, one or more layers of the nonwoven material can include from about 5 gsm to about 150 gsm, from about 5 gsm to about 100 gsm, or from about 10 gsm to about 50 gsm of cellulose fibers. In particular embodiments, one or more layers can include about 18 gsm, about 25 gsm, about 54 gsm, about 62 gsm, about 69 gsm, or about 70 gsm of cellulose fibers.

[0052] Synthetic fibers In addition to the use of cellulose fibers, the subject matter of the present disclosure 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 production of nonwoven materials. Various bicomponent fibers suitable for use in the subject matter of the present disclosure are disclosed in U.S. Patent No. 5,372,885 and U.S. Patent No. 5,456,982, both of which are hereby incorporated by reference in their entirety. 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 having 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 of polyester and a sheath made of polyethylene. In another embodiment, the bicomponent fiber has a core made of polypropylene and a sheath made of polyethylene.

[0054] The denier of the bicomponent fiber is preferably in the range of about 1.0 dpf to about 4.0 dpf, more preferably in the range of 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 polyethylene sheath modified with maleic anhydride. T255 is manufactured in various deniers, cut lengths and core-sheath configurations, and a preferred configuration has a denier of about 1.7 dpf to 2.0 dpf and 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 2.0 dpf and a length of 6 mm. In an alternative embodiment, the bicomponent fiber is Trevira 1663, T255 with 2.0 dpf and a length of 3 mm.

[0055] Bicomponent fibers are typically commercially produced by melt spinning. In this procedure, each molten polymer is extruded through a die, such as a spinneret, and then the molten polymer is drawn to remove it from the face of the spinneret. This is followed by solidification of the polymer by heat transfer to the surrounding fluid medium, such as cooling air, and then winding of the solid filaments. Non-limiting examples of further processes after melt spinning can also include high-temperature drawing or cold drawing, heat treatment, crimping, and cutting. This overall manufacturing process is generally carried out as a discontinuous two-step process that initially involves spinning of the filaments and their convergence into tows containing multiple filaments. During the spinning process, some stretching of the filaments occurs just as the molten polymer is pulled away from the face of the spinneret, which can also be referred to as drawdown. This is followed by a second step where the spun fibers are drawn or stretched to increase molecular alignment and crystallinity, imparting enhanced strength and other physical properties to the individual filaments. Subsequent processes can include, but are not limited to, heat setting, crimping, and cutting of the filaments into fibers. The drawing or stretching step can involve stretching of the core, the sheath, or both the core and the sheath of the bicomponent fiber, depending on the materials comprising 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 carried out in a continuous process. During the fiber manufacturing process, it is desirable to add various materials to the fibers after the melt spinning process at various subsequent steps in the process. These materials can be referred to as "finishes" and include, but are not limited to, active agents such as lubricants and antistatic agents. Finishes are typically supplied by an aqueous-based solution or emulsion. Finishes can impart desirable properties for both the production of bicomponent fibers and for the users of the fibers, for example, in an airlaid or wetlaid process.

[0057] A number of other processes are included before, during, and after the spinning and drawing steps and are disclosed in U.S. Patent Nos. 4,950,541; 5,082,899; 5,126,199; 5,372,885; 5,456,982; 5,705,565; 2,861,319; 2,931,091; 2,989,798; 3,038,235; 3,081,490; 3,117,362; 3,121,254; 3,188,689; 3,237,245; 3,249,669; 3,457,342; 3,466,703; 3,469,279; 3,500,498; 3,585,685; 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; 4,370,114; 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 hereby incorporated by reference in their entirety.

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

[0059] The bicomponent fibers of the subject matter of the present disclosure can provide enhanced performance in terms of elongation and strength for any partially stretched core bicomponent fiber, so the range for either the core or the sheath is not limited to any particular polymer. The degree to which the partially stretched bicomponent fiber is stretched is not limited, as different degrees of stretching result in different enhancements in performance. The range of partially stretched bicomponent fibers includes fibers having various core-sheath configurations including, but not limited to, concentric, eccentric, parallel, sea-island, pie-segmented, and other variations. The relative mass percentages of the core and sheath components of the total fiber can be varied. In addition, the scope of the present subject matter extends to the use of partially stretched homopolymers such as polyester, polypropylene, nylon, and other melt-spinnable polymers. The scope of the present subject matter also extends to multicomponent fibers that can have three or more polymers as part of the fiber structure.

[0060] The nonwoven material of the present disclosure can include bicomponent fibers. In certain embodiments, one or more layers of the nonwoven material can include bicomponent fibers in the range of about 1 gsm to about 40 gsm, about 5 gsm to about 30 gsm, or about 10 gsm to about 25 gsm. In specific embodiments, one or more layers of the nonwoven material can include bicomponent fibers of about 8 gsm, about 12 gsm, about 21 gsm, about 25 gsm, or about 27 gsm. In alternative embodiments, the bicomponent layer can include bicomponent fibers in the range 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 in the range of about 0.5 dtex to about 20 dtex. In some embodiments, the dtex value can be in the range of about 1.3 dtex to about 15 dtex, or about 1.5 dtex to about 10 dtex, or about 1.7 dtex to about 6.7 dtex, or 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, acrylic, polyamide (including but not limited to nylon 6, nylon 6 / 6, nylon 12, polyaspartic acid, polyglutamic acid), polyamine, polyimide, polyacrylic acid (including but not limited to polyacrylamide, polyacrylonitrile, esters of methacrylic acid and acrylic acid), polycarbonate (including but not limited to polybisphenol A carbonate, polypropylene carbonate), polydiene (including but not limited to polybutadiene, polyisoprene, polynorbornene), polyepoxide, polyester (including but not limited to polyethylene terephthalate, polybutylene terephthalate, polytrimethylene terephthalate, polycaprolactone, polyglycolide, polylactide, polyhydroxybutyrate, polyhydroxyvalerate, polyethylene adipate, polybutylene adipate, polypropylene succinate), polyether (including but not limited to polyethylene glycol (polyethylene oxide), polybutylene glycol, polypropylene oxide, polyoxymethylene (paraformaldehyde), polytetramethylene ether (polytetrahydrofuran), polyepichlorohydrin), polyfluorocarbon, formaldehyde polymer (including but not limited to urea - formaldehyde, melamine - formaldehyde, phenol formaldehyde), natural polymer (including but not limited to cellulosic, chitosan, lignin, wax), polyolefin (including but not limited to polyethylene, polypropylene, polybutylene, polybutene, polyoctene), polyphenylene (including but not limited to polyphenylene oxide, polyphenylene sulfide, polyphenylene ether sulfone), silicon - containing polymer (including but not limited to polydimethylsiloxane, polycarbomethylsilane), polyurethane, polyvinyl (including but not limited to polyvinyl butyral, polyvinyl alcohol, esters and ethers of polyvinyl alcohol, polyvinyl acetate, polystyrene, polymethylstyrene, polyvinyl chloride, polyvinyl pyrrolidone,fibers made from various polymers including, but not limited to, polymethyl vinyl ether, polyethyl vinyl ether, polyvinyl methyl ketone, polyacetal, polyarylate, and copolymers (including, but not limited to, polyethylene-co-vinyl acetate, polyethylene-co-acrylic acid, polybutylene terephthalate-co-polyethylene terephthalate, polylauryl lactam-block-polytetrahydrofuran), polybutylene succinate, and polylactic acid-based polymers.

[0063] In a specific embodiment, the synthetic fiber layer includes high dtex staple fibers in the range of 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 fiber can have a dtex value of about 6.7 dtex.

[0064] In other specific embodiments, the synthetic layer includes synthetic filaments. The synthetic filaments can be formed by a spinning and / or extrusion process. For example, such a process may be similar to the method described above for the melt spinning process. The synthetic filaments can include one or more continuous strands. In some embodiments, the synthetic filaments can include polypropylene.

[0065] staple fiber In certain embodiments, the nonwoven material of the present disclosure can include at least one layer comprising short fibers. The short fibers can provide high capillary action and increased distribution of liquids in the nonwoven material. Suitable short fibers 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. The short fibers can include fibers having a length of from about 1 mm to about 8 mm, from about 2 mm to about 8 mm, from about 3 mm to about 6 mm, or from about 5 mm to about 6 mm. In certain embodiments, the short 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 include short fibers. In certain embodiments, one or more layers of the nonwoven material can include short fibers of from about 5 gsm to about 150 gsm, from about 5 gsm to about 100 gsm, or from about 10 gsm to about 50 gsm. In certain embodiments, one or more layers can include about 15 gsm, about 30 gsm, about 75 gsm, or about 100 gsm of short fibers.

[0067] Long fibers In certain embodiments, the nonwoven material of the present disclosure can include at least one layer comprising long fibers. The long fibers can provide increased liquid collection of liquids in a relatively short time. Suitable long fibers for use in the nonwoven material of the present disclosure can include the regenerated cellulose fibers, synthetic fibers, and combinations thereof disclosed herein. The long fibers can include fibers having a length of from about 8 mm to about 70 mm, from about 10 mm to about 60 mm, from about 15 mm to about 50 mm, or from 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 include long fibers. In certain embodiments, one or more layers of the nonwoven material can include long fibers in an amount of from about 10 gsm to about 150 gsm, from about 10 gsm to about 100 gsm, from about 20 gsm to about 60 gsm, from about 25 gsm to about 50 gsm, or from about 30 gsm to about 35 gsm. In certain specific embodiments, the nonwoven material can include long fibers 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.

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

[0070] In certain embodiments, the nonwoven material can include at least one layer containing synthetic fibers formed as a card web in an amount of from about 10 gsm to about 150 gsm, from about 10 gsm to about 100 gsm, from about 20 gsm to about 60 gsm, from about 25 gsm to about 50 gsm, or from about 30 gsm to about 35 gsm. In certain specific embodiments, the nonwoven material can include at least one layer containing synthetic fibers as a card 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 one embodiment, the nonwoven material described herein can 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, urethane, urethane-based binders, acrylic binders, thermoplastic binders, natural polymer-based binders, and mixtures thereof.

[0072] Suitable binders include, but are not limited to, copolymers, 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 and other stabilizer-containing vinyl acetate ethylene ( "VAE") copolymers, polyvinyl alcohol-polyvinyl acetate blends such as Wacker Vinac 911, polyvinyl acetate homopolymers, polyvinylamines such as BASF Luredur, acrylic resins, cationic acrylamide, polyacrylamides such as Bercon Berstrength 5040 and Bercon Berstrength 5150, hydroxyethyl cellulose, starches such as National Starch CATO RTM 232, National Starch CATO RTM 255, National Starch Optibond, National Starch Optipro or National Starch OptiPLUS, guar gum, styrene-butadiene, urethane, urethane-based binders, thermoplastic binders, acrylic binders, and carboxymethyl cellulose such as Hercules Aqualon CMC. In certain embodiments, the binder is a natural polymer-based binder. Non-limiting examples of natural polymer-based binders include polymers derived from starch, cellulose, chitin, and other polysaccharides.

[0073] In certain 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 solids level of about 10% incorporating about 0.75% by weight of Aerosol OT (Cytec Industries, West Paterson, N.J.), which is an anionic surfactant. Other classes of liquid binders such as styrene-butadiene and acrylic binders can also be used. In certain 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, N.J.).

[0074] In certain embodiments, the binder is not water-soluble. Examples of such binders include, but are not limited to, Vinnapas 124 and 192 (Wacker), which can have opacifying and bleaching agents including, but not limited to, titanium dioxide dispersed in an emulsion. Other binders include, but are not limited to, Elite 22 and Elite 33 from Celanese Emulsions (Bridgewater, N.J.).

[0075] In certain 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 material is less than about 175°C. Examples of suitable thermoplastic materials include, but are not limited to, suspensions of thermoplastic binders and thermoplastic powders. In certain embodiments, the thermoplastic binder material 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 the WD4047 urethane binder solution supplied by HB Fuller. In one embodiment, the binder is the Michem Prime 4983-45N dispersion of ethylene acrylic acid ("EAA") supplied by Michelman. In some embodiments, the binder is the Dur-O-Set Elite 22LV emulsion of a VAE binder supplied by Celanese Emulsions (Bridgewater, N.J.). As noted above, in certain embodiments, the binder is crosslinkable. It is also 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, N.J.), Wacker Vinnapas or AF192 (Wacker Chemie AG, Munich, Germany), and the like. Various permanent wet strength agents are described in U.S. Patent No. 2,345,543, U.S. Patent No. 2,926,116, and U.S. Patent No. 2,926,154, the disclosures of which are hereby incorporated by reference in their entirety. Other permanent wet strength binders include, but are not limited to, polyamine-epichlorohydrin, polyamide epichlorohydrin, or polyamide-amine epichlorohydrin resins, which are collectively referred to as "PAE resins." Non-limiting exemplary permanent wet strength binders include Kymene 557H or Kymene 557LX (Hercules Inc., Wilmington, DE), described in U.S. Patent No. 3,700,623 and U.S. Patent No. 3,772,076, which are hereby incorporated by reference in their entirety.

[0077] Alternatively, in certain embodiments, the binder is a temporary wet strength binder. Examples of temporary wet strength binders include, but are not limited to, Hercobond® (Hercules Inc., Wilmington, Del.), Parez® 750 (American Cyanamid Company, Wayne, N.J.), Parez® 745 (American Cyanamid Company, Wayne, N.J.). 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. Patent Nos. 3,556,932, 5,466,337, 3,556,933, 4,605,702, 4,603,176, 5,935,383, and 6,017,417, all of which are incorporated herein by reference in their entirety.

[0078] In certain embodiments, the binder can be applied as an emulsion in an amount in the range of 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. The binder can be applied to one side of the fibrous layer, preferably the outer-facing layer. Alternatively, the binder can be applied in equal or disproportionate amounts to both sides of the layer. In certain embodiments, the binder can be applied to at least one outer surface of the nonwoven material.

[0079] Other additives The materials of the subject matter of the present disclosure can also include other additives. For example, the materials can include superabsorbent polymers (SAP). Types of superabsorbent polymers that may be used in the subject matter of the present disclosure include granular forms of SAP such as powders, irregular granules, spherical particles, staple fibers, and other elongated particles, but are not limited thereto. In certain embodiments, the materials can include superabsorbent fibers (SAF; manufactured by Technical Absorbents Limited, 9 dtex, 5.8 mm). U.S. Patent No. 5,147,343, U.S. Patent No. 5,378,528, U.S. Patent No. 5,795,439, U.S. Patent No. 5,807,916, U.S. Patent No. 5,849,211, and U.S. Patent No. 6,403,857 are hereby incorporated by reference in their entirety and describe various superabsorbent polymers and methods for manufacturing superabsorbent polymers. An example of a superabsorbent polymer forming system is a crosslinked acrylic copolymer of a metal salt of acrylic acid and other monomers such as acrylamide or 2-acrylamido-2-methylpropanesulfonic acid. Many conventional granular superabsorbent polymers are based on poly(acrylic acid) crosslinked with any of several polyfunctional comonomer crosslinking agents well known in the art during polymerization. Examples of polyfunctional crosslinking agents are described in U.S. Patent No. 2,929,154, U.S. Patent No. 3,224,986, U.S. Patent No. 3,332,909, and U.S. Patent No. 4,076,673, which are hereby incorporated by reference in their entirety. For example, crosslinked carboxylated polyelectrolytes can be used to form superabsorbent polymers. It is known that other water-soluble polyelectrolyte polymers are useful in the preparation of superabsorbents by crosslinking, and examples of these polymers include carboxymethyldextran, carboxymethylcellulose, chitosan salts, gelatin salts, and the like. However, they are generally not used on a commercial scale to enhance the absorbency of disposable absorbent articles mainly due to their relatively high cost.Superabsorbent polymer particles useful in the practice of the present subject matter are commercially available from several manufacturers, such as BASF, Dow Chemical (Midland, Mich.), Stockhausen (Greensboro, N.C.), 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 can 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 can be biodegradable. In some embodiments, the SAP can include high-capacity SAP, high-speed SAP, or combinations thereof. Specific examples of high-capacity SAPs include K-Boost (XGF-450, manufactured by Como Cascades LLC (Beavertown, OR)). Specific examples of high-speed SAPs include K-Boost (XGF-463, manufactured by Como Cascades EEC (Beavertown, OR)).

[0081] In certain embodiments, the SAP can be used in the layer in an amount in the range of about 5% to about 50% based on the total mass of the structure. In certain 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 mass of the structure. In certain 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 mass of the structure. In certain embodiments, the amount of SAP in the layer can be in the range of about 5 gsm to about 50 gsm, about 5 gsm to about 25 gsm, about 10 gsm to about 50 gsm, or about 12 gsm to about 40 gsm, or about 15 gsm to about 25 gsm. In certain specific embodiments, the SAP can be used in the layer in an amount of about 10 gsm or about 20 gsm.

[0082] Nonwoven material The subject matter of the present disclosure provides an improved nonwoven material having several advantages over various commercially available materials. The materials of the present disclosure have been achieved with improved overall absorption performance in terms of liquid trapping, distribution, and rewetting compared to conventional materials that include higher content synthetic materials such as superabsorbent polymers (SAP). Thus, advantageously, the nonwoven materials of the present disclosure, which contain less amounts of synthetic additives, provide increased absorption performance. In certain aspects, the materials of the present disclosure have the ability to significantly reduce absorbent substances and achieve comparable or improved overall absorption performance. Absorption performance is measured by increased fluid trapping or improved drying characteristics while maintaining a low basis weight relative to commercially available products. Further, the nonwoven materials of the present disclosure reduce the amount of synthetic materials such as SAP compared to various commercially available materials.

[0083] The disclosed nonwoven materials containing various components can be used in absorbent systems. In certain embodiments, the nonwoven materials of the present disclosure can be used as an absorbent core in absorbent systems, such as personal care products like light incontinence products, and feminine hygiene products like panty liners. Such an absorbent core can have a specific multilayer structure that includes a layer of stiff fibers, such as bonded microcellulosic fibers like eucalyptus fibers. The structure can further include a layer of bonded coarse cellulosic fibers, such as softwood fibers. Optionally, the structure can further include a superabsorbent polymer (SAP). When combined with a conventional acquisition distribution layer (ADL), such as a card layer, such nonwoven materials can exhibit improved performance in terms of liquid acquisition, distribution, and rewetting compared to conventional absorbent cores having a higher SAP content. In certain embodiments, the nonwoven materials of the present disclosure can be used as an acquisition distribution layer (ADL) in absorbent systems, such as personal care products like 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 a sufficient dry state compared to other nonwovens, such as carding materials using longer (i.e., between about 8 mm and about 70 mm) synthetic fibers. However, as described above, card webs with longer fibers are generally more elastic than conventional airlaid webs, and nonwovens containing longer fibers generally do not have acceptable liquid distribution and storage properties. In certain embodiments, the nonwoven materials of the present disclosure provide the absorbent characteristics of a fibrous network of bonded long fibers and have either bonded short fibers containing superabsorbent polymers embedded in the form of powders (SAP) or fibers (SAF) or a network of bonded short fibers. Such nonwoven materials surprisingly and advantageously increase liquid storage and distribution performance. In certain embodiments, the nonwoven materials of the present disclosure provide an integrated multilayer hybrid liquid acquisition distribution (ADL) material with increased fluid absorption and rewetting performance compared to conventional airlaid. Such a structure combines a bonded card web with one or more layers of an airlaid web with a specific configuration and fiber content.Other aspects of the present disclosure provide an integrated multi-functional hybrid absorbent structure with improved liquid collection, distribution, storage, and rewetting characteristics. In addition to a layer of longer bonded fibers that provide faster fluid uptake and increased rewetting 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 microcellulosic fibers such as hardwood fibers, e.g., eucalyptus fibers. Such nonwoven materials surprisingly and advantageously provide increased liquid collection, distribution, storage, and rewetting characteristics while allowing for a reduced basis weight of the absorbent system and the use of less synthetic materials such as SAP compared to conventional multi-component absorbent systems that include separate conventional acquisition distribution layer (ADL) materials and liquid storage absorbent components.

[0084] The subject matter of the present disclosure provides a nonwoven material. In certain embodiments, the nonwoven material includes at least 2 layers, at least 3 layers, or at least 4 layers.

[0085] In certain embodiments, the nonwoven material can include at least 2 layers, each layer including a specific fiber 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 in part on their outer surfaces using a binder. In certain embodiments, the synthetic fibers can include bicomponent fibers. In certain embodiments, the cellulose fibers of the second layer can include microcellulose fibers. In certain embodiments, the cellulose fibers of the second layer can include eucalyptus pulp.

[0086] In one embodiment, the nonwoven material can include a first layer containing long fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can contain short fibers. The second layer can be bonded at least in part on its outer surface using a binder. In one embodiment, the long fibers can include synthetic fibers. In a particular embodiment, the long fibers can include synthetic fibers formed as a card web. In one embodiment, the short fibers can include cellulose fibers.

[0087] In one embodiment, the nonwoven material can include at least three layers, each layer containing a specific fiber content. In a particular embodiment, the nonwoven material may be a three-layer nonwoven structure. The nonwoven material can include a first layer containing cellulose fibers and synthetic fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can contain a superabsorbent polymer (SAP). The nonwoven material can further include a third layer adjacent to the second layer. The third layer can contain cellulose fibers and synthetic fibers. The first and third layers can be bonded at least in part on their outer surfaces using a binder. In one embodiment, the synthetic fibers can include bicomponent fibers. In one embodiment, the cellulose fibers of the third layer can include microcrystalline cellulose fibers. In a particular embodiment, the cellulose fibers of the third layer can include eucalyptus pulp.

[0088] In one embodiment, the nonwoven material can include a first layer containing long fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can contain short fibers. The nonwoven material can further include a third layer adjacent to the second layer. The third layer can contain short fibers. The third layer can be bonded at least in part on its outer surface using a binder. In one embodiment, the long fibers can include synthetic fibers. In a particular embodiment, the long fibers can include synthetic fibers formed as a card web. In one embodiment, the short fibers of the second and third layers can include a blend of short fibers. For example, without limitation, the short fibers of the second and third layers can include synthetic fibers and cellulose fibers. In one embodiment, the synthetic fibers of the second and third layers can include bicomponent fibers. In one embodiment, the cellulose fibers of the third layer can include eucalyptus pulp.

[0089] In one embodiment, the nonwoven material can include at least four layers, each layer including a specific fiber content. In a particular embodiment, the nonwoven material can be a four-layer nonwoven structure. The nonwoven material can include a first layer containing cellulose fibers and synthetic fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can contain cellulose fibers and synthetic fibers. The nonwoven material can further include a third layer adjacent to the second layer. The third layer can contain a superabsorbent polymer (SAP). The nonwoven material can further include a fourth layer adjacent to the third layer. The fourth layer can contain cellulose fibers and synthetic fibers. The first and fourth layers can be bonded at least in part on their outer surfaces using a binder. In one embodiment, the synthetic fibers can include bicomponent fibers. In one embodiment, the cellulose fibers of the fourth layer can include microcrystalline cellulose fibers. In a particular embodiment, the cellulose fibers of the fourth layer can include eucalyptus pulp.

[0090] In one embodiment, the nonwoven material can include a first layer containing long fibers. The nonwoven material can further include a second layer adjacent to the first layer. The second layer can contain short fibers. The nonwoven material can further include a third layer adjacent to the second layer. The third layer can contain additional additives such as superabsorbent polymer (SAP). The nonwoven material can further include a fourth layer adjacent to the third layer. The fourth layer can contain short fibers. The fourth layer can be bonded at least in part on its outer surface using a binder. In one embodiment, the long fibers of the first layer can include synthetic fibers. In a particular embodiment, the long fibers of the first layer can include synthetic fibers formed as a card web. In one embodiment, the short fibers of the second and fourth layers can include a blend of short fibers. For example, without limitation, the short fibers of the second and fourth layers can include synthetic fibers and cellulose fibers. In one embodiment, the synthetic fibers of the second and fourth layers can include bicomponent fibers. In one embodiment, the cellulose fibers of the fourth layer can 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, and each layer includes a specific fiber content. In one embodiment, the first layer can include a blend of cellulose fibers and synthetic fibers. In one embodiment, the synthetic fibers of 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 a particular embodiment, the first layer can include about 25 gsm, about 30 gsm, about 40 gsm, about 54 gsm, about 62 gsm, or about 70 gsm of cellulose 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 a particular embodiment, the first layer can include about 12 gsm, about 21 gsm, about 25 gsm, or about 30 gsm of synthetic fibers.

[0092] In certain embodiments, the first layer can include long fibers in an amount of from about 20 gsm to about 60 gsm, from about 25 gsm to about 50 gsm, or from about 30 gsm to about 35 gsm. In certain embodiments, the first layer can include 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 certain embodiments, the first layer can include synthetic fibers formed as a card web in an amount of from about 20 gsm to about 60 gsm, from about 25 gsm to about 50 gsm, or from about 30 gsm to about 35 gsm. In certain embodiments, the first layer can include synthetic fibers formed as a card 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 certain embodiments, the nonwoven material can include a second layer. The second layer can include a blend of cellulose fibers and synthetic fibers. In certain 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 from about 5 gsm to about 70 gsm, from about 10 gsm to about 65 gsm, or from about 15 gsm to about 50 gsm. In certain embodiments, the second layer can include cellulose fibers in an amount 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 from about 15 gsm to about 40 gsm, from about 20 gsm to about 35 gsm, or from about 25 gsm to about 35 gsm. In certain embodiments, the second layer can include synthetic fibers in an amount 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, without limitation, the second layer can include a superabsorbent polymer (SAP) in an amount of from about 5 gsm to about 30 gsm, from about 15 gsm to about 25 gsm, or from about 10 gsm to about 20 gsm. In certain embodiments, the second layer can include a superabsorbent polymer (SAP) in an amount of about 10 gsm or about 20 gsm.

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

[0095] In certain embodiments, the nonwoven material can include a third layer. The third layer can include a superabsorbent polymer (SAP). Alternatively, in certain 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 certain 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 from about 5 gsm to about 70 gsm, from about 10 gsm to about 65 gsm, or from 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 of cellulose fibers. The synthetic fibers can be present in the third layer in an amount of from about 15 gsm to about 40 gsm, from about 20 gsm to about 35 gsm, or from 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 an alternative embodiment, the third layer can include a superabsorbent polymer (SAP). For example, but not by way of limitation, the third layer can include a superabsorbent polymer (SAP) in an amount of from about 5 gsm to about 30 gsm, from about 15 gsm to about 25 gsm, or from about 10 gsm to about 20 gsm. In certain embodiments, the third layer can include about 10 gsm or about 20 gsm of superabsorbent polymer (SAP).

[0096] In certain embodiments, the nonwoven material can include a third layer. The third layer can include short fibers. In certain embodiments, the third layer can include a blend of synthetic fibers such as cellulose fibers and bicomponent fibers. In certain embodiments, the cellulose fibers of the third layer can include fine cellulose fibers such as eucalyptus pulp. In certain embodiments, the third layer can include short fibers in an amount from about 5 gsm to about 100 gsm, from about 10 gsm to about 80 gsm, or from about 15 gsm to about 75 gsm. In certain embodiments, the third layer can include short fibers of about 50 gsm, about 55 gsm, about 70 gsm, or about 75 gsm. The cellulose fibers can be present in the third layer in an amount from about 5 gsm to about 70 gsm, from about 10 gsm to about 65 gsm, or from 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 of cellulose fibers. The synthetic fibers can be present in the third layer in an amount from about 15 gsm to about 40 gsm, from about 20 gsm to about 35 gsm, or from 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, without limitation, the third layer can include a superabsorbent polymer (SAP) in an amount from about 5 gsm to about 30 gsm, from about 15 gsm to about 25 gsm, or from about 10 gsm to about 20 gsm. In certain embodiments, the third layer can include about 10 gsm or about 20 gsm of superabsorbent polymer (SAP).

[0097] In certain 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 certain 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 from about 5 gsm to about 70 gsm, from about 10 gsm to about 65 gsm, or from about 15 gsm to about 50 gsm. In certain embodiments, the fourth layer can include about 25 gsm, about 35 gsm, about 50 gsm, or 62 gsm of cellulose fibers. The synthetic fibers can be present in the fourth layer in an amount of from about 15 gsm to about 40 gsm, from about 20 gsm to about 35 gsm, or from about 25 gsm to about 35 gsm. In certain embodiments, the fourth layer can include about 8 gsm, about 15 gsm, about 20 gsm, or about 25 gsm of synthetic fibers.

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

[0099] In certain embodiments, at least one outer surface of the nonwoven material can be coated using a binder. The binder can be applied as an emulsion in an amount in the range of 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 specific 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 and distribution layer In another aspect, the subject matter of the present disclosure provides an absorbent core including at least one layer adjacent to a collection and distribution layer, such as a multi-layer nonwoven material. In one aspect, the subject matter of the present disclosure provides a collection and distribution layer (ADL) including at least one layer adjacent to an absorbent core, such as a multi-layer nonwoven material. Such nonwoven materials of the present disclosure, including various other materials, can be used to provide an absorbent system. The hybrid system of the present disclosure can include a collection and distribution layer bonded to the core, and in this way, both the collection layer and the core can be provided in a single structured hybrid system.

[0101] The nonwoven material of the present disclosure as an absorbent core in an absorbent system including a collection and distribution layer such as a card layer also has improved performance compared to conventional absorbent cores with a higher SAP content in terms of liquid collection, distribution, and rewetting. In certain embodiments, the nonwoven material of the present disclosure can be used in an absorbent system including a topsheet. In certain embodiments, the nonwoven material of the present disclosure as an absorbent core 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 material of the present disclosure as a collection and distribution layer in an absorbent system including an absorbent core provides a hybrid absorbent structure with improved liquid collection, distribution, and storage properties in a single integrated structure. In certain 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 certain specific embodiments, the absorbent system can have a total basis weight of about 214 gsm, about 218 gsm, or about 221 gsm.

[0103] Features of the nonwoven material The nonwoven materials of the present disclosure are capable of improving 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. Further, when the nonwoven material includes an absorbent core and / or a collection and distribution layer, the material is capable of improving fluid collection characteristics. Further, the nonwoven materials of the subject matter of the present disclosure can quickly absorb fluids. The use of bicomponent fibers in the nonwoven materials of the present disclosure can provide a shorter collection time. Further, the use of fine cellulose fibers such as eucalyptus pulp in the bottommost layer of the nonwoven material improves liquid distribution. Such fine cellulose fibers can also provide increased fluid retention and thus low rewetting.

[0104] In certain embodiments, a nonwoven material as described above 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 material 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 the material to absorb the fluid can be referred to as the "collection time". By way of example and not limitation, the collection time can be measured using the procedures described in Examples 2, 4, and 6 below. Further, the nonwoven materials of the present disclosure can collect and hold more liquid before leakage occurs. In certain embodiments, the nonwoven material can collect and hold at least about 4.0 g, at least about 3.5 g or at least 3.0 g before liquid leakage.

[0105] Furthermore, the nonwoven material of the present disclosure can improve drying characteristics and exhibits improved fluid retention. For example, after absorbing fluid, the amount of fluid released by squeezing the nonwoven material can be measured. In certain embodiments, a rewetting test or a humidity sensation test can be used to squeeze the nonwoven material as described in the various examples below and measure the released fluid. In certain 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 specific embodiments, less than about 2.8 g, less than about 0.11 g or less than about 0.05 g is released. The nonwoven material of the present disclosure contains no SAP at all or contains a relatively small amount, and even with a lower basis weight compared to conventional products, the rewetting performance is improved.

[0106] The nonwoven material of the present disclosure can improve liquid distribution characteristics. In certain embodiments, the nonwoven material can provide a longer wicking distance compared to conventional products, providing a drier feel and increased comfort to the end user from a dry state perspective. A longer wicking distance provides, for example, increased utilization of the absorbent material in a personal hygiene product during use. In certain embodiments, the nonwoven material of the present disclosure can have a wicking distance of from about 80 mm to about 200 mm, from about 80 mm to about 160 mm, from about 90 mm to about 150 mm or from about 100 to about 125 mm. In specific embodiments, the nonwoven material 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 certain embodiments of the subject matter of the present disclosure, at least a portion of at least one outer layer is coated with a binder. In particular embodiments of the subject matter of the present disclosure, at least a portion of each outer layer is coated with a binder. In certain embodiments, the first and third layers are coated with a binder in an amount in the range of 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 certain 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 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 certain 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 the nonwoven material refers to the caliper of the entire nonwoven material including all layers. In certain 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 manufacturing a nonwoven material To assemble the materials used in the practice of the subject matter of the present disclosure for manufacturing a material, various methods can be used including traditional dry forming methods such as air laying and carding, or other forming techniques such as spunlace or air-jet, but not limited thereto. Preferably, the material can be prepared by the airlaid method. The airlaid method 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 for producing a product having separate layers. This enables a great versatility of various products that can be manufactured

[0111] In one embodiment, this material is prepared as a continuous airlaid web. The airlaid web is typically prepared by shredding or defibrating a sheet of cellulose pulp, typically by a hammer mill, to yield individualized fibers. Instead of a pulp sheet of virgin fibers, recycled airlaid edge trimmings, as well as off-specification transitional materials resulting from grade changes and other airlaid manufacturing waste, can be fed to a hammer mill or other shredder. The ability to recycle manufacturing waste in this way contributes to an improvement in the economics of the overall process. Next, the individualized fibers, whether from virgin, recycled, or any source, are pneumatically conveyed to the forming head of an airlaid web former. Several manufacturers, including Dan-Web Forming of Aarhus, Denmark, M&J Fibretech A / S of Horsens, Denmark, Rando Machine Corporation, Macedon, N.Y. (which is described in U.S. Patent No. 3,972,092), Margasa Textile Machinery of Cerdanyola del Valles, Spain, and DOA International of Weis, Austria, manufacture airlaid web formers suitable for use in the subject matter of this disclosure. Many of these formers differ in the way they open the fibers and pneumatically convey them to the forming wire, but they are all capable of manufacturing the webs of the subject matter of this disclosure. The Dan-Web forming head includes a rotating or oscillating perforated drum, which helps maintain the separation of the fibers until they are drawn by vacuum onto a perforated forming conveyor or forming wire. In the M&J machine, the forming head is basically a rotary oscillator over a screen. The rotary oscillator may be provided with a series or group of rotating propellers or fan blades. Other fibers, such as synthetic thermoplastic fibers, are opened, weighed, and mixed in a fiber dosing system such as a textile feeder supplied by Laroche S.A. of Cours-La Ville, France. In certain embodiments, such an airlaid machine can be equipped with a customized forming head, or a head capable of layer individualized long fibers.From a textile feeder, the fibers are pneumatically conveyed to the forming head of an airlaid machine where they are further mixed with comminuted cellulose pulp fibers from a hammer mill and deposited onto a continuously moving forming wire. If a defined layer is desired, separate forming heads may be used for each type of fiber. Alternatively or additionally, if so desired, one or more layers can be pre-made before combining with additional layers.

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

[0113] In one aspect, the nonwoven materials of the present disclosure comprising at least one layer containing long fibers and at least one layer containing short fibers can be prepared according to various methods. In one embodiment, at least one layer of short fibers can be airlaid onto at least one layer containing long fibers. In certain embodiments, the long fibers can be formed into a card web. Thus, the nonwoven material can have a structure comprising another layer of long fibers bonded to one 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 place long fibers on top of a layer containing short fibers.

[0114] Uses and End Uses The nonwoven material of the subject matter of the present disclosure can be used for any application known in the art. For example, in various absorbent articles, the nonwoven material can be used alone or as a component, for example, as an absorbent core and / or a collection and distribution layer (ADL). In certain embodiments, the nonwoven material can be used in absorbent articles that absorb and retain body fluids. Such absorbent articles include baby diapers, adult incontinence products, light incontinence products and panty liners, feminine hygiene products such as sanitary napkins, and the like.

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

Examples

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

[0117] (Example 1) Absorbent Structure This example provides an absorbent structure that can provide improved collection, distribution, and storage functions. The absorbent structure can be used as a component of an absorbent core, for example, in personal hygiene products.

[0118] Structure B was a nonwoven substrate containing a multilayer core structure to provide permanent storage with the use of superabsorbent polymer (SAP). Structure B was formed on Danweb's airlaid production line. The first layer contained 12 gsm of bicomponent fiber (Trevira, 70% PE / PET core, 1.7 dtex, 6 mm) blended with 25 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully processed pulp, Leaf River). The next layer contained 25 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully processed pulp, Leaf River) blended with 12 gsm of bicomponent fiber (Trevira, 70% PE / PET 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, 70% PE / PET core, 1.7 dtex, 6 mm). A polymer binder of 5 gsm (by dry mass) in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) was sprayed on each of the eucalyptus layer and the outer fluff layer. 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] The structure C was a nonwoven substrate containing a multilayer core structure for providing permanent storage through the use of superabsorbent polymer (SAP). The 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 the 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 cellulose fiber (Georgia-Pacific, GP 4723, fully processed 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 polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The total basis weight of the structure C was 175 gsm. The structure C contained approximately 5.7% SAP.

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

[0123]

Table 4

[0124] The structure D was a nonwoven substrate containing a multilayer core structure for permanent storage. The 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 fibers (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 fibers (Georgia-Pacific, GP 4723, fully processed pulp) blended with 27 gsm of bicomponent fibers (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The top and bottom layers were sprayed with 4 gsm (by dry weight) of a polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The basis weight of the structure D was 175 gsm. The structure D did not contain SAP.

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

[0126]

Table 5

[0127] The structure F was a nonwoven substrate containing a multilayer core structure for providing permanent storage with the use of superabsorbent polymer (SAP). The 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 the 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 cellulose fiber (Georgia-Pacific, GP 4723, fully processed pulp) blended with 21 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The top and bottom layers were sprayed with 5 gsm (by dry mass) of polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The basis weight of the structure F was 175 gsm. The structure F contained approximately 11.5% SAP.

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

[0129]

Table 6

[0130] The structure H was a nonwoven substrate containing a multilayer core structure for providing permanent storage with the use of superabsorbent polymer (SAP). The 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, manufactured by 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 processed 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 mass) of a polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The basis weight of the structure H was 175 gsm. The structure H contained approximately 5.7% SAP.

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

[0132]

Table 7

[0133] Structure I was a nonwoven substrate containing a multilayer core structure to provide permanent storage through the use 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 the forming wire. The next layer contained 20 gsm of starch-based SAP 1, K-Boost (XGF-450, manufactured by 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 processed pulp) blended with 21 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The top and bottom layers were sprayed with 5 gsm (by dry weight) of polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The basis weight of Structure I was 175 gsm. Structure I contained approximately 11.5% SAP.

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

[0135]

Table 8

[0136] The structure J was a nonwoven substrate containing a multilayer core structure for providing permanent storage with the use of superabsorbent polymer (SAP). The structure J was formed on a Danweb airlaid pilot line. The first layer included 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 included 10 gsm of starch-based SAP 2, K-Boost (XGF-450, manufactured by Como Cascades LLC (Beavertown, OR)) applied on top of the previous layer. The next layer included 62 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully processed 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 mass) of a polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The basis weight of the structure J was 175 gsm. The structure J contained approximately 5.7% SAP.

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

[0138]

Table 9

[0139] The structure K was a nonwoven substrate containing a multilayer core structure to provide permanent storage using superabsorbent polymer (SAP). The 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, manufactured by 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 processed pulp) blended with 21 gsm of bicomponent fiber (Trevira, PE / PET 70% core, 1.7 dtex, 6 mm). The top and bottom layers were sprayed with 5 gsm (by dry mass) of a polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The basis weight of the structure K was 175 gsm. The structure K contained approximately 11.5% SAP.

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

[0141]

Table 10

[0142] (Example 2) Female sanitary napkin application - effective collection time, rewetting, retention before leakage, and uptake (structures B-D, F, and H-K) In female sanitary napkin applications, structures B-D, F, and H-K were tested for effective collection time, rewetting, retention before leakage, and liquid uptake characteristics as absorbent cores in combination with a commercially available collection and distribution layer (structure G), compared to commercially available absorbent cores (structures A and E).

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

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

[0145] Structural body G was a commercially available collection and distribution layer. Structural body G was a 34 gsm card web (Shalag Nonwovens, TABCW, product code STACT8H34) containing polyester fibers. Structural body G provided the ADL component of the absorbent system being tested. Each of the composites or articles being tested included the top and bottom layers which were structural body G.

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

[0147] The test apparatus included a 29.2 cm × 19.1 cm × 0.6 cm rigid plastic plate with a cut hole of 1.9 cm inner diameter in the center. A weighed stainless steel cylinder with an inner diameter of 1.9 cm was placed on top of the hole. The cylinder had a height of 5.1 cm, and the completed apparatus had a total height of 5.7 cm and a total mass of 747.3 g.

[0148] A prepared composite material or article (6.5 cm × 20.5 cm or 6.5 cm × 21.5 cm) containing a sample combined with a capture distribution layer was compressed at 4 bar with a roller press to simulate the stress of the conversion process. Using 4 mL of synthetic blood, it was discharged onto the composite material or article at a rate of 10 mL / min according to the test to be performed. The collection time from the start of discharge was measured until the synthetic blood was no longer visible in the discharge cylinder. A total of three discharges were performed to obtain collection times #1, #2, and #3. The time interval between discharges 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 injection time (IT), which was 24 seconds (i.e., the time it takes for all of the liquid (in this case 4 mL) to be delivered to the absorbent system being tested).

[0149] After measuring the three collection times, the rewetting characteristics of each material were analyzed. After measuring the third collection time, three square plies (10.1 cm × 10.1 cm) of pre-weighed collagen (Coffi collagen, Viscofan, USA) were placed on the composite material or article to be tested. A thin plexiglass plate and a weight were placed on the collagen ply for 1 minute. The plexiglass and the weight applied a total pressure of 1.7 kPa. The collagen ply was weighed to determine the rewetting results. The result of each test was the average of three measurements.

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

[0151] Figures 1 and 2 show a comparison of the effective collection time and rewetting for structures B, C, and D with commercially available cores (structures A and E), respectively. Figures 3 and 4 show structures B, C, and D with improved performance over either of the commercially available cores (structures A and E). Without being bound by a particular theory, it is hypothesized that the bottom layer of structures B, C, and D has a higher capillary pressure than the top layer of these structures, can efficiently distribute liquid from the discharge location, thereby leaving sufficient void volume to accept more liquid, and in this way enables better utilization of the absorbent core. The high capillary pressure of these layers can also enable the retention of liquid away from the surface of the core and the collection and distribution layer components of the absorbent system that includes the experimental cores (structures B, C, and D). This results in low rewetting as shown in Figure 2.

[0152] As shown in Figure 1, the absorbent system that includes the experimental cores (structures B, C, and D) can collect liquid significantly faster than the absorbent systems that include commercially available cores (structures A and E). This results in a shorter effective collection time as shown in Figure 1. The results of Figure 1 show that absorbent systems that include experimental cores (structures B, C, and D) that contain relatively small amounts of SAP or no SAP (about 11.5%, about 5.7%, and 0%, respectively) had improved performance compared to commercially available control absorbent cores (20% and 30% SAP) that have a similar or higher total basis weight. Structures B, C, and D contain fewer synthetic components than conventional absorbent cores, are more economical, and yet showed improved performance.

[0153] Figures 3 and 4 show a comparison of the effective collection time and rewetting for structures C, D, F, H, I, J, and K with a commercially available core (structure A), respectively. Figures 3 and 4 show that structures C, D, F, H, I, J, and K have improved performance compared to the commercially available core (structure A). Without being bound by theory, it is hypothesized that the bottom layer of structures C, D, F, H, I, J, and K has a higher capillary pressure than the top layer of these structures, can efficiently distribute the liquid from the discharge location, thereby leaving sufficient void volume to receive more liquid, and in this way enables better utilization of the absorbent core. The high capillary pressure of these layers can also keep the liquid away from the surface of the core and the collection and distribution layer components of the absorbent system including the experimental cores (structures C, D, F, H, I, J, and K). This gives a low rewetting as shown in Figure 4. Thus, a low rewetting as shown in Figure 4 is provided.

[0154] The results in Figure 3 show that the absorbent systems (structures C, D, F, H, I, J, and K) including the experimental cores can collect liquid significantly faster than the absorbent systems (structure A) including the commercially available core. The results in Figure 3 show absorbent systems including experimental cores (structures C, D, F, H, I, J, and K) containing a relatively small amount of SAP or no SAP (about 11.5%, about 5.7%, and 0%, respectively) compared to a commercially available control absorbent core (20% SAP) having a similar basis weight. Structures C, D, F, H, I, J contain a smaller amount of synthetic components than conventional absorbent cores, are economical, and show improved performance.

[0155] Retention force and wicking distance tests before leakage Samples were tested for fluid retention and distributability. The liquid collection characteristics of each structure were measured using a synthetic blood solution to test the retention force and suction distance before leakage. Synthetic blood from Johnson, Moen & Co., Inc. (Rochester, MN) (Lot#201141; February 2014) was used. The synthetic blood had a surface tension of 40 - 44 mN / m (ASTM F23.40 - F1670) and 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 formulation agents.

[0156] The test apparatus included a mesh net (5 / 8"×5 / 8" mesh) hung on a test bench sized 30.5 cm×15.2 cm. The mesh net was placed 12.7 cm lower in the center for level comparison. Synthetic blood was administered by a peristaltic pump at a rate of 10 mL / min and dropped 7.6 cm before landing on the test substrate. A droplet receiver was prepared directly under the sample under the mesh net to receive the synthetic blood, which was taken as the end point of the test. A schematic depiction of the test apparatus is shown in Figure 5.

[0157] Samples were cut to a standard size of 20.3 cm×6.4 cm and measured for initial thickness and basis weight. If the sample had a backsheet and passed through the conversion process, the sample was tested directly. Samples without a backsheet had a 0.7 mm plastic sheet pasted on the back of the sample. A plastic sheet was cut to the same size as the sample (20.3 cm×6.4 cm). Adhesive was applied along two lines approximately 1.3 cm from each long side on the back of the sample. Then, a 0.7 mm plastic sheet was applied to the back of the sample. The plastic sheet was gently pushed down onto the adhesive to ensure that the collection characteristics were not changed before compression.

[0158] The untransformed samples were compressed using a roller press at a pressure of 4 bar to simulate the pressure to be transformed. After compressing the samples, the thickness of the samples was measured and the samples were tested. The peristaltic pump was set to 10 mL / min, and a 10 mL graduated cylinder and a timer were used to verify the output. A droplet receiver was placed under the mesh net to receive leakage.

[0159] The sample was placed directly under the mesh net using the back plate. The long side of the sample was parallel to the long side of the mesh net. The peristaltic pump line was installed 3 inches above the sample and centered such that the synthetic blood dripped directly onto the sample. The peristaltic pump was activated and the timer was started as soon as the first droplet of synthetic blood landed on the sample. The timer was stopped as soon as the first droplet of synthetic blood dripped from the sample into the droplet receiver. The peristaltic pump was stopped, the time was recorded in seconds, and the suction distance was measured. The suction distance was measured at the bottom of the sample, which was a measure of liquid distribution (mm). The results of each test were the results of three measurements.

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

[0161] Figures 6A-C provide the test results of the holding force before leakage compared to a commercially available core. Figure 6A provides the results of the holding force before leakage of Structure B. Figure 6B provides the results of the holding force before leakage of Structures C, H, and I. Figure 6C provides the results of the holding force before leakage of Structures F, J, and K. The data in Figures 6A-C indicate that the experimental structures B, C, D, F, H, I, J, and K have better performance than the commercially available cores (Structures A and E). Without being bound by theory, it is hypothesized that the bottom layer of the experimental structures has a higher capillary pressure than the top layer of these structures, can efficiently distribute the liquid from the discharge location, thereby leaving sufficient void volume to accept more liquid, and thus enables better utilization of the absorbent core. The high capillary pressure of these layers can also enable the retention of liquid away from the surface of the core. The results in Figures 6A-C suggest that the experimental cores can collect more liquid. The results in Figures 6A-C further suggest that the experimental cores can provide a structure that can hold more liquid compared to an absorbent system including commercially available cores (Structures A and E) before leakage occurs. Structures B, C, D, F, H, I, J, which have a relatively small amount of SAP compared to the commercially available control absorbent core, have improved performance, contain fewer synthetic components, and are more economical than conventional absorbent cores. In particular, Structures H, I, J, and K each have a very low synthetic component content since these structures each contain a biodegradable starch-based SAP.

[0162] Figures 7A-C provide the suction test results as compared to commercially available cores (Structures A and E). Figure 7A provides the suction test results of Structure B. Figure 7B provides the suction test results of Structures C, H, and I. Figure 7C provides the suction test results of Structures F, J, and K. The data in Figures 7A-C indicate that the experimental Structures B, C, F, H, I, J, and K have improved performance over the commercially available cores (Structures A and E). Without being bound by theory, it is hypothesized that the bottom layer of the experimental structures has a higher capillary pressure than the top layer of these structures, can efficiently distribute liquid from the discharge location, thereby leaving sufficient void volume to accept more liquid, and thus enables better utilization of the absorbent core. The high capillary pressure of these layers also enables holding liquid away from the surface of the core. The results in Figures 7A-C suggest that liquid can be distributed further from the discharge location in the experimental cores than in the case of systems including commercially available cores (Structures A and E).

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

[0164] Structural body 1A was an integral type of two-sided hybrid nonwoven material. When used as a collection and distribution layer (ADL), the top layer contained a synthetic nonwoven component, and the bottom layer contained cellulose fibers bonded with a latex binder. The structural body 1A was formed using an experimental pad forming machine. The structural body 1A was formed by placing an amount of 18.0 gsm of cellulose fibers (Georgia-Pacific, GP 4723, fully processed pulp, Leaf River) on a layer of 34 gsm air-permeable bonded card nonwoven web (Shalag Nonwovens, product code STACT8H34). 3.0 gsm (based on its dry mass) of a polymer binder in the form of an emulsion (Vinnapas 192, Wacker, 15%) containing 0.20 gsm of a surfactant (Aerosol OT 75, Cytec Industries) was sprayed onto the cellulose fiber layer. The structural body 1A was cured in an oven (145 °C, 4 minutes) to bond the cellulose fibers and the card nonwoven together. The total basis weight of the structural body 1A was 55 gsm.

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

[0166]

Table 11

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

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

[0169]

Table 12

[0170] The structure 2 was a multi-layer integrated structure formed on Danweb's airlaid pilot line. The structure 2 included a synthetic fiber layer oriented in layers to enable collection and rewetting, as well as a multi-layer core structure that provided permanent liquid storage and distribution. Carded nonwoven fabric (Shalag Nonwovens, product code STACT8H34) was used as a carrier for the airlaid nonwoven fabric structure. The first layer included 69 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully processed 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) mixed with 8 gsm of bicomponent fiber (Trevira, 1.5 dtex, 6 mm). The bicomponent fiber included a PE sheath (70%) and a PET core (30%). A polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant) at 5 gsm (based on dry mass) was sprayed onto the eucalyptus layer. The total basis weight of the structure 2 was 200 gsm.

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

[0172]

Table 13

[0173] The structure 3 was a multi-layer integrated structure formed on the airlaid pilot line of Danweb. The structure 3 included a synthetic fiber layer oriented in layers to enable collection and rewetting, and a multi-layer core structure that provided permanent liquid storage and liquid distribution using a superabsorbent polymer (SAP). Carded nonwoven fabric (Shalag Nonwovens, product code STACT8H34) was used as a carrier for the airlaid nonwoven fabric structure. The first layer included 62 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully processed 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 included 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). The eucalyptus layer was sprayed with 5 gsm (by dry mass) of a polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The total basis weight of the structure 3 was 200 gsm.

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

[0175]

Table 14

[0176] The structure 4 was a multi-layer integrated structure formed on the airlaid pilot line of Danweb. The structure 4 included a synthetic fiber layer oriented in layers to enable collection and rewetting, and a multi-layer core structure that provided permanent liquid storage and uptake using superabsorbent polymer (SAP). Card nonwoven fabric (Shalag Nonwovens, product code STACT8H34) was used as a carrier for the airlaid nonwoven fabric structure. The first layer included 54 gsm of cellulose fiber (Georgia-Pacific, GP 4723, fully processed 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 included 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). The eucalyptus layer was sprayed with 5 gsm (by dry weight) of a polymer binder in the form of an emulsion (Vinnapas 192 (Wacker) + 0.8% Aerosol OT 75 surfactant). The total basis weight of the structure 4 was 200 gsm.

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

[0178]

Table 15

[0179] (Example 4) Female sanitary napkin application - Liquid collection time and rewetting test (Structure 1A) In the application of female sanitary napkins, the structure 1A was tested for liquid collection and rewetting characteristics as a collection and distribution layer in an absorbent system containing a commercially available absorbent core, compared with a commercially available absorbent system.

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

[0181] Liquid collection time and rewetting test The liquid collection time and rewetting of absorbent systems containing Control 1, Control 2, and Control 3 were evaluated in the same manner as the absorbent system containing Structure 1A. The test device included a Plexiglas plate with an attached stainless steel cylinder (748 g, 2.2 cm inner diameter) and was placed on top of the absorbent system being tested. Synthetic blood (Johnson, Moen & Co., Inc., ASTM F1670 synthetic blood, viscosity 5.56 mPa / s, surface tension 40 - 44 mN / m) at a rate of 10 mL / min was delivered to the top of the absorbent system using a mini pump (Fisher Scientific), and 7 mL of the synthetic blood was discharged into the absorbent system. The mini pump and timer were started simultaneously and discharged into the absorbent system for 42 seconds. The total collection time #1 (TAT#1) was measured from the start of the synthetic blood administration 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 the 10-minute idle time between the start of the previous discharge and the start of the next discharge. The absorbent system was allowed to stand for an additional 10 minutes after the third discharge. Thereafter, four Coffi collagen sheets (Viscofan, 17.8 cm × 10 cm) were placed on top of the test device. A thin Plexiglas plate and weight were placed on top of the Coffi sheet for 1 minute. The Plexiglas plate and weight applied a total of 0.86 kPa to an area of 20.3 cm × 6.4 cm. Thereafter, the Coffi collagen sheet was weighed to determine rewetting. Rewetting was the difference in mass of the Coffi collagen sheet before and after the test. The collection time and rewetting results were the average of three measurements.

[0182] Test results are provided in FIGS. 8 and 9 and Tables 14 and 15.

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

[0184] As shown in FIG. 8 and Table 14, the absorbent system including the structure 1A as the collection and distribution layer had a higher liquid collection performance than all control collection and distribution commercially available nonwoven materials.

[0185]

Table 16

[0186] FIG. 9 is a graphical depiction of the results of the rewetting test. As shown in FIG. 9 and Table 15, the absorbent system including the structure 1A as the collection and distribution layer can provide more comfort to the end user from the perspective of the dry state than all control collection and distribution commercially available nonwoven materials. Overall, the absorbent system including the structure 1 had the lowest rewetting at 0.11 g.

[0187]

Table 17

[0188] (Example 5) Diaper application - Rewetting test (Structure IB) Regarding the rewetting characteristics, the structure IB was tested as the collection and distribution layer in a diaper application in comparison with commercially available diaper products.

[0189] Sample preparation A commercially available diaper containing a 50 gsm card nonwoven collection and distribution layer was used as the control diaper and tested for rewetting. The rubber band around the entire control diaper was removed. The original 50 gsm card nonwoven collection and distribution layer was left inside the diaper as it was. The control diaper was tested without further calendering since it had been calendered during its manufacturing process.

[0190] The same commercial diaper was disassembled. The original 50 gsm card nonwoven collection and distribution layer was removed and replaced with Structure IB (19.0 cm × 8.0 cm). The nonwoven top sheet of the diaper was placed back on the diaper. Then, the diaper was compressed at a pressure of 4 bar via a roller press.

[0191] Rewetting test In the same manner as the control diaper, the rewetting of the diaper containing Structure IB as the collection and distribution layer was evaluated. The test equipment was placed on the diaper. The test equipment applied approximately 2.8 kPa on the diaper. The test equipment 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 and distribution layer corresponding to the front side of the diaper. By operating a pump that delivered the solution at a rate of 7 mL / sec for 10.7 seconds, 75 mL of 0.9% sodium chloride (NaCl) solution was discharged onto the control diaper. When 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 discharged onto the product. When the liquid was completely absorbed, a 20-minute timer was started. At 20 minutes, the test equipment was removed. Eight pieces of Curity (10 cm × 10 cm nonwoven, All Purpose Sponges, Covidien) were spread out to increase the covered area to 20 cm × 10 cm. The eight pieces of Curity were placed on the wet diaper to cover the entire 19.0 cm × 8.0 cm collection and distribution layer. The foam-delivery cylinder-weight was placed back on the diaper, and the delivery cylinder was placed at the end opposite the area where the diaper had been discharged. A 5-minute timer was started. At 5 minutes, the Curity was weighed to calculate the rewetting value. The final result of the rewetting was the average of the results of three tests.

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

[0193] (Example 6) Feminine Hygiene Napkin Application - Liquid Collection Time, Rewetting, and Uptake Tests (Structures 2 - 4) Structures 2 - 4 were tested for liquid collection, rewetting, and uptake characteristics in comparison to the absorbent systems of commercially available feminine hygiene napkins (Controls A - D).

[0194] Properties of the Samples Control A was a commercially available sanitary napkin (Sannap A). The absorbent system had a total basis weight of 325 gsm. The collection - distribution layer included a TABCW layer with a basis weight of approximately 46 gsm and an Aerotex sheet with a basis weight of approximately 77 gsm. The core was a hydrogen - bonded Aerotex 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 approximately 206 gsm. The collection - distribution layer was an Aerotex sheet with a basis weight of approximately 97 gsm. The core was an Aerotex sheet containing more than approximately 10% SAP material. The core had a basis weight of approximately 109 gsm.

[0196] Control C was a commercially available sanitary napkin (Sannap C). The absorbent system had a total basis weight of approximately 241 gsm. The collection - distribution layer was an Aerotex sheet with a basis weight of approximately 102 gsm. The core was an Aerotex sheet containing more than approximately 10% SAP material. The core had a basis weight of approximately 139 gsm.

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

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

[0199] Liquid collection time and rewetting test The liquid collection time and rewetting of Structures 2-4 were evaluated in the same manner as the commercially available sanitary napkins being tested (Controls A-D). The absorbent system (6.5 cm × 20.5 cm or 6.5 cm × 21.5 cm) was roller pressed at 4 bar pressure. Figures 12 and Table 16 provide the thickness of Structures 2-4 before and after 4 bar compression.

[0200] [Table 18]

[0201] The test equipment included a plexiglass plate with a cylinder (748 g, inner diameter 2.2 cm) placed on top of the absorbent system. 4 mL of synthetic blood (Johnson, Moen & Co., Inc., synthetic blood of ASTM F1670, viscosity 5.56 mPa / s, surface tension 40 - 44 mN / m) was delivered to the top at a rate of 10 mL / min using a mini pump (Fisher Scientific) and discharged into the absorbent system. The mini pump and timer were started simultaneously and discharged into the absorbent system for 24 seconds. The total collection time #1 (TAT#1) was measured from the moment the administration of synthetic blood 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 the 10-minute empty time between the start of the previous discharge and the start of the next discharge. After the third discharge, the absorbent system was left standing for an additional 10 minutes. Then, 4 pieces of Coffi collagen sheets (Viscofan, USA) (10 cm × 10 cm) were placed on top of the test equipment. A thin plexiglass plate and a weight were placed on the Coffi sheet for 1 minute. The plexiglass plate and weight applied a total of 0.86 kPa to a 20 cm × 6.4 cm area. Then, the Coffi sheet was weighed to determine rewetting. The collection time and rewetting results were the average of three measurements.

[0202] Test results are provided in Figures 13 and 14, and Tables 17 and 18.

[0203] Figure 13 graphically shows the effective collection time (EAT) obtained for each of the multifunctional integrated structures (Structures 2 - 4) of the experiments to be tested, as shown in Table 17, and for the control commercial sanitary napkins (Controls A - D). The EAT value was the difference between the total collection time (TAT) and the injection time (IT). Each discharge volume was 4 mL, and the liquid was delivered at a rate of 10 mL / min. Thus, the duration of IT was 24 seconds, and EAT = TAT - 24 seconds. As shown in Figure 13 and Table 17, the basis weight of Structures 2 - 4 was lower than that of the absorbent systems of the commercial products (Controls A - D), but the liquid collection performance of all the experimental structures was higher than that of the commercial sanitary napkins containing the original absorbent material.

[0204]

Table 19

[0205] As shown in Table 18, FIG. 14 graphically shows the rewetting results obtained for each of the multifunctional integrated structures of the experiments to be tested and for a control commercially available sanitary napkin. As shown in FIGS. 14 and 18, the basis weights of Structures 2-4 are lower than those of the absorbent systems included in the commercial products (Controls A-D), and Structures 2-4 either do not contain SAP or contain a relatively small amount, but all of the rewetting of Structures 2-4 has improved performance (e.g., lower rewetting values) compared to commercial sanitary napkins containing the original absorbent material.

[0206]

Table 20

[0207] Uptake distance test After the total collection times #1, #2, and #3, each structure was further tested for uptake and the rewetting measurements were completed. The sample was turned over so that the bottom side of the core was on top. A standard measuring rule was used to measure the visible stain vertically along the structure. The measurement was taken from the outer edge of the stain on one side to the outer edge of the stain on the other side parallel to the long side of the structure.

[0208] The test results are provided in FIGS. 15 and 19.

[0209] As shown in Table 19, FIG. 15 graphically shows the uptake results obtained for each of the multifunctional integrated structures of the experiments to be tested and for a control commercially available sanitary napkin. As shown in FIGS. 15 and 19, the uptake distances measured for all of Samples 2-4 were longer than those of the commercial sanitary napkins containing the original absorbent material (Controls A-D). The longer uptake 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 subject matter of the present disclosure also contemplates other embodiments having other combinations of the features disclosed and claimed herein. Accordingly, the specific features presented herein can be combined with one another in other ways within the scope of the subject matter of the present disclosure such that the subject matter of the present disclosure includes any suitable combination of the features disclosed herein. The foregoing description of specific embodiments of the subject matter of the present disclosure has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the subject matter of the present disclosure to the embodiments disclosed.

[0212] It will be apparent to those skilled in the art that various changes and modifications can be made in the systems and methods of the subject matter of the present disclosure without departing from the spirit or scope of the subject matter of the present disclosure. Accordingly, it is intended that the subject matter of the present disclosure cover the 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 hereby incorporated by reference in their entirety.

Claims

1. a first layer comprising cellulosic fibers and bicomponent fibers; and a second layer adjacent to the first layer, the second layer comprising fine cellulose fibers and bicomponent fibers; A multi-layer nonwoven material, wherein at least a portion of the first layer and the second layer are coated with a binder.

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

3. 3. The multilayer nonwoven material of claim 2 having an effective collection time of about 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 less than or equal to about 0.20 g.

7. 7. The multi-layer nonwoven material of claim 6, having a Rewet Value of about 0.15 g or less.

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

9. 10. The multi-layer nonwoven material of claim 1, wherein the fine cellulosic 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.

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

13. a first layer comprising cellulosic and synthetic fibers; a second layer adjacent to the first layer, the second layer comprising cellulosic and synthetic fibers; a third layer adjacent to the second layer, the third layer comprising a superabsorbent polymer (SAP); and a fourth layer adjacent to the third layer, the fourth layer including fine cellulose fibers and synthetic fibers; A multi-layer nonwoven material, wherein at least a portion of said first and fourth layers are coated with a binder.

14. 14. The multi-layer nonwoven material of claim 13, wherein the fine cellulosic fibers comprise eucalyptus pulp.

15. 14. The multi-layer nonwoven material of claim 13, wherein the synthetic fibers comprise bicomponent fibers.

16. 14. An absorbent article comprising the multi-layer nonwoven material of claim 13.

17. a first layer comprising long fibers; and a second layer adjacent to the first layer, the second layer comprising staple fibers; A multi-layer nonwoven material, wherein at least a portion of said second layer is coated with a binder.

18. 20. The multi-layer nonwoven material of claim 17, having an effective collection time of about 15 seconds or less.

19. 20. The multi-layer nonwoven material of claim 18, having an effective collection time of about 1 second or less.

20. 20. The multi-layer nonwoven material of claim 17, having a Rewet Value of less than or equal to about 0.50 g.

21. 21. The multi-layer nonwoven material of claim 20, having a Rewet Value of less than or equal to about 0.05 g.

22. 20. The multi-layer nonwoven material of claim 17, having a wicking distance of at least about 140 mm.

23. 23. The multi-layer nonwoven material of claim 22, having a wicking distance of at least about 180 mm.

24. 20. The multi-layer nonwoven material of claim 17, wherein the long fibers comprise synthetic fibers, regenerated cellulose fibers, or a combination thereof.

25. 25. The multi-layer nonwoven material of claim 24, wherein the long fibers comprise synthetic fibers formed as a carded web.

26. 20. The multi-layer nonwoven material of claim 17, wherein the staple fibers comprise synthetic fibers, cellulosic fibers, regenerated cellulose fibers, or combinations thereof.

27. 20. The multi-layer nonwoven material of claim 17, wherein the filaments have a length between about 8 mm and about 70 mm.

28. 20. The multi-layer nonwoven material of claim 17, wherein the staple fibers have a length between about 1 mm and about 8 mm.

29. 20. An absorbent article comprising the multi-layer nonwoven material of claim 17.

30. a first layer comprising synthetic fibers formed as a carded web; and a second layer adjacent to the first layer, the second layer comprising cellulose fibers; A multi-layer nonwoven material, wherein at least a portion of said second layer is coated with a binder.

31. 31. The multi-layer nonwoven material of claim 30, wherein the synthetic fibers have a length between about 8 mm and about 70 mm.

32. 31. An absorbent article comprising the multi-layer nonwoven material of claim 30.

33. a first layer comprising synthetic fibers formed as a carded web; a second layer adjacent to the first layer, the second layer comprising cellulosic fibers and bicomponent fibers; and a third layer adjacent to the second layer, the third layer comprising cellulosic fibers and bicomponent fibers; A multi-layer nonwoven material, wherein at least a portion of said third layer is coated with a binder.

34. 34. The multi-layer nonwoven material of claim 33, wherein the synthetic fibers have a length between about 8 mm and about 70 mm.

35. 34. The multi-layer nonwoven material of claim 33, wherein the cellulose fibers of the third layer comprise fine cellulose fibers.

36. 36. The multi-layer nonwoven material of claim 35, wherein the cellulosic fibers of the third layer comprise eucalyptus pulp.

37. 34. An absorbent article comprising the multi-layer nonwoven material of claim 33.

38. a first layer comprising synthetic fibers formed as a carded web; a second layer adjacent to the first layer, the second layer comprising cellulosic fibers and bicomponent fibers; a third layer adjacent to the second layer, the third layer comprising a superabsorbent polymer (SAP); and a fourth layer adjacent to the third layer, the fourth layer comprising cellulosic, bicomponent fibers; A multi-layer nonwoven material, wherein at least a portion of said fourth layer is coated with a binder.

39. 40. The multi-layer nonwoven material of claim 38, wherein the synthetic fibers have a length between about 8 mm and about 70 mm.

40. 40. The multi-layer nonwoven material of claim 38, wherein the cellulose fibers of the fourth layer comprise fine cellulose fibers.

41. 41. The multi-layer nonwoven material of claim 40, wherein the cellulosic fibers of the fourth layer comprise eucalyptus pulp.

42. 40. An absorbent article comprising the multi-layer nonwoven material of claim 38.

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