KR20240051215A - Top sheet layer for absorbent articles - Google Patents

Abstract

The present invention generally relates to absorbent articles that can have an improved feeling of comfort next to the wearer's skin and a reduced feeling of wetting and rewetting. The absorbent article can have a wearer-facing, liquid-permeable topsheet layer and a garment-facing, liquid-impermeable backsheet layer. The absorbent core may be positioned between the topsheet layer and the backsheet layer. The topsheet layer may be formed from non-chemically reinforced natural fibers.

Description

Top sheet layer for absorbent articles

The present invention relates to topsheet layers for absorbent articles.

Products such as absorbent articles are often used to collect and retain body exudates containing, for example, urine, menstrual fluid and/or blood. Comfort, absorbency, and discretion are three key product attributes and areas of interest to the wearer. In particular, the wearer will often protect his underwear, outerwear, or bed sheets from stains, as these products will absorb significant amounts of body exudates while minimizing leakage, and the wearer will avoid the subsequent embarrassment caused by these stains. I am interested in finding out if it will help me avoid.

Currently, a wide variety of products for absorption of body exudates are available in the form of feminine pads, sanitary napkins, panty shields, panty liners, incontinence clothing, diapers, training panties, youth pants, swim pants, etc. These products generally have an absorbent core positioned between a body-facing, liquid-permeable topsheet layer and a garment-facing, liquid-impermeable backsheet layer. The edges of the topsheet layer and the backsheet layer are often joined together at their periphery to form a seal to contain the absorbent core and body exudates contained through the topsheet layer and into the product.

Wearers of these conventional absorbent products are interested in having these products exhibit reduced wetness if they become soiled or soiled during use. Unfortunately, when these products become contaminated, the topsheet layer often remains damp, or at least feels damp, for some time throughout the period of use. The topsheet layer may often be absorbent, being made from hydrophilic constituent materials, such as natural fibers. These materials often retain some noticeable moisture on their surfaces after contamination, resulting in an uncomfortable, wet sensation during continued use of the product.

As a result of the wearer's desire to experience a reduced wet sensation from the product during long-term use (both for physical comfort as well as skin-health reasons), manufacturers have developed a number of technological approaches to deal with this sensation following contamination of the product. explored. Manufacturers have attempted to reduce both the initial sensation of wetness and also the ongoing sensation of "rewetting", where the product absorbs fluid or liquid, such as menstrual blood or urine, through the topsheet layer and transfers it to the inner layer of the absorbent article. , releasing the fluid or liquid from the inner layer back to the topsheet layer under continuous wearing pressure. This release of fluid/liquids back into the topsheet layer often leads to the wearer's perception of subsequent wetness. Manufacturers of these products have specifically designed the individual topsheet layers for reduced wetting (and rewetting), based on chemical strengthening of the topsheet layer to provide the topsheet layer with hydrophobic properties. In this regard, a hydrophobic topsheet layer can help an absorbent product exhibit an extended dryness at the product's skin-contacting surface. Additionally, liquid/fluid retained within the inner layers of the product may have less tendency to pass through the topsheet layer back to the wearer's skin as a result of the hydrophobic inner surface properties of the topsheet layer. In some instances, the topsheet layer thus acts as a one-way valve, allowing moisture to pass in one direction and remain below the user-facing, skin-contacting surface. However, these chemically enhanced hydrophobic topsheet layers are not suitable for consumers who may have sensitive skin and/or may have a preference for absorbent products with natural topsheet layers.

As a result, there remains a need for improved products, such as absorbent articles, that have an improved feeling of comfort on the wearer's skin and reduce the feeling of wetting and rewetting without the need for chemical strengthening of the topsheet layer.

In various embodiments, topsheet layers for use in absorbent articles can have non-chemically reinforced natural fibers. In various embodiments, the natural fiber is cotton fiber.

In various embodiments, natural fibers are present in an amount greater than 50% by weight based on the total weight of the topsheet layer. In various embodiments, natural fibers are present in an amount greater than 75% by weight based on the total weight of the topsheet layer.

In various embodiments, the topsheet layer is hydrophobic. In various embodiments, the topsheet layer has a water contact angle of ^90o to ^150o . In various embodiments, the topsheet layer has a water contact angle of ^130o to ^140o .

In various embodiments, the topsheet layer has a whiteness index of less than 70.

In various embodiments, an absorbent article can have a topsheet layer, a backsheet layer, and an absorbent core positioned between the topsheet layer and the backsheet layer as described herein.

In various embodiments, the method of making the topsheet layer described herein involves boiling the natural fibers in a sodium hydroxide solution (0.1 to 10 g/L) at a temperature of 60 ^o - 100 ^o C for 30 to 240 minutes. There may be a refining step. In various embodiments, refining of natural fibers is accomplished by boiling the natural fibers in a sodium hydroxide solution (0.5 to 2.0 g/L) at a temperature of 80 ^o - 90 ^o C for 120 to 180 minutes.

In various embodiments, natural fibers are not bleached.

The present invention generally relates to absorbent articles that can have an improved feeling of comfort next to the wearer's skin and a reduced feeling of wetting and rewetting. The absorbent article can have a wearer-facing, liquid-permeable topsheet layer and a garment-facing, liquid-impermeable backsheet layer. The absorbent core may be positioned between the topsheet layer and the backsheet layer. Both the topsheet layer and the backsheet layer may extend beyond the outermost perimeter edges of the absorbent core and may be fully or partially joined together circumferentially using known bonding techniques to form a sealed perimeter area. . For example, the topsheet layer and the backsheet layer can be bonded together by adhesive bonding, ultrasonic bonding, or any other suitable bonding method known in the art. The topsheet layer may be formed from non-chemically reinforced natural fibers.

Justice:

As used herein, the term "absorbent article" refers to clothing or other end-use products, including, but not limited to, sanitary napkins, feminine pads, panty liners, panty shields, incontinence clothing, diapers, training panties, youth pants, swim pants, etc. refers to personal hygiene absorbent products.

As used herein, the term “airlaid” refers herein to a web made by an airlaying process. In the airlaying process, bundles of small fibers, with a typical length ranging from about 3 to about 52 mm, are separated and entrained in an air source and then deposited onto a forming screen, usually with the aid of a vacuum source. The randomly deposited fibers are then bonded together, for example using hot air to activate the binder component or latex adhesive. Airlaying is taught, for example, in U.S. Pat. No. 4,640,810 to Laursen et al., which is incorporated herein by reference in its entirety for all purposes.

As used herein, the term “bonded” refers to the joining, adhesion, connection, attachment, etc. of two elements. Two elements will be considered to be joined together when they are joined, glued, connected or attached to each other, either directly or indirectly, such as when bonded to an intermediate element. Bonding may occur, for example, through adhesives, pressure bonding, thermal bonding, ultrasonic bonding, stitching, suturing, and/or welding.

As used herein, the term "bonded carded web" refers to combing or carding (combing or carding) that separates or separates staple fibers and aligns them in the machine direction to form a fibrous nonwoven web oriented approximately in the machine direction. Refers to a web manufactured from staple fibers that are passed through a carding unit. The materials may be bonded together by methods that may include point bonding, vent bonding, ultrasonic bonding, adhesive bonding, etc.

As used herein, the term “hydrophilic” refers to a surface having a water contact angle of less than ^90o .

As used herein, the term “hydrophobic” refers to a surface that has the property of repelling fluids with a water contact angle of 90 ^o to 150 ^o .

As used herein, the term “superhydrophobic” refers to a surface having a water contact angle greater than ^150o .

As used herein, the term "machine direction" (MD) refers to the length of a fiber in the direction in which the fiber is made, and the term "cross machine direction" refers to the width of the fiber in a direction generally perpendicular to the machine direction. “In contrast to (CD).

As used herein, the term "meltblown web" refers to a converging, high-velocity web in which a molten thermoplastic material is extruded as molten fibers through a plurality of fine, usually circular die capillaries, thereby attenuating the fibers of the molten thermoplastic material. refers to nonwoven webs formed by extrusion into a gas (e.g., air) stream to reduce their diameter to a diameter that may be the diameter of a microfiber. The meltblown fibers are then transported by a high-velocity gas flow and deposited on the collecting surface, forming a web of randomly dispersed meltblown fibers. This process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin et al., which is incorporated herein by reference in its entirety for all purposes. In general, meltblown fibers may be microfibers that are substantially continuous or discontinuous, generally less than 10 μm in diameter, and are generally tacky when deposited onto a collection surface.

As used herein, the term “nonwoven” or “nonwoven web” refers herein to a web that has a structure of individual fibers or yarns that are interlaid, although not in a discernible manner as in a knitted fabric. Nonwovens or webs are formed by many processes, such as meltblown processes, spunbond processes, through-air bonded carded web (also known as BCW and TABCW) processes, etc. The basis weight of the nonwoven web may generally vary, such as from about 5, 10, or 20 gsm to about 120, 125, or 150 gsm.

As used herein, the term “spunbond web” refers to a web containing small diameter, substantially continuous fibers. Fibers are made by extruding molten thermoplastic material from the capillaries of a plurality of fine, generally circular spinnerettes and then reducing the diameter of the extruded fibers by, for example, extractive stretching and/or other known spunbonding mechanisms. It is formed by rapid reduction. The manufacture of spunbond webs includes, for example, U.S. Patents 4,340,563 to Appel et al., 3,692,618 to Dorschner et al., 3,802,817 to Matsuki et al., 3,338,992 to Kinney, 3,341,394 to Kinney, and 3,341,394 to Hartman. Nos. 3,502,763, 3,502,538 to Levy, 3,542,615 to Dobo et al., and 5,382,400 to Pike et al., each of which is hereby incorporated by reference in its entirety for all purposes. Spunbond fibers are generally not sticky when deposited on a collecting surface. Spunbond fibers may sometimes have a diameter of less than about 40 μm, often from about 5 to about 20 μm.

As used herein, the terms “superabsorbent polymer”, “superabsorbent” or “SAP” will be used interchangeably and refer to a polymer that is capable of absorbing and retaining extremely large amounts of liquid relative to its own weight. will refer to polymers. Water-absorbing polymers, classified as crosslinkable hydrogels, absorb aqueous solutions through hydrogen bonds and other polar forces with water molecules. The water absorption capacity of SAP is based in part on the degree of ionization (a factor of ion concentration in an aqueous solution) and the functional polar groups of SAP that have an affinity for water. SAP is typically prepared by polymerization of acrylic acid mixed with sodium hydroxide in the presence of an initiator to form sodium polyacrylate salt (sometimes referred to as sodium polyacrylate). Other materials are also used to prepare superabsorbent polymers, such as polyacrylamide copolymers, ethylene maleic anhydride copolymers, cross-linked carboxymethylcellulose, polyvinyl alcohol copolymers, cross-linked polyethylene oxide, and A starch-conjugated copolymer of polyacrylonitrile is prepared. SAP may be present in the absorbent article in the form of particles or fibers or as a coating layer on other materials or fibers.

Absorbent Supplies:

The present invention generally relates to absorbent articles that can have an improved feeling of comfort next to the wearer's skin and a reduced feeling of wetting and rewetting. The absorbent article can have a wearer-facing, liquid-permeable topsheet layer and a garment-facing, liquid-impermeable backsheet layer. The absorbent core may be positioned between the topsheet layer and the backsheet layer. Both the topsheet layer and the backsheet layer may extend beyond the outermost perimeter edges of the absorbent core and may be fully or partially joined together circumferentially using known bonding techniques to form a sealed perimeter region. . For example, the topsheet layer and the backsheet layer can be bonded together by adhesive bonding, ultrasonic bonding, or any other suitable bonding method known in the art. The topsheet layer may be formed from non-chemically reinforced natural fibers.

Top sheet layer:

The topsheet layer defines a wearer-facing side of the absorbent article that is in direct contact with the wearer's body and is liquid permeable to receive body exudates. The topsheet layer preferably provides for comfort and compliance and functions to direct body exudates away from the wearer's body through its own structure and towards the absorbent core. The topsheet layer preferably retains little or no liquid in its structure to provide a relatively comfortable, non-irritating surface next to the skin of the wearer of the absorbent article.

The topsheet layer may be comprised of any woven, non-woven sheet material that is readily penetrable to body exudates that may come into contact with the body facing side of the topsheet layer. In various embodiments, the topsheet layer may be comprised of various nonwoven webs, such as hydroentangled spunlace webs or vented bonded carded webs. In various embodiments, the topsheet layer may be comprised of natural fibers. Examples of suitable natural fibers include cotton fibres, rayon fibres, wheat straw fibres, rice straw fibres, flax fibres, bamboo fibres, jute fibres, hemp fibres, sisal fibres, bagasse fibres, hesperae fibres, silver grass, marine or fresh water algae. /seaweed, and combinations thereof, but are not limited thereto. In various embodiments, the natural fibers can be cotton fibers, bamboo fibers, or combinations thereof. In various embodiments, the natural fiber can be cotton fiber. In various embodiments, the topsheet layer has at least 50, 60, 75, 95, 99, or 100% natural fibers by weight, based on the total weight of the topsheet layer. In various embodiments, the topsheet layer has at least 75, 95, 99, or 100% natural fibers by weight based on the total weight of the topsheet layer. In various embodiments, the topsheet layer has at least 95, 99, or 100% natural fibers by weight based on the total weight of the topsheet layer.

Natural fibers that are still in their raw form (i.e. have not gone through a purification step) are hydrophobic. Common refining steps include ginning, carding, combing, refining, and bleaching. For example, with respect to cotton fiber, ginning is the first step in refining the raw cotton and separating the cotton fluff from cotton seeds and other foreign debris (e.g., plant stems, plant stems, and plant leaves). Then, the cotton lint goes through carding to remove tangles within the cotton lint, individualize and align the cotton fibers within the cotton lint, and remove foreign debris passing through the ginning stage. The carded cotton fibers are processed through a combing step where any residual debris is removed and the cotton fibers are smoothed. After ginning, carding and combing, the cotton fibers are still hydrophobic and will undergo a scouring process to remove some of the "impurities" that coat the cotton fibers. For example, with respect to cotton fibers, cellulose is the major component of cotton fibers and accounts for approximately 94% of the dry weight of cotton fibers. Other components of cotton fiber (approximately % dry weight of cotton fiber) include proteins (1.3%), pectic substances (1.2%), ash (1.2%), waxes (0.6%), total sugars (0.3%), and pigments (trace amounts). ), and other non-cellulosic materials (1.4%) ( Industrial Crops and Products , 11(2-3):173-178, March 2000). Scouring is the process of removing proteins, pectic substances, waxes, and other non-cellulosic substances from cotton fibers to produce hydrophilic cotton fibers. A typical scouring process involves boiling cotton fibers in a solution of sodium hydroxide (20 to 50 g/liter) for 1 to 8 hours at a temperature above 120 ^o C. After the scouring process, cellulose is the main remaining material of cotton fiber, while proteins, pectic substances, waxes and other non-cellulosic materials are removed. After the scouring process, the cotton fiber is very hydrophilic, and the appearance of the cotton fiber is clean and smooth. These hydrophilic cotton fibers have good body exudate absorption, good breathability, and good softness. After the conventional scouring process, the natural pigments of the cotton fibers remain in the cotton fibers and the cotton fibers may appear tan. Bleaching of cotton fibers not only gives the cotton fibers a white appearance, but also increases the overall absorbency of the cotton fibers and can remove any final residual impurities.

After the refining process, cotton fibers can be formed into woven or non-woven materials through manufacturing processes such as spunlacing, air bonding, air laying, wet laying, etc. For example, to increase suitability for use in absorbent articles, such as the topsheet layer of an absorbent article, woven or nonwoven materials formed from purified cotton fibers may be chemically strengthened to enhance the woven or nonwoven materials. It may undergo a finishing process to change its hydrophilic properties. After the purification process, cotton fiber has high hydrophilicity. Although hydrophilicity facilitates the absorption and penetration of body exudates through the topsheet layer of an absorbent article containing purified cotton fibers, such topsheet layer typically retains any residual body exudates remaining in the topsheet layer and the topsheet layer, such as the absorbent core. It remains wet due to body exudates passing from components beneath the sheet layer back to (and through) the topsheet layer. For example, a wearer of an absorbent article having a topsheet layer containing purified natural fibers, such as cotton fibers, may retain the topsheet layer and absorb moisture from components beneath the topsheet layer, such as the absorbent core, into the topsheet layer (and Discomfort and lack of confidence in the absorbent article may be experienced due to residual body exudates passing back (through the topsheet layer). As a result of the wearer's desire to experience a reduced wet sensation from the product during long-term use (both for physical comfort as well as skin-health reasons), manufacturers have developed a number of technological approaches to deal with this sensation following contamination of the product. explored. Manufacturers have attempted to reduce both the initial sensation of wetness and also the ongoing sensation of "rewetting", where the product absorbs fluid or liquid, such as menstrual blood or urine, through the topsheet layer and transfers it to the inner layer of the absorbent article. , releasing the fluid or liquid from the inner layer back to the topsheet layer under continuous wearing pressure. This release of fluid/liquids back into the topsheet layer often leads to the wearer's perception of subsequent wetness. Manufacturers of these products have specifically designed the individual topsheet layers for reduced wetting (and rewetting), based on chemical strengthening of the topsheet layer to provide the topsheet layer with hydrophobic properties. To chemically modify the hydrophilic properties of woven or non-woven materials containing purified natural fibers such as cotton fibers, hydrophobic chemical compounds such as paraffin-based or silicone-based compounds have been used to treat woven or non-woven materials. In this regard, a chemically enhanced hydrophobic topsheet layer can help the absorbent article exhibit an extended dry feel at the skin-contacting surface of the absorbent article. Additionally, body exudates retained within the inner layers of the absorbent article may be less likely to pass through the topsheet layer back to the wearer's skin as a result of the hydrophobic interior surface properties of the topsheet layer. In some cases, the topsheet layer therefore acts as a one-way valve, allowing moisture to pass in one direction and remain below the user-facing, skin-contacting surface. However, these chemically enhanced hydrophobic topsheet layers are suitable for wearers of absorbent articles who may have sensitive skin and/or may prefer absorbent products with an all-natural (i.e., non-chemically enhanced) topsheet layer. don't do it

Purification of natural fibers, particularly cotton fibers, to provide the wearer of the absorbent article with an absorbent article having a topsheet layer formed from non-chemically reinforced natural fibers while still having hydrophobic properties. The process may vary from the conventional purification process described herein. Raw natural fibers, such as cotton, can still undergo ginning, carding, and combing as described herein, as these are the mechanical steps used to refine the raw cotton. However, the refining step is the primary step within the conventional refining process in which the structure of the cotton fiber is modified to change its natural hydrophobic properties into cotton fibers with hydrophilic properties. A typical scouring process involves boiling cotton fibers in a solution of sodium hydroxide (20 to 50 g/liter) for 1 to 8 hours at a temperature above 120 ^° C. After the scouring process, cellulose is the main remaining material of cotton fiber, while proteins, pectic substances, waxes and other non-cellulosic materials are removed. Wax is a major element of natural cotton fiber that provides hydrophobic properties to cotton fiber. Removing wax from cotton fiber changes the cotton fiber from having hydrophobic properties to having hydrophilic properties. Because in addition to wax, other impurities including proteins, pectic substances, and other non-cellulosic substances will remain in the cotton fiber, it is not feasible to completely eliminate the scouring process from the refining process. These impurities need to be removed from the cotton fiber while retaining the presence of wax. Accordingly, the scouring process can be modified to remove impurities such as proteins, pectic substances, and other non-cellulosic substances from the cotton fibers while retaining the wax that maintains the hydrophobic properties of the cotton fibers. In various embodiments, the modified scouring process step includes boiling the cotton fibers in a sodium hydroxide solution (0.1 to 10 g/L) at a temperature of 60 to 100 ^o C for 30 minutes to 4 hours. In various embodiments, the modified scouring process step includes boiling the cotton fibers in a sodium hydroxide solution (0.5 to 2.0 g/L) at a temperature of 80 to 90 ^o C for 2 to 3 hours. This modified scouring process can result in non-chemically strengthened cotton fibers with hydrophobic properties. In various embodiments, non-chemically reinforced cotton fibers can have a water contact angle of 90 ^o - 150 ^o . In various embodiments, non-chemically reinforced cotton fibers can have a water contact angle of 130 ^o - 140 ^o . Depending on the modified scouring process, the topsheet layer made from these natural fibers, such as cotton fibers, can have non-chemically reinforced natural fibers with hydrophobic properties, which can reduce the wetness that can be felt by the wearer of the absorbent article. there is.

As described herein, within a conventional refining process, the bleaching step, in addition to removing any final residual impurities after the conventional refining process, provides the cotton fiber with a white appearance that changes from the natural pigment, which may appear tan. can do. The bleaching step of a conventional purification process may remove impurities from the cotton fibers, and in modified purification processes, the bleaching step may be bypassed entirely, with the goal of maintaining the hydrophobic properties of the cotton fibers without chemical strengthening. Because the bleaching step can be completely bypassed, according to the modified purification process described herein, the topsheet layer made from unbleached natural fibers, such as cotton fibers, can be scanned using a CR-20 color reader manufactured by Konica Minolta. When measured, it may have a whiteness index of less than 70.

In various embodiments, the topsheet layer may contain a plurality of perforations formed to allow body exudates to more easily pass into the absorbent core. The perforations may be arranged randomly or uniformly throughout the topsheet layer, or may be located in narrow longitudinal bands or strips arranged along the longitudinal centerline of the absorbent article. The size, shape, diameter and number of holes may vary to suit the specific needs of the absorbent article.

In various embodiments, the topsheet layer may have a basis weight ranging from about 5, 10, 15, 20, or 25 gsm to about 50, 100, 120, 125, or 150 gsm. For example, in embodiments, the topsheet layer may be constructed from a through air bonded carded web having a basis weight ranging from about 15 gsm to about 100 gsm. In various embodiments, the topsheet layer may be comprised of a cotton material and may have a basis weight of about 25 gsm to about 35 gsm.

Absorbent Core:

The absorbent core may be positioned between the topsheet layer and the backsheet layer. The absorbent core can generally be any single layer structure or combination of layer components that can exhibit some level of compressibility, compliance, can be non-irritating to the wearer's skin, and can absorb and retain liquids and other body exudates. there is. In various embodiments, the absorbent core may be formed from a variety of different materials and may include any number of layers desired. For example, the absorbent core may include cellulosic fibers (e.g., wood pulp fibers), other natural fibers, synthetic fibers, woven or non-woven sheets, scrim netting or other stabilizing structures, superabsorbent materials, bonding materials, and interfaces. It may include one or more layers (e.g., two layers) of absorbent web material of active agents, selected hydrophobic and hydrophilic materials, pigments, lotions, odor suppressants, etc., and combinations thereof. In one embodiment, the absorbent web material may include a matrix of cellulose fluff and may also include a superabsorbent material. Cellulose fluff may comprise a mixture of wood pulp fluff. An example of wood pulp fluff can be identified under the trademark NB 416, available from Weyerhaeuser Corp., which is a bleached, highly absorbent wood pulp containing primarily softwood fibers.

In various embodiments, if desired, the absorbent core may include an optional amount of superabsorbent material. Examples of suitable superabsorbent materials include poly(acrylic acid), poly(methacrylic acid), poly(acrylamide), poly(vinyl ether), maleic anhydride copolymer with vinyl ether and α-olefin, poly(vinyl pyrroli). money), poly(vinylmorpholinone), poly(vinyl alcohol) and salts and copolymers thereof. Other superabsorbent materials include hydrolyzed acrylonitrile-grafted starch, acrylic acid grafted starch, methyl cellulose, chitosan, carboxymethyl cellulose, hydroxypropyl cellulose, and natural gums such as alginate, xanthan gum, and locus bean gum. It may include unmodified natural polymers and modified natural polymers. Blends of natural superabsorbent polymers and fully or partially synthetic superabsorbent materials may also be useful. Superabsorbent material may be present in the absorbent core in any amount as desired.

Regardless of the combination of absorbent materials used in the absorbent core, the absorbent materials can be formed into a web structure by employing various conventional methods and techniques. For example, the absorbent web may be formed by techniques such as, but not limited to, dry forming techniques, air forming techniques, wet forming techniques, foam forming techniques, etc., as well as combinations thereof. Methods and apparatus for practicing these techniques are known in the art.

The shape of the absorbent core may vary as desired and may include, but is not limited to, any of a variety of shapes including, but not limited to, triangular, rectangular, dog-shaped, or oval. In various embodiments, the absorbent core can have a shape that generally corresponds to the overall shape of the absorbent article. While the dimensions of the absorbent core may be substantially similar to the dimensions of the absorbent article, it will be appreciated that the dimensions of the absorbent core, while similar, are often smaller than the dimensions of the entire absorbent article so as to be properly contained therein.

For example, suitable materials and/or structures for absorbent cores include U.S. Pat. It may include, but is not limited to, those described in Application Publication No. 2010/0174260, and each of these documents is incorporated by reference in its entirety.

As noted above, in various embodiments, the absorbent core may be of a single layer structure and may include, for example, a matrix of cellulose fluff and superabsorbent material. In various embodiments, the absorbent core may have at least two layers of material, such as a wearer facing layer and a garment facing layer. In various embodiments, the two layers may be identical to each other. In various embodiments, the two layers may be different. In these embodiments, the two layers can provide the absorbent article with different absorbent properties as deemed appropriate. In various embodiments, the body-facing layer of the absorbent core may be comprised of an airlaid material, and the garment-facing layer of the absorbent core may be comprised of a compressed sheet containing a superabsorbent polymer. In this embodiment, the airlaid material may have a basis weight of about 40 to about 200 gsm, and the superabsorbent polymer-containing compressed sheet may be comprised of cellulosic pulp and SAP having a basis weight of about 40 to about 400 gsm while surrounded by a tissue carrier. It may be a cellulose fluff based material which may be a combination of.

Back sheet layer:

The backsheet layer is generally liquid impermeable and is the portion of the absorbent article that faces the wearer's clothing. The backsheet layer can allow passage of air or vapor to leave the absorbent article while still blocking passage of liquid. In general, any liquid impermeable material can be used to form the backsheet layer. The backsheet layer may be comprised of a single or multiple layers, with one or more of these layers themselves comprising similar or different materials. Suitable materials that may be used may be microporous polymer films such as polyolefin films of polyethylene or polypropylene, nonwovens and nonwoven laminates, and film/nonwoven laminates. The specific structure and composition of the backsheet layer may be selected from a variety of known films and/or fabrics, with the specific material selected as appropriate to provide the desired level of liquid barrier, strength, abrasion resistance, tactility, aesthetics, etc. is selected. In various embodiments, polyethylene film may be used, which may have a thickness ranging from about 0.2 to 0.5 mils to about 3.0 or 5.0 mils. An example of a backsheet layer may be a polyethylene film, such as available from Pliant Corporation, Schaumburg, Illinois. Another example may include calcium carbonate filled polypropylene film. In another embodiment, the backsheet layer may be a hydrophobic nonwoven material with moisture barrier properties, such as a nonwoven laminate, such as spunbond, meltblown, meltblown, spunbond, or a four-ply laminate. Accordingly, the backsheet layer may have a single or multi-layer configuration, such as a configuration of multiple film layers or a laminate of films and non-woven fibrous layers. Suitable backsheet layers include US Patent No. 4,578,069 to Whitehead et al., US Pat. No. 4,376,799 to Tusim et al., US Pat. No. 5,695,849 to Shawver et al., US Patent No. 6,075,179 to McCormack et al., and US Patent No. 6,376,095 to Cheung et al. , each of which is incorporated herein by reference in its entirety.

For the sake of simplicity and brevity, any range of values set forth in the invention is intended to consider all values within the range, and is intended to support claims reciting any subrange with endpoints that are all numerical values within the particular range in question. must be interpreted. As a hypothetical example, the disclosure of the range 1 to 5 would include the following ranges 1 to 5; 1 to 4; 1 to 3; 1 to 2; 2 to 5; 2 to 4; 2 to 3; 3 to 5; 3 to 4; and 4 to 5.

Dimensions and values disclosed herein should not be construed as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each of these dimensions is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm.”

All documents cited in the detailed description are, in relevant part, incorporated herein by reference; Citing any literature should not be construed as an admission that this is prior art for the present invention. To the extent that any meaning or definition of a term in this specification is inconsistent with any meaning or definition of a term in a document incorporated by reference, the meaning or definition assigned to a term in this specification will apply.

Although specific embodiments of the invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications may be made without departing from the spirit and scope of the invention. Accordingly, the appended claims are intended to cover all such changes and modifications as fall within the scope of the present invention.

When introducing elements of the subject matter or preferred embodiment(s) of the subject matter, the phrases "a", "one", "the", and "the" mean that one or more of the elements are present. will be. The terms “comprising,” “comprising,” and “having” are inclusive and mean that additional elements other than those listed may be present. Many modifications and variations of the present invention may be made without departing from the spirit and scope of the present invention. Accordingly, the above-described exemplary embodiments should not be used to limit the scope of the present invention.

Claims (12)

A topsheet layer for use in an absorbent article, the topsheet layer comprising non-chemically reinforced natural fibers. The topsheet layer of claim 1, wherein the natural fibers are cotton fibers. The topsheet layer of claim 1, wherein the natural fibers are present in an amount greater than 50% by weight based on the total weight of the topsheet layer. The topsheet layer of claim 3, wherein the natural fibers are present in an amount greater than 75% by weight based on the total weight of the topsheet layer. The topsheet layer of claim 1, wherein the topsheet layer is hydrophobic. The top sheet layer of claim 5, wherein the top sheet layer has a water contact angle of 90 ^o to 150 ^o . The top sheet layer of claim 6, wherein the top sheet layer has a water contact angle of 130 ^o to 140 ^o . The topsheet layer of claim 1, wherein the topsheet layer has a whiteness index of less than 70. An absorbent article comprising the topsheet layer of claim 1, the backsheet layer, and an absorbent core positioned between the topsheet layer and the backsheet layer. A method of manufacturing the top sheet layer of claim 1, comprising the steps of boiling natural fibers in a sodium hydroxide solution (0.1 to 10 g/L) at a temperature of 60 ^o - 100 ^o C for 30 to 240 minutes to refine the natural fibers. Including, method. The method of claim 10, wherein the refining of the natural fibers is carried out by boiling the natural fibers in a sodium hydroxide solution (0.5 to 2.0 g/L) at a temperature of 80 ^o - 90 ^o C for 120 to 180 minutes. 11. The method of claim 10, wherein the natural fibers are not bleached.