Absorbent article with spacer woven fabric

Abstract

The present invention provides an absorbent article comprising a liquid permeable topsheet having a wearer facing surface and an opposite garment facing surface wherein the topsheet comprises a nonwoven having a plurality of pores; a liquid impermeable backsheet; an absorbent core disposed between the topsheet and the backsheet; and a fluid management layer disposed between the topsheet and the absorbent core, the fluid management layer comprising a spacer woven fabric wherein the nonwoven comprises a first surface forming the wearer-facing surface of the topsheet and a second surface forming the garment-facing surface of the topsheet, the first surface has a first contact angle of no less than about 90 degrees as measured according to a contact angle test, and wherein the spacer woven fabric comprises a top surface, a bottom surface, and a plurality of yarns interconnecting the first surface and the second surface wherein the first surface and the second surface are spaced apart from each other.

Description

Technical Field

[0001] The present invention relates to an absorbent article that includes a fluid management layer that includes a spaced woven fabric. Background Art

[0002] Absorbent articles for personal hygiene, such as sanitary napkins, adult incontinence underwear, disposable diapers for infants and toddlers, and / or training pants for toddlers, are designed to absorb and contain body exudates, particularly large amounts of menstrual fluid, urine, and / or loose stools (collectively referred to as "fluids").

[0003] Users of such disposable absorbent articles have several concerns. Leakage of products such as menstrual pads, diapers, sanitary napkins, and incontinence pads is an important concern. To prevent fluid leakage, it is desirable for the absorbent article to provide a high collection rate. The feeling of dampness is also a concern, so it is necessary to effectively reduce or prevent backflow of fluid from other components of the absorbent article back to the topsheet. Another desirable characteristic of the absorbent article is to present a clean user contact surface with fewer color spots.

[0004] These absorbent articles are typically designed to include several layers that provide different functions. The liquid-permeable topsheet is arranged closest to the wearer's skin and should be able to quickly absorb the excreted fluid. The backsheet is disposed on the opposite clothes-facing side of the article. The absorbent core, which desirably includes various absorbent materials, is expected to quickly absorb body fluids from the topsheet and have a high fluid storage capacity.

[0005] It is known that hydrophilic topsheets exhibit a faster collection rate than hydrophobic topsheets. However, because they capture or retain fluid, they tend to cause a feeling of dampness and / or, due to the high affinity of the constituent fibers for the fluid, the fluid flows back through the topsheet. Absorbent articles with hydrophobic topsheets may be preferred by some consumers because they provide a dry feeling and have good results in obscuring / masking menstrual fluid / urine contamination. However, hydrophobic topsheets only absorb fluid via capillary forces, which results in a slower collection rate and causes fluid leakage problems.

[0006] The absorbent cores commonly used in absorbent articles include various absorbent materials. To meet the need for thin absorbent articles, absorbent cores typically include a large amount of superabsorbent polymer. Superabsorbent polymers have a high absorption capacity but a relatively slow absorption rate, such that absorbent articles having an absorbent core that includes a large amount of superabsorbent polymer often cannot instantaneously absorb a large amount of fluid excreted within a few seconds.

[0007] Absorbent articles typically employ a fluid management layer between a topsheet and an absorbent core. The fluid management layer can rapidly receive a large amount of fluid from the topsheet and temporarily store the fluid before it is absorbed by the absorbent core. Thus, one desired function of the fluid management layer is to rapidly collect fluid from the topsheet and transfer it to the absorbent core in an efficient manner. Another desired function is to reduce the amount of fluid in the topsheet to avoid a wet feeling.

[0008] To rapidly remove fluid from the topsheet, one approach is to develop a fluid management layer that has good wicking properties to distribute the fluid along the plane of the fluid management layer, thereby reducing the fluid concentration at the loading point, and has high capillary forces to draw the fluid downward from the topsheet. Small pore sizes in the plane direction or the z - direction can contribute to both wicking properties and capillary forces. While smaller holes in the fluid management layer enhance wicking properties and capillary forces, they also create a high flow resistance for fluid to penetrate the fluid management layer, which results in a slow collection speed. Thus, there is typically a trade - off between collection speed and wet sensation (re - wetting).

[0009] WO2005 / 051657A discloses a multi - layer fluid management fabric composite that includes a three - dimensional fabric spacer forming a first layer of the fabric composite, a plurality of stacked moisture - absorbing cores located outside the spacer, and a liquid - impermeable sheath located outside the absorbent cores. The three - dimensional fabric spacer in WO2005 / 051657A includes a first face, an opposite second face, and intermediate spacer yarns interconnecting the first face and the second face. WO2014 / 1011927 discloses an absorbent article that includes a fluid flow control member, which is a spacer woven fabric located between a topsheet and an absorbent core, wherein the spacer woven fabric includes a top layer, a bottom layer, and a yarn interconnecting layer between the top layer and the bottom layer.

[0010] Accordingly, there is a need for an absorbent article that can provide a rapid fluid collection speed without compromising a dry sensation or low re - wetting.

[0011] There is also a continuing need for an absorbent article that can provide improved surface cleanliness of body fluids without compromising fluid handling properties such as rapid fluid collection speed and reduced re - wetting. SUMMARY OF THE INVENTION

[0012] The present invention provides an absorbent article, which comprises: a liquid-permeable topsheet having a surface facing the wearer and an opposite surface facing the clothing, wherein the topsheet comprises a nonwoven fabric having a plurality of pores; a liquid-impermeable backsheet; an absorbent core disposed between the topsheet and the backsheet; and a fluid management layer disposed between the topsheet and the absorbent core, the fluid management layer comprising a spacer woven fabric. The nonwoven fabric comprises a first surface forming the surface of the topsheet facing the wearer and a second surface forming the surface of the topsheet facing the clothing, the first surface having a first contact angle of not less than about 90 degrees as measured by a contact angle test, and wherein the spacer woven fabric comprises a top surface, a bottom surface, and a plurality of yarns interconnecting the first surface and the second surface, wherein the first surface and the second surface are spaced apart from each other.

[0013] Due to the unique combination of a topsheet comprising a hydrophobic nonwoven fabric forming the surface facing the wearer and a fluid management layer comprising a spacer woven fabric, the absorbent article of the present invention can provide a fast liquid acquisition speed and a clean surface without compromising the dry sensory feeling.

[0014] These and other features, aspects, and advantages of the present invention will become apparent to those skilled in the art upon reading this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a perspective view of an exemplary absorbent article.

[0016] Figure 2 is a cross-sectional view taken along 2-2 of the absorbent article. Figure 1 is a schematic view of the nonwoven fabric constituting the topsheet of the absorbent article.

[0017] Figure 3A is a schematic view of the nonwoven fabric constituting the topsheet of the absorbent article.

[0018] Figure 3B is a schematic view of the nonwoven fabric constituting the topsheet of the absorbent article.

[0019] Figure 4 is a schematic view of the nonwoven fabric constituting the topsheet of the absorbent article.

[0020] Figure 5 is a schematic view of the nonwoven fabric constituting the topsheet of the absorbent article.

[0021] Figure 6 is a top view of an exemplary topsheet of the absorbent article of the present invention.

[0022] Figure 7 is a top view of another exemplary topsheet of the absorbent article of the present invention.

[0023] Figure 8AAn image of an exemplary water droplet having a contact angle greater than 90 degrees according to the contact angle measurement method disclosed herein.

[0024] Figure 8B An image of an exemplary water droplet having a contact angle not greater than 90 degrees according to the contact angle measurement method disclosed herein.

[0025] Figure 9A A perspective view of a moisture permeable plate for collecting time measurements.

[0026] Figure 9B For Figure 9A A plan view of the moisture permeable plate.

[0027] Figure 9C For Figure 9B A plan view of a cross-section of the moisture permeable plate in the 9C-9C direction.

[0028] Figure 9D For Figure 9B A plan view of part pf of the moisture permeable plate.

[0029] Figure 9E For Figure 9B A plan view of a cross-section of the moisture permeable plate in the 9E-9E direction.

[0030] Figure 10A An SEM plan view image of an exemplary spacer woven fabric.

[0031] Figure 10B For Figure 10A The processed image.

[0032] Figure 11 A cross-sectional image of an exemplary spacer woven fabric. Detailed Description

[0033] All ranges are inclusive and combinable. The digits of the significant figures neither limit the quantity indicated nor the precision of the measurement. All numerical values should be understood to be modified by the word "about" unless otherwise specifically indicated.

[0034] As used herein, the term "absorbent article" includes disposable diapers, sanitary napkins, pantiliners, incontinence pads, interlabial pads, breast pads, sweat sheets, animal excrement disposal articles, animal diapers, and the like.

[0035] As used herein, the term "joined" refers to the condition where a first member is directly or indirectly attached or connected to a second member. In the case where the first member is attached or connected to an intermediate member, and the intermediate member is in turn attached or connected to the second member, the first member and the second member are indirectly joined.

[0036] As used herein, the term "consolidated" is used to describe the fibers of a nonwoven material that have been interlaced, entangled, and / or pushed / pulled in the positive and / or negative Z-direction (the thickness direction of the nonwoven material). Some exemplary methods for consolidating the fibers of a nonwoven web include hydroentangling and needling. Hydroentangling uses multiple high-pressure water jets to entangle the fibers.

[0037] As used herein, the term "carded" is used to describe the structural characteristics of the fluid management layer described herein. Carded nonwovens utilize fibers that are cut to a specific length, which are otherwise referred to as "short length fibers". The short length fibers can be any suitable length. For example, the short length fibers can have a length of up to 120 mm or can have a length as short as 10 mm. However, if a particular group of fibers is short length fibers (e.g., viscose fibers), then each viscose fiber in the carded nonwoven has a length that is primarily the same, i.e., short length. It is noted that in the case of including additional short fiber length fiber types such as polypropylene fibers, each polypropylene fiber in the carded nonwoven also has a length that is primarily the same. However, the short length of the viscose fibers and the short length of the polypropylene fibers can be different.

[0038] In contrast, continuous filaments such as those produced by a spunbond process or a meltblown process do not produce short length fibers. Instead, these filaments have an indefinite length and are not cut to a specific length as described for their short fiber length counterparts.

[0039] The "longitudinal" direction is the direction that extends parallel to the maximum linear dimension of the article (usually the longitudinal axis) and includes directions within 45° of the longitudinal direction. When used herein, the "length" of an article or its component generally refers to the size / distance of the maximum linear dimension, or usually refers to the size / distance of the longitudinal axis of the article or its component.

[0040] The "lateral" or "transverse" direction is orthogonal to the longitudinal direction, i.e., lies in the same principal plane as the article and the longitudinal axis, and the transverse direction is parallel to the transverse axis. When used herein, the "width" of an article or its component is the size / distance of the dimension that is orthogonal to the longitudinal direction of the article or its component, i.e., orthogonal to the length of the article or its component, and generally it refers to the distance / size of the dimension that is parallel to the transverse axis of the article or component.

[0041] As used herein, the terms "hydrophilic" and "hydrophobic" have the meanings widely accepted in the art with respect to the contact angle of water on a material surface. Thus, a material having a water contact angle measured by a contact angle test greater than about 90° is considered hydrophobic, and a material having a water contact angle measured by a contact angle test less than about 90° is considered hydrophilic.

[0042] Absorbent article

[0043] Absorbent articles will now be generally discussed and further illustrated in the form of sanitary napkin 100, as Figure 1 and Figure 2 exemplarily represented. Figure 1 FIG. is a plan view of an exemplary sanitary napkin 100 in a flat configuration and turned with the wearer side facing up. Figure 2 FIG. is a cross-sectional view taken along line Figure 1 2-2 of the absorbent article.

[0044] Referring to Figure 1 and Figure 2 , an absorbent article (such as sanitary napkin 100) according to the present invention includes a topsheet 24 having a surface facing the wearer and a surface facing the clothing located opposite the surface facing the wearer. The topsheet 24 includes a nonwoven fabric 30, wherein the top surface 32 of the nonwoven fabric 30 forms the surface of the topsheet 24 facing the wearer.

[0045] The absorbent article further includes a backsheet 26 having a surface facing the clothing and a surface facing the wearer located opposite the surface facing the clothing and at least partially joined to the topsheet 24. The absorbent article further includes an absorbent core 28 positioned between the topsheet 24 and the backsheet 26. The absorbent article further includes a fluid management layer 27 located between the topsheet 24 and the absorbent core 28. The absorbent article may further include additional fluid collection and / or distribution layers 25 (or systems). The absorbent article may further include a pair of side flaps or wings 23. The topsheet 24, the backsheet 26, the fluid management layer 27, the absorbent core 28, and other optional elements may be assembled in various well-known configurations.

[0046] The backsheet 26 and the topsheet 24 can be secured together in a variety of ways. The topsheet 24 and the backsheet 26 can be joined to each other by heat bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or hemming using an adhesive. A fluid-impermeable hem seal can prevent lateral migration of fluid through the edges of the product ("wicking") and inhibit side soiling of the user's undergarments.

[0047] When the absorbent article is a sanitary napkin as shown in Figure 1 , as is typical for sanitary napkins and the like, the sanitary napkin may have a female undergarment adhesive disposed on the clothing-facing side of the backsheet 26. The female undergarment adhesive can be any adhesive known in the art for this purpose and can be covered with a release paper as is well known in the art prior to use. If side flaps or wings are present, the female undergarment adhesive can be applied to the clothing-facing side to contact and adhere to the underside of the user's undergarment.

[0048] Top sheet

[0049] The topsheet is generally liquid-permeable and is configured to receive fluids being discharged from the body and to assist in directing the fluids toward the fluid management layer and / or toward the absorbent core. One important quality of the topsheet is its ability to reduce the accumulation of fluids on the topsheet before the fluids can be absorbed by the absorbent article. Another desirable quality of the topsheet is to reduce backflow of the topsheet. It is also desirable for the topsheet to present a clean user contact surface with fewer color spots.

[0050] The topsheet in the present invention is the part of the absorbent article that contacts the wearer's skin during use of the article. As is known to those of ordinary skill in the art, the topsheet may be joined to parts of the backsheet, the absorbent core, and / or any other layer. Additionally, at least a portion or all of the topsheet may be liquid-permeable, allowing body fluids to easily penetrate through its thickness.

[0051] The topsheet in the present invention has a wearer-facing surface that forms the surface of the absorbent article facing the wearer and an opposite clothing-facing surface, and includes a nonwoven fabric that has a plurality of pores.

[0052] The nonwoven fabric constituting the topsheet includes a first surface that forms the wearer-facing surface of the topsheet and a second surface that forms the clothing-facing surface of the topsheet. The first surface of the nonwoven fabric has a first contact angle of not less than about 90 degrees, or not less than 95 degrees, or not less than 100 degrees as measured by a contact angle test. The second surface of the nonwoven fabric may have a second contact angle of not less than about 90 degrees as measured by a contact angle test. The second surface of the nonwoven fabric may have a second contact angle of less than about 90 degrees as measured by a contact angle test. In one embodiment, the difference between the first contact angle and the second contact angle is at least about 10 degrees, or at least about 15 degrees, or at least about 20 degrees as measured by a contact angle test. The nonwoven fabric with a second surface having a second contact angle of less than about 90 degrees may provide a faster acquisition rate compared to the nonwoven fabric with a second surface having a second contact angle of not less than about 90 degrees.

[0053] The nonwoven fabric includes a first layer that includes hydrophobic fibers. The nonwoven fabric may also include a second layer that includes hydrophilic fibers. When the nonwoven fabric forms the topsheet of the absorbent article according to the present invention, the first layer forms the wearer-facing surface of the topsheet. When the nonwoven fabric includes a first layer and an optional second layer, the first layer forms the wearer-facing surface of the topsheet, and the second layer forms the clothing-facing surface of the topsheet.

[0054] When the nonwoven fabric forming the topsheet of the absorbent article according to the present invention includes two or more layers, the two or more layers may form an integral structure or may remain as discrete layers. The integral structure herein is intended to mean that although it may be formed of several sub-layers or layers having different properties and / or compositions from each other, they are mixed in some way in the boundary region such that a region where different sub-layers transition from one to another can be recognized, rather than a distinct boundary between the sub-layers. Such an integral structure is generally constructed by forming each sub-layer on top of another in a continuous manner (e.g., using air-laying or wet-laying deposition). Or each sub-layer in the sub-layers is produced in a separate step, and the sub-layers are combined together in a face-to-face relationship. The sub-layers may be integrated by known consolidation or bonding methods, such as spunlace, hydroentangling, calendering, air-through bonding, and resin bonding.

[0055] Generally, no adhesive is used between sub-layers of a single material. However, in some cases, there may be adhesives and / or binders, but their contents are generally low.

[0056] When describing the topsheet of the present invention herein, the terms layer, sub-layer, and stratum / strata are interchangeable. Regarding the description of the topsheet having an integral structure, the terms layer and stratum are interchangeable.

[0057] When the topsheet in the present invention includes two or more layers that remain as discrete layers, the two or more layers may be at least partially attached to each other by, for example, thermal bonding, adhesive bonding, ultrasonic bonding, or any combination thereof.

[0058] The topsheet in the present invention may have various structures.

[0059] See Figure 3A and Figure 3B , the nonwoven fabric 30 constituting the topsheet disclosed herein includes at least a first layer 1. The first layer 1 includes a first surface 3 forming the surface of the topsheet facing the wearer and an opposite second surface 4.

[0060] See Figure 4 and Figure 5 , the nonwoven fabric 30 constituting the topsheet disclosed herein may include a first layer 1 forming the surface of the topsheet facing the wearer and a second layer 2 forming the surface of the topsheet facing the clothing.

[0061] See Figure 4 , the nonwoven fabric 30 may have an integral structure, and the first layer 1 and the second layer 2 are mixed in the boundary region, rather than having a distinct boundary between the two layers.

[0062] See Figure 5, the nonwoven fabric 30 can be a laminate of separate layers, in this case a first layer 1 and a second layer 2, which are joined to each other in a face-to-face relationship. The first layer 1 has a first surface 3 and a second surface 4 that form the wearer-facing surface of the topsheet. The second layer has a first surface 10 and a second surface 11 that form the garment-facing surface of the topsheet. Still referring to Figure 5 , the topsheet 24 can include a plurality of protrusions 9. The nonwoven fabric 30 can include a landing area 8 between most of the holes 5. The landing area can be generally flat. Most of the protrusions 9 can protrude outward from the landing area 8 of the nonwoven fabric 30.

[0063] The plurality of protrusions 9 can be evenly distributed on the wearer-facing surface of the topsheet. The plurality of protrusions 9 can be evenly distributed and form a shape or pattern on the wearer-facing surface of the topsheet. Most of the protrusions 9 can be surrounded by at least one landing area 8 and / or a plurality of holes 5. The landing area 8, the holes 5, and the protrusions 9 can form a three-dimensional surface on the wearer-facing surface of the topsheet.

[0064] In some embodiments, most of the protrusions 9 can be hollow. When the topsheet includes a first layer 1 and a second layer 2, when viewed from the first surface 3 of the first layer 1, the protrusions 9 protrude from the landing area 8 of the first layer 1 in the same direction, and the first layer 1 and the second layer 2 are spaced apart from each other. The hollow between the first layer and the second layer can improve the breathability of the topsheet.

[0065] The nonwoven fabric can include a plurality of holes 5. The nonwoven fabric 30 can include at least one non-hole area that substantially does not have holes. The non-hole area can be a flat landing area 8 and / or a protrusion 9. Refer to Figure 6 and Figure 7 , the nonwoven fabric 30 that constitutes the topsheet 24 can include at least one non-hole area, in this case the landing area 8, that does not have holes. The non-hole area can completely surround the holes. The non-hole areas can together form a generally continuous grid in the entire wearer-facing surface of the topsheet, while the holes can be discrete elements dispersed in and surrounded by the continuous grid.

[0066] Refer to Figure 7 , the non-hole area can be a plurality of discrete areas defined by the holes. Each of the plurality of discrete non-hole areas has a perimeter formed by a continuous line of holes.

[0067] When the topsheet described herein is incorporated into an absorbent article, when the article is in use, a plurality of optionally provided protrusions can protrude toward the wearer's skin and away from the absorbent core of the absorbent article.

[0068] This three-dimensional first layer of the nonwoven fabric provides better softness to the topsheet. It also helps keep the wearer's skin away from body fluids in the landing area, as the protrusions substantially create a space between the wearer's skin and the body fluids.

[0069] In the present invention, the nonwoven fabric constituting the topsheet may have a basis weight of about 20 g / m 2 to about 100 g / m 2 、or about 30 g / m 2 to about 60 g / m 2 、or about 20 g / m 2 to about 50 g / m 2 、or about 30 g / m 2 to about 50 g / m 2 .

[0070] First layer

[0071] The first layer of the nonwoven fabric contains hydrophobic thermoplastic fibers. In one embodiment, 100% of the constituent fibers of the first layer are hydrophobic fibers.

[0072] The thermoplastic fibers may be selected from polyester, polypropylene, polyethylene, polyether, polyamide, polyhydroxyalkanoate, polysaccharide, and combinations thereof. Additionally, other synthetic fibers such as rayon, polyethylene, and polypropylene fibers may also be used within the scope of the present disclosure.

[0073] The thermoplastic fibers can be single-component fibers (i.e., a single synthetic material or mixture used to form the entire fiber), multi-component fibers such as bicomponent fibers (i.e., the fiber is divided into multiple regions that include two or more different synthetic materials or mixtures thereof), and combinations thereof.

[0074] The first layer may include semi-synthetic fibers made from polymers, specifically hydroxy polymers. The topsheet may also include semi-synthetic fibers made from polymers, specifically hydroxy polymers. Non-limiting examples of suitable hydroxy polymers include polyvinyl alcohol, starch, starch derivatives, chitosan, chitosan derivatives, cellulose derivatives such as viscose fiber, gums, arabinans, galactans, Lyocell (Tencel ® ), and combinations thereof.

[0075] The first layer may also include cellulose-based fibers, optionally selected from the group consisting of wheat straw fiber, rice straw fiber, flax fiber, bamboo fiber, cotton fiber, jute fiber, hemp fiber, sisal fiber, bagasse fiber, Yucca filamentosa fiber, and combinations thereof.

[0076] Some examples of the first layer may include, but are not limited to: spunbond nonwovens; carded nonwovens; air-laid nonwovens; hydroentangled nonwovens, needled nonwovens, and nonwovens having relatively specific properties to be able to deform easily.

[0077] The first layer can be formed by many methods, such as air-laying, wet-laying, meltblowing, spunbonding, needling, and carding.

[0078] Hydrophilic fibers can be made hydrophobic by treating them with a hydrophobic treatment agent such as a hydrophobic surfactant, for example, by spraying or applying a hydrophobic treatment agent to the hydrophilic fibers with a kiss roll, by dipping the fibers into the hydrophobic treatment agent, or by including the hydrophobic treatment agent as part of the polymer melt in the production of thermoplastic fibers. When melted and re-solidified, the treatment agent will tend to remain at the surface of the fiber.

[0079] The first layer can be a carded nonwoven layer.

[0080] The hydrophobic fibers constituting the first layer 1 have a contact angle higher than about 90 degrees or higher than about 100 degrees. The contact angle of the constituent fibers of the first layer 1 can be no greater than 150 degrees, or can also be no greater than 130 degrees. The hydrophobicity of the constituent fibers can be adjusted by appropriately adjusting the degree of hydrophobization treatment of the thermoplastic fibers, for example, the type and content of the hydrophobization treatment.

[0081] The hydrophobic fibers constituting the first layer can have a fiber fineness of no greater than 4 denier, or 2.5 denier, or no greater than 2 denier, or no greater than 1.5 denier.

[0082] The first layer can have a basis weight of about 5 g / m 2 to about 30 g / m 2 、or about 8 g / m 2 to about 30 g / m 2 、or about 8 g / m 2 to about 17 g / m 2 、or about 8 g / m 2 to about 14 g / m 2 .

[0083] Second layer :

[0084] The nonwoven fabric constituting the topsheet disclosed herein may include a second layer, and the second layer contains hydrophilic fibers.

[0085] The fibers constituting the second layer can be natural fibers, synthetic fibers, or a combination of natural fibers and synthetic fibers. In one embodiment, the second layer contains thermoplastic fibers.

[0086] The list of synthetic fibers corresponds to the list disclosed above for the topsheet and the first layer.

[0087] Hydrophobic fibers can be made hydrophilic by treating them with a hydrophilic treating agent such as a hydrophilic surfactant, for example, by spraying the hydrophobic thermoplastic with the hydrophilic treating agent, dipping the fibers in the treating agent, or including the hydrophilic treating agent as part of the polymer melt in the production of the thermoplastic fibers. Upon melting and re-solidifying, the treating agent will tend to remain at the surface of the fibers.

[0088] The hydrophilic fibers constituting the second layer can have a fiber fineness of not more than 4 denier, or 2.5 denier, or not more than 2 denier, or not more than 1.5 denier.

[0089] The second layer can have a basis weight of about 10 g / m 2 to about 70 g / m 2 、or about 15 g / m 2 to about 60 g / m 2 、or about 10 g / m 2 to about 40 g / m 2 of basis weight.

[0090] The first web and / or the second web can be made of a carded fiber web (such as a parallel fiber web, a semi-random fiber web, a random fiber web, a cross fiber web, an interlaced fiber web, etc.), an air-laid fiber web, a wet-laid fiber web, a spunbond fiber web, etc. The first fiber web and the second fiber web can be the same or different.

[0091] The heat treatment of each web or synthetic fiber web can be carried out using any conventionally known heat treatment method. Examples of preferred treatment methods include heat treatment devices such as a hot air permeation type heat treatment device, a hot air blowing heat treatment device, an infrared heat treatment device, etc. These heat treatment apparatuses are usually provided with a conveying support for supporting and conveying the fiber web. The heat treatment can be carried out under these conditions: such that the sheath component of the first and second core / sheath type composite fibers is sufficiently melted and / or softened and bonded at the contact points or intersection points of the fibers, and such that the crimps of the first and second core / sheath type composite fibers do not collapse.

[0092] All aspects of the first layer described above equally apply to the first layer in the topsheet including the first layer and the second layer, except for the second layer including hydrophilic fibers.

[0093] Hole

[0094] The topsheet of the present invention may include a plurality of apertures. In essence, nonwovens have apertures between the fibers. The apertures in the present disclosure are significantly larger in size than such apertures and are not intended to include such apertures. To ensure the stability of the material, regardless of their specific shape and width, the minimum edge-to-edge distance between most of the apertures is at least 0.5 mm, or at least 1.5 mm or 2.0 mm. This distance is measured on the first surface of the topsheet.

[0095] The shape of the apertures can vary. For example, the shape of the apertures as seen from the first surface of the first layer can be circular, oval, rectangular, or polygonal. In one embodiment, the apertures have a circular shape, an oval shape, or a polygonal shape.

[0096] The three-dimensional shape of the apertures can be cylindrical (e.g., having a circular or oval bottom), prismatic (e.g., having a polygonal bottom), or frustoconical or pyramidal.

[0097] See Figures 3A to 5 , each of the apertures 5 can have a sidewall 6. See Figure 3A , the sidewall 6 can extend outwardly away from the non-apertured region of the second surface of the topsheet. The sidewalls of the apertures can form a funnel or a channel. The sidewall 6 may not extend outwardly as Figure 3B shown.

[0098] The apertures can be tapered and have a conical shape such that the diameter of the aperture is larger at the portion of the aperture adjacent to the first surface of the nonwoven than at the bottom edge of the aperture.

[0099] Such a tapered configuration helps to reduce the risk of backflow, i.e., the backflow of body fluids from components below the topsheet, such as the absorbent core, and through the topsheet. For a hydrophobic topsheet with apertures, backflow mainly occurs through the apertures. The tapered shape of the apertures can help to reduce backflow because the diameter of the aperture towards the absorbent core is smaller than the diameter of the aperture in the first layer.

[0100] The plurality of apertures can also vary in width.

[0101] The size of the apertures can be determined to achieve the desired fluid and / or air permeability performance and other properties desired by the wearer. If the apertures are too small, the fluid may not be able to pass through the apertures, either because the fluid source is not aligned with the apertures or because, for example, the diameter of the soft feces is larger than the apertures. If the apertures are too large, the skin area that can be contaminated by "backflow" from the article increases.

[0102] Each of the plurality of apertures can have a size between 0.2 mm 2 and 1.5 mm 2 , 0.2 mm 2 and 1.0 mm 2 , or 0.25 mm 2 and 0.5 mm 2a size within a range, and / or a diameter within a range of 0.3 mm to 1.5 mm, or 0.3 mm to 1 mm, or 0.4 mm to 0.8 mm. The plurality of holes may have a regular shape selected from the group consisting of: circular, oval, triangular, square, rectangular, parallelogram, trapezoidal, polygonal, hourglass, star, and any combination thereof.

[0103] For the purpose of rapid fluid collection speed, the nonwoven fabric constituting the topsheet has an opening area of at least 2.5%, or at least 3%, or at least 5%. The nonwoven fabric may have an opening area of not more than about 30%, or not more than 25%, or not more than 20% for the purpose of reducing or preventing backflow.

[0104] Figure 6 and Figure 7 is a schematic top view of an exemplary nonwoven fabric 30 constituting the topsheet 24. See Figure 7 , in some embodiments, the nonwoven fabric 30 may include clusters of holes. The term "clusters of holes" as used herein means a hole pattern in which at least one hole has at least three adjacent holes, and each of one hole and at least three adjacent holes has an edge-to-edge spacing S (the shortest distance between the edge of one hole and the edge of an adjacent hole) of not more than about 2.5 mm, preferably not more than about 2 mm.

[0105] When used as a component of an absorbent article, the hole pattern in the topsheet may be coordinated with, for example, graphics, markings, printing, inks, colors, and / or patterned adhesives located in the topsheet of the absorbent article or in another component.

[0106] Fluid management layer

[0107] One function of the fluid management layer is to rapidly collect liquid or other body exudates from the topsheet and transfer or distribute them to the absorbent core in an efficient manner.

[0108] The fluid management layer in the absorbent article of the present invention is disposed directly or indirectly on top of the absorbent core. The fluid management layer includes a spaced woven fabric, and the spaced woven fabric includes a top surface, a bottom surface, and a plurality of yarns interconnecting the first surface and the second surface, wherein the first surface and the second surface are spaced apart from each other.

[0109] The top surface and the bottom surface of the spaced woven fabric may have the same configuration or different configurations to direct the fluid flow velocity.

[0110] The spacer woven fabric may include thermoplastic fibers, including polyester, polyamide, polyolefins (such as polyethylene and polypropylene), or any mixture thereof. The spacer woven fabric may also include absorbent fibers. Optional absorbent fibers may provide absorption of liquid intrusions from the surface facing the wearer or the topsheet. Any suitable absorbent material may be used for the absorbent fibers. Some examples of absorbent materials include cotton, pulp, rayon, or regenerated cellulose, or combinations thereof. The spacer woven fabric may not include absorbent materials, such as absorbent fibers and superabsorbent polymers. The top and bottom surfaces of the spacer woven fabric may be made of the same fibers or different fibers. At least one of the top and bottom surfaces includes polyethylene terephthalate ("PET") fibers.

[0111] The spacer woven fabric may also include surfactants to facilitate fluid penetration for rapid drainage and not retain the fluid unnecessarily for a long time, thus maintaining the free volume capacity for the next gush of fluid.

[0112] The spacer woven fabric may have a basis weight of about 150 gsm to 350 gsm, or about 200 gsm to about 300 gsm, or about 150 gsm to about 250 gsm.

[0113] The spacer woven fabric may have a thickness in the range of about 1.0 mm to about 2.5 mm as measured according to the spacer woven fabric size test. If the thickness is too small, it may negatively affect the fluid collection speed. If the thickness is too high, the absorbent article including the spacer woven fabric may not fit well on the wearer's body.

[0114] Each yarn in the spacer woven fabric that interconnects the first and second sides disclosed herein may include from about 2 filaments to about 60 filaments. The multiple filaments constituting the yarn create inter-filament microchannels that can enhance fluid wicking and faster fluid transport. The filaments constituting the yarn may have a fineness of 1.5 dtex to 10 dtex, or 3 dtex to 8 dtex, or 2 dtex to 5 dtex. If the filaments are too thin, it may negatively affect the elasticity and fluid collection speed of the spacer woven fabric. If the filaments are too thick, the material may be hard and have higher rewetting.

[0115] The top and bottom surfaces of the spacer woven fabric may have openings to ensure rapid inflow and effective distribution of body fluids. The bottom surface of the spacer woven fabric may have a tighter structure than the top surface, having relatively small openings. In one embodiment, the top surface of the spacer woven fabric includes openings having an opening area of not less than about 0.2 mm as measured according to the spacer woven fabric size test 2 of the opening area.

[0116] The yarn can form channels for fluid flow between the first side and the second side to efficiently distribute and transfer the fluid to the absorbent core. Additionally, due to the large void space between the first side and the second side in the spacer woven fabric, the spacer woven fabric can accommodate and temporarily hold a relatively large volume of fluid. Thus, the discharged body fluid can be effectively received into the spacer woven fabric and can be made to flow to the body fluid-absorbing portion of the absorbent core including the absorbent material. Especially when the absorbent core includes a superabsorbent polymer having a high absorption capacity but a relatively slow absorption rate, the fluid management layer disposed above the absorbent core enables the absorbent core to make full use of its high absorption capacity by temporarily holding the fluid volume.

[0117] The spacer woven fabric is oriented in the absorbent article in such a way that the top surface of the spacer woven fabric faces the direction of the topsheet and the bottom surface of the spacer woven fabric faces the direction of the backsheet.

[0118] Moreover, due to the unique spacer woven fabric structure, the absorbent article of the present invention can have a high compressive strength without significantly increasing the basis weight or volume of the absorbent article.

[0119] Absorbent core

[0120] The absorbent core includes absorbent material.

[0121] The absorbent material in the absorbent core can be any liquid-absorbing material commonly used in disposable absorbent articles, such as comminuted wood pulp (commonly referred to as airfelt or fluff). Examples of other suitable liquid-absorbing materials include creped cellulose wadding; meltblown polymers, including co-formed meltblown polymers; chemically hardened, modified or crosslinked cellulose fibers; tissue paper (including tissue wraps and tissue laminates), absorbent foams, absorbent sponges, superabsorbent polymers (abbreviated herein as "SAP"), absorbent gelling materials, or any other known absorbent materials or combinations of materials. The term "superabsorbent polymer" as used herein refers to an absorbent material which can be a crosslinked polymer and which, when measured using the Centrifugal Retention Capacity (CRC) test (EDANA method WSP241.2-05E), can generally absorb at least 10 times its own weight of 0.9% saline solution. The SAP can specifically have a CRC value of more than 20 g / g, or more than 24 g / g, or from 20 g / g to 50 g / g, or from 20 g / g to 40 g / g, or from 24 g / g to 30 g / g. The SAP can generally be in particulate form (superabsorbent polymer particles), but other forms of SAP, such as for example superabsorbent polymer foams, are not excluded.

[0122] Back sheet

[0123] Any conventional liquid-impermeable backsheet material commonly used for absorbent articles can be used as the backsheet. In some embodiments, noxious odors emitted from the absorbed body excretions cannot permeate through the backsheet, so that noxious odors do not escape. The backsheet may or may not be breathable.

[0124] Measurement

[0125] 1. Contact angle test

[0126] All tests were conducted in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0127] Rectangular samples measuring 10 mm × 50 mm were cut from the raw material nonwoven fabric or the topsheet of the disposable absorbent article, taking care not to touch the sample surface or damage the structure of the material. The samples had a length of 5 cm and, if cut from the absorbent article, were aligned with the longitudinal centerline of the absorbent article. The samples were gently handled by the edges using tweezers and mounted flat on the sample stage of an optical microscope such as a Keyence VHX 5000 or equivalent. The appropriate light source, magnification, and camera position were adjusted to clearly display a cross-sectional view of the sample.

[0128] A water droplet with a volume of approximately 0.05 ml was gently deposited onto the sample from a short distance of no more than 1 cm above the test surface of the sample. High-resolution images of the water droplet on the test surface of the nonwoven sample were obtained using a Keyence VHX 5000 or equivalent instrument. These steps were repeated to obtain multiple water droplet images. Appropriate water droplet images, where each water droplet was oriented such that the projection of the water droplet extending from the nonwoven surface was approximately maximized. As Figure 8A and Figure 8B shown by line 3700 in, the contact angle between the water droplet and the sample was measured directly from the captured images, accurate to 0.1 degree. Figure 8A is an exemplary image of a water droplet with a contact angle greater than 90°. Figure 8B is an exemplary image of a water droplet with a contact angle less than 90°.

[0129] Measurements were performed on areas of the nonwoven fabric where there were no holes. Five individual droplets were imaged, from which ten contact angles were measured, i.e., one contact angle was measured on each side of each imaged droplet. The arithmetic mean of the ten contact angle values was calculated, accurate to 0.1 degree, and reported as the surface contact angle.

[0130] 2. Artificial menses fluid ("AMF") preparation

[0131] AMF consists of a mixture of defibrinated sheep blood, phosphate buffered saline solution, and a mucin component, and has a viscosity between 7.15 cSt and 8.65 cSt at 23°C ± 1°C.

[0132] Use a low-viscosity rotational viscometer (such as a Cannon LV-2020 Rotary Viscometer (Cannon Instrument Co., State College, US) with a UL adapter) or equivalent to perform the viscosity on the AMF. Select a spindle of appropriate size within the viscosity range and operate and calibrate the instrument according to the manufacturer. Measurements are made at 23 °C ± 1 °C and at 60 rpm. Report the results accurate to 0.01 cSt.

[0133] Defibrinated sheep blood

[0134] Use defibrinated sheep blood with a packed cell volume of 38% or greater collected under sterile conditions (purchased from Cleveland Scientific, Inc., Bath, OH, US) or equivalent.

[0135] Phosphate buffered saline solution

[0136] The phosphate-buffered saline solution consists of two separately prepared solutions (Solution A and Solution B). To prepare 1 L of Solution A, add 1.38 ± 0.005 g of sodium dihydrogen phosphate monohydrate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to a certain volume. Mix well. To prepare 1 L of Solution B, add 1.42 ± 0.005 g of disodium hydrogen phosphate anhydrous and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to a certain volume. Mix well. Add 450 ± 10 mL of Solution B to a 1000 mL beaker and stir at low speed on a magnetic stirrer. Insert a calibrated pH probe (accurate to 0.1) into the beaker with Solution B and add sufficient Solution A while stirring to bring the pH to 7.2 ± 0.1.

[0137] Mucus component

[0138] The mucus component is a mixture of phosphate buffered saline solution, aqueous potassium hydroxide solution, porcine gastric mucin, and aqueous lactic acid solution. The amount of porcine gastric mucin added to the mucus component directly affects the final viscosity of the prepared AMF. The successful range of porcine gastric mucin is typically between 38 grams and 50 grams. To prepare approximately 500 mL of the mucus component, 460 ± 10 mL of a previously prepared phosphate buffered saline solution and 7.5 ± 0.5 mL of a 10% w / v aqueous potassium hydroxide solution are added to a 1000 mL heavy glass beaker. The beaker is placed on a stirring hot plate, and while stirring, the temperature is brought to 45°C ± 5°C. A predetermined amount of porcine gastric mucin (±0.50 g) is weighed and slowly sprinkled onto the previously prepared liquid that has reached 45°C without agglomeration. The beaker is covered and mixing is continued. Within 15 minutes, the temperature of the mixture is brought above 50°C but not exceeding 80°C. While maintaining this temperature range, heating is continued under gentle stirring for 2.5 hours, then the beaker is removed from the hot plate and cooled to below 40°C. Next, 1.8 ± 0.2 mL of a 10% v / v aqueous lactic acid solution is added and mixed well. The mucus component mixture is autoclaved at 121°C for 15 minutes and cooled for 5 minutes. The mixture of the mucus component is removed from the autoclave and stirred until the temperature reaches 23°C ± 1°C.

[0139] Allow the temperature of the sheep blood and the mucus component to reach 23°C ± 1°C. Using a 500 mL graduated cylinder, measure the volume of the entire batch of the mucus component and add it to a 1200 mL beaker. An equal volume of sheep blood is added to the beaker and mixed well. Using the viscosity method described previously, ensure that the viscosity of the AMF is between 7.15 cSt - 8.65 cSt. If not, dispose of the batch and make another batch as needed to adjust the mucus component.

[0140] Unless intended for immediate use, the qualified AMF should be refrigerated at 4°C. After preparation, the AMF can be stored in an airtight container at 4°C for up to 48 hours. Before testing, the AMF must be brought to 23°C ± 1°C. After the test is completed, discard any unused portion.

[0141] 3. Re-wet test

[0142] For an absorbent article loaded with an artificial menstrual fluid (AMF) as described herein, measure the rewetting.

[0143] After dispensing 3.0 ml, 6.0 ml, 9.0 ml, and 12 ml of the AMF, measure the amount of fluid remaining on the topsheet at 0.1 psi and 0.5 psi pressures, i.e., the rewetting. All tests are conducted in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0144] Remove the test product from all packaging, being careful not to press or pull on the product during handling. Do not attempt to smooth out wrinkles. Condition the test product at 23°C ± 2°C and 50% ± 2% relative humidity for at least 2 hours prior to testing.

[0145] Place the test product on a flat, horizontal surface with the body side facing up and load a moisture vapor transmission plate at the center of the test product to apply a pressure of 0.25 psi on the test product.

[0146] See Figures 9A to 9E , the moisture vapor transmission plate 9001 is constructed of plexiglass with overall dimensions of 10.2 cm long by 10.2 cm wide by 3.2 cm high. The longitudinal channel 9007 extending along the length of the plate is 13 mm deep and 28 mm wide at the top plane of the plate, where the side walls slope downward at 65° to a base 15 mm wide. The central test fluid well recess 9009 is 26 mm long, 24 mm deep and 38 mm wide at the top plane of the plate, where the side walls slope downward at 65° to a base 15 mm wide. At the bottom of the test fluid well recess 9009, there is an "H"-shaped test fluid reservoir 9003 that leads to the bottom of the plate to introduce fluid onto the article below. The test fluid reservoir 9003 has a total length ("L") of 25 mm, a width ("W") of 15 mm and a depth ("D") of 8 mm. The longitudinal legs of the reservoir are 4 mm wide and have rounded ends with a radius 9010 of 2 mm. The legs are spaced 3.5 mm apart. The central strut has a radius 9011 of 3 mm and houses opposing electrodes 9004 spaced 6 mm apart. The sides of the reservoir bow outward at a radius 9012 of 14 mm defined by the total width W of 15 mm. Two well recesses 9002 (80.5 mm long × 24.5 mm wide × 25 mm deep) located outside the lateral channels are filled with lead shot to adjust the overall mass of the plate to provide a confinement pressure of 0.25 psi (17.6 gf / cm 2 ) on the test area. The electrodes 9004 are embedded in the plate 9001 so as to connect the external banana jack 9006 to the inner wall of the fluid reservoir 9003. A circuit interval timer is inserted into the jack 9006 to the inner wall 9005 of the fluid reservoir 9003.

[0147] Carefully dispense 3.0 ml of AMF into the center of the test article through the opening of the moisture permeable plate using a pipette within 2 seconds. Once a surge is obtained, remove the plate and start the timer for 3 minutes. After removing the plate, quickly obtain an image of the top sheet of the test product using a color scanner HPScanjet G4010 or equivalent, and clean the scanner surface after each scan. In the stain size and redness tests described below, the images will be analyzed to measure the stain size and redness on the top sheet. At the end of 3 minutes, place 5 pre-weighed (referred to as "dry weight") filter papers (typical laboratory filter papers, such as Ahlstrom #632 12.7 cm × 12.7 cm filter papers) on top of the approximate center of the area contaminated with the fluid. Apply the required mass to create a pressure of 0.1 psi on top of the test product and hold it under pressure for 5 seconds. Weigh the filter papers again (referred to as "wet weight"). The difference between the wet weight and the dry weight of the filter paper is the light pressure backflow at the fluid addition amount.

[0148] Repeat the above steps until a total of 12.0 ml of fluid has been dispensed onto the test product. For surge levels of 3.0 ml, 6.0 ml, 9.0 ml, and 12.0 ml, report the backflow values accurate to 0.001 grams. In a similar manner, test a total of three replicate samples for each test product to be evaluated. Calculate the arithmetic mean of the replicates accurate to 0.001 grams and report it as the backflow at 0.1 psi.

[0149] Perform the same backflow test by applying the required mass to create a pressure of 0.5 psi on top of the test product to obtain the backflow at 0.5 psi.

[0150] Calculate the total backflow according to the following formula.

[0151] Total backflow (g) = Backflow at 0.1 psi + Backflow at 0.5 psi

[0152] 4. Spot size and redness test

[0153] For surge levels of 3.0 ml, 6.0 ml, 9.0 ml, and 12.0 ml, measure the size and redness of the stain visible on the top sheet of the absorbent article due to the fluid remaining on the top sheet on the top sheet images of the test product obtained in the above backflow test.

[0154] 4.1 Spot size test

[0155] Perform image analysis using an image analysis program such as Image J software (version 1.52p or above, National Institute of Health, USA) or equivalent. The image needs to be calibrated for distance using an image of a scale to determine the image resolution.

[0156] Open the top sheet image in Image J. Set the scale according to the image resolution. Crop the image in the central region to make a minimum bounding rectangle selection around the entire area of the color spots visible on multiple pads. Convert the image type to 8-bit. Apply a Gaussian blur filter to smooth the image with a Gaussian function of Sigma (radius) 2. Then use the "Minimum" thresholding method to convert the filtered 8-bit grayscale image to a binary image to find the boundary of the color spot area (caused by the fluid remaining on the top sheet) relative to the lighter-colored color spot area from the subsequent layer.

[0157] Obtain the area of the selected color spot area on the top sheet and record it as the top sheet color spot size, accurate to 0.01 cm 2 Repeat the complete process for three substantially similar parallel products. The average of the three individual recorded measurements of the top sheet color spot size is accurate to 0.01 cm 2 Top sheet color spot size.

[0158] 4.2 Spot redness test

[0159] The redness of the color spots on the top sheet is expressed as the color spot redness saturation integral, which is calculated based on the color representation of three parameters using the HSB color model: hue (0° to 360°), saturation (0 to 100), and brightness (0 to 100). Select a suitable hue range (for example, a combination of 240° to 360° and 0° to 45°) for the top sheet image to represent the total red color spot on the top sheet of the test product. For the red color spot area selected based on the hue range, obtain the saturation histogram and count the pixels corresponding to each color saturation level in the selected saturation range of 35 to 100. The color spot redness saturation integral is calculated using the following formula:

[0160]

[0161] where P i is defined as the count of pixels at color saturation level i.

[0162] 5. Collection time test

[0163] Measure the acquisition time of the absorbent article loaded with AMF as described herein using a moisture permeable plate and an electronic circuit interval timer. Record the time required for the absorbent article to acquire one dose of AMF. All tests are conducted in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0164] See Figures 9A to 9E, the moisture permeable plate 9001 is constructed of plexiglass with overall dimensions of 10.2 cm long by 10.2 cm wide by 3.2 cm high. The longitudinal channel 9007 extending along the length of the plate is 13 mm deep and 28 mm wide at the top plane of the plate, where the side walls slope downward at 65° to a 15 mm wide base. The central test fluid well recess 9009 is 26 mm long, 24 mm deep and 38 mm wide at the top plane of the plate, where the side walls slope downward at 65° to a 15 mm wide base. At the bottom of the test fluid well recess 9009, there is an "H" - shaped test fluid reservoir 9003, which leads to the bottom of the plate to introduce the fluid onto the underlying article. The test fluid reservoir 9003 has a total length ("L") of 25 mm, a width ("W") of 15 mm and a depth ("D") of 8 mm. The longitudinal legs of the reservoir are 4 mm wide and have rounded ends with a radius 9010 of 2 mm. The legs are spaced 3.5 mm apart. The central pillar has a radius 9011 of 3 mm and houses opposing electrodes 9004 spaced 6 mm apart. The sides of the reservoir bow outward at a radius 9012 of 14 mm defined by the total width W of 15 mm. Two well recesses 9002 (80.5 mm long × 24.5 mm wide × 25 mm deep) located outside the lateral channels are filled with lead shot to adjust the overall mass of the plate to provide a confinement pressure of 0.25 psi (17.6 gf / cm 2 ). The electrodes 9004 are embedded in the plate 9001 so as to connect the external banana socket 9006 to the inner wall of the fluid reservoir 9003. The circuit interval timer is inserted into the socket 9006 to the inner wall 9005 of the fluid reservoir 9003. The circuit interval timer (not shown in the figures) is inserted into the jack 9006 and monitors the impedance between the two electrodes 9004 and measures the time from when the AMF is introduced into the reservoir 9003 until the AMF is discharged from the reservoir. The timer has a resolution of 0.01 seconds.

[0165] Remove the test product from all packaging, being careful not to press or pull on the product during handling. Do not attempt to smooth out wrinkles. Prior to testing, condition the test sample at 23°C ± 2°C and 50% ± 2% relative humidity for at least 2 hours.

[0166] The required mass of the moisture permeable plate must be calculated for the specific dimensions of the test article such that a confining pressure of 1.72 kPa is applied. Determine the longitudinal mid - point and the lateral mid - point of the absorbent core of the article. Measure and record the lateral width of the core, accurate to 0.1 cm. The required mass of the moisture permeable plate is calculated as the core width multiplied by the length of the moisture permeable plate (10.2 cm) multiplied by 17.6 gf / cm 2 , and record the required mass, accurate to 0.1 g. Add lead shot to the plate to obtain the calculated mass.

[0167] Connect the electronic circuit interval timer to the moisture permeable plate 9001 and zero the timer. Place the test product on a flat, horizontal surface with the body side facing up. Gently place the moisture permeable plate 9001 on the center of the test product to ensure that the "H" shaped reservoir 9003 is centered over the test area.

[0168] Using a mechanical pipette, precisely aspirate 3.00 mL ± 0.05 mL of AMF into the test fluid reservoir 9003. Dispense the fluid along the molded lip at the bottom of the reservoir 9003 within 3 seconds or less without splashing. After the fluid has been collected, record the collection time accurate to 0.01 second. Thoroughly clean the electrode 9004 before each test.

[0169] In a similar manner, test a total of three replicate samples for each test product to be evaluated. Calculate the arithmetic mean of the replicates accurate to 0.01 second and report it as the collection time (seconds).

[0170] 6. Spacer woven fabric dimension test

[0171] Measure the spacer woven fabric dimensions using scanning electron microscope (SEM) images. Obtain and analyze the SEM images as follows to determine the spacer woven fabric dimensions.

[0172] (1) Sample preparation

[0173] When the spacer woven fabric is available in raw material form, cut a sample of size 10 mm × 5 mm from the raw material. When the spacer woven fabric is a component of the final product, use a blade to remove a sample from the spacer woven fabric layer in the final product to provide a sample with a size of 10 mm × 5 mm. Cryogenic spray (such as Sunto ™ Freezing spray, Sunto (HK) International, China) can be used to remove the sample from other components of the final product. During the separation process, care should be taken to prevent stretching of the spacer woven fabric. If necessary, the sample can be removed from the final product by immersing the component in tetrahydrofuran (THF) and gently stirring for 15 minutes and soaking for 5 minutes.

[0174] (2) SEM image acquisition

[0175] SEM images are obtained using a scanning electron microscope (SEM) (such as Tabletop Microscope TM3000 (Hitachi, Japan)) or equivalent. Mount the sample flat or vertically on a horizontal sample stage for top view images such as Figure 10A and for side view images such as Figure 11Cross-sectional view image, where the second side of the spacer woven fabric is attached to the carbon tape. The sample is then sputter-coated with platinum to avoid charging and to improve the overall conductivity under the conditions of a 15 mA current and a 120 s coating time. Subsequently, the platinum-coated sample is transferred to the SEM sample vacuum chamber for imaging.

[0176] Select an appropriate magnification and working distance such that the top surface 112 or the cross-sectional structure is appropriately magnified for measurement. For cross-sectional imaging, orient the cross-sectional edge of the sample such that it is substantially aligned with the horizontal direction. The spacer woven fabric sample is imaged at an acceleration voltage of 5 kV and saved as an 8-bit jpeg image containing a linear distance scale for calibration.

[0177] (3) Image analysis and segmentation

[0178] Use an image analysis program such as ImageJ software (version 1.52p or higher, National Institutes of Health, USA) or an equivalent to perform the analysis. Open the sample image in ImageJ. The SEM image needs to be calibrated for distance with the corresponding scale bar and then trimmed to remove the scale bar and the image information label, so that only the sample view is saved for subsequent image processing.

[0179] Then, using the "minimum" thresholding method, convert the 8-bit grayscale image to a binary image (where the "black" foreground pixels correspond to the surface opening regions): If the grayscale level (GL) value histogram (ranging from 0 to 255, with a bin for each grayscale level value i having a propensity P i exactly has two local maxima, the threshold t of the grayscale level value is defined as the value at which P t-1 > P t and P t ≤ P t+1 . If the histogram has more than two local maxima, iteratively smooth the histogram using a windowed arithmetic mean of size 3, and perform this smoothing iteratively until exactly two local maxima exist. The grayscale level value threshold t is defined as the value at which P t-1 > P t and P t ≤ P t+1 . This program identifies the grayscale level (GL) value of the smallest population between the deep pixel peak located at the opening and the shallower pixel peak of the sample material. If the histogram contains zero or one local maximum, the method cannot continue and the output parameters are not defined.

[0180] (4) Top surface opening area, major axis length and minor axis length

[0181] See Figure 10B, according to the ratio of the binary image obtained in the image resolution setting (3). Set the measurement result to include an analysis of the top surface opening area and shape descriptors (i.e., the major axis length and minor axis length after replacing the area selection with the best - fitting ellipse while maintaining the same area, orientation, and centroid as the original selection). After tracing these openings along their outer edges and excluding smaller openings smaller than 0.020 mm 2 or incomplete openings at the edges of the acquired images, obtain the area, major axis length, and minor axis length values of the top surface openings. At least ten openings need to be detected from the SEM images used for measurement. See Figure 10B , in the case where an opening is divided into Figure 10B sub - openings 1 and 6 by a fiber (fibers), these sub - openings are ignored. Analyze the area values of all these openings to calculate the mean and standard deviation of the top surface opening area, accurate to 0.001 mm 2 , and calculate the relative standard deviation (RSD, defined as the standard deviation divided by the mean and multiplied by 100), accurate to 0.1%. Analyze the major axis or minor axis length readings of all these openings separately to calculate the corresponding mean and standard deviation values, accurate to 0.01 mm, and the RSD, accurate to 0.1%. Prepare and analyze a total of three substantially similar replicate samples. Calculate the arithmetic mean of the three replicates, accurate to 0.01 mm, and report separately as the top surface opening area, major axis length, and minor axis length.

[0182] (5) Spacer woven fabric thickness

[0183] Rotate the cross - sectional SEM image so that the top surface 112 of the spacer woven fabric 110 is horizontally aligned. See Figure 11 , measure the thickness of the spacer woven fabric at the position of the yarn 116 that vertically connects the top surface 112 and the bottom surface 114 of the spacer woven fabric 110. Still see Figure 11 , the bottom edge of the bottom surface 114 of the spacer woven fabric 110 is defined by the top surface of the carbon tape layer attached to the sample holder. The top edge of the top surface 112 of the spacer woven fabric 110 is determined by the vertex positions of each yarn 116 that vertically connects the two surfaces. Measure the vertical distance between the vertex position of the yarn 116 and the bottom edge of the bottom surface 114 of the spacer woven fabric 110 for at least five consecutive stacks of filaments. Calculate the arithmetic mean of these distance measurements, accurate to 0.01 mm. Prepare and analyze a total of three substantially similar replicate samples. Calculate the arithmetic mean of the three replicates, accurate to 0.01 mm, and record as the spacer woven fabric thickness.

[0184] Example

[0185] Example 1. Nonwoven fabric for top sheet

[0186] Produce various nonwoven substrates having the configurations shown in Table 1.

[0187] Nonwoven 1: An 18 gsm spunbond nonwoven having the holes shown in Figure 6 is made of 100% 2 denier hydrophobic PP fibers. See Figure 6 , Nonwoven 1 has hole 5a which has at least three adjacent holes 5b, 5c, and 5d, wherein the edge-to-edge spacing S between hole 5a and each of holes 5b, 5c, and 5d is 2.7 mm.

[0188] Nonwoven 2: An 18 gsm carded breathable nonwoven is manufactured using 1.5 denier hydrophobic PE / PET sheath / core bicomponent fibers. Holes having the pattern shown in Figure 7 are formed in the nonwoven to produce Nonwoven 2. See Figure 7 , Nonwoven 2 has hole 5a which has at least three adjacent holes 5b, 5c, and 5d, wherein each edge-to-edge spacing S between hole 5a and each of holes 5b, 5c, and 5d is 1 mm, 1 mm, and 2 mm respectively. Hole 5e has at least three adjacent orifices 5f, 5g, and 5h, wherein each edge-to-edge spacing S between hole 5e and each of holes 5f, 5g, and 5h is approximately 1.5 mm, 1.5 mm, and 1 mm respectively.

[0189] Nonwoven 3: A first fiber web of 11 gsm is manufactured by laying 1.5 denier hydrophobic sheath / core PE / PET bicomponent fibers constituting the first layer on a conveyor belt. A second fiber web of 13 gsm is manufactured by laying 2 denier hydrophilic PE / PP sheath / core bicomponent fibers constituting the second layer on the conveyor belt. The second fiber web is covered on the first fiber web, and the covered fiber webs are subjected to heat treatment at a temperature of 130 °C to 140 °C. The heat treatment is carried out using a hot air through-type heat treatment device having a breathable conveyor belt. In the heat treatment, the overlapping webs are placed on the breathable conveyor belt of the heat treatment device in such a manner that the surface of the first fiber web contacts the breathable conveyor belt. According to the contact angle test, the 2 denier hydrophobic PE / PET bicomponent fibers have a fiber contact angle of 121.4°, and the 2 denier hydrophilic PE / PET bicomponent fibers have a fiber contact angle of 62.3°.

[0190] Nonwoven 4: A precursor nonwoven 4 is manufactured according to the same method as for manufacturing Nonwoven 3, using the same hydrophobic fibers and hydrophilic fibers as in Nonwoven 3. Holes having the pattern shown in Figure 7 are formed in the precursor nonwoven 4 to produce Nonwoven 4.

[0191] Nonwoven 5: A 24 gsm carded breathable nonwoven made using 2 denier hydrophilic PE / PP bicomponent fibers.

[0192] The contact angles on the top surface and the opposite bottom surface of the nonwoven were measured according to the contact angle test and are shown in Table 1 below. The contact angle of Nonwoven 4 was not tested on the condition that Nonwoven 4 is the same as Nonwoven 3 in nonwoven composition and structure, except that it has pores.

[0193] Table 1

[0194]

[0195] Example 2. Absorbent article

[0196] Sanitary napkins 1 to 8 as exemplary absorbent articles have a topsheet made of the nonwoven substrate and the fluid management layer in Example 1, an absorbent core specified in Table 2, and a common backsheet. Sanitary napkins 1 to 5 were manufactured using a common fluid management layer and absorbent core, and sanitary napkins 6 to 8 were manufactured using a common fluid management layer and absorbent core.

[0197] According to the acquisition speed test and rewet test disclosed herein, the acquisition speed and rewet at 0.1 psi / g and 0.5 psi / g of each of sanitary napkins 1 to 8 were tested. The topsheet saturation integral was measured and calculated according to the stain size and redness test. Table 2 below includes the measurement results.

[0198] Table 2

[0199]

[0200] 290 gsm spacer woven fabric *1 : Figure 10A and Figure 11 the PET-based textile material shown in. The thickness of the spacer woven fabric was 1.65 mm, the top surface opening area was 0.43 mm 2 , the major axis length was 0.28 mm, and the minor axis length was 0.19 mm according to Measurement 6. Spacer woven fabric size test.

[0201] 88 gsm SAPP *2 : A nonwoven containing pulp and 22 gsm AGM.

[0202] Table 2 - continued

[0203]

[0204] Nonwoven laminate *3: The top layer is a 35 gsm carded breathable adhesive nonwoven fabric, and the bottom layer is a 40 gsm airlaid nonwoven fabric.

[0205] 120 gsm airlaid core* 4 : An airlaid nonwoven fabric containing pulp and 27 gsm AGM.

[0206] Compared with sanitary napkins 3 and 5 to 8, sanitary napkins 1, 2 and 4 according to the present invention exhibit significantly faster acquisition times and lower total rewet and topsheet saturation integral values.

[0207] Sanitary napkin 1 and sanitary napkin 6 differ in the fluid management layer and the absorbent core, but have the same topsheet. Sanitary napkin 2 and sanitary napkin 7 differ in the fluid management layer and the absorbent core, but have the same topsheet. Compared with sanitary napkins 6 and 7, sanitary napkins 1 and 2 respectively exhibit significant improvements in acquisition time and total rewet, and significantly lower topsheet saturation integrals.

[0208] Compared with substrates 3 to 5, substrate 1 with nonwoven fabric 1 as the topsheet and substrate 2 with nonwoven fabric 2 as the topsheet exhibit relatively slower acquisition times at the first gush (i.e., the first 3 ml). The 100% hydrophobic topsheets in substrates 1 and 2 may require longer times for the first gush to wet the topsheet. However, at the second, third and fourth gushes (6 ml, 9 ml and 12 ml respectively), both substrates 1 and 2 exhibit rapid acquisition times.

[0209] The sizes and values disclosed herein should not be construed as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to represent the recited value and a range functionally equivalent around that value. For example, a dimension disclosed as "40 mm" is intended to represent "about 40 mm".

[0210] Unless expressly excluded or otherwise limited, each document cited herein, including any cross-reference or related patent or application, is incorporated herein by reference in its entirety. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein, or that it alone or in any combination with any one or more other references teaches, suggests or discloses any such invention. Further, when any meaning or definition of a term in this invention conflicts with the same term's meaning or definition in a document incorporated by reference, the meaning or definition assigned to the term in this invention shall govern.

[0211] While specific embodiments of the present invention have been illustrated and described, it will be apparent to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, it is intended that all such changes and modifications that fall within the scope of the present invention be covered by the appended claims.

Claims

1. An absorbent article, the absorbent article comprising: a liquid-permeable topsheet having a wearer-facing surface and an opposite garment-facing surface, wherein the topsheet comprises a nonwoven fabric that comprises a plurality of holes, a liquid-impermeable backsheet, an absorbent core disposed between the topsheet and the backsheet, and a fluid management layer disposed between the topsheet and the absorbent core, the fluid management layer comprising a spaced woven fabric, wherein the nonwoven fabric comprises a first surface forming the wearer-facing surface of the topsheet and a second surface forming the garment-facing surface of the topsheet, the first surface having a first contact angle of not less than about 90 degrees as measured by a contact angle test, and wherein the spaced woven fabric comprises a top surface, a bottom surface, and a plurality of yarns interconnecting the first surface and the second surface, wherein the first surface and the second surface are spaced apart from each other.

2. The absorbent article according to claim 1, wherein the nonwoven fabric comprises a first layer that comprises hydrophobic fibers.

3. The absorbent article according to claim 1 or 2, wherein the second surface of the nonwoven fabric has a second contact angle of not less than about 90 degrees as measured by a contact angle test.

4. The absorbent article according to claim 1, wherein the second surface of the nonwoven fabric has a second contact angle of less than about 90 degrees as measured by a contact angle test.

5. The absorbent article according to claim 4, wherein the nonwoven fabric further comprises a second layer that comprises hydrophilic fibers, the second layer forming the garment-facing surface of the topsheet.

6. The absorbent article according to claim 5, wherein the nonwoven fabric has a one-piece structure.

7. The absorbent article according to claim 5, wherein the nonwoven fabric is a laminate that comprises the first layer and the second layer.

8. The absorbent article according to any one of claims 4 to 7, wherein the difference between the first contact angle and the second contact angle is at least about 10 degrees as measured by a contact angle test.

9. The absorbent article according to claim 2 or 5, wherein the basis weight of the first layer is not greater than 14 gsm.

10. The absorbent article according to any one of the preceding claims, wherein the plurality of holes comprises at least one hole having at least three adjacent holes spaced apart with an edge-to-edge spacing of not greater than about 2.5 mm.

11. The absorbent article according to any one of the preceding claims, wherein each of the yarns comprises from about 2 to 60 filaments.

12. The absorbent article according to claim 11, wherein the filaments have a fineness of 1.5 dtex to 10 dtex.

13. The absorbent article according to any one of the preceding claims, wherein the top surface of the spacer woven fabric includes openings having an opening area of not less than about 0.2 mm as measured according to the spacer woven fabric size test. 2 ​ 14. The absorbent article according to any one of the preceding claims, wherein the spaced woven fabric has a thickness in the range of about 1.0 mm to about 2.5 mm as measured by a spaced woven fabric size test.

15. The absorbent article according to any one of the preceding claims, wherein the absorbent core comprises a superabsorbent polymer.

16. The absorbent article according to any one of the preceding claims, wherein the absorbent article further comprises an additional fluid acquisition and / or distribution layer between the topsheet and the fluid management layer.

Images