Absorbent article having spacer fabric

Abstract

The present invention provides an absorbent article comprising: a liquid-pervious topsheet having a wearer-facing surface and an opposite garment-facing surface, the topsheet comprising a nonwoven fabric containing a plurality of holes; a liquid-impervious 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 comprising 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 about 90 degrees or greater when measured according to a contact angle test; and the spacer woven fabric comprising a top surface, a bottom surface, and a plurality of yarns interconnecting the first surface and the second surface, the first surface and the second surface being spaced apart from each other.

Description

[Technical Field]

[0001] The present invention relates to an absorbent article comprising a fluid handling layer that includes a spacer fabric. [Background technology]

[0002] Absorbent articles for personal hygiene, such as sanitary napkins, adult incontinence underwear, baby diapers, and / or training pants for infants, are designed to absorb and contain bodily exudates, particularly large amounts of menses, urine, and / or liquid feces (collectively "fluids").

[0003] Users of such disposable absorbent articles have several concerns. Leakage from products such as sanitary pads, diapers, sanitary napkins, and incontinence pads is a significant concern. To prevent fluid leakage, it is desirable for absorbent articles to provide a high collection rate. Wet feel is also a significant concern, so rewet, which is the return of fluid from other components of the absorbent article to the topsheet, needs to be effectively reduced or prevented. Additionally, presenting a clean, user-contacting surface that is less likely to stain, is a desirable feature of absorbent articles.

[0004] These absorbent articles are generally designed to include several layers that provide different functions. A liquid-permeable topsheet is positioned closest to the wearer's skin and should be able to rapidly absorb excreted fluids. A backsheet is positioned on the opposite side of the article, facing the garment. An absorbent core, comprised of various absorbent materials, is desirable for rapid absorption of body fluids from the topsheet and for high fluid storage capacity.

[0005] Although hydrophilic topsheets are known to exhibit faster collection rates compared to hydrophobic topsheets, hydrophilic topsheets tend to cause a wet feeling when acquiring or retaining fluid, and / or fluid backflows through the topsheet due to the high affinity of the constituent fibers for fluid. Absorbent articles having hydrophobic topsheets may be preferred by some consumers because they provide a dry feel and good blurring / masking effect on menstrual / urine stains, but hydrophobic topsheets absorb fluid only by capillary forces, which results in a slower collection rate and causes problems with fluid leakage.

[0006] The absorbent cores commonly used in absorbent articles contain various absorbent materials. To meet the needs of thin absorbent articles, the absorbent cores often contain a large amount of superabsorbent polymer. Superabsorbent polymers have high absorption capacity but a relatively slow absorption rate. As a result, absorbent articles having absorbent cores containing a large amount of superabsorbent polymer often cannot instantly absorb a large amount of fluid discharged within a few seconds.

[0007] Absorbent articles typically employ a fluid management layer between the topsheet and the absorbent core, which can rapidly receive large amounts of fluid from the topsheet and temporarily store the fluid before it is absorbed by the absorbent core. One desirable function of a fluid management layer is to quickly collect fluids or other body exudates from the topsheet and transfer them to the absorbent core in an efficient manner. Another 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 fluid along the planar direction of the fluid management layer and high capillary force to draw fluid from the topsheet, thereby reducing fluid concentration at the load point. Both wicking properties and capillary force can be contributed by small pore size in either the planar direction or the z-direction. Small pore size in the fluid management layer improves wicking properties and capillary force, but it also results in high flow resistance for fluid to penetrate the fluid management layer, thereby slowing down the collection rate. Therefore, there is typically a trade-off between collection rate and wetness sensation (or rewet).

[0009] WO 2005 / 051657(A) discloses a multilayer fluid handling woven composite including a three-dimensional woven spacer forming a first layer of the woven composite, a plurality of overlying moisture-absorbent cores outside the spacer, and a liquid-impermeable jacket outside the absorbent core. The three-dimensional woven spacer in WO 2005 / 051657(A) comprises a first facing, an opposing second facing, and intermediate spacer yarns interconnecting the first and second facings. WO 2014 / 1011927 discloses an absorbent article including a fluid flow control member that is a spacer fabric disposed between a topsheet and an absorbent core, the spacer fabric including a top layer, a bottom layer, and an interconnecting layer of yarns between the top and bottom layers. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] International Publication No. 2005 / 051657(A) [Patent Document 2] International Publication No. 2014 / 1011927 Summary of the Invention [Problem to be solved by the invention]

[0011] Therefore, there is a need for absorbent articles that can provide rapid fluid acquisition rates without compromising dry feeling or low rewet.

[0012] Additionally, there is a continuing need for absorbent articles that can provide improved surface cleanliness to bodily fluids without compromising fluid handling properties such as rapid fluid acquisition rates and reduced rewet. [Means for solving the problem]

[0013] The present invention provides an absorbent article comprising: a liquid-pervious topsheet having a wearer-facing surface and an opposite garment-facing surface, the topsheet comprising a nonwoven fabric containing a plurality of apertures; a liquid-impervious 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 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 about 90 degrees or greater as measured according to a contact angle test, and the spacer woven fabric comprises a top surface, a bottom surface, and a plurality of yarns interconnecting the first and second surfaces, the first and second surfaces being spaced apart from each other.

[0014] The unique combination of a topsheet comprising a hydrophobic nonwoven fabric forming the donning surface and a fluid handling layer comprising a spacer woven fabric allows the absorbent article of the present invention to provide a fast liquid collection rate and a clean surface without compromising the dry feeling sensation.

[0015] These and other features, aspects, and advantages of the present invention will become apparent to those of ordinary skill in the art upon reading this disclosure. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is an exemplary perspective view of an absorbent article. [Figure 2] 2 is a cross-sectional view of the absorbent article of FIG. 1 taken along line 2-2. [Figure 3A] FIG. 1 is a schematic diagram of a nonwoven fabric that constitutes the top sheet of an absorbent article. [Figure 3B] FIG. 1 is a schematic diagram of a nonwoven fabric that constitutes the top sheet of an absorbent article. [Figure 4] FIG. 1 is a schematic diagram of a nonwoven fabric that constitutes the top sheet of an absorbent article. [Figure 5] FIG. 1 is a schematic diagram of a nonwoven fabric that constitutes the top sheet of an absorbent article. [Figure 6] 1 is a schematic top view of an exemplary topsheet of an absorbent article of the present invention. [Figure 7] FIG. 2 is a schematic top view of another exemplary topsheet of an absorbent article of the present invention. [Figure 8A] 1 is an image of an exemplary water droplet having a contact angle greater than 90 degrees according to the contact angle test method disclosed herein. [Figure 8B] 1 is an image of an exemplary water droplet having a contact angle of 90 degrees or less according to the contact angle test method disclosed herein. [Figure 9A] FIG. 1 is a perspective view of a strikethrough plate for capture time measurements. [Figure 9B] FIG. 9B is a plan view of the shine-through plate of FIG. 9A. [Figure 9C] 9C is a plan view of the cross section of the see-through plate of FIG. 9B taken along the direction 9C-9C. [Figure 9D] FIG. 9C is a plan view of a portion of the shine-through plate of FIG. 9B. [Figure 9E] 9E is a plan view of the cross section of the see-through plate of FIG. 9B taken along the direction 9E-9E. [Figure 10A] 1 is a SEM top view image of an exemplary spacer fabric. [Figure 10B] This is a processed image of Figure 10A. [Figure 11] 1 is a cross-sectional image of an exemplary spacer fabric. DETAILED DESCRIPTION OF THE INVENTION

[0017] All ranges are inclusive and combinable. The number of significant digits does not imply a limitation on the quantities stated or on the precision of the measurements. Unless specifically stated otherwise, all numerical quantities are understood to be modified by the word "about."

[0018] As used herein, the term "absorbent article" includes disposable diapers, sanitary napkins, panty liners, incontinence pads, interlabial pads, nursing pads, sweat wipes, animal waste management articles, animal diapers, and the like.

[0019] As used herein, the term "joined" refers to a state in which a first member is directly or indirectly affixed or connected to a second member. A first member and a second member are indirectly joined when the first member is affixed or connected to an intermediate member, which is affixed or connected to a second member.

[0020] As used herein, the term "integrated" is used to describe fibers of a nonwoven material in which the fibers are twisted, entangled, and / or pushed / pulled in the positive Z direction and / or the negative Z direction (through the thickness of the nonwoven material). Some exemplary processes for consolidating the fibers of a nonwoven web include spunlacing and needlepunching. Spunlacing uses multiple high-pressure water jets to entangle the fibers.

[0021] As used herein, the term "carded" is used to describe the structural characteristics of the fluid handling layer described herein. Carded nonwovens use fibers cut to a specific length, also known as "staple filaments." The staple filaments may be of any suitable length. For example, the staple filaments may have a length of up to 120 mm, or as little as 10 mm. However, when a particular group of fibers is staple filaments, such as viscose fibers, the length of each of the viscose fibers in the carded nonwoven is generally the same, i.e., staple length. It is worth noting that when additional staple fiber length fiber types, such as polypropylene fibers, are included, the length of each of the polypropylene fibers in the carded nonwoven is also generally the same. However, the staple length of the viscose and the staple length of the polypropylene may be different.

[0022] In contrast, continuous filaments, such as those produced by spunbonding or meltblown processes, do not result in staple length fibers. Instead, these filaments are of indefinite length and are not cut to specific lengths as described for staple length fibers.

[0023] The "longitudinal" direction is the direction extending parallel to the largest linear dimension of an article, typically the longitudinal axis of the article, including directions within 45° of the longitudinal direction. As used herein, the "length" of an article or a component thereof generally refers to the size / distance of the largest linear dimension of the article or part thereof, or typically refers to the size / distance of its longitudinal axis.

[0024] The "lateral" or "transverse" direction is the direction perpendicular to the longitudinal direction, i.e., in the same plane as the majority and longitudinal axis of the article, and the transverse direction is parallel to the lateral axis. As used herein, the "width" of an article or component thereof refers to the size / distance of the dimension perpendicular to the longitudinal direction of the article or component, i.e., perpendicular to the length of the article or component, and typically refers to the distance / size of the dimension parallel to the lateral axis of the article or component.

[0025] As used herein, the terms "hydrophilic" and "hydrophobic" have their well-established meanings in the art with respect to the contact angle of water on a material surface. Thus, materials having a water contact angle of greater than about 90 degrees as measured by a contact angle test are considered hydrophobic, and materials having a water contact angle of less than about 90 degrees as measured by a contact angle test are considered hydrophilic.

[0026] absorbent articles Absorbent articles will now be generally described and further illustrated in the form of a sanitary napkin 100, as illustratively shown in Figures 1 and 2. Figure 1 is a plan view of an exemplary sanitary napkin 100 in a flat, wearer-facing configuration. Figure 2 is a cross-sectional view of the absorbent article of Figure 1 taken along line 2-2.

[0027] 1 and 2, an absorbent article according to the present invention, such as a sanitary napkin 100, includes a topsheet 24 having a wearer-facing surface and a garment-facing surface disposed opposite the wearer-facing surface. The topsheet 24 includes a nonwoven 30, the uppermost surface 32 of which forms the wearer-facing surface of the topsheet 24.

[0028] The absorbent article further includes a backsheet 26 having a garment-facing surface and a wearer-facing surface disposed opposite the garment-facing surface, the backsheet 26 being at least partially joined to the topsheet 24. The absorbent article also includes an absorbent core 28 disposed 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 an additional fluid acquisition and / or distribution layer 25 (or system). The absorbent article may further include a pair of flaps or wings 23. The topsheet 24, backsheet 26, fluid management layer 27, and absorbent core 28, as well as other optional elements, can be assembled in a variety of well-known configurations.

[0029] 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 one another by using adhesives, heat bonding, pressure bonding, ultrasonic bonding, dynamic mechanical bonding, or a crimp seal. A fluid-tight crimp seal can resist the lateral migration of fluids through the edges of the product ("wicking"), preventing side soiling of the user's undergarments.

[0030] If 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 panty fastening adhesive disposed on the garment-facing side of the backsheet 26. The panty fastening adhesive may be any known adhesive used in the art for this purpose and may be covered with a release paper prior to use, as is well known in the art. If flaps or wings are present, the panty fastening adhesive may be applied to the garment-facing side so as to contact and adhere to the underside of the user's panties.

[0031] Top sheet Topsheets are generally liquid pervious and are configured to receive fluids discharged from the body and help direct the fluids toward the fluid management layer and / or absorbent core. One important property of a topsheet is its ability to reduce pooling of fluids on the topsheet before they can be absorbed by the absorbent article. Another desirable quality of a topsheet is to reduce rewet of the topsheet. Also, presenting a clean, user-contacting surface that is less likely to stain is a desirable feature of a topsheet.

[0032] The topsheet of the present invention is the portion of the absorbent article that contacts the wearer's skin during use of the article. The topsheet may be joined to portions of the backsheet, absorbent core, and / or other layers, as known to those skilled in the art. Further, at least a portion of the topsheet, or all of it, can be liquid permeable, permitting bodily fluids to readily penetrate through its thickness.

[0033] The topsheet of the present invention comprises a nonwoven fabric containing a plurality of apertures, having a wearer-facing surface that forms the wearer-facing surface of the absorbent article and an opposite garment-facing surface.

[0034] The nonwoven fabric constituting the topsheet includes 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 of the nonwoven fabric has a first contact angle of about 90 degrees or more, or 95 degrees or more, or 100 degrees or more, as measured according to the Contact Angle Test. The second surface of the nonwoven fabric can have a second contact angle of about 90 degrees or more, as measured according to the Contact Angle Test. The second surface of the nonwoven fabric can have a second contact angle of less than about 90 degrees, as measured according to the Contact Angle Test. In one embodiment, the difference between the first and second contact angles is at least about 10 degrees, or at least about 15 degrees, or at least about 20 degrees, as measured according to the Contact Angle Test. A nonwoven fabric having a second surface with a second contact angle of less than about 90 degrees can provide a faster collection rate compared to a nonwoven fabric having a second surface with a second contact angle of about 90 degrees or more.

[0035] The nonwoven fabric comprises a first layer comprising hydrophobic fibers. The nonwoven fabric may further comprise a second layer comprising hydrophilic fibers. When the nonwoven fabric forms the topsheet of an absorbent article according to the present invention, the first layer forms the surface of the topsheet that faces the wearer. When the nonwoven fabric comprises a first layer and an optional second layer, the first layer forms the surface of the topsheet that faces the wearer, and the second layer forms the surface of the topsheet that faces the garment.

[0036] When the nonwoven fabric forming the topsheet of the absorbent article according to the present invention comprises two or more layers, the two or more layers may form a unitary structure or remain separate layers. A unitary structure in this specification means that the nonwoven fabric may be formed from several sublayers or layers having distinct properties and / or compositions, but that these sublayers or layers are somehow interwoven at the boundary regions so that, instead of clear boundaries between the sublayers, it is possible to identify areas where the different sublayers transition to one another. Such a unitary structure is typically constructed by forming different sublayers one on top of the other in a continuous manner, for example, using airlaid or wetlaid deposition. Alternatively, each sublayer is manufactured in a separate process, and the sublayers are combined together in a face-to-face relationship. The sublayers can be combined through known combining or bonding processes, such as spunlacing, hydroentangling, calendar bonding, through-air bonding, and resin bonding.

[0037] Typically, no adhesive is used between the sub-layers of the monolithic material, although in some cases adhesives and / or binders may be present, typically in lesser amounts.

[0038] When describing topsheets of the present invention herein, the terms layer, sublayer, and tier are interchangeable. With respect to describing topsheets having a unitary structure, the terms layer and tier are interchangeable.

[0039] When the topsheet herein comprises two or more layers that remain as separate layers, the two or more layers may be at least partially attached to one another by, for example, thermal bonding, adhesive bonding, ultrasonic bonding, or any combination thereof.

[0040] The topsheet of the present invention can have a variety of constructions.

[0041] 3A and 3B, the nonwoven fabric 30 comprising the topsheet disclosed herein includes at least a first layer 1. The first layer 1 has a first surface 3 that forms the wearer-facing surface of the topsheet, and an opposing second surface 4.

[0042] Referring to Figures 4 and 5, the nonwoven fabric 30 comprising the topsheet disclosed herein may include a first layer 1 that forms the wearer-facing surface of the topsheet, and a second layer 2 that forms the garment-facing surface of the topsheet.

[0043] Referring to FIG. 4, the nonwoven fabric 30 may have a monolithic structure, where the first layer 1 and second layer 2 are intermingled at the boundary region instead of having a distinct boundary between the two layers.

[0044] Referring to Figure 5, the nonwoven 30 may be a laminate of separate layers (in this case, a first layer 1 and a second layer 2) that are joined together in a face-to-face relationship. The first layer 1 has a first surface 3 that forms the wearer-facing surface of the topsheet, and a second surface 4. The second layer has a first surface 10 and a second surface 11 that forms the garment-facing surface of the topsheet. Continuing to refer to Figure 5, the topsheet 24 may include a plurality of protrusions 9. The nonwoven 30 may include land areas 8 between most of the apertures 5. The land areas may be substantially flat. Most of the protrusions 9 may protrude outward from the land areas 8 of the nonwoven 30.

[0045] The plurality of protrusions 9 may be uniformly distributed on the wearer-facing surface of the topsheet. The plurality of protrusions 9 may also be non-uniformly distributed and may form a shape or pattern on the wearer-facing surface of the topsheet. A majority of the protrusions 9 may be surrounded by at least one land area 8 and / or a plurality of holes 5. The land areas 8, holes 5, and protrusions 9 may form a three-dimensional surface on the wearer-facing surface of the topsheet.

[0046] 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 in the same direction from the land areas 8 of the first layer 1, and the first layer 1 and the second layer 2 are spaced apart. The hollow space between the first layer and the second layer can improve the breathability of the topsheet.

[0047] The nonwoven may comprise a plurality of holes 5. The nonwoven 30 may include at least one non-porous region that is substantially free of holes. The non-porous region may be a flat land area 8 and / or a protrusion 9. Referring to Figures 6 and 7, the nonwoven 30 that makes up the topsheet 24 may include at least one non-porous region, in this case a non-porous land area 8. The non-porous region may completely surround a hole. The non-porous regions may together form a generally continuous grid across the entire wearer-facing surface of the topsheet, while the holes may be separate elements distributed within and surrounded by the continuous grid.

[0048] 7, the non-porous region may be a plurality of distinct regions defined by holes, each of the plurality of distinct non-porous regions having a perimeter formed by a continuous line of holes.

[0049] When the topsheet described herein is incorporated into an absorbent article, the optional plurality of protrusions may protrude toward the wearer's skin and away from the absorbent core of the absorbent article when the article is in use.

[0050] This three-dimensional first layer of nonwoven provides greater softness to the topsheet and also helps to keep the wearer's skin away from bodily fluids in the land areas, as the protrusions essentially create spaces between the wearer's skin and bodily fluids.

[0051] The nonwoven fabric constituting the top sheet in the present invention may have a basis weight of about 20 to about 100 g / m2, or about 30 to about 60 g / m2, or about 20 to about 50 g / m2, or about 30 to about 50 g / m2.

[0052] First layer The first layer of the nonwoven fabric comprises hydrophobic thermoplastic fibers, and in one embodiment, 100% of the constituent fibers of the first layer are hydrophobic fibers.

[0053] The thermoplastic fibers may be selected from the group consisting of polyester, polypropylene, polyethylene, polyether, polyamide, polyhydroxyalkanoate, polysaccharide, and combinations thereof. In addition, other synthetic fibers such as rayon, polyethylene, and polypropylene fibers may be used within the scope of the present disclosure.

[0054] Thermoplastic fibers may be monocomponent fibers (i.e., a single synthetic material or mixture comprises the entire fiber), multicomponent fibers such as bicomponent fibers (i.e., the fiber is divided into multiple regions, and the regions contain two or more different synthetic materials or mixtures thereof), and combinations thereof.

[0055] The first layer may also comprise a polymer, specifically a semi-synthetic fiber made from a hydroxyl polymer. The topsheet may also comprise a polymer, specifically a semi-synthetic fiber made from a hydroxyl polymer. Non-limiting examples of suitable hydroxyl polymers include polyvinyl alcohol, starch, starch derivatives, chitosan, chitosan derivatives, cellulose derivatives such as viscose, gum, arabinan, galactan, lyocell (Tencel®), and combinations thereof.

[0056] The first layer may also comprise cellulosic fibers, which may be selected from the group consisting of wheat straw fibers, rice straw fibers, flax fibers, bamboo fibers, cotton fibers, jute fibers, hemp fibers, sisal fibers, bagasse fibers, hesper aloe fibers, and combinations thereof.

[0057] Some examples of the first layer include, but are not limited to, spunbond nonwoven fabrics, carded nonwoven fabrics, carded air-through nonwoven fabrics, spunlace nonwoven fabrics, needle-punched nonwoven fabrics, and nonwoven fabrics that have relatively special properties such that they can be easily deformed.

[0058] The first layer can be formed by many processes, such as, for example, air-laid processes, wet-laid processes, melt-blown processes, spunbond processes, needle-punched processes, and carded processes.

[0059] Hydrophilic fibers can be made hydrophobic by treating them with a hydrophobic treatment, such as a hydrophobic surfactant, for example, by spraying or kiss-roll coating the hydrophobic treatment onto the hydrophilic fibers, by dipping the fibers in the hydrophobic treatment, or by including the hydrophobic treatment as part of the polymer melt when manufacturing the thermoplastic fibers. Upon melting and resolidification, the treatment tends to remain on the surface of the fiber.

[0060] The first layer may be a carded nonwoven.

[0061] The hydrophobic fibers constituting the first layer 1 have a contact angle greater than about 90 degrees, or greater than about 100 degrees. The contact angle of the constituent fibers of the first layer 1 may be 150 degrees or less, or 130 degrees or less. The hydrophobicity of the constituent fibers can be adjusted by appropriately adjusting the level of the hydrophobic treatment agent of the thermoplastic fibers, for example, the type and content of the hydrophobic treatment.

[0062] The hydrophobic fibers comprising the first layer may have a fineness of 4 denier or less, or 2.5 denier or less, or 2 denier or less, or 1.5 denier or less.

[0063] The first layer may have a basis weight of from about 5 g / m2 to about 30 g / m2, or from about 8 g / m2 to about 30 g / m2, or from about 8 g / m2 to about 17 g / m2, or from about 8 g / m2 to about 14 g / m2.

[0064] Second layer: The nonwoven fabric comprising the topsheet disclosed herein may include a second layer comprising hydrophilic fibers.

[0065] The constituent fibers of the second layer may be natural fibers, synthetic fibers, or a combination of natural and synthetic fibers. In one embodiment, the second layer comprises thermoplastic fibers.

[0066] The list of synthetic fibers corresponds to the list disclosed above for the topsheet and first layer.

[0067] 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, by dipping the fiber in the treating agent, or by including the hydrophilic treating agent as part of the polymer melt when manufacturing the thermoplastic fiber. Upon melting and resolidification, the treating agent tends to remain on the surface of the fiber.

[0068] The hydrophilic fibers making up the second layer may have a fineness of 4 denier or less, or 2.5 denier or less, or 2 denier or less, or 1.5 denier or less.

[0069] The second layer may have a basis weight of from about 10 g / m 2 to about 70 g / m 2 , or from about 15 g / m 2 to about 60 g / m 2 , or from about 10 g / m 2 to about 40 g / m 2 .

[0070] The first layer and / or second layer web may be made of carded webs such as parallel webs, semi-random webs, random webs, cross webs, crisscross webs, airlaid webs, wet-laid webs, spunbond webs, etc. The first and second fibrous webs may be the same or different.

[0071] The heat treatment of each web or composite fiber web can be carried out using any conventionally known heat treatment method. Examples of preferred treatment processes include heat treatment devices such as hot air through-type heat treatment devices, hot air blow-type heat treatment devices, and infrared heat treatment devices. These heat treatment devices are usually equipped with a transport support element for supporting and transporting the fiber web. The heat treatment may be carried out under conditions such that the sheath components of the first core / sheath type composite fiber and the second core / sheath type composite fiber are sufficiently melted and / or softened to bond at the contact points or intersections between the fibers, and the crimp of the first core / sheath type composite fiber and the second core / sheath type composite fiber is not broken.

[0072] With the exception of the second layer comprising hydrophilic fibers, all aspects described above for the first layer are equally applicable to the first layer in a topsheet comprising a first and second layer.

[0073] hole The topsheet of the present invention may contain a plurality of holes.Nonwoven fabrics inherently have pores between fibers.The openings in the present disclosure have a size significantly larger than such pores and are not intended to include such pores.To ensure the stability of the material, regardless of their specific shape and width, the minimum edge-to-edge distance between the majority of the holes 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.

[0074] The pores may vary in shape. For example, the pores may have a circular, elliptical, rectangular, or polygonal shape when viewed from the first surface of the first layer. In one embodiment, the pores have a circular, elliptical, or polygonal shape.

[0075] The three-dimensional shape of the pores may be cylindrical (eg, having a circular or elliptical base), prism (eg, having a polygonal base), or truncated cone or pyramid.

[0076] 3A-5, each of the holes 5 can have a sidewall 6. Referring to FIG. 3A, the sidewall 6 may extend outward, away from the non-perforated area of ​​the second surface of the topsheet. The sidewall of the hole may form a funnel or channel. The sidewall 6 may not extend outward, as shown in FIG. 3B.

[0077] The holes may be tapered and conically shaped such that the diameter of the hole is larger in the portion of the hole adjacent the first surface of the nonwoven than the diameter of the hole at the bottom edge of the hole.

[0078] Such a tapered configuration helps reduce the risk of rewet, i.e., the risk of bodily fluids moving back into and through the topsheet from components below the topsheet (such as the absorbent core). In the case of a perforated hydrophobic topsheet, rewet occurs primarily through the pores. The tapered shape of the pores can help reduce rewet because the diameter of the pores toward the absorbent core is smaller than the diameter of the pores in the first layer.

[0079] The holes may also vary in width.

[0080] The size of the holes can be determined to achieve the desired fluid and / or air penetration performance, as well as other performance expectations of the wearer. If the holes are too small, fluid may not pass through the holes, either due to poor alignment between the fluid source and the hole location, or due to the tendency of fecal masses, for example, having a diameter larger than the hole, to flow through. If the holes are too large, the skin area that can be contaminated by "rewet" from the article increases.

[0081] Each of the plurality of holes is 0.2 mm 2 ~1.5mm 2 , 0.2mm 2 ~1.0mm2 , or 0.25 mm 2 ~0.5mm 2 and / or a diameter ranging from 0.3 mm to 1.5 mm, or from 0.3 mm to 1 mm, or from 0.4 mm to 0.8 mm. The plurality of holes may have a regular shape selected from the group consisting of a circle, an oval, a triangle, a square, a rectangle, a parallelogram, a trapezoid, a polygon, an hourglass, a star, and any combination thereof.

[0082] The nonwoven comprising the topsheet has an open area of ​​at least 2.5%, or at least 3%, or at least 5% for the purpose of fast fluid acquisition rate. The nonwoven may have an open area of ​​about 30% or less, or 25% or less, or 20% or less for the purpose of reducing or preventing rewet.

[0083] 6 and 7 are schematic top views of an exemplary nonwoven fabric 30 that comprises the topsheet 24. Referring to Figure 7, in some embodiments, the nonwoven fabric 30 may include clustered holes. The term "clustered holes" herein is intended to mean a hole pattern in which at least one hole has at least three adjacent holes, and the hole and each of the at least three adjacent holes have an edge-to-edge spacing S (shortest space between the edge of one hole and the edge of an adjacent hole) of about 2.5 mm or less, preferably about 2 mm or less.

[0084] The hole pattern in the topsheet, when used as a component of an absorbent article, may cooperate with, for example, graphics, marks, print, ink, color, and / or patterned adhesive disposed in the topsheet or in another component of the absorbent article.

[0085] Fluid Treatment Layer One of the functions of the fluid management layer is to quickly collect liquids or other body exudates from the topsheet and transfer and distribute them in an efficient manner to the absorbent core.

[0086] The fluid management layer in the absorbent article of the present invention is disposed directly or indirectly on the absorbent core and comprises a spacer fabric having a top surface, a bottom surface, and a plurality of yarns interconnecting the first surface and the second surface, the first surface and the second surface being spaced apart from each other.

[0087] The top and bottom surfaces of the spacer fabric may have the same configuration or may have different configurations to direct the fluid flow rate.

[0088] The spacer fabric may comprise thermoplastic fibers including polyester, polyamide, polyolefins such as polyethylene and polypropylene, or any mixture thereof. The spacer fabric may further comprise absorbent fibers. The optional absorbent fibers may provide for absorption of bodily fluid waste from the wearer-facing surface or topsheet. Any suitable absorbent material may be utilized for the absorbent fibers. Some examples of absorbent materials include cotton, pulp, rayon, or regenerated cellulose, or combinations thereof. The spacer fabric may be free of absorbent materials such as absorbent fibers and superabsorbent polymers. The top and bottom surfaces of the spacer fabric may be made from the same fibers or different fibers. At least one of the top and bottom surfaces comprises polyethylene terephthalate ("PET") fibers.

[0089] The spacer fabric may also contain surfactants to promote fluid penetration so that it drains quickly and does not retain fluid unnecessarily long, thus maintaining free volume capacity for the next burst of fluid.

[0090] The spacer fabric may have a basis weight of about 150 gsm to about 350 gsm, or about 200 gsm to about 300 gsm, or about 150 gsm to about 250 gsm.

[0091] The spacer fabric may have a caliper ranging from about 1.0 mm to about 2.5 mm, as measured according to the Spacer Fabric Size Test. If the caliper is too low, fluid collection rate may be adversely affected. If the caliper is too high, an absorbent article including the spacer fabric may not fit adequately to the wearer's body.

[0092] Each of the yarns interconnecting the first and second surfaces of the spacer fabric disclosed herein may contain from about 2 filaments to about 60 filaments. The multiple filaments that make up the yarn create interfilament microchannels that can improve fluid wicking and faster fluid transport. The filaments that make up the yarn may have a fineness of 1.5 to 10 dtex, or 3 to 8 dtex, or 2 to 5 dtex. If the filaments are too thin, the elasticity and fluid acquisition rate of the spacer fabric may be adversely affected. If the filaments are too thick, the material may become stiff with higher rewet.

[0093] The top and bottom surfaces of the spacer fabric may have numerous openings to ensure rapid inflow and effective distribution of bodily fluids. The bottom surface of the spacer fabric may have a more compact structure with relatively smaller openings than the top surface. In one embodiment, the top surface of the spacer fabric includes openings, the openings being approximately 0.2 mm in size as measured according to the Spacer Fabric Size Test. 2 The opening area is more than 100 mm.

[0094] The yarns may form channels for fluid flow between the first and second surfaces to efficiently distribute and transfer fluid to the absorbent core. Additionally, the large void space between the first and second surfaces of the spacer fabric allows the spacer fabric to accommodate and temporarily retain a relatively large volume of fluid. This allows excreted body fluids to be effectively received by the spacer fabric and then transferred to the absorbent core's absorbent portion. In particular, when the absorbent core contains a superabsorbent polymer with a high absorption capacity but a relatively slow absorption rate, a fluid management layer disposed on the absorbent core temporarily retains the fluid volume, allowing the absorbent core to fully utilize its high absorption capacity.

[0095] The spacer fabric is oriented in the absorbent article so that the top surface of the spacer fabric faces toward the topsheet and the bottom surface of the spacer fabric faces toward the backsheet.

[0096] Additionally, the unique spacer woven fabric structure allows the absorbent article of the present invention to have high compression resistance without significantly increasing the basis weight or volume of the absorbent article.

[0097] absorbent core The absorbent core comprises an absorbent material.

[0098] The absorbent material in the absorbent core can be any liquid-absorbent material commonly used in disposable absorbent articles, such as ground wood pulp, commonly called airfelt or fluff. Other examples of suitable liquid-absorbent materials include crimped cellulose mass, meltblown polymers including coform, chemically stiffened, modified, or crosslinked cellulose fibers, tissue, including tissue wraps and tissue laminates, absorbent foams, absorbent sponges, superabsorbent polymers (abbreviated herein as "SAP"), absorbent gelling materials, or any other known absorbent material or combination of materials. As used herein, the term "superabsorbent polymer" refers to absorbent materials, which may be crosslinked polymers, that are typically capable of absorbing at least 10 times their weight in 0.9% saline solution, as measured using the Centrifuge Retention Capacity (CRC) test (EDANA Method WSP241.2-05E). The SAP may specifically have a CRC value of more than 20 g / g, or more than 24 g / g, or 20-50 g / g, or 20-40 g / g, or 24-30 g / g. The SAP may typically be in particulate form (superabsorbent polymer particles), although this does not exclude the use of other forms of SAP, such as, for example, superabsorbent polymer foam.

[0099] back seat Any conventional liquid-impermeable backsheet material commonly used for absorbent articles can be used as the backsheet. In some embodiments, the backsheet can be impermeable to malodorous gases generated by absorbed bodily exudates, thereby preventing the escape of malodors. The backsheet can be breathable or non-breathable.

[0100] measurement 1. Contact angle test All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0101] Cut a 10 mm x 50 mm rectangular specimen from the raw nonwoven or topsheet material of a disposable absorbent article, taking care not to touch the surface of the specimen or disrupt the structure of the material. The specimen should be 5 cm long and, when cut from the absorbent article, aligned with the longitudinal centerline of the absorbent article. Gently handle the specimen by the edges using forceps and place it flat on the sample stage of an optical microscope, such as a Keyence VHX 5000 or equivalent. Adjust the light source, magnification, and camera position appropriately to clearly show the cross-section of the specimen.

[0102] A single water droplet with a volume of approximately 0.05 mL is gently placed on the test specimen from a close distance of 1 cm or less above the test surface of the specimen. A Keyence VHX 5000 or equivalent instrument is used to obtain a high-resolution image of the water droplet on the test surface of the nonwoven fabric specimen. These steps are repeated to obtain multiple water droplet images. In a suitable water droplet image, each water droplet is oriented so as to approximately maximize the projection of the water droplet extending from the nonwoven fabric surface. The contact angle between the water droplet and the test specimen is measured directly from the captured image to the nearest 0.1 degree, as shown by line 3700 in Figures 8A and 8B. Figure 8A is an example image of a water droplet with a contact angle greater than 90°. Figure 8B is an example image of a water droplet with a contact angle less than 90°.

[0103] Measurements are taken on an area of ​​the test nonwoven where no openings are present. Five separate droplets are imaged, from which 10 contact angles are measured, one on each side of each imaged droplet. The arithmetic mean of the 10 contact angle values ​​is calculated to the nearest 0.1 degrees and reported as the surface contact angle.

[0104] 2. Artificial Menstrual Fluid (AMF) Preparation AMF consists of a mixture of defibrinated sheep blood, phosphate-buffered saline solution, and mucus components, and has a viscosity of 7.15 cSt to 8.65 cSt at 23±1°C.

[0105] Viscosity for AMF is performed using a low viscosity rotational viscometer, such as a Cannon LV-2020 Rotary Viscometer with a UL adapter (Cannon Instrument Co., State College, US) or equivalent. The appropriate size spindle for the viscosity range is selected, and the instrument is operated and calibrated according to the manufacturer. Measurements are taken at 23±1°C and 60 rpm. Results are reported to the nearest 0.01 cSt.

[0106] Defibrated sheep blood Defiberized sheep blood (available from Cleveland Scientific, Inc., Bath, Ohio, US) or equivalent with a hematocrit of 38% or greater, collected under sterile conditions, is used.

[0107] Phosphate-buffered saline solution Phosphate buffered saline consists of two individually prepared solutions (Solution A and Solution B). To prepare 1 L of Solution A, add 1.38 ± 0.005 g of sodium phosphate monobasic monohydrate and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to volume. Mix thoroughly. To prepare 1 L of Solution B, add 1.42 ± 0.005 g of sodium phosphate dibasic anhydrous and 8.50 ± 0.005 g of sodium chloride to a 1000 mL volumetric flask and add distilled water to volume. Mix thoroughly. Add 450 ± 10 mL of Solution B to a 1000 mL beaker and stir at low speed on a stir plate. Insert a calibrated pH probe (accurate to 0.1) into the beaker of Solution B and, while stirring, add enough Solution A to bring the pH to 7.2 ± 0.1.

[0108] Mucus components The mucus component is a mixture of phosphate-buffered saline, aqueous potassium hydroxide, gastric mucin, and aqueous lactic acid. The amount of gastric mucin added to the mucus component directly affects the final viscosity of the prepared AMF. A good range for gastric mucin is usually 38 to 50 grams. To prepare approximately 500 mL of mucus component, add 460 ± 10 mL of the previously prepared phosphate-buffered saline solution and 7.5 ± 0.5 mL of 10% w / v aqueous potassium hydroxide solution to a 1000 mL sturdy glass beaker. Place the beaker on a stirring hotplate and, while stirring, bring the temperature to 45°C ± 5°C. Weigh out the required amount of gastric mucin (± 0.50 g) and slowly sprinkle it into the previously prepared liquid at 45°C to avoid clumping. Cover the beaker and continue mixing. Allow the temperature of the mixture to exceed 50°C but not exceed 80°C for 15 minutes. Continue heating with gentle stirring while maintaining this temperature range for 2.5 hours, then remove the beaker from the hot plate and allow to cool to below 40°C. Next, add 1.8±0.2 mL of 10% v / v aqueous lactic acid solution and mix thoroughly. Autoclave the mucus component mixture at 121°C for 15 minutes and allow to cool for 5 minutes. Remove the mucus component mixture from the autoclave and stir until the temperature reaches 23°C±1°C.

[0109] Bring the temperature of the sheep blood and mucus components to 23°C ± 1°C. Using a 500 mL graduated cylinder, measure the volume of the entire batch of mucus components and add that volume to a 1200 mL beaker. Add an equal volume of sheep blood to the beaker and mix thoroughly. Using the viscosity method described above, verify that the viscosity of the AMF is between 7.15 and 8.65 cSt. If not, discard the batch and adjust the mucus components as needed to make another batch.

[0110] Certified AMF must be refrigerated at 4°C unless intended for immediate use. AMF may be stored in an airtight container at 4°C for a maximum of 48 hours after preparation. Prior to testing, AMF must be brought to 23°C ± 1°C. Any unused portion is discarded after testing is completed.

[0111] 3.Rewetting test Rewet is measured for absorbent articles filled with artificial menstrual fluid ("AMF") as described herein.

[0112] The amount of fluid remaining on the topsheet, i.e., rewet under pressures of 0.1 psi and 0.5 psi, is measured after 3.0 mL, 6.0 mL, 9.0 mL, and 12 mL of AMF are dispensed. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0113] The test product is removed from all packaging, taking care not to press down or pull on the product during handling. No attempt is made to smooth out wrinkles. Prior to testing, the test product is conditioned for at least 2 hours at 23°C ± 2°C and 50% ± 2% relative humidity.

[0114] The test product is placed body side up on a flat horizontal surface, a strike-through plate is placed in the center of the test product, and 0.25 psi pressure is applied to the test product.

[0115] 9A-9E, the see-through plate 9001 is constructed from Plexiglas with overall dimensions of 10.2 cm long x 10.2 cm wide x 3.2 cm high. A longitudinal channel 9007 running the length of the plate is 13 mm deep and 28 mm wide at the top surface of the plate, with lateral walls sloping downward at 65 degrees to a 15 mm wide base. A central test fluid well 9009 is 26 mm long, 24 mm deep, and 38 mm wide at the top surface of the plate, with lateral walls sloping downward at 65 degrees to a 15 mm wide base. At the base of the test fluid well 9009 is an "H" shaped test fluid reservoir 9003 that opens to the bottom of the plate for fluid to be introduced onto the underlying articles. The test fluid reservoir 9003 has an overall 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 with rounded ends and a 2 mm radius 9010. The legs are 3.5 mm apart. The central post has a 3 mm radius 9011 and houses opposing electrodes 9004 spaced 6 mm apart. The sides of the reservoir bow outward at a 14 mm radius 9012 bounded by an overall width W of 15 mm. Two wells 9002 (80.5 mm long x 24.5 mm wide x 25 mm deep) located outside the lateral channels are filled with lead shot to adjust the overall mass of the plate and provide 0.25 psi (17.6 gf / cm) pressure in the test area. 2 ) provides a confining pressure. Electrodes 9004 are embedded in plate 9001 and connect external banana jacks 9006 to the inner wall of fluid reservoir 9003. A circuit interval timer plugs into jack 9006 to the inner wall 9005 of fluid reservoir 9003.

[0116] Using a pipette, carefully dispense 3.0 mL of AMF through the open hole in the bleed-through plate onto the center of the test article within 2 seconds. Once the spurt of fluid is captured, remove the plate and start a 3-minute timer. After removing the plate, quickly capture images of the test product's top sheet using a color scanner, HP Scanjet G4010 or equivalent, cleaning the scanner surface after each scan. Analyze the images to measure the stain size and redness on the top sheet under the Stain Size and Redness Test described below. At the end of the 3 minutes, place five pre-weighed (referred to as "dry weight") filter papers (typical laboratory filter paper, e.g., Ahlstrom #632 12.7 cm x 12.7 cm filter paper) approximately centered over the fluid-stained area. Apply the required mass to generate a pressure of 0.1 psi on top of the test product and hold it under pressure for 5 seconds. Reweigh the filter papers (referred to as "wet weight"). The difference between the wet and dry weight of the filter paper is the rewet due to light pressure on the added volume of fluid.

[0117] The above steps are repeated until a total of 12.0 mL of fluid has been dispensed onto the test product. Rewet values ​​are reported to the nearest 0.001 gram for squirt levels of 3.0 mL, 6.0 mL, 9.0 mL, and 12.0 mL. Similarly, a total of three replicate samples are tested for each test product being evaluated. The arithmetic mean of the replicates is calculated to the nearest 0.001 gram and reported as rewet at 0.1 psi.

[0118] To obtain a rewet at 0.5 psi, the same rewet test is performed by applying the mass necessary to generate a pressure of 0.5 psi to the top of the test product.

[0119] The total rewet is calculated according to the following formula:

[0120] Total rewet (g) = rewet at 0.1 psi + rewet at 0.5 psi 4. Size and redness test of stains The size and redness of the stain visible on the topsheet of the absorbent article due to the fluid remaining on the topsheet is measured on the topsheet images of the test product collected in the Rewet Test described above for squirt levels of 3.0 mL, 6.0 mL, 9.0 mL, and 12.0 mL.

[0121] 4.1 Stain size test Image analysis is performed using an image analysis program such as ImageJ software (version 1.52p or higher, National Institutes of Health, USA) or equivalent. Images need to be distance calibrated using an image of a ruler to determine image resolution.

[0122] Open the image of the top sheet in ImageJ. Set the scale according to the image resolution. Crop the image in the central region and make a minimum bounding rectangle selection around the entire stain area visible across multiple pad layers. Convert the image type to 8-bit. Apply a Gaussian blur filter to smooth the image with a Gaussian function with a sigma (radius) of 2. Then, convert the filtered 8-bit grayscale image to a binary image using the "minimum" threshold method to find the boundary of the stain area on the top sheet against lighter colored stain areas from subsequent layers (as a result of fluid remaining on the top sheet).

[0123] The area of ​​the selected stain area on the top sheet was determined and the stain size on the top sheet was calculated as 0.01 cm 2 This entire procedure is repeated on three substantially identical replicate articles. Of the three individual recorded measurements of topsheet stain size, the topsheet stain size is recorded to the nearest 0.01 cm. 2 It is the average of the units.

[0124] 4.2 Dirt redness test The stain redness on the topsheet is shown as the stain redness saturation integral, which is calculated based on the HSB color model using color representation with three parameters: hue (0° to 360°), saturation (0 to 100), and lightness (0 to 100). A suitable hue range, for example, a combination of 240° to 360° and 0° to 45°, is selected for the topsheet image to represent the entire red stain on the topsheet of the test product. For the red stain area selected based on the hue range, a saturation histogram is obtained, and pixels corresponding to each color saturation level within the selected saturation range of 35 to 100 are counted. The stain redness saturation integral is calculated using the following formula:

[0125]

number

[0126] 5. Collection Time Test The collection time is measured for absorbent articles loaded with the AMF described herein using a wicking plate and an electronic interval timer. The time required for the absorbent article to collect one dose of AMF is recorded. All measurements are performed in a laboratory maintained at 23°C ± 2°C and 50% ± 2% relative humidity.

[0127] 9A-9E, the see-through plate 9001 is constructed from Plexiglas with overall dimensions of 10.2 cm long x 10.2 cm wide x 3.2 cm high. A longitudinal channel 9007 running the length of the plate is 13 mm deep and 28 mm wide at the top surface of the plate, with lateral walls sloping downward at 65 degrees to a 15 mm wide base. A central test fluid well 9009 is 26 mm long, 24 mm deep, and 38 mm wide at the top surface of the plate, with lateral walls sloping downward at 65 degrees to a 15 mm wide base. At the base of the test fluid well 9009 is an "H" shaped test fluid reservoir 9003 that opens to the bottom of the plate for fluid to be introduced onto the underlying articles. The test fluid reservoir 9003 has an overall 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 with rounded ends and a 2 mm radius 9010. The legs are 3.5 mm apart. The central post has a 3 mm radius 9011 and houses opposing electrodes 9004 spaced 6 mm apart. The sides of the reservoir bow outward at a 14 mm radius 9012 bounded by an overall width W of 15 mm. Two wells 9002 (80.5 mm long x 24.5 mm wide x 25 mm deep) located outside the lateral channels are filled with lead shot to adjust the overall mass of the plate and provide 0.25 psi (17.6 gf / cm) pressure in the test area. 2 ) to provide a confining pressure. Electrode 9004 is embedded in plate 9001 and connects an external banana jack 9006 to the inner wall of fluid reservoir 9003. A circuit interval timer is plugged into jack 9006 to the inner wall 9005 of fluid reservoir 9003. A circuit interval timer (not shown) is plugged into jack 9006 and monitors the impedance between the two electrodes 9004 to measure the time from the introduction of AMF into reservoir 9003 until the AMF is expelled from the reservoir. The timer has a resolution of 0.01 seconds.

[0128] The test product is removed from all packaging, taking care not to press down or pull on the product during handling. No attempt is made to smooth out wrinkles. Prior to testing, the test specimen is conditioned for at least 2 hours at 23±2°C and 50%±2% relative humidity.

[0129] The required mass of the penetrator plate must be calculated for the specific dimensions of the test article so that a confining pressure of 1.72 kPa is applied. Determine the longitudinal and lateral midpoints of the absorbent core of the article. Measure and record the lateral width of the core to the nearest 0.1 cm. The required mass of the penetrator plate is calculated by multiplying the core width by the penetrator plate length (10.2 cm) to get 17.6 gf / cm 2 The mass is calculated as the mass multiplied by 1 / 2 and recorded to the nearest 0.1 g. Add lead shot to the plate to achieve the calculated mass.

[0130] Connect the electronic interval timer to the strike-through plate 9001 and zero the timer. Place the test product on a flat, horizontal surface with the body side facing up. Gently place the strike-through plate 9001 over the center of the test product, ensuring the "H" shaped reservoir 9003 is centered over the test area.

[0131] Using a mechanical pipette, pipette exactly 3.00 mL±0.05 mL of AMF into the test fluid reservoir 9003. The fluid is dispensed along the molded lip at the bottom of the reservoir 9003 without splashing within a period of 3 seconds or less. After the fluid is captured, the capture time is recorded to the nearest 0.01 second. Before each test, the electrode 9004 is thoroughly cleaned.

[0132] Similarly, a total of three replicate samples are tested for each test product being evaluated. The arithmetic mean of the replicates is calculated to the nearest 0.01 second and reported as Collection Time (seconds).

[0133] 6.Spacer fabric size test The spacer fabric dimensions are measured using scanning electron microscope (SEM) images. SEM images are obtained and analyzed as follows to determine the spacer fabric dimensions.

[0134] (1) Preparation of test specimens When the spacer fabric is available in its raw material form, test specimens measuring 10 mm x 5 mm are cut from the raw material. If the spacer fabric is a component of the final product, a razor blade is used to remove the test specimen from the layer of spacer fabric in the final product to provide a test specimen measuring 10 mm x 5 mm. A cryogenic spray (e.g., Sunto™ Freeze Spray, Sunto (HK) International, China) can be used to remove the test specimen from other components of the final product. Care should be taken to prevent stretching of the spacer fabric during the separation process. If necessary, the test specimens may be removed from the final product by immersing the component in tetrahydrofuran (THF), gently agitating for 15 minutes, and then soaking for 5 minutes.

[0135] (2) SEM image acquisition SEM images were obtained using a scanning electron microscope (SEM), such as a Tabletop Microscope TM3000 (Hitachi, Japan) or equivalent. The specimen, with the second side of the spacer fabric attached to carbon tape, was mounted flat or vertically on a horizontal specimen stage for top-view images such as Figure 10A and cross-sectional images such as Figure 11, respectively. The specimen was then sputtered with platinum to avoid charging and improve overall conductivity under conditions of a current of 15 mA and a coating time of 120 seconds. The platinum-coated specimen was then transferred into the SEM specimen vacuum chamber for imaging.

[0136] An appropriate magnification and working distance are selected so that the top surface 112 or cross-sectional structure is suitably magnified for measurement. For cross-sectional imaging, the cross-sectional edges of the specimen are oriented so that they are substantially aligned horizontally. The spacer fabric specimen is imaged at an accelerating voltage of 5 kV and saved as an 8-bit jpeg image including a linear distance scale for calibration.

[0137] (3) Image analysis and segmentation Analysis is performed using an image analysis program such as ImageJ software (version 1.52p or higher, National Institutes of Health, USA) or equivalent. Open the specimen image in ImageJ. The SEM image needs to be distance calibrated using the corresponding scale bar and then cropped to remove the scale bar and image information label so that only the specimen view is saved for subsequent image processing.

[0138] The 8-bit grayscale image is then converted into a binary image (with "black" foreground pixels corresponding to the surface opening regions) using a "minimum" thresholding method: a histogram of gray level (GL) values ​​(ranging from 0 to 255, with one bin representing the trend P for each gray level i) i If the maxima of the sigma-based gradient (including the maxima) have exactly two maxima, the threshold gradation value t is t-1 >P t and P t ≦P t+1 If the histogram has more than two maxima, the histogram is iteratively smoothed using a windowed arithmetic mean of size 3 until there are exactly two maxima. The threshold tone value t is defined as the value where P t-1 >P t and P t ≦P t+1 This procedure identifies the gray level (GL) value for the minimum population located between the dark pixel peak of the aperture and the lighter pixel peak of the specimen material. If the histogram contains either zero or one maximum, the method cannot proceed further and no output parameter is defined.

[0139] (4) Top opening area, major axis length and minor axis length Referring to Figure 10B, set the scale for the binary image acquired in (3) according to the image resolution. Set the measurements to include the analysis of the top opening area and shape descriptor (i.e., the ratio between the major axis length and the minor axis length after replacing the area selection with a best-fit ellipse by keeping the same area, orientation, and centroid as the original selection). The values ​​of the area, major axis length, and minor axis length of the top opening are calculated by tracing these openings by their outer edges, and the size of the edge of the acquired image is 0.020 mm. 2 The area is obtained after excluding small or incomplete openings smaller than 10 mm. For the measurement, at least 10 openings must be detected from the SEM image. Referring to Figure 10B, if one opening is divided into sub-openings 1 and 6 in Figure 10B by a fiber (multiple fibers), those sub-openings are ignored. The area values ​​of all these openings are analyzed to obtain the average and standard deviation of the top surface opening area of ​​0.001 mm. 2 The relative standard deviation (RSD, defined as the standard deviation divided by the mean multiplied by 100) of the aperture area is calculated to the nearest 0.1%. All of these aperture major and minor axis length readings are analyzed separately, and the corresponding mean and standard deviation values ​​are calculated to the nearest 0.01 mm, with the RSD to the nearest 0.1%. A total of three substantially similar replicate specimens are prepared and analyzed. The arithmetic mean of the three replicates is calculated to the nearest 0.01 mm and reported as the top surface aperture area, major axis length, and minor axis length, respectively.

[0140] (5) Spacer fabric thickness The cross-sectional SEM image is rotated so that the top surface 112 of the spacer fabric 110 is aligned horizontally. Referring to FIG. 11, the thickness of the spacer fabric is measured at the location of the yarns 116 that vertically connect the top surface 112 and bottom surface 114 of the spacer fabric 110. Still referring to FIG. 11, the bottom edge of the bottom surface 114 of the spacer 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 fabric 110 is determined from the apex position of each yarn 116 that vertically connects the two surfaces. The vertical distance between the apex position of the yarns 116 and the bottom edge of the bottom surface 114 of the spacer fabric 110 is measured for at least five consecutive piles of filaments. The arithmetic mean of these distance measurements is calculated to the nearest 0.01 mm. Three substantially identical replicate specimens are prepared and analyzed. The arithmetic mean of the three replicates is calculated to the nearest 0.01 mm and reported as the spacer fabric thickness. [Example]

[0141] Example 1. Nonwoven fabric for top sheet Various nonwoven substrates were manufactured having the configurations shown in Table 1.

[0142] Nonwoven Fabric 1 with Apertures Shown in Figure 6: An 18 gsm spunbond nonwoven fabric was produced from 100% 2 denier hydrophobic PP fiber. Referring to Figure 6, Nonwoven Fabric 1 has a aperture 5a with at least three adjacent apertures 5b, 5c, and 5d, and the edge-to-edge spacing S between aperture 5a and each of apertures 5b, 5c, and 5d is 2.7 mm.

[0143] Nonwoven Fabric 2: An 18 gsm carded air-through nonwoven fabric was produced using 1.5 denier hydrophobic PE / PET sheath / core bicomponent fibers. This nonwoven fabric was then formed with the pattern shown in Figure 7 to produce Nonwoven Fabric 2. Referring to Figure 7, Nonwoven Fabric 2 has a hole 5a with at least three adjacent holes 5b, 5c, and 5d, with the edge-to-edge spacings S between hole 5a and holes 5b, 5c, and 5d being 1 mm, 1 mm, and 2 mm, respectively. Hole 5e has at least three adjacent holes 5f, 5g, and 5h, with the edge-to-edge spacings S between hole 5e and holes 5f, 5g, and 5h being approximately 1.5 mm, 1.5 mm, and 1 mm, respectively.

[0144] Nonwoven Fabric 3: A first 11 gsm fibrous web was produced by placing 1.5 denier hydrophobic sheath / core PE / PET bicomponent fibers, which constituted the first layer, on a conveyor belt. A second 13 gsm fibrous web was produced by placing 2 denier hydrophilic PE / PP sheath / core bicomponent fibers, which constituted the second layer, on a conveyor belt. The second fibrous web was then superimposed on the first fibrous web, and the superimposed webs were heat-treated at a temperature of 130°C to 140°C. The heat treatment was carried out using a hot air passing heat treatment device equipped with a breathable conveyor belt. During the heat treatment, the superimposed webs were placed on the breathable conveyor belt of the heat treatment device so that the surface of the first fibrous web was in contact with the breathable conveyor belt. The 2 denier hydrophobic PE / PET bicomponent fibers had a fiber contact angle of 121.4°, and the 2 denier hydrophilic PE / PET bicomponent fibers had a fiber contact angle of 62.3°.

[0145] Nonwoven fabric 4: Precursor nonwoven fabric 4 was produced using the same hydrophobic and hydrophilic fibers as nonwoven fabric 3, and according to the same process as nonwoven fabric 3. Holes were formed in precursor nonwoven fabric 4 in the pattern shown in Figure 7 to produce nonwoven fabric 4.

[0146] Nonwoven Fabric 5: A 24 gsm carded air-through nonwoven fabric was produced using 2 denier hydrophilic PE / PP bicomponent fibers.

[0147] According to the contact angle test, the contact angles of the top surface and the opposite bottom surface of the nonwoven fabric were measured and are shown below in Table 1. The contact angle of Nonwoven Fabric 4 was not tested considering that Nonwoven Fabric 4 has the same nonwoven composition and structure as Nonwoven Fabric 3 except that it has holes.

[0148] [Table 1]

[0149] Example 2. Absorbent article Sanitary napkins 1-8 are exemplary absorbent articles having a topsheet made from the nonwoven substrate of Example 1, a fluid management layer, an absorbent core specified in Table 2, and a common backsheet. Sanitary napkins 1-5 were manufactured using a common fluid management layer and absorbent core, and sanitary napkins 6-8 were manufactured using a common fluid management layer and absorbent core.

[0150] The collection rate and rewet at 0.1 psi / g and 0.5 psi / g of each of sanitary napkins 1-8 were tested according to the Collection Rate Test and Rewet Test disclosed herein. The topsheet saturation integral was measured and calculated according to the Stain Size and Redness Test. The results are shown in Table 2 below.

[0151] [Table 2] 290gsm spacer fabric *1 PET-based woven material shown in Figures 10A and 11. The thickness of the spacer fabric was 1.65 mm and the top open area was 0.43 mm, as measured according to Measurement 6. 2 The major axis length is 0.28 mm and the minor axis length is 0.19 mm. Spacer woven fabric size test. 88gsm SAPP *2 : Nonwoven fabric containing pulp and 22 gsm AGM.

[0152] [Table 3] Nonwoven fabric laminate*3 : 35gsm carded air-through bonded nonwoven top layer and 40gsm airlaid nonwoven bottom layer. 120gsm airlaid core *4 : Airlaid nonwoven containing pulp and 27 gsm AGM.

[0153] Sanitary napkins 1, 2 and 4 according to the present invention exhibit significantly faster collection times and lower total rewet and topsheet saturation integral values ​​compared to sanitary napkins 3 and 5-8.

[0154] Sanitary napkins 1 and 6 have different fluid management layers and absorbent cores but the same topsheet. Sanitary napkins 2 and 7 have different fluid management layers and absorbent cores but the same topsheet. Sanitary napkins 1 and 2 show significant improvements in collection time and total rewet, as well as significantly lower topsheet saturation integrals, compared to sanitary napkins 6 and 7, respectively.

[0155] Substrate 1, which has Nonwoven 1 as the topsheet, and Substrate 2, which has Nonwoven 2 as the topsheet, show relatively slow collection times for the first squirt, i.e., the first 3 mL, compared to Substrates 3 to 5. The 100% hydrophobic topsheets in Substrates 1 and 2 may require longer for the first squirt to wet the topsheet. However, both Substrates 1 and 2 show fast collection times of 6 mL, 9 mL, and 12 mL on the second, third, and fourth squirts, respectively.

[0156] The dimensions and values ​​disclosed herein should not be understood as being strictly limited to the exact numerical values ​​recited. Instead, unless otherwise indicated, each such dimension 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."

[0157] All documents cited herein, including cross-referenced or related patents or applications, are incorporated herein by reference in their entirety, unless expressly excluded or otherwise limited. The citation of any document shall not be deemed to be prior art to any invention disclosed or claimed herein, or to teach, suggest, or disclose any such invention, either alone or in combination with any other reference or references. Furthermore, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall control.

[0158] While particular embodiments of the present invention have been illustrated and described, it would be obvious 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. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.

Claims

1. An absorbent article comprising: a liquid-pervious topsheet having a wearer-facing surface and an opposite garment-facing surface, said topsheet comprising a nonwoven fabric containing a plurality of apertures; a liquid impermeable backsheet; an absorbent core disposed between the topsheet and the backsheet; a fluid management layer disposed between the topsheet and the absorbent core, the fluid management layer comprising a spacer fabric; 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 about 90 degrees or greater when measured according to a Contact Angle Test; The spacer fabric includes a top surface, a bottom surface, and a plurality of yarns interconnecting the first surface and the second surface, and the first surface and the second surface are spaced apart from each other.

2. The absorbent article of claim 1 , wherein the nonwoven fabric comprises a first layer comprising hydrophobic fibers.

3. 3. The absorbent article of claim 1 or 2, wherein the second surface of the nonwoven has a second contact angle of about 90 degrees or greater when measured according to a Contact Angle Test.

4. 10. The absorbent article of claim 1, wherein the second surface of the nonwoven has a second contact angle of less than about 90 degrees when measured according to a Contact Angle Test.

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

6. The absorbent article of claim 5 , wherein the nonwoven fabric has a unitary structure.

7. The absorbent article of claim 5 , wherein the nonwoven fabric is a laminate including the first layer and the second layer.

8. 8. The absorbent article of any one of claims 4 to 7, wherein the difference between said first contact angle and said second contact angle is at least about 10 degrees when measured according to a Contact Angle Test.

9. The absorbent article of claim 2 or 5, wherein the first layer has a basis weight of 14 gsm or less.

10. 10. The absorbent article of any one of claims 1 to 9, wherein the plurality of apertures includes at least one aperture having at least three adjacent apertures spaced apart by an edge-to-edge space of about 2.5 mm or less.

11. The absorbent article of any one of claims 1 to 10, wherein each of said yarns comprises between about 2 and 60 filaments.

12. The absorbent article according to claim 11, wherein the filament fineness is 1.5 to 10 dtex.

13. The top surface of the spacer fabric includes an opening, the opening having a size of about 0.2 mm as measured according to the Spacer Fabric Size Test. ２ The absorbent article according to claim 1 , having the above open areas.

14. The absorbent article of any one of claims 1 to 13, wherein the spacer fabric has a caliper in the range of about 1.0 mm to about 2.5 mm when measured according to the Spacer Fabric Dimensional Test.

15. The absorbent article of any one of claims 1 to 14, wherein the absorbent core comprises a superabsorbent polymer.

16. 16. The absorbent article of 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 handling layer.

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