JP7190883B2 - absorbent article - Google Patents

Description

The present invention relates to absorbent articles.

Sheets containing water-retentive fibers, such as cotton fibers, that absorb and retain water are known as topsheets of absorbent articles. For example, Patent Literature 1 discloses a fiber sheet containing cotton fibers, which is used as a topsheet. This fiber sheet includes a cotton fiber layer and a synthetic fiber nonwoven fabric, and is formed in a state in which the cotton fiber layer partially enters the nonwoven fabric.

In general, water-retentive fibers such as cotton fibers have a good texture and are therefore suitably used for underwear that comes in contact with the skin. However, since cotton fibers have high water retention properties, when a sheet containing cotton fibers is used as a topsheet of an absorbent article, the topsheet absorbs liquid excrement (liquid excrement) excreted by the wearer. It can hold and retain moisture. As a result, the wearer may experience discomfort as they continue to be in contact with the wet, damp topsheet. That is, when a sheet containing cotton fibers is used as the topsheet, there is a problem of low dryness.

According to the description of Patent Document 1, the fiber sheet containing cotton fibers disclosed in Patent Document 1 has the following characteristics. In the fiber sheet, the cotton fiber layer is embedded in the nonwoven fabric in the thickness direction, so the amount of fibers gradually increases from the cotton fiber layer toward the center of the fiber sheet in the thickness direction, that is, the inter-fiber distance gradually increases. become smaller. As a result, the capillary force gradually increases from the cotton fiber layer toward the central portion of the fiber sheet in the thickness direction, and the ability to draw liquid from the cotton fiber layer into the interior of the sheet increases. Therefore, the dryness of the surface of the fiber sheet can be enhanced.

Japanese Patent Application Laid-Open No. 2004-324038

However, the fiber sheet containing cotton fibers of Patent Document 1 has the following problems. The synthetic fiber layer located on the opposite side of the cotton fiber layer across the center of the fiber sheet in the thickness direction is a synthetic fiber layer. Therefore, the fiber amount gradually decreases from the central portion in the thickness direction of the fiber sheet toward the synthetic fiber layer, that is, the inter-fiber distance gradually increases. As a result, the capillary force gradually decreases from the central portion in the thickness direction of the fiber sheet toward the synthetic fiber layer. In this case, although the fiber sheet can draw the liquid absorbed from the cotton fiber layer side to the central portion in the thickness direction of the fiber sheet, it becomes difficult to transfer the liquid to the synthetic fiber layer side. Therefore, when a fiber sheet is used as a topsheet of an absorbent article, the topsheet can draw in the liquid excretions excreted by the wearer from the cotton fiber layer to the central portion in the thickness direction, but the thickness direction of the topsheet is not sufficient. It becomes difficult to migrate from the central part to the synthetic fiber layer. That is, it becomes difficult for liquid excrement to migrate from the surface sheet to the absorbent body, and the absorption performance of the absorbent article may be lowered, for example, the absorption rate may be lowered or the absorption amount may be lowered.

An object of the present invention is to provide an absorbent article capable of improving the absorption performance while improving the feel of the surface sheet.

The absorbent article of the present invention is as follows. (1) An absorbent article comprising a topsheet, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, wherein the topsheet is a first fiber layer containing water-retentive fibers. and a second fiber layer adjacent to the non-skin side of the first fiber layer and containing hydrophobic fibers and water-retentive fibers, wherein the surface of the first fiber layer on the skin side is the surface of the top sheet. The water-retentive fibers among the fibers constituting the first fiber layer, constituting the skin-side surface, the non-skin-side surface of the second fiber layer constituting the non-skin-side surface of the surface sheet, and is higher than the ratio of the water-retaining fibers among the fibers constituting the second fiber layer, and the average fiber length of the water-retaining fibers of the second fiber layer is the water-retaining fiber of the first fiber layer an absorbent article that is shorter than the average fiber length of the absorbent fibers.

In the present absorbent article, the proportion of the water-retaining fibers in the first fiber layer located on the skin side of the topsheet is relatively high, so the feel of the topsheet can be improved. In addition, since the average fiber length of the water-retentive fibers contained in the first fiber layer is relatively long, it is possible to suppress the occurrence of fluff due to insufficient entanglement of the fibers due to an excessively short average fiber length. A decrease in the feel of the sheet can be suppressed.
At that time, since the average fiber length of the water-retaining fibers contained in the second fiber layer is shorter than the average fiber length of the water-retaining fibers contained in the first fiber layer, the fibers constituting the second fiber layer are brought closer to each other. can be made Therefore, since the average distance between fibers in the second fiber layer can be made shorter than the average distance between fibers in the first fiber layer, the capillary phenomenon can be caused more strongly in the second fiber layer, and the first fiber The liquid excretion excreted on the skin-side surface of the layer can be quickly drawn into the second fiber layer. Liquid excretions drawn into the second fiber layer can be rapidly transferred to the absorbent body through the second fiber layer by the hydrophobic fibers.
At this time, in the first fibrous layer, the liquid excrement can be drawn into the second fibrous layer while being widely diffused in the plane direction by the water-retentive fibers having a relatively long average fiber length. As a result, the liquid excretion spread widely in the plane direction by the surface sheet can be absorbed in a wide area in the plane direction of the absorbent body, so that the absorption performance can be enhanced.
This makes it possible to improve the absorption performance while improving the feel of the surface sheet.

The absorbent article of the present invention is (2) an absorbent article comprising a topsheet, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, wherein the topsheet is a water-retaining and a second fiber layer adjacent to the non-skin side of the first fiber layer and containing hydrophobic fibers and water-retaining fibers, wherein the skin side of the first fiber layer constitutes the skin-side surface of the topsheet, the non-skin-side surface of the second fiber layer constitutes the non-skin-side surface of the topsheet, and constitutes the first fiber layer The ratio of the water-retaining fibers among the fibers is higher than the ratio of the water-retaining fibers among the fibers constituting the second fiber layer, and the fiber density of the first fiber layer is the same as that of the second fiber layer. It may be an absorbent article that is less than the fiber density. Here, the fiber density is the density of the number of fibers.

In the present absorbent article, the proportion of the water-retaining fibers in the first fiber layer located on the skin side of the topsheet is relatively high, so the feel of the topsheet can be improved.
At that time, since the fiber density of the second fiber layer is higher than the fiber density of the first fiber layer, the fibers constituting the second fiber layer can be brought closer to each other. Therefore, since the average distance between fibers in the second fiber layer can be made shorter than the average distance between fibers in the first fiber layer, the capillary phenomenon can be caused more strongly in the second fiber layer, and the first fiber The liquid excretion excreted on the skin-side surface of the layer can be quickly drawn into the second fiber layer. Liquid excretions drawn into the second fiber layer can be rapidly transferred to the absorbent body through the second fiber layer by the hydrophobic fibers.
At this time, in the first fibrous layer, the liquid excrement can be drawn into the second fibrous layer while being widely diffused in the planar direction by the water-retentive fibers. As a result, the liquid excretion spread widely in the plane direction by the surface sheet can be absorbed in a wide area in the plane direction of the absorbent body, so that the absorption performance can be enhanced.
This makes it possible to improve the absorption performance while improving the feel of the surface sheet.

(3) The absorbent article of the present invention further comprises (3) an auxiliary sheet having a fiber density higher than that of the second fiber layer, between the topsheet and the absorbent body (2) above. Absorbent article, may be.
Since the present absorbent article further comprises an auxiliary sheet having a fiber density higher than that of the second fiber layer, the liquid excretion drawn into the second fiber layer is stabilized in the auxiliary sheet by capillary action. can be migrated As a result, the liquid excrement can be more stably transferred from the topsheet to the absorbent body via the auxiliary sheet, and the absorption performance can be improved while improving the feel of the topsheet.

(4) The hydrophobic fibers contained in the second fiber layer include heat-fusible fibers that are heat-fused to each other, any one of (1) to (3) above. It may be the absorbent article according to any one of the items.
In the present absorbent article, since the heat-fusible fibers are heat-fused to each other in the second fibrous layer, the shape of the second fibrous layer can be stably maintained. Therefore, even if the average fiber length of the water-retaining fibers contained in the second fiber layer is relatively short, the water-retaining fibers can be stably held evenly among the hydrophobic fibers. As a result, the liquid excretion drawn into the second fiber layer can be stably transferred to the absorbent body without unevenness, and the absorption performance can be improved.

(5) The absorbent article according to (4) above, wherein at least part of the heat-fusible fibers of the second fibrous layer are exposed on the skin-side surface of the first fibrous layer. It may be an absorbent article as described.
In the absorbent article, part of the heat-fusible fibers of the second fiber layer are present in the first fiber layer so as to be exposed on the surface of the first fiber layer, so that the water-retaining fibers of the first fiber layer can be stably held between the heat-fusible fibers. As a result, even if the average distance between the fibers of the first fiber layer is relatively long and the strength of the first fiber layer is relatively low, it is possible to suppress sagging. In addition, by holding the water-retentive fibers of the first fiber layer between the heat-fusible fibers, it is also possible to suppress fluffing. These can improve the feel of the first fiber layer. In addition, since a part of the heat-fusible fibers in the second fiber layer having no water retention exists in the first fiber layer, the first fiber layer to the second fiber layer via the heat-fusible fibers can be separated from each other. can facilitate the transfer of liquid waste to As a result, liquid excretion can be stably transferred to the absorber.

The absorbent article of the present invention has (6) a compressed portion in which the top sheet and the absorbent body are compressed in the thickness direction of the absorbent article, and the thermal fusion bondability of the second fiber layer is improved. The absorbent article according to (4) or (5) above, wherein at least part of the fibers are exposed on the inner surface of the compressed portion.
In the present absorbent article, a part of the heat-fusible fibers of the second fiber layer are present in the first fiber layer so as to be exposed on the inner surface of the compressed portion, so that the first fiber layer in the compressed portion The water-retentive fibers can be stably held between the heat-fusible fibers. Thus, even if the strength of the first fiber layer in the compressed portion is relatively low, the first fiber layer in the compressed portion can be prevented from becoming flattened or fluffed, and the touch of the first fiber layer in the compressed portion can be improved. In addition, since a part of the heat-fusible fibers in the second fiber layer having no water retention exists in the first fiber layer in the compressed portion, the first fibers in the compressed portion through the heat-fusible fibers Transfer of liquid waste from the layer to the second fibrous layer can be facilitated. As a result, liquid excretion can be more stably transferred to the absorbent body.

In the absorbent article of the present invention, (7) the compressed portion includes a low-density portion having a shallow depth in the thickness direction of the absorbent article and a high-density portion having a deep depth in the thickness direction of the absorbent article. and, wherein at least part of the heat-fusible fibers of the second fiber layer are exposed on the surface of the low-density portion, even if the absorbent article according to (6) above. good.
In the absorbent article, part of the heat-fusible fibers of the second fiber layer are present in the first fiber layer so as to be exposed on the surface of the low-density portion, so that the first fiber layer in the low-density portion The water-retentive fibers can be stably held between the heat-fusible fibers. As a result, even if the strength of the first fiber layer in the low-density portion is relatively weak, it is possible to suppress sagging and fluffing, and the touch of the first fiber layer in the low-density portion can be improved. . In addition, since a portion of the heat-fusible fibers in the second fiber layer that do not have water retentivity exist in the first fiber layer in the low-density portion, the first fiber in the low-density portion via the heat-fusible fibers Transfer of liquid excreta from one fibrous layer to the second fibrous layer can be facilitated. As a result, the liquid excretion can finally be more stably transferred to the absorber.

In the absorbent article of the present invention, (8) the surface sheet includes a plurality of projections extending along the longitudinal direction of the absorbent article and positioned at intervals in the width direction of the absorbent article; and a plurality of recesses extending along the longitudinal direction of the product and positioned between adjacent protrusions, wherein the top sheet has a fiber density of S1 at the top of the protrusions, and a fiber density at the bottom of the recesses. Any of the above (1) to (7), wherein S1<S3<S2, where S2 is the density and S3 is the fiber density in the region between the top of the protrusion and the bottom of the recess. It may be the absorbent article according to any one of the items.
In the absorbent article according to claim 8, in the surface sheet, the fiber density is Capillary action works toward the bottom of the concavity, which is densely packed. Therefore, the liquid excretion excreted on the most skin-side surface of the topsheet (the top of the convex portion or its vicinity) can be more easily drawn into the bottom of the concave portion located near the non-skin-side surface of the topsheet. As a result, the liquid excrement can be more stably transferred from the skin-side surface of the topsheet to the absorbent body via the non-skin-side surface of the topsheet. In addition, the above fiber density gradient makes it difficult to rewet back the liquid excretion once absorbed. Furthermore, since the fiber density of the convex portion is low, the wearer can feel the softness. Therefore, it is possible to improve the absorption performance while improving the texture of the surface sheet.

In the absorbent article of the present invention, (9) the surface sheet is formed by compressing the first fiber layer and the second fiber layer in the thickness direction of the absorbent article in each of the plurality of recesses. The absorbent article according to (8) above may have a plurality of depressions.
In this absorbent article, the first fiber layer and the second fiber layer are compressed and fixed to each other in the plurality of depressions, and therefore the water-retaining fibers of the first fiber layer are compressed. As a result, fluffing of the water-retentive fibers can be suppressed, and the texture of the topsheet can be maintained satisfactorily.

In the absorbent article of the present invention, (10) the average fiber length of the hydrophobic fibers in the second fiber layer is longer than the average fiber length of the water-retaining fibers in the first and second fiber layers, It may be an absorbent article according to any one of (1) to (9) above.
In this absorbent article, the average fiber length of the hydrophobic fibers in the second fiber layer is longer than the average fiber length of the water-retaining fibers in the first and second fiber layers. Therefore, at least part of the hydrophobic fibers of the second fiber layer can reach the inside of the first fiber layer. As a result, the liquid excretion in the first fibrous layer can be more easily transferred to the second fibrous layer, and the liquid excretion transferred to the second fibrous layer can be more easily transferred to the absorbent body. can.

In the absorbent article of the present invention, (11) the water-retentive fibers contained in the topsheet are cellulosic fibers, the absorbent body contains cellulosic fibers (excluding pulp fibers), and is contained in the topsheet. A part of the cellulosic fibers may be the absorbent article according to any one of (1) to (10) above, which is in contact with the cellulosic fibers contained in the absorbent body. .
In this absorbent article, cellulosic fibers with high liquid diffusibility communicate from the first fiber layer of the surface sheet to the absorbent body via the second fiber layer. Therefore, liquid excretion can be diffused directly from the surface sheet to the absorbent body by utilizing the diffusion of liquid excrement by the cellulosic fibers. Thereby, absorption performance can be improved.

In the absorbent article of the present invention, (12) the fibers constituting the topsheet are arranged in the longitudinal direction of the topsheet at both ends in the width direction of the topsheet more than at the central portion in the width direction of the topsheet. It may be the absorbent article according to any one of (1) to (11) above, which is oriented in a direction.
In the present absorbent article, since the fiber orientation of the surface sheet is more random in the central portion, the liquid excrement can be uniformly diffused concentrically, and the fiber orientation is more in the longitudinal direction in the both end portions. By doing so, the liquid excrement that has reached both ends can be diffused in the longitudinal direction. That is, the absorbent article can be used as a whole, and the absorbent performance can be enhanced. In addition, since the number of fibers exposed from the edges of the topsheet is reduced at both ends of the topsheet, the friction against the skin is reduced and the deterioration of the touch can be suppressed.

The absorbent article of the present invention is (13) the absorbent article according to any one of (1) to (12) above, wherein the water-retentive fiber contained in the topsheet is cotton. good.
In the present absorbent article, since the water-retentive fiber is cotton, it is possible to further maintain or improve the absorption performance while improving the texture of the surface sheet.

(14) The absorbent article of the present invention further comprises an auxiliary sheet positioned between the topsheet and the absorbent body, wherein the widthwise dimension of the topsheet is equal to the widthwise dimension of the auxiliary sheet. The absorbent article according to any one of (1) to (13) above may be smaller than the above.
When the edge of the surface sheet containing a large amount of water-retaining fibers is rubbed, the water-retaining fibers are likely to come loose from the edge and fall off. Therefore, in the present absorbent article, the widthwise dimension of the auxiliary sheet is larger than the widthwise dimension of the topsheet containing a large amount of water-retentive fibers. That is, in a plan view, a pair of extending portions are formed on the auxiliary sheet outside the widthwise end edges of the topsheet. Therefore, the force that the absorbent article receives from the thighs of the wearer can be received by the pair of extending portions at both ends in the width direction of the auxiliary sheet. can be made scratch-resistant. As a result, it is possible to prevent the water-retentive fibers from being frayed and dropped from both edges of the topsheet in the width direction due to rubbing at both edges of the topsheet in the width direction, thereby suppressing a decrease in touch feeling.

ADVANTAGE OF THE INVENTION According to this invention, the absorbent article which can improve absorptive performance can be provided, making the feel of a surface sheet favorable.

1 is a plan view showing a configuration example of an absorbent article according to an embodiment; FIG. FIG. 2 is a cross-sectional view taken along line II-II of FIG. 1; 2A and 2B are a plan view and a cross-sectional view showing a configuration example of a surface sheet according to an embodiment; FIG. 1 is a schematic diagram showing a configuration example of an absorbent article manufacturing apparatus according to an embodiment; FIG. It is sectional drawing explaining the manufacturing method of the absorbent article which concerns on embodiment.

A sanitary napkin will be described as an example of the absorbent article according to the embodiment. However, the types and uses of the absorbent article of the present invention are not limited to those examples, and can be applied to other absorbent articles as long as they do not depart from the scope of the subject matter of the present invention. Other absorbent articles include, for example, pantiliners, light incontinence pads, and disposable diapers.

(First embodiment)
1 and 2 are diagrams showing configuration examples of a sanitary napkin 1 according to an embodiment. 1 is a plan view showing the unfolded state of the sanitary napkin 1, FIG. 2(a) is a cross-sectional view taken along line II-II of FIG. 1, and FIG. 2(b) is FIG. 2(a). 1 is a partially enlarged cross-sectional view of FIG. The sanitary napkin 1 of this embodiment has a longitudinal direction L, a width direction W and a thickness direction T which are orthogonal to each other. In the sanitary napkin 1 depicted in FIG. 1, the upper and lower sides of the figure are the front and rear sides in the longitudinal direction L, and the left and right sides are the left and right sides in the width direction W, respectively, and the front side with respect to the paper surface. and the back side are the upper side and the lower side in the thickness direction T, respectively. The sanitary napkin 1 has a longitudinal center line CL (virtual line) extending in the longitudinal direction _L through the center of the width direction W, and a width direction center line _CW (virtual line) extending in the width direction W through the center of the longitudinal direction L. line). The direction and the side toward the longitudinal center line CL are defined as the inward direction and the inner side in the width direction _W , respectively, and the direction and the side away from the longitudinal center line CL are defined as the outward direction and the outer side in the width direction W, respectively. On the other hand, the direction and the side toward the center line _CW in the width direction are defined as the inward direction and the inner side in the longitudinal direction L, respectively, and the direction and the side away from the center line CW are defined as the outward direction and the outer side in the longitudinal direction L, respectively. When the sanitary napkin 1 placed on a plane including the longitudinal direction L and the width direction W is viewed from the upper side in the thickness direction T, it is called "planar view", and the shape grasped in plan view is called "planar shape". An arbitrary direction within a plane including the longitudinal direction L and the width direction W is called a "planar direction". When the sanitary napkin 1 is put on by the wearer placed on it, the side relatively close to the wearer's skin surface and the side farther from the wearer's skin in the thickness direction T are referred to as "skin side" and "non-skin side". It says. These definitions are commonly used for each material of the sanitary napkin 1 as well.

In the present embodiment, the sanitary napkin 1 (excluding the wing portion) has a substantially rectangular shape that is long in the longitudinal direction L and short in the width direction W in a plan view, and that both edges in the longitudinal direction L are substantially semicircular. . However, the shape is not particularly limited as long as it is long in the longitudinal direction L and short in the width direction W, and examples thereof include rounded rectangles, ellipses, hourglass shapes, and similar shapes. The sanitary napkin 1 has wings 9 extending outward in the width direction W from a substantially rectangular portion, and the wings 9 have a substantially trapezoidal shape. However, the shape of the wing portion 9 may be semicircular or semielliptical, for example.

In this embodiment, the sanitary napkin 1 comprises a topsheet 2 forming the skin-side surface of the sanitary napkin 1 , a backsheet 3 forming the non-skin-side surface of the sanitary napkin 1 , and a topsheet 2 . and an absorbent body 4 arranged between the backsheet 3 and the backsheet 3. Moreover, in this embodiment, the sanitary napkin 1 further includes an auxiliary sheet 5 and a pair of side sheets 6 , 6 . The auxiliary sheet 5 is arranged so as to overlap the non-skin side of the top sheet 2 . Each of the pair of side sheets 6, 6 is joined to both ends of the auxiliary sheet 5 in the width direction W on the non-skin side so that the inner end in the width direction W overlaps, and the outer side in the width direction W procrastinating. Therefore, in this embodiment, the absorbent body 4 is positioned between the top sheet 2, the auxiliary sheet 5, and the pair of side sheets 6, 6 and the back sheet 3. As shown in FIG. However, an exterior sheet may be provided on the non-skin side of the backsheet 3 .

The topsheet 2 is a liquid-permeable sheet and includes a first fiber layer 2a and a second fiber layer 2b. The skin-side surface of the first fiber layer 2 a constitutes the skin-side surface of the topsheet 2 . The second fiber layer 2b is adjacent to the non-skin side of the first fiber layer 2a. In this embodiment, the non-skin-side surface of the second fibrous layer 2b constitutes the non-skin-side surface of the topsheet 2, so the topsheet 2 has a two-layer structure. However, the second fibrous layer 2b may include one or more fibrous layers on the non-skin side, so the topsheet 2 as a whole may have a three-layer or multi-layer structure.

The first fiber layer 2a contains water retentive fibers.
The water-retentive fiber is not particularly limited as long as it has a property of absorbing and retaining water (water retentivity). Examples of water-retentive fibers include cellulosic fibers. Cellulosic fibers are not particularly limited as long as they contain cellulose, and examples thereof include natural cellulose fibers, regenerated cellulose fibers, refined cellulose fibers and semi-synthetic cellulose fibers. Examples of natural cellulose fibers include plant fibers such as seed hair fibers (example: cotton), pistil fibers (example: hemp), leaf vein fibers (example: Manila hemp), and fruit fibers (example: palm). Cotton includes, for example, Hirszum cotton (example: Upland cotton), Barbadense cotton, Arboreum cotton, and Helvaceum cotton. Organic cotton or pre-organic cotton (trademark) may be used as cotton. However, organic cotton means cotton certified by GOTS (Global Organic Textile Standard). Regenerated cellulose fibers include fibers such as rayon, e.g., viscose rayon obtained from viscose, polynosic and modal, cuprammonium rayon (also referred to as "cupra") obtained from cuprammonium salt solutions of cellulose. . As the purified cellulose fiber, lyocell, specifically pulp, is dissolved in an aqueous solution of N-methylmorpholine N-oxide to form a spinning stock solution (dope), and extruded into a dilute solution of N-methylmorpholine N-oxide. Examples include fibers. Purified cellulose is commercially available, for example, as Tencel™. Semi-synthetic cellulose fibers include fibers such as semi-synthetic cellulose, such as acetate fibers, such as triacetate and diacetate. Among these, natural cellulose fibers are preferred, cotton is more preferred, and Hirsutum cotton is even more preferred, from the viewpoint of water retention and texture. In the present embodiment, the water-retentive fiber is Hirsutum cotton (hereinafter also simply referred to as "cotton").

The second fiber layer 2b contains hydrophobic fibers and water retentive fibers.
Hydrophobic fibers are not particularly limited as long as they are hydrophobic fibers. Hydrophobic fibers include, for example, thermoplastic resin fibers. The thermoplastic resin fiber is not particularly limited as long as it contains a thermoplastic resin. Examples of thermoplastic resins include olefin resins such as polyethylene (PE), polypropylene (PP), and ethylene-vinyl acetate copolymer (EVA), and polyester resins such as polyethylene terephthalate (PET) and polylactic acid (PLA). Known resins such as resins and polyamide resins such as 6-nylon may be used, and these resins may be used alone or in combination of two or more. In addition, the structure of fibers made of such a thermoplastic resin is not particularly limited, and examples thereof include composite fibers such as core-sheath type fibers, side-by-side type fibers, and island/sea type fibers; hollow type fibers; Flat, Y-shaped, C-shaped, and other modified cross-section fibers; Latent crimped or actual crimped three-dimensional crimped fibers; A single structured fiber may be used, or two or more types of fibers may be used in combination. In this embodiment, the hydrophobic fiber is a PET/PE core-sheath type composite fiber. The water-retaining fibers are the same as the water-retaining fibers of the first fiber layer 2a. In addition, "hydrophobic" refers to a property that is difficult to blend with water or difficult to retain moisture. It means the degree.

In the first fiber layer 2a and the second fiber layer 2b, the ratio of the water-retaining fibers among the fibers constituting the first fiber layer 2a is higher than the ratio of the water-retaining fibers among the fibers constituting the second fiber layer 2b. There are many. As a result, at least the surface sheet 2 can be made to have a good texture. Furthermore, in the first fiber layer 2a and the second fiber layer 2b, the average fiber length of the water-retaining fibers of the second fiber layer 2b is shorter than the average fiber length of the water-retaining fibers of the first fiber layer 2a. As a result, the fibers constituting at least the second fibrous layer 2b are brought closer to each other, that is, the distance between the fibers is shortened, so that capillary action can be caused more strongly and the liquid excrement can be strongly drawn. Specifically, for example, it is as shown below.

The ratio of the water-retentive fibers among the fibers constituting the first fiber layer 2a is preferably 70 to 100% by mass, more preferably 80 to 100% by mass, more preferably 90 to 100% by mass, from the viewpoint of enhancing the feel of the surface sheet 2. % is more preferred. A content of 70% by mass or more makes it easier for the wearer to recognize the first fiber layer 2a as a water-retaining fiber, thus ensuring good touch feeling. Among the fibers constituting the first fiber layer 2a, the fibers other than the water-retentive fibers are not particularly limited as long as they are fibers capable of forming a liquid-permeable layer, and examples thereof include thermoplastic resin fibers. In this embodiment, the proportion of water-retentive fibers is 100% by mass.

The fineness of the water-retentive fibers of the first fiber layer 2a is not particularly limited, and examples thereof include 0.8 to 15 dtex. The fiber length of the water-retentive fibers of the first fiber layer 2a is, for example, 10 to 80 mm. If the fiber length is less than 10 mm, the fiber length is too short, making it difficult for the fibers to entangle with each other, and there is a risk that sufficient strength cannot be obtained. above 80 mm, some of such fibers may extend in the width direction W, resulting in fiber spanning from one thigh edge of the wearer to the other thigh edge; In this case, due to the liquid diffusion effect of the water-retentive fibers, the liquid excrement adhering to the central portion of the sanitary napkin 1 in the width direction W may spread to both thighs and cause discomfort to the wearer. . The fiber length is preferably 15-60 mm, more preferably 20-40 mm. Correspondingly, the average fiber length of the water-retentive fibers of the first fiber layer 2a is, for example, 15 to 50 mm, preferably 20 to 45 mm, and more preferably 25 to 40 mm.

The latitude, fiber length, and average fiber length of the fibers other than the water-retaining fibers in the first fiber layer 2a are also about the same as those of the water-retaining fibers (0.5 to 2 times) is preferred. However, in this embodiment, no fibers other than the water-retentive fibers are used.

The ratio of the water-retaining fibers in the fibers forming the second fiber layer 2b is not particularly limited as long as it is lower than the ratio of the water-retaining fibers in the first fiber layer 2a. The proportion of the water-retentive fibers is, for example, 50 to 90% by mass. If it is less than 50% by mass, there is a possibility that the tactile sensation may deteriorate when pressure is applied in the thickness direction. If it exceeds 90% by mass, the effect of preventing fluffing by the hydrophobic fiber may be reduced. The proportion of the water-retentive fiber is preferably 60-85% by mass, more preferably 70-80% by mass. Correspondingly, the proportion of hydrophobic fibers in the second fiber layer 2b is, for example, 10 to 50% by weight, preferably 15 to 40% by weight, and more preferably 20 to 30% by weight. The second fiber layer 2b may contain a third fiber in addition to the water-retentive fiber and the hydrophobic fiber.

The fineness of the water-retentive fibers of the second fiber layer 2b is not particularly limited, and examples thereof include 0.8 to 15 dtex. The fiber length of the water-retaining fibers of the second fiber layer 2b is not particularly limited as long as the average fiber length is shorter than the average fiber length of the water-retaining fibers of the first fiber layer 2a, and is, for example, 3 to 40 mm. If the length is less than 3 mm, the fiber length is too short and the fibers are difficult to entangle with each other, failing to obtain sufficient strength. If it exceeds 40 mm, the dynamic freedom of the fibers in the web state during manufacturing of the second fiber layer 2b is low, and the water-retaining fibers cannot enter the gaps between the hydrophobic fibers, resulting in the second fiber layer. It becomes difficult to shorten the inter-fiber distance in 2b, which in turn makes it difficult to increase the fiber density. The fiber length of the water-retentive fibers of the second fiber layer 2b is preferably 5 to 35 mm, more preferably 10 to 35 mm. The average fiber length of the water-retentive fibers of the second fiber layer 2b is correspondingly 5 to 30 mm, preferably 10 to 25 mm, and more preferably 15 to 20 mm.
Further, it is also possible to use a mixed water-retaining fiber in which at least two types of water-retaining fibers having a fiber length within the above range and having a long fiber length and a water-retaining fiber having a short fiber length are mixed. As an example, the water-retaining fibers having a long fiber length are, for example, 15 to 40 mm (preferably 20 to 35 mm), and the water-retaining fibers having a short fiber length are, for example, 3 to 25 mm (preferably 5 to 20 mm) fibers. can be long. In this case, the water-retaining fibers having a long fiber length can enhance the water-retaining property and the texture of the second fiber layer 2b, while the water-retaining fibers having a short fiber length can increase the inter-fiber distance of the second fiber layer 2b.

The latitude of the hydrophobic fibers of the second fiber layer 2b is not particularly limited, and examples thereof include 1.1 to 8.8 dtex. However, the ease of entanglement between the hydrophobic fibers of the second fiber layer 2b and the water-retentive fibers that are the main fibers of the first fiber layer 2a, that is, the ease of transfer of liquid excrement from the first fiber layer 2a , From the viewpoint of separation prevention between the first fiber layer 2a and the second fiber layer 2b, the latitude of the hydrophobic fibers of the second fiber layer 2b is higher than the fineness of the water-retaining fibers of the first fiber layer 2a. Small (thin fiber diameter) is preferred.
Moreover, the fiber length of the hydrophobic fibers of the second fiber layer 2b is not particularly limited, and is, for example, 10 to 80 mm. However, the ease of entanglement between the hydrophobic fibers of the second fiber layer 2b and the water-retentive fibers that are the main fibers of the first fiber layer 2a, that is, the ease of transfer of liquid excrement from the first fiber layer 2a , from the viewpoint of separation prevention between the first fiber layer 2a and the second fiber layer 2b, the fiber length of the hydrophobic fiber of the second fiber layer 2b is It is preferably longer than the fiber length of the elastic fiber. The average fiber length of the hydrophobic fibers of the second fiber layer 2b is correspondingly 15 to 50 mm, for example.

The thickness of each of the first fiber layer 2a and the second fiber layer 2b is not particularly limited, and may be, for example, 0.05 to 4 mm, preferably 0.1 to 3 mm, more preferably 0.2 to 2 mm. However, from the viewpoint of improving the touch of the first fiber layer 2a and from the viewpoint of suppressing rewet back to the wearer's skin, the thickness of the first fiber layer 2a is relatively thick, and the thickness of the second fiber layer 2b is relatively large. A relatively thin thickness is preferred. The thickness of the surface sheet 2 is not particularly limited, and is, for example, 0.1 to 5 mm, preferably 0.4 to 4 mm, more preferably 0.8 to 3 mm.

However, the ratio of types of fibers in a sheet such as a fiber layer is measured as follows.
That is, by coloring the water-retentive fibers and the hydrophobic fibers with different colors, the ratio of the types of fibers is measured. (1) A sample of 70 mm×70 mm is cut out of the surface sheet 2 . (2) By performing a coloring treatment with the reagent Kayastain Q (Shikisensha Co., Ltd.), only the water-retentive fibers are dyed blue, and only the hydrophobic fibers are colored yellow. (3) Digital Microscope VHX-100 manufactured by KEYENCE CORPORATION By measuring the ratio of blue and yellow when viewed from the skin side of the sample (first fiber layer 2a) in a range of 50 mm × 50 mm, It is the ratio of the types of fibers in the first fiber layer 2a. On the other hand, by measuring the ratio of blue and yellow when viewed from the non-skin surface (second fiber layer 2b) in a range of 50 mm×50 mm, the ratio of the types of fibers in the second fiber layer 2b is determined.

Also, the distance between fibers in a sheet such as a fiber layer is measured according to the following measuring method. (1) A sample of 10 mm×10 mm is cut out of the surface sheet 2 . (2) Using a digital microscope VHX-100 (lens VH-Z20R + variable illumination attachment VH-K20) manufactured by Keyence Corporation, imaging magnification: 200 times, measurement area: vertical 1300 μm × horizontal 1735 μm, surface sheet Images are taken from each of the front surface (first fiber layer 2a) and the rear surface (second fiber layer 2b) of 2. At that time, images are taken five times in total for each depth of 20 μm in the depth range of 0 to 100 μm for each of the front surface and the back surface. (3) From each image obtained, the area of the region where no fiber exists is determined. At that time, the presence or absence of fibers in each pixel is determined based on whether the brightness of each pixel in each obtained image is lower or higher than a predetermined brightness (threshold value). judge. However, light is transmitted only through the area where no fiber exists, and the area is bright, that is, the luminance is high. As a result, the area of the part without fibers in the imaging area is obtained. (4) The void ratio is calculated by subtracting the determined area of the fiber-free site from the area of the imaging region (measured area) and dividing by the area of the imaging region (measured area). The calculation is performed for each 20 μm deep image to calculate five porosities. (5) By calculating the average of the five porosities, the porosities of the front surface (first fiber layer 2a) and the back surface (second fiber layer 2b) of the topsheet 2 are determined. By comparing the size of the porosity, the size of the inter-fiber distance can be determined. That is, when the porosity is large, it can be considered that the inter-fiber distance is large. For example, the surface of the topsheet 2, that is, the skin side (first fiber layer 2a: for example, 100% cotton surface) has a porosity of 25.4%, and the back surface, that is, the non-skin side (second fiber layer 2b: for example, The surface of 60% cotton + 40% synthetic fiber) had a porosity of 24.5%.

In addition, the fiber length and average fiber length of the fibers of the sheet such as the fiber layer are measured in accordance with "A7.1.1 Method A (standard method ) is measured according to "Method for Measuring the Length of Individual Fibers on a Graduated Glass Plate". The above method is a test method corresponding to ISO 6989 issued in 1981.

Also, the basis weight of a sheet such as a fiber layer is measured according to the following measuring method. A single fiber layer is prepared, and the fiber layer is cut into a size of 5 cm x 5 cm to obtain a sample, and the mass is measured after drying in an atmosphere of 100°C or higher. The basis weight of the sample is then calculated by dividing the measured mass by the area of the sample. A value obtained by averaging the grammage of 10 samples is taken as the grammage of the sheet.

Also, the thickness of a sheet such as a fiber layer is measured according to the following measuring method. Using a digital microscope VHX-100 manufactured by KEYENCE CORPORATION, an enlarged image is taken from a direction perpendicular to the cut surface of the surface sheet 2 . The magnified image is an image magnified such that the entire topsheet 2 in the thickness direction T can be photographed, and the magnifying power is, for example, 20 to 50 times. The thickness of each fiber layer is measured in the 2D image converted from the obtained 3D image. The thickness of the topsheet 2 is the average value of the thicknesses measured at three different cut surfaces.

As described above, in the sanitary napkin 1, the proportion of water-retentive fibers in the first fiber layer 2a located on the skin side of the topsheet 2 is relatively high, so the feel of the topsheet 2 can be improved. . In addition, since the average fiber length of the water-retentive fibers contained in the first fiber layer 2a is relatively long, it is possible to suppress the occurrence of fluff due to insufficient entanglement of the fibers due to an excessively short average fiber length. A decrease in the feel of the surface sheet 2 can be suppressed.
At that time, since the average fiber length of the water-retaining fibers contained in the second fiber layer 2b is shorter than the average fiber length of the water-retaining fibers contained in the first fiber layer 2a, the fibers constituting the second fiber layer 2a are can be brought closer together. Therefore, since the average distance between the fibers of the second fiber layer 2b can be made shorter than the average distance between the fibers of the first fiber layer 2a, the capillary phenomenon can be caused more strongly in the second fiber layer 2b, The liquid excretion excreted on the skin-side surface of the first fiber layer 2a can be quickly drawn into the second fiber layer 2b. Liquid excretion drawn into the second fibrous layer 2b can be rapidly transferred to the absorbent body 4 via the second fibrous layer 2b by the hydrophobic fibers.
At this time, in the first fibrous layer 2a, the liquid excrement can be drawn into the second fibrous layer 2b while being widely diffused in the plane direction by the water-retentive fibers having a relatively long average fiber length. As a result, the liquid excretion widely spread in the plane direction of the topsheet 2 can be absorbed in a wide area of the absorbent body 4 in the plane direction, so that the absorption performance can be enhanced.
As a result, the absorbent performance of the sanitary napkin 1 can be improved while the surface sheet 2 has a good texture.

In addition, when the second fiber layer 2b includes one or more fiber layers on the non-skin side, that is, when the topsheet 2 has a three-layer or multilayer structure as a whole, from the viewpoint of further increasing the liquid permeability, It is preferable that the fiber layer closer to the non-skin side surface of the topsheet 2 has a relatively lower ratio of water-retaining fibers and a shorter average fiber length of the water-retaining fibers.

In this embodiment, the fiber density of the first fiber layer 2a is lower than that of the second fiber layer 2b. That is, there is a gradient of fiber density such that the fiber density increases from the first fiber layer 2a to the second fiber layer 2b.
In the sanitary napkin 1 having such a configuration, liquid excretion excreted on the skin-side surface of the topsheet 2, that is, the surface of the first fiber layer 2a when worn is first drawn into the first fiber layer 2a. can be done. Thereafter, the liquid excretion drawn into the first fiber layer 2a can be stably transferred to the second fiber layer 2b due to the fiber density gradient. As a result, the layer ( Examples: Auxiliary sheet, liquid excrement can be stably transferred to the absorbent body 4). Therefore, it is possible to improve the absorption performance while improving the texture of the topsheet 2 . The surface sheet 2 of the sanitary napkin 1 may not have such a gradient of fiber density.
However, when one or more fiber layers are further provided on the non-skin side surface of the second fiber layer 2b, that is, when the topsheet 2 has a three-layer or multi-layer structure, the non-skin side surface of the topsheet 2 It is preferable that the fiber layer closer to the fiber layer has a relatively higher fiber density. As a result, the liquid permeability from the skin-side fiber layer to the non-skin-side fiber layer can be further enhanced, and liquid excrement can be more stably transferred to the auxiliary sheet and the absorbent body 4 .

However, when the second fiber layer 2b includes one or more fiber layers on the non-skin side, that is, when the topsheet 2 has a three-layer or multi-layer structure as a whole, the non-skin side of the topsheet 2 Preferably, the fiber layer closer to the surface has a relatively higher fiber density. As a result, the liquid permeability from the skin-side fiber layer to the non-skin-side fiber layer can be further enhanced, and liquid excrement can be more stably transferred to the auxiliary sheet and the absorbent body 4 .

In addition, the fiber density of a sheet such as a fiber layer is measured, for example, by the following measuring method.
(1) A sample of 10 mm×10 mm is cut out of the surface sheet 2 . (2) Enlarge and observe a cut surface of the sample parallel to the thickness direction T using a scanning electron microscope (manufactured by JEOL Ltd.: JCM-5100). The magnification is such that the cross section of 30 to 60 fibers can be measured within one screen (example: 150 to 500 times). (3) The observation area is divided into three equal layers in the thickness direction T into a layer on the skin side, an intermediate layer, and a layer on the non-skin side. is used as the second fiber layer 2b, and the number of fiber cross-sections in each fiber layer is measured. That is, the number of cross-sections of the cut fiber is counted on a cut plane of a predetermined area. (4) Convert the number of obtained fiber cross sections into the number of fiber cross sections per 1 mm ² , and take this as the fiber density (fibers/mm ² ). The measurement is performed at three locations, and the average value of the measured values is taken as the fiber density of the sample. That is, the density of the number of fibers is used as the fiber density. In other words, the number of fibers per unit area in a cross section parallel to the thickness direction T is used as the fiber density. As the fiber density, the number of fibers per unit volume may be used. The number of fibers per unit volume can be determined by, for example, X-ray CT analysis. The fiber density per unit area and the fiber density per unit volume have different numerical values, but the relative comparison of the fiber densities between the fiber layers (example: comparison of size) is the same.

In this embodiment, the hydrophobic fibers included in the second fiber layer 2b include heat-fusible fibers that are heat-fused to each other. That is, the heat-fusible fibers included in the hydrophobic fibers have joint points (fusion points) where the heat-fusible fibers are joined to each other by heat-sealing. Such heat-fusible fibers bonded together can be viewed as forming a kind of matrix of thermoplastic resin fibers within the second fiber layer 2b.
In the sanitary napkin 1 having such a configuration, the shape of the second fibrous layer 2b can be stably maintained by the heat-fusible fibers heat-fused to each other in the second fibrous layer 2b. Therefore, even if the average fiber length of the water-retaining fibers contained in the second fiber layer 2b is relatively short, the water-retaining fibers can be stably held between (within the matrix of) the heat-fusible fibers without unevenness. As a result, the liquid excretion drawn into the second fiber layer 2b can be stably transferred to the absorbent body 4 (and the auxiliary sheet 5) evenly, and the absorption performance can be improved. In addition, the hydrophobic fibers of the sanitary napkin 1 may not include such heat-sealable fibers that are heat-sealed to each other.

In the present embodiment, at least part of the heat-fusible fibers of the second fiber layer 2b are exposed on the skin-side surface of the first fiber layer 2a. That is, the heat-fusible fibers of the second fiber layer 2b stably retain the shape of the second fiber layer 2b, and at least a portion thereof continuously extends from the second fiber layer 2b to the first fiber layer 2a. They enter and further reach the skin-side surface of the first fiber layer 2a.
In the sanitary napkin 1 having such a configuration, the heat-fusible fibers of the second fiber layer 2b continuously extend into the first fiber layer 2a, so that the water-retentive fibers of the first fiber layer 2a can be stably held between the heat-fusible fibers. As a result, even if the average distance between the fibers of the first fiber layer 2a is relatively long and the strength of the first fiber layer 2a is relatively low, it is possible to suppress sagging. In addition, by holding the water-retentive fibers of the first fiber layer 2a between the heat-fusible fibers, it is possible to suppress fluffing. These can improve the feel of the first fiber layer 2a. In addition, since a part of the heat-fusible fibers in the second fiber layer 2b that do not have water retentivity exists in the first fiber layer 2a, the first fiber layer 2a is separated from the first fiber layer 2a via the heat-fusible fibers. Transfer of liquid excrement to the two-fiber layer 2b can be promoted. As a result, liquid excretion can be stably transferred to the absorbent body 4 (and the auxiliary sheet 5). The heat-fusible fibers of the second fibrous layer 2b of the sanitary napkin 1 do not have to be exposed on the surface of the first fibrous layer 2a.

In this embodiment, the fibers forming the topsheet 2 are oriented in the longitudinal direction L of the topsheet 2 at both ends in the width direction W of the topsheet 2 rather than at the central portion in the width direction W of the topsheet 2 . is doing. That is, in the width direction W, in the surface sheet 2, the orientation of the fibers in the central portion in the longitudinal direction L is relatively small, and the orientation of the fibers in the longitudinal direction L is relatively large in the ends.
In the sanitary napkin 1 having such a structure, since the fiber orientation of the topsheet 2 is relatively random in the central portion, the liquid excrement can be diffused substantially concentrically, and the fibers are oriented in the longitudinal direction L at both ends. Therefore, the liquid excrement that has reached both ends can be diffused in the longitudinal direction L. That is, the sanitary napkin 1 can be used as a whole, and the absorption performance can be enhanced. In addition, since the number of fibers exposed from the edges is reduced at both ends of the topsheet 2 in the width direction W, the friction against the skin is reduced and the deterioration of the touch can be suppressed. The fiber orientation of the surface sheet 2 of the sanitary napkin 1 does not have to be relatively large in the longitudinal direction L at both ends in the width direction W.

In the sanitary napkin 1, the excretory opening contact area XA is set at the center in the width direction W near the center in the longitudinal direction L and slightly forward in plan view. The excretory opening contact area XA is an area that faces or contacts the excretory opening of the wearer when the sanitary napkin 1 is worn. The excretory opening contact area XA is set according to the type and application of the absorbent article. The excretory opening contact area XA is, for example, slightly forward in the center of the absorbent body 4 in the longitudinal direction L, and has a length of about 1/4 to 1/2 of the total length of the absorbent body 4 in the longitudinal direction L, and is set at approximately the center of the absorbent body 4 with a width of about 1/2 to 1/3 of the total length in the width direction W of the absorbent body 4 .

In this embodiment, the sanitary napkin 1 includes a pair of compressed portions (compressed grooves) 12, 12 that are positioned continuously or intermittently on both outer sides in the width direction W of the excretory opening contact area XA. In the present embodiment, the sanitary napkin 1 further includes a pair of pressing portions (pressing grooves) 13, 13 rearward in the longitudinal direction L of the pair of pressing portions 12, 12, and the length of the excretory opening contact area XA. Compressed portions (compressed grooves) 11 and 14 are provided on the front and rear sides in the direction L, respectively, and a plurality of dotted compressed portions 15 are provided in the excretory opening contact area XA. The compressed portions 11 to 15 are formed by compressing the top sheet 2 and the absorbent body 4 in the thickness direction T. As shown in FIG. That is, the surface sheet 2, the auxiliary sheet 5, and the absorbent body 4 (the skin-side core wrap 4b and absorbent core 4a) are compressed in the thickness direction T to form. At that time, each pressed part is weakly pressed and formed at a shallow position, and a low density part LPA having a relatively low fiber density and a strongly pressed part LPA formed at a deep position and having a relatively high fiber density and a high density part HPA. However, the criteria for "shallow" and "deep" are the skin-side surface of the topsheet 2 . The low density LPA and high density HPA can be referred to as the shallow bottom and deep bottom of each squeeze. The low-density portion LPA and the high-density portion HPA of the compressed portions 11-15 are located within the absorbent core 4a. However, the high density portion HP may reach the core wrap 4b on the non-skin side. The shape of the compression parts 11 to 15 is arbitrary. The sanitary napkin 1 may not include at least one of the pressing portions 11-15.

In this embodiment, at least part of the heat-fusible fibers of the second fiber layer 2b are exposed on the inner surface of at least one of the compressed portions 11-15.
In the sanitary napkin 1 having such a configuration, the heat-fusible fibers are present in the first fiber layer 2a so as to be exposed on the inner surface of the pressing portion, so that the first fiber layer 2a is exposed even in the pressing portion. The water-retentive fibers can be stably held between the heat-fusible fibers. As a result, even if the strength of the first fiber layer 2a is relatively low in the compressed portion, it is possible to prevent the first fiber layer 2a from becoming saggy or fuzzy, and the texture of the first fiber layer 2a in the compressed portion can be improved. can. In addition, since a portion of the heat-fusible fibers in the second fiber layer 2b that do not have water retentivity exist in the first fiber layer 2a in the compressed portion, the first fibers in the compressed portion through the heat-fusible fibers Transfer of liquid excrement from the first fiber layer 2a to the second fiber layer 2b can be promoted. As a result, liquid excretion can be more stably transferred to the absorbent body 4 (and the auxiliary sheet 5). In the sanitary napkin 1, the heat-fusible fibers do not have to be exposed on the inner surface of the compressed portion.

In this embodiment, at least part of the heat-fusible fibers of the second fiber layer 2b are exposed on the surface of the low-density portion LPA of at least one of the compressed portions 11-15.
In the sanitary napkin 1 having such a configuration, the heat-fusible fibers are present in the first fiber layer 2a so as to be exposed on the surface of the low-density portion LPA, so that the first fiber layer in the low-density portion LPA is The water-retentive fibers of 2a can be stably held between the heat-fusible fibers. As a result, even if the strength of the first fiber layer 2a in the low-density portion LPA is relatively low, it is possible to prevent the first fiber layer 2a in the low-density portion LPA from becoming saggy and fuzzy, thereby improving the feel of the first fiber layer 2a in the low-density portion LPA. be able to. In addition, since a portion of the heat-fusible fibers in the second fiber layer 2b that do not have water retentivity exist in the first fiber layer 2a in the low-density portion LPA, the heat-fusible fibers are Transfer of liquid excrement from the first fiber layer 2a to the second fiber layer 2b in the dense part LPA can be promoted. As a result, the liquid excretion can be finally transferred to the absorbent body 4 (and the auxiliary sheet 5) in a more stable manner. In the sanitary napkin 1, the heat-fusible fibers do not have to be exposed on the surface of the low-density portion LPA.

In this embodiment, the surface sheet 2 has an uneven structure. FIG. 3 shows a configuration example of the topsheet 2 according to the embodiment, FIG. 3(a) is a plan view of the topsheet 2, and FIG. 3(b) is a cross section along line IIb-IIb in FIG. 3(a). It is a diagram. The first fiber layer 2a has a first upper surface 2aE on the upper side in the thickness direction T and a first lower surface 2aF on the lower side, and the second fiber layer 2b has a second upper surface 2bE on the upper side in the thickness direction T and a lower side and a second lower surface 2bF. The first lower surface 2aF and the second upper surface 2bE are imaginary boundaries between the two fiber layers, but they are not strict boundaries because some of the fibers of the two fiber layers are entangled with each other and enter the other fiber layer. The first fiber layer 2a extends continuously along the longitudinal direction L on the first upper surface 2aE. and a plurality of concave portions 22 extending between the convex portions 21 adjacent to each other. In this embodiment, each of the plurality of protrusions 21 is formed solid. Since each of the plurality of protrusions 21 is formed solid in this manner, each protrusion 21 is less likely to be crushed, and liquid transfers from each protrusion 21 to the absorber 4, which is likely to come into contact with the wearer's body. Since it has excellent properties, it is possible to improve the dryness of the surface of each projection 21 .

The second fiber layer 2b has a substantially flat shape except for a depressed portion 23 (described later) formed by pressing. However, the second upper surface 2bE may swell slightly upward in the thickness direction T at a position corresponding to the convex portion 21 . In addition, the second fiber layer 2b extends continuously along the longitudinal direction L on the second lower surface 2bF in the same manner as the first fiber layer 2a (but in the opposite direction of the thickness direction T), and is spaced apart in the width direction W. and a plurality of recesses extending continuously along the longitudinal direction L and located between adjacent protrusions. In this case, the positions of the projections 21 and the recesses 22 of the first fiber layer 2a and the positions of the projections and the recesses of the second fiber layer 2b are preferably the same in plan view.

The first fiber layer 2a and the second fiber layer 2b are joined to each other by entangling. The entangling method includes, for example, the spunlace method or the water jet method. However, the interlacing method is not limited to this example, and other interlacing methods such as the air-through method may be used.

In the present embodiment, S1 is the fiber density of the top portion 21T of the convex portion 21, S2 is the fiber density of the bottom portion 22B of the concave portion 22, and the area MP between the top portion 21T of the convex portion 21 and the bottom portion 22B of the concave portion 22 is When the fiber density is S3, S1<S3<S2.
In the sanitary napkin 1 having such a configuration, the surface sheet has a dense fiber density S3 from the tops 21T of the protrusions 21 having a sparse fiber density S1 via the region MP having a medium fiber density S2. Capillary action works toward the bottom 22B of the recess 22 . Therefore, the liquid excretion excreted on the most skin-side surface of the topsheet 2 (tops 21T of the projections 21 or the vicinity thereof) is removed from the bottoms 22B of the recesses 22 located near the non-skin-side surface of the topsheet 2. It can be easier to draw into. As a result, the liquid excrement can be more stably transferred from the skin-side surface of the topsheet 2 to the absorbent body 4 (and the auxiliary sheet 5) via the non-skin-side surface of the topsheet 2 . In addition, the fiber density gradient (S1<S3<S2) makes it difficult to rewet back liquid excretion once absorbed. Furthermore, since the fiber density of the protrusions 21 is low, the wearer can feel the softness. Therefore, it is possible to improve the absorption performance while improving the texture of the surface sheet. In addition, the sanitary napkin 1 may not have the uneven structure on the topsheet 2, and may not have the fiber density gradient.

In this embodiment, the topsheet 2 has a plurality of depressions 23 in the thickness direction T in each of the plurality of recesses 22, where the first fiber layer 2a and the second fiber layer 2b are compressed. The plurality of recessed portions 23 are intermittently arranged along the longitudinal direction L in each recessed portion 22 at equal intervals or non-equidistant intervals. The recessed portions 23 may or may not be located at the same positions in the longitudinal direction L in the recessed portions 22 adjacent to each other in the width direction W. In this embodiment, the recesses 22 are arranged in a checkered pattern. Moreover, the shape of the recessed portion 23 in plan view is arbitrary, such as an elliptical shape.
In the sanitary napkin 1 having such a configuration, the first fiber layer 2 and the second fiber layer 2b are fixed by compression in the thickness direction T in the plurality of depressions 23, and thus the first fiber layer retains water. Compressed fibres. As a result, fluffing of the water-retentive fibers can be suppressed, and the texture of the topsheet can be maintained satisfactorily. Note that the sanitary napkin 1 does not have to have the recesses 23 in the topsheet 2 .

In this embodiment, the auxiliary sheet 5 is a liquid-permeable sheet. Examples of the auxiliary sheet 5 include liquid-permeable nonwoven fabrics, woven fabrics, and composite sheets thereof. The auxiliary sheet 5 has a slightly larger shape in the width direction W than the topsheet 2 . The auxiliary sheet 5 has a pair of loop portions 5L, 5L at both ends in the width direction W. As shown in FIG. Both sides of the auxiliary sheet 5 in the width direction W of the pair of loop parts 5L and 5L are folded back in a loop shape to the inside of the auxiliary sheet 5 in the width direction W and to the non-skin side (lower side in the thickness direction T). formed by The ends of both sides of the folded-back auxiliary sheet 5 are attached to a pair of inner ends of the pair of side sheets 6, 6 facing each other along the longitudinal direction L. ) are joined to each other. Note that the loop portion 5L does not include an elastic member. Further, the ends of both sides of the folded back auxiliary sheet 5 are joined to the non-skin side surface of the auxiliary sheet 5 by a pair of adhesive portions extending intermittently or continuously along the longitudinal direction L. As shown in FIG.

In the surface sheet 2 of the present embodiment containing a large amount of water-retaining fibers, when the edges are rubbed, the water-retaining fibers are likely to come loose and fall off from the edges. Here, in the present embodiment, the dimension in the width direction W of the auxiliary sheet 5 is larger than the dimension in the width direction W of the topsheet 2 . That is, in a plan view, portions of the auxiliary sheet 5 outside both edges in the width direction W of the top sheet 2 extend outward in the width direction W to form a pair of extension portions. In this embodiment, a pair of loop portions 5L, 5L are formed at both end portions of the auxiliary sheet 5 in the width direction W as the pair of extending portions. As a result, the force that the sanitary napkin 1 receives from the thighs of the wearer can be received by the pair of loop portions 5L, 5L (the pair of extension portions), and both edges of the topsheet 2 in the width direction W It is possible to make it difficult to rub against the thighs. As a result, it is possible to prevent the water-retentive fibers from being frayed and dropped from both edges in the width direction W of the topsheet 2 due to rubbing at both edges in the width direction W of the topsheet 2, thereby suppressing a decrease in touch feeling. In particular, when the pair of loop portions 5L and 5L are used as the pair of extension portions, the force that the sanitary napkin 1 receives from the wearer's thighs is softly received by the pair of loop portions 5L and 5L. The texture felt by the wearer can be improved. Especially when the water-retentive fiber is cotton, these effects are remarkable.

In this embodiment, the auxiliary sheet 5 has a fiber density higher than that of the second fiber layer 2b. In the sanitary napkin 1 having such a configuration, the liquid excretion drawn into the second fiber layer 2b can be stably transferred to the auxiliary sheet 5 by capillary action. As a result, the liquid excretion can be more stably transferred from the surface sheet 2 to the absorbent body 4 via the auxiliary sheet 5, and the absorption performance can be improved while the touch of the surface sheet 2 is improved. In addition, when the fiber density of the first fiber layer 2a<the fiber density of the second fiber layer 2b<the fiber density of the auxiliary sheet 5, liquid excrement is further stabilized on the auxiliary sheet 5 by capillary action. It is preferable because it can be transferred systematically. The sanitary napkin 1 may not have the auxiliary sheet 5 or the loop portion 5L.

In this embodiment, the auxiliary sheet 5 contains water-retentive fibers corresponding to the topsheet 2, and when the topsheet 2 contains cellulosic fibers (preferably cotton), cellulosic fibers (preferably cotton) are used. preferably included. In the sanitary napkin 1 having such a structure, water-retentive fibers with high liquid diffusibility, preferably cellulosic fibers, more preferably cotton, extend from the first fiber layer of the top sheet 2 through the second fiber layer to the auxiliary sheet 5 . is connected to Therefore, by utilizing the diffusion of liquid excretion by these fibers, the liquid excretion can be more stably transferred from the topsheet 2 to the absorbent body 4 via the auxiliary sheet 5, and the texture of the topsheet 2 can be improved. can be improved while improving the absorption performance. In the sanitary napkin 1, the auxiliary sheet 5 may not contain water-retentive fibers, cellulosic fibers, or cotton. In this case, the auxiliary sheet 5 may be, for example, a nonwoven fabric made of hydrophobic fibers, among which a nonwoven fabric made of thermoplastic resin fibers is publicly used.

The absorbent body 4 is a layer having liquid absorption performance and liquid retention performance, and in the present embodiment, it has a shape elongated in the longitudinal direction L in plan view and having substantially semicircular ends in the longitudinal direction L. As shown in FIG. In this embodiment, the absorbent body 4 includes an absorbent core 4a and a core wrap 4b covering it. The absorbent core 4a includes, for example, a liquid-retaining substance containing water-absorbing fibers such as pulp fibers, and a water-absorbing material such as superabsorbent polymer (SAP). The core wrap 4b may be, for example, a liquid-permeable sheet containing a hydrophilic nonwoven fabric such as tissue.

In this embodiment, when the topsheet 2 contains cellulosic fibers (preferably cotton), the absorber 4 preferably contains cellulosic fibers (preferably cotton) corresponding to the topsheet 2 . In that case, part of the cellulosic fibers contained in the topsheet 2 is preferably in contact with the cellulosic fibers contained in the absorbent body 4 .
In the sanitary napkin 1 having such a structure, the cellulose-based fibers with high liquid diffusibility pass from the first fiber layer 2a of the top sheet 2 through the second fiber layer 2b (in some cases, through the auxiliary sheet 5). It communicates up to the absorber 4 . Therefore, liquid excretion can be directly diffused from the topsheet 2 to the absorbent body 4 by utilizing the diffusion of liquid excrement by the cellulosic fibers. Thereby, absorption performance can be improved. The absorbent body 4 of the sanitary napkin 1 may not contain cellulosic fibers or cotton.

In this embodiment, the side sheet 6 is a water-repellent sheet. As the side sheet 6, for example, a water-repellent nonwoven fabric or a breathable synthetic resin film can be used. Further, in this embodiment, the backsheet 3 is a liquid-impermeable sheet. Examples of the backsheet 3 include liquid-impermeable nonwoven fabrics, synthetic resin films, and composite sheets thereof. In this embodiment, the wing portions 9 are formed by the side sheets 6 and the back sheet 3 .

In the sanitary napkin 1 of the present embodiment, the top sheet 2 is joined to the auxiliary sheet 5 with an adhesive (example: hot-melt adhesive), and faces the absorbent body 4 in the auxiliary sheet 5 and the pair of side sheets 6, 6. The part is glued to the absorbent body 4 . The portions of the pair of side sheets 6, 6 and the absorbent body 4 facing the backsheet 3 are joined to the backsheet 3 with an adhesive or the like.

In this embodiment, the sanitary napkin 1 further includes a plurality of adhesive portions 7 and a pair of adhesive portions 8,8. The plurality of adhesive portions 7 have, for example, a substantially rectangular shape, are arranged on the non-skin side surface of the backsheet 4 so as to overlap the absorber 4 in plan view, extend continuously in the longitudinal direction L, and extend in the width direction. Lined up intermittently on W. The pair of adhesive portions 8, 8 has, for example, a substantially rectangular shape, is arranged on the non-skin side surface of the backsheet 4 so as to overlap with the pair of wing portions 9, 9 in plan view, and is continuous in the longitudinal direction L. extended. As the adhesive parts 7 and 8, for example, a hot melt adhesive can be used.

Next, an example of a method for manufacturing the sanitary napkin 1 according to this embodiment will be described.

FIG. 4 is a schematic diagram showing a configuration example of a manufacturing apparatus 300 for the sanitary napkin 1. As shown in FIG. 5A and 5B are diagrams schematically illustrating a method for manufacturing the sanitary napkin 1. FIG. The manufacturing apparatus 300 has a transport direction MD, a transverse direction CD, and a vertical direction TD for transporting materials such as sheets and semi-finished products. In this embodiment, the longitudinal direction, width direction and thickness direction of the materials and semi-finished products are all the same as the transport direction MD, the transverse direction CD and the vertical direction TD.

First, the first carding machine 110 forms the second fiber web P11 corresponding to the second fiber layer 2b. The first carder 110 is a dry roller card using a single card or double card commonly used for forming fibrous webs. The second fibrous web P11 contains water retentive fibers and hydrophobic fibers. The second fibrous web P11 is conveyed in the conveying direction MD by a conveying device (not shown).
Next, the second carding machine 120 forms the first fiber web P12 corresponding to the first fiber layer 2a. The second carding machine 120 is also a dry roller card similar to the first carding machine 110 . The first fibrous web P12 contains water retentive fibers. The first fibrous web P12 is laminated on the second fibrous web P11 being conveyed by the conveying device. As a result, a composite fiber web P13 having a two-layer structure in which the first fiber web P12 and the second fiber web P11 are laminated is formed, and is transported in the transport direction MD by the transport device. The ratio of each fiber in each fiber web can be controlled by the ratio of raw fibers supplied to each carding machine.

Next, the composite fiber web P13 having a two-layer structure is subjected to water jet treatment by a water jet treatment machine 130 to entangle the fibers. Thereby, a first continuous sheet (spunlaced nonwoven fabric) P14 is formed. Here, in the water jet treatment, the composite fiber web P13 is placed on a continuously moving mesh belt, and a high-pressure water jet is jetted from the upper surface side of the composite fiber web P13 to entangle the fibers. The properties of the first continuous sheet P14 obtained by the water jet treatment can be appropriately adjusted and changed by the mass of each fiber web, the hole diameter of the injection nozzle, the number of holes (pitch) of the injection nozzle, the passing speed of the fiber web, and the like. . After that, the first continuous sheet P14 that has passed through the water jet processor 130 is dried by the dryer 140 . The dried first continuous sheet P15 is transported in the transport direction MD by the transport device.

The method for forming the fiber web corresponding to each fiber layer is not limited to the method described above, and for example, a wet method may be employed. Also, the web bonding method is not limited to the method described above, and for example, a hydroentanglement method, a needle punch method, or the like may be employed. Further, the first continuous sheet P15 is manufactured in a manufacturing factory different from the manufacturing factory of the sanitary napkin 1, wound into a roll, and then supplied in the state of a roll to the manufacturing factory of the sanitary napkin 1. good too.

Next, the first continuous sheet P16, which is the first continuous sheet P15 transported by a transport device (not shown) or rewound from a roll (not shown), is transported in the transport direction MD and shaped. It is supplied to device 210 . Here, the shaping device 210 includes shaping rolls 210a and 210b having uneven portions extending in the circumferential direction and meshing with each other on the outer peripheral surface. Then, the first continuous sheet P16 is sandwiched between the uneven portions of the shaping rolls 210a and 210b, and is shaped into an uneven structure extending in the transport direction MD. After that, the first continuous sheet P16 is transported in the transport direction MD. Thereby, a continuous topsheet P16 for the topsheet 2 is formed.

Next, the continuous auxiliary sheet AS for the auxiliary sheet 5 unwound from the material roll WR3 is supplied to the heating device 220 while being transported in the transport direction MD. Next, the continuous auxiliary sheet AS is supplied to the coating device 302 after undergoing a heat treatment to restore bulk. One surface of the continuous auxiliary sheet AS is coated with an adhesive (example: hot-melt adhesive) in a predetermined pattern (example: spiral pattern). After that, the continuous auxiliary sheet AS and the continuous topsheet P16 are supplied to the joining device 230 while being transported in the transport direction MD, and sandwiched between a pair of joining rolls 230a and 230b of the joining device 230 to be joined. Thereby, a continuous surface sheet P17 is formed as shown in FIG. 5(a).

Next, the continuous surface sheet P17 is supplied to the coating device 303 while being transported in the transport direction MD. Then, the continuous surface sheet P17 is applied with an adhesive (eg, hot-melt adhesive) along the conveying direction MD on the lower surface of the continuous surface sheet P17 (the continuous auxiliary sheet AS) in the vertical direction TD and at the end portion in the transverse direction CD. agent) is applied in a predetermined pattern. Next, the continuous surface sheet P17 is supplied to the loop forming device 240 while being transported in the transport direction MD. Both end portions of the continuous auxiliary sheet AS of the continuous surface sheet P17 in the transverse direction CD are folded toward the central portion in a loop shape by a folding jig such as a sailor of the loop forming device 240 . As a result, a pair of side portions ASL, ASL corresponding to the pair of loop portions 5L, 5L are formed on both sides of the continuous surface sheet P17 in the transverse direction CD. Thereby, a continuous surface sheet P18 is formed as shown in FIG. 5(b).

Next, the continuous side sheet SS for the side sheet 6 unwound from the material roll WR4 is supplied to the cutting device 250 while being transported in the transport direction MD. Then, the continuous side sheet SS is cut into two halves in the transverse direction CD along the transport direction MD at the center position in the transverse direction CD to form a pair of continuous side sheets SSa and SSb adjacent to each other in the transverse direction CD. be done. After that, a pair of continuous side sheets SSa and SSb are supplied to a pair of coating devices 303a and 303b. Each of the pair of continuous side sheets SSa and SSb is coated with an adhesive (eg, hot-melt adhesive) in a predetermined pattern (eg, stripe pattern) on the inner edge in the transverse direction CD. Next, the pair of continuous side sheets SSa, SSb and the continuous top sheet P8 are supplied to the joining device 260 while being transported in the transporting direction MD, and sandwiched between the pair of joining rolls 260a, 260b of the joining device 260, spliced. Thereby, the pair of side portions ASL, ASL of the continuous surface sheet P18 and the pair of continuous side sheets SSa, SSb are respectively joined. Thereby, a continuous topsheet P2 is formed as shown in FIG. 5(c).

Next, the continuous topsheet P2 is supplied to the applicator 305, and an adhesive (example: hot-melt adhesive) is applied in a predetermined pattern on the side closer to the pair of continuous side sheets SSa and SSb. Next, the continuous surface sheet P2 and the absorbers P3 arranged in the transport direction MD at predetermined intervals are supplied to the joining device 270 while being transported in the transport direction MD. Then, the continuous surface sheet P2 and the absorbent body P3 are sandwiched between a pair of joining rolls 270a and 270b of the joining device 270 and joined. Thereby, a semi-finished product P4 is formed. Subsequently, the semi-finished product P4 is supplied to the pressing device 280 while being transported in the transport direction MD. In the pressing device 280, an embossing roll 280a having a convex portion for pressing on its outer peripheral surface and an anvil roll 280b are arranged to face each other. Then, the semi-finished product P4 is sandwiched and squeezed between the embossing roll 280a and the anvil roll 280b. As a result, compressed portions 11 to 15 extending from the continuous surface sheet P2 to the absorbent body P3 are formed in the vertical direction TD, thereby forming the semi-finished product P5. In addition, each pressing part may be pressed by a mutually different pressing apparatus. Next, the continuous backsheet BS for the backsheet 3 is fed from the fourth material roll WR4 to the joining device 290 while being transported in the transport direction MD. One surface of the continuous backsheet BS is coated with an adhesive (example: hot-melt adhesive) by a coating device 306 . On the other hand, the semi-finished product P5 is supplied to the joining device 290 while being transported in the transport direction MD. Then, the continuous backsheet BS and the semi-finished product P5 are sandwiched between a pair of joining rolls 290a and 290b of the joining device 290 and joined. As a result, as shown in FIG. 5(d), a semi-finished product P6 is formed by laminating the continuous backsheet BS and the semi-finished product P5 in the vertical direction TD. Thereafter, a release sheet CT (adhesive portions 7 and 8) with an adhesive is attached to the semi-finished product P6. A napkin 1 is formed.

As described above, the sanitary napkin 1 is manufactured.

However, as a method for interlacing the composite fiber web P13 having a two-layer structure, an air-through method may be used. That is, it is a method in which the composite fiber web P13 is transported to a heating device, and the fibers of the composite fiber web P13 are entangled with heated air in the heating device.

(Second embodiment)
Hereinafter, the sanitary napkin 1 of the second embodiment will be mainly described with respect to the differences from the sanitary napkin 1 of the first embodiment. The sanitary napkin 1 of this embodiment differs from the sanitary napkin 1 of the first embodiment in that the fiber density of the first fibrous layer 2a is lower than that of the second fibrous layer 2b. That is, in the sanitary napkin 1 of the present embodiment, there is a fiber density gradient such that the fiber density increases from the first fiber layer 2a toward the second fiber layer 2b. Here, the fiber density is the density of the number of fibers.

In the sanitary napkin 1 having such a structure, since the fiber density of the second fiber layer 2b is higher than that of the first fiber layer 2a, the fibers forming the second fiber layer 2b can be made closer to each other. can. Therefore, since the average distance between the fibers of the second fiber layer 2b can be made shorter than the average distance between the fibers of the first fiber layer 2a, the capillary phenomenon can be caused more strongly in the second fiber layer 2b, Liquid excrement excreted on the skin-side surface of the topsheet 2, that is, the surface of the first fiber layer 2a when worn, can be drawn into the first fiber layer 2a. Liquid excretion drawn into the second fibrous layer 2b can be rapidly transferred to the absorbent body 4 via the second fibrous layer 2b by the hydrophobic fibers. As a result, the layer ( Examples: Auxiliary sheet, liquid excrement can be stably transferred to the absorbent body 4).
At this time, in the first fibrous layer 2a, the liquid excrement can be drawn into the second fibrous layer 2b while being widely diffused in the planar direction by the water-retentive fibers. As a result, the liquid excretion widely spread in the plane direction of the topsheet 2 can be absorbed in a wide area of the absorbent body 4 in the plane direction, so that the absorption performance can be enhanced.
Therefore, it is possible to improve the absorption performance while improving the texture of the topsheet 2 .

In this embodiment, as in the first embodiment, the average fiber length of the water-retaining fibers of the second fiber layer 2b may be shorter than the average fiber length of the water-retaining fibers of the first fiber layer 2a. does not have to be short. If it is short, it is possible to obtain the same effect as when the fiber density of the first fiber layer 2a is lower than that of the second fiber layer 2b in the first embodiment.

On the other hand, if it is not short, the fiber length of the water-retentive fibers of the second fiber layer 2b is not particularly limited, and can take the same value as in the case of the first fiber layer 2a, for example, 10 to 80 mm. mentioned.

The absorbent article of the present invention is not limited to the above-described embodiments, and can be appropriately combined and modified without departing from the scope and spirit of the present invention.

1 sanitary napkin (absorbent article)
2 surface sheet 2a first fiber layer 2b second fiber layer

Claims (10)

An absorbent article comprising a topsheet, a backsheet, and an absorbent body positioned between the topsheet and the backsheet, and having a longitudinal direction, a width direction, and a thickness direction ,
The surface sheet is
a first fiber layer containing water-retentive fibers;
a second fiber layer adjacent to the non-skin side of the first fiber layer and containing hydrophobic fibers and water-retentive fibers;
with
The skin-side surface of the first fiber layer constitutes the skin-side surface of the topsheet,
The non-skin-side surface of the second fiber layer constitutes the non-skin-side surface of the surface sheet,
The ratio of the water-retaining fibers among the fibers constituting the first fiber layer is higher than the ratio of the water-retaining fibers among the fibers constituting the second fiber layer,
The hydrophobic fibers contained in the second fiber layer include heat-fusible fibers that are heat-fused to each other,
at least part of the heat-fusible fibers of the second fiber layer are exposed on the skin-side surface of the first fiber layer ,
The fibers constituting the topsheet are more oriented in the longitudinal direction of the topsheet at both ends of the topsheet in the width direction than at the central portion of the topsheet in the width direction.
absorbent article. An auxiliary sheet having a fiber density higher than that of the second fiber layer is further provided between the surface sheet and the absorbent body,
The absorbent article according to claim 1. Having a compressed portion in which the top sheet and the absorbent body are compressed in the thickness direction of the absorbent article,
At least part of the heat-fusible fibers of the second fiber layer are exposed on the inner surface of the pressing portion,
The absorbent article according to claim 1 or 2. The pressing section is
a low-density portion having a shallow depth in the thickness direction of the absorbent article ;
a high-density portion having a large depth in the thickness direction of the absorbent article ;
including
At least part of the heat-fusible fibers of the second fiber layer are exposed on the surface of the low-density portion,
The absorbent article according to claim 3. The surface sheet is
a plurality of protrusions extending along the longitudinal direction of the absorbent article and positioned at intervals in the width direction of the absorbent article;
a plurality of recesses extending along the longitudinal direction of the absorbent article and positioned between adjacent protrusions;
has
In the surface sheet, S1 is the fiber density at the top of the protrusions, S2 is the fiber density at the bottom of the recesses, and S3 is the fiber density in the region between the top of the protrusions and the bottom of the recesses. Then, S1<S3<S2,
5. The absorbent article according to any one of claims 1-4. The surface sheet has a plurality of recessed portions compressed from the first fiber layer toward the second fiber layer in the thickness direction of the absorbent article in each of the plurality of recessed portions,
The absorbent article according to claim 5. The average fiber length of the hydrophobic fibers of the second fiber layer is longer than the average fiber length of the water-retentive fibers of the first fiber layer and the second fiber layer,
7. The absorbent article according to any one of claims 1-6. The water-retentive fibers contained in the surface sheet are cellulosic fibers,
The absorbent body contains cellulosic fibers,
part of the cellulosic fibers contained in the topsheet is in contact with the cellulosic fibers contained in the absorbent body;
8. The absorbent article according to any one of claims 1-7. The water-retentive fiber contained in the topsheet is cotton,
9. The absorbent article according to any one of claims 1-8 . further comprising an auxiliary sheet positioned between the surface sheet and the absorbent body,
the widthwise dimension of the topsheet is smaller than the widthwise dimension of the auxiliary sheet;
10. The absorbent article according to any one of claims 1-9 .

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