JP2023102625A - absorbent article - Google Patents

Abstract

To provide an absorbent article with good cushioning property, pleasant feel, and excellent liquid absorbent performance.SOLUTION: An absorbent article comprises a surface sheet 1 and an absorber 2, and the surface sheet 1 is constituted of a nonwoven fabric having a plurality of ridge parts 11 arranged so as to protrude a skin-contact surface side 1T and a bottom part 12 provided between the adjacent ridge parts 11 and 11. Each of the plurality of ridge parts 11 comprises a top part 11A and wall parts 11B supporting the top part 11A. The wall parts 11B extend perpendicularly to the bottom part 12, and an opening hole 13 penetrating between the skin-contact side 1T and a non skin-contact side 1B is provided on the top part 11A.SELECTED DRAWING: Figure 2

Description

The present invention relates to absorbent articles.

Nonwoven fabrics are often used for topsheets constituting absorbent articles such as sanitary napkins and diapers. Techniques for imparting an uneven shape to this nonwoven fabric from the viewpoint of good touch and cushioning properties have been conventionally known (for example, Patent Document 1).
Some of the surface sheets have pores from the viewpoint of improving liquid permeability. For example, in the perforated uneven nonwoven fabric for the surface sheet described in Patent Document 2, the wall surface of the convex portion has a shape in which the wall surface gently undulates from the bottom portion, and the top portion of the convex portion supported by the smooth wall surface has openings. In the absorbent article described in Patent Literature 3, a non-woven fabric is used as the surface sheet, which is composed of a plurality of ridges and a bottom, and in which holes are arranged in the bottom.

JP 2013-119673 A JP 2017-93867 A JP-A-2020-467

In the perforated uneven nonwoven fabric described in Patent Document 2, since the walls of the protrusions have a gently undulating shape, the protrusions are likely to be crushed at the perforated portions depending on the magnitude of the pressure from the skin side.
On the other hand, in the absorbent article described in Patent Document 3, the nonwoven fabric forming the surface sheet has pores at the bottom of the uneven structure. As a result, the susceptibility of the projections to being crushed due to openings is suppressed. However, since the openings are located at the bottom, the openings are blocked by the absorbent material placed directly below. Therefore, depending on the situation such as a large amount of excretion, the absorbability of highly viscous liquids such as loose stools is not yet sufficient, and there is room for improvement. In addition, there is a possibility that the openings in the bottom part may become a part where hot-melt type adhesive or the like that joins the topsheet and the absorbent body comes into contact with the skin, and there is room for improvement in terms of touch.
Thus, it has been difficult to improve the liquid permeability of the surface sheet provided in the absorbent article while improving the cushioning property and the accompanying touch feeling due to the uneven structure, and it has been difficult to achieve all of these.

In view of the above points, the present invention relates to an absorbent article that has good cushioning properties, good texture, and excellent liquid absorbency.

The present invention is an absorbent article comprising a liquid-permeable topsheet on the skin-contacting side and an absorbent body arranged on the non-skin-contacting side of the topsheet, wherein the topsheet is made of a nonwoven fabric having a plurality of ridges arranged so as to protrude toward the skin-contacting side and a bottom provided between adjacent ridges, each of the plurality of ridges having a top and a wall supporting the top, the wall being perpendicular to the bottom. and the top portion is provided with an opening penetrating between the skin-contacting surface side and the non-skin-contacting surface side.

The absorbent article of the present invention has good cushioning properties, good touch, and excellent liquid absorbency.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a partially cutaway perspective view schematically showing a diaper as a preferred embodiment of the absorbent article according to the present invention from the side of the skin contacting surface. FIG. 4 is a partial perspective view showing an example of a surface sheet; FIG. 3 is a cross-sectional view of the surface sheet shown in FIG. 2 taken along the line III-III. FIG. 3 is a cross-sectional view of the surface sheet shown in FIG. 2 taken along line IV-IV. FIG. 3 is a cross-sectional view of the surface sheet shown in FIG. 2 taken along the line VV. FIG. 3 is a cross-sectional view showing hanging ribs arranged at the edges of the openings at the tops of the ridges of the surface sheet shown in FIG. 2 ; FIG. 3 is a partially enlarged cross-sectional view showing the periphery of the rim of the opening and portions other than the periphery of the ridge on the side of the skin contacting surface of the top of the ridge of the topsheet shown in FIG. 2 ; FIG. 8 is a plan view showing, from the skin-contacting surface side, the periphery of the opening shown in FIG. 7 and portions other than the periphery of the periphery; FIG. 4 is an explanatory view showing measurement positions of the existence density of fibers existing around the edge of an aperture. FIG. 4 is an explanatory view showing measurement positions of density of fibers existing in a portion other than the peripheral portion of an aperture. FIG. 2 is a process diagram schematically showing a part of a preferred method for manufacturing the topsheet included in the diaper of the present embodiment, wherein (A) shows a step of placing a fiber web on a male support material, (B) shows a process of shaping the fiber web by pressing it with a female support material from above, (C) shows a process of removing the female support material from the fiber web after shaping and subjecting it to a hot air treatment, and (D) shows a state in which the nonwoven fabric formed by the hot air treatment is turned upside down. (A) is a plan view of the male support member, and (B) is a cross-sectional view of the male support member. FIG. 4 is a plan view of a support female member; FIG. 4 is a plan view showing a state in which a male support member and a female support member are combined;

A preferred embodiment of an absorbent article according to the present invention will be described below with reference to the drawings.
FIG. 1 shows a state in which an unfoldable diaper 10 of the present embodiment (hereinafter also simply referred to as diaper 10) is unfolded and viewed from the skin contact surface side. The unfolded state refers to a state in which each part is stretched and the diaper 10 is unfolded. In this state, the diaper 10 has a longitudinal direction Y and a width direction X orthogonal to the longitudinal direction Y. As shown in FIG. The longitudinal direction Y of the diaper 10 corresponds to the direction connecting the abdomen portion F, the crotch portion C, and the back portion R corresponding to the parts of the body of the wearer wearing the absorbent article. The width direction X of the diaper 10 corresponds to the direction in which the left and right legs are connected at the wearer's crotch.
As a term indicating the relative positional relationship in the thickness direction of the diaper 10, the side that contacts the wearer's skin is called the skin-contacting side or front side, and the opposite side is called the non-skin-contacting side or back side. These terms are also used as terms that indicate relative positional relationships in the member configuration of the absorbent article, even for members that do not have a surface that contacts the wearer's skin. Further, the direction located in front of the wearer when worn is referred to as the front or front side, and the direction located in the rear side is referred to as the rear or rear side. The normal direction of the front surface or back surface of the absorbent article is referred to as the thickness direction.

The diaper 10 includes, as constituent members, a liquid-permeable topsheet 1 arranged on the skin-contacting side, and an absorbent body 2 arranged on the non-skin-contacting side of the topsheet 1 . Further, a liquid-impermeable back sheet 3 is arranged on the non-skin-contacting side of the absorbent body 2 . The diaper 10 has a pair of fastening tapes 4 on both sides of the back portion R for fastening around the waist of the wearer. Each of the pair of fastening tapes 4, 4 is pulled outward in the width direction X of the dorsal portion R, wound around the ventral portion F, and looped in the landing zone on the non-skin-contacting side of the ventral portion F. Can be detachably engaged with the tape (not shown).

In the diaper 10, three-dimensional gathers 6, 6 formed by the side sheets 5 are arranged on both sides of the topsheet 1 in the longitudinal direction Y. As shown in FIG. Furthermore, leg gathers 8, 8 are arranged in the leg openings 7, 7. As shown in FIG. The three-dimensional gathers 6 are in contact with the skin on both sides of the crotch of the wearer, and the leg gathers 8 are in contact with the skin in the vicinity of the groin, respectively, to improve the leakage prevention of excreted liquid.

These components can be formed from various materials commonly used in absorbent articles.
For example, the fiber material that can be used for the nonwoven fabric forming the surface sheet 1 includes polyolefin fibers such as polyethylene (hereinafter also referred to as PE) fibers and polypropylene (hereinafter also referred to as PP) fibers; polyethylene terephthalate (hereinafter also referred to as PET) and polyamide fibers obtained by using a thermoplastic resin alone; Examples of such conjugate fibers include fibers having a core-sheath structure in which the sheath component is PE or low melting point PP. Representative examples of core-sheath structure fibers include core-sheath structure fibers such as PET component (core) and PE component (sheath), PP component (core) and PE component (sheath), PP component (core) and low-melting PP component (sheath), and the like.

The fiber material preferably includes PE fiber, polyolefin fiber such as PP fiber, PE composite fiber, or PP composite fiber. The PE composite fiber has a composite composition containing a PET component and a PE component, and the PP composite fiber preferably contains a PET component and a low melting point PP component. More specifically, conjugate fibers containing a PET component (core) and a PE component (sheath), and conjugate fibers containing a PET component (core) and a low melting point PP component (sheath) can be mentioned. These fibers can be used alone or in combination of two or more to form a nonwoven fabric. In addition, the nonwoven fabric may contain fibers other than thermoplastic fibers.

Examples of the absorbent body 2 include those in which an absorbent core such as a hydrophilic fiber stack, a hydrophilic fiber and superabsorbent polymer material stack, or a hydrophilic fiber, superabsorbent polymer material, and thermoplastic synthetic resin fiber stack is covered with a core wrap sheet. Alternatively, it may be a water-absorbent sheet in which a superabsorbent polymer material is sandwiched between a plurality of fiber sheets. Examples of the hydrophilic fibers include cellulose fibers and synthetic fibers which are hydrophilized with a surfactant or the like, if necessary. The superabsorbent polymer material includes, for example, starch-based, cellulose-based, and synthetic polymer-based high-molecular compounds capable of absorbing and retaining 20 times or more of their own weight in water or saline. Examples of the core wrap sheet include thin paper such as tissue paper and hydrophilic non-woven fabric.

As the backsheet 3, for example, a moisture-permeable film alone, a composite sheet obtained by laminating a film and a nonwoven fabric, or a water-repellent nonwoven fabric (SMS, SMMS, etc.) is used. It is preferable to use a moisture-permeable film alone as a leak-proof material from the viewpoint of cost and matching with an anti-slip adhesive. Examples of the film material in this case include a film obtained by extruding a thermoplastic resin and an inorganic filler incompatible therewith by melt-kneading and stretching the extruded film to a predetermined size to form micropores, or a nonporous film that is essentially highly compatible with water and capable of discharging water vapor like a permeable membrane.

Next, the surface sheet 1 will be described in detail.
As shown in FIG. 2, the topsheet 1 has a skin-contacting side 1T and a non-skin-contacting side 1B. The topsheet 1 is made of a nonwoven fabric having a plurality of ridges 11 arranged so as to protrude from the skin-contacting surface 1T, and a bottom 12 provided between adjacent ridges 11, 11. As shown in FIG. Thereby, the surface sheet 1 has an uneven structure in the thickness direction. The ridges 11 are three-dimensional fiber layers erected in the thickness direction of the topsheet 1 and come into contact with the wearer's skin at positions higher than the bottom 12 on the skin contact surface side 1T. The bottom portion 12 is a fiber layer at the bottom of a concave portion recessed on the non-skin contacting side 1B between the ridges 11, 11 and forms the outer surface of the non-skin contacting side 1B. The bottom portion 12 is joined to the absorbent body 2 with a hot-melt adhesive or the like. By having the above structure, the surface sheet 1 has a soft feel to the wearer's skin with the fiber layer of the ridges 11, and at the same time suppresses the contact area with the skin at the bottom 12 and provides breathability in the recessed space at the position of the bottom 12. Therefore, the surface sheet 1 is comfortable to the touch, and the stuffiness between the surface sheet 1 and the skin is suppressed.
In the example of FIG. 1, the topsheet 1 is directly bonded to the absorbent body 2, but the present invention is not limited to this, and another member such as an intermediate sheet having a liquid diffusion function may be interposed between the topsheet 1 and the absorbent body 2. In this case, the bottom portion 12 of the topsheet 1 will be joined to the intermediate sheet.

In the diaper 10 of this embodiment, as shown in FIG. 2, a plurality of ridges 11 are provided so as to protrude from the bottom 12 toward the skin contact surface. The ridges 11 are three-dimensional fiber layers that protrude from the skin-contacting surface side 1T of the topsheet 1 and stand upright in the thickness direction of the topsheet 1 . More specifically, the ridge portion 11 includes a top portion 11A on the skin contact surface side 1T and a wall portion 11B that supports the top portion 11A.
The plurality of ridges 11 each extend in one direction in plan view from the skin-contacting surface 1T of the topsheet 1, and are spaced apart from each other in a direction crossing the one direction. The one direction and the direction crossing the one direction can be appropriately set on the surface of the surface sheet 1 on the skin contact surface side 1T according to the purpose of the absorbent article. In the example shown in FIG. 2 , the one direction is the longitudinal direction Y of the diaper 10 , and the direction crossing the one direction is the width direction X of the diaper 10 . Thereby, the plurality of ridges 11 extend parallel to each other along the longitudinal direction Y of the diaper 10 . Due to the arrangement of the ridges 11, the diffusion direction of the excreted liquid on the topsheet 1 can be easily guided in the longitudinal direction Y, which is the extending direction of the ridges 11, and the diffusion of the excreted liquid in the width direction X can be suppressed, and the liquid leakage prevention property of the diaper 10 can be enhanced.

The multiple ridges 11 have the same height along the extending direction. The "same height" means that the height measured using a microscope VHX6000 (trade name, manufactured by KEYENCE CORPORATION) is within the range of 0.8 times or more and 1.2 times or less of the measured average value.

Each of the plurality of ridges 11 includes a top portion 11A and a wall portion 11B that supports the top portion 11A. The top portion 11A is a fiber layer that contacts the wearer's skin, and the wall portion 11B is a fiber layer that connects the top portion 11A and the bottom portion 12 in the thickness direction. Wall portion 11B extends perpendicularly to bottom portion 12 . The wall portion 11B connects the top portion 11A and the bottom portion 12 vertically.

The surface sheet 1 has the following characteristic excellent cushioning properties due to the structure described above. That is, since the vertical walls 11B support the tops 11A, the topsheet 1 is not easily crushed in the compression direction under a low load such as touched by a finger, and has appropriate elasticity due to the fiber structure of the walls 11. In addition, due to the elasticity and deformability of the fiber structure of the wall portion 11, the surface sheet 1 gradually increases in compressive deformation as the load increases from a low load. At the same time, the wall portion 11B that supports the top portion 11A of the topsheet 1 vertically connects the top portion 11A and the bottom portion 12, so that even if the body pressure of the wearer when wearing the diaper 10 is applied, the topsheet 1 is easily prevented from collapsing to the absorber 2 side, and the distance between the topsheet 1 and the absorber 2 side is easily maintained. More specifically, in the topsheet 1, the wall portion 11B extending perpendicularly to the bottom portion 12 softly supports the top portion 11A with an elastic fiber structure, and the wall portion 11B is supported by the bottom portion 12 without openings, so that the compressive deformation gradually increases as the load increases from a low load, and moreover, the ridges 11 exhibit a unique excellent cushioning property that makes it difficult for the ridges 11 to sag. As a result, the surface sheet 1 has a soft thickness with elasticity, and the above uneven structure further improves the texture.

The "perpendicular" of the wall portion 11B means not only when the angle θ with respect to the bottom portion 12 shown in FIG. By being in this range, the wall portion 11B has a shape extending at an angle recognized as substantially 90° in the thickness direction of the topsheet 1 . The angle θ means the angle of intersection between the plane of the top sheet 1 on the bottom 12 side and the wall 11B. Specifically, as shown in FIG. 3, in a cross section orthogonal to the direction in which the ridge 11 extends (in FIG. 2, a thickness direction cross section at the position of line III-III along the width direction X), it means an internal angle among the angles formed by the center line M of the width of the fiber layer of the wall portion 11B and the straight line L connecting the lower surface of the adjacent bottom portion 12. This angle θ can be determined by observing a photomicrograph of a section taken along the line III-III obtained by the aforementioned microscope.
In addition, when the topsheet 1 incorporated in the absorbent article (diaper 10) is measured alone, the adhesive force of the adhesive is weakened by cooling means such as cold spray, and the topsheet 1 is removed from the product and the above measurement is performed. This method of taking out the surface sheet 1 is similarly applied to other measurements in this specification.

In the example shown in FIG. 3, the wall portion 11B extends linearly between the top portion 11A and the bottom portion 12, and the entire wall portion 11B stands vertically with respect to the bottom portion 12. As shown in FIG. However, the configuration is not limited to this, and the wall portion 11B may include a curved or wavy portion extending between the top portion 11A and the bottom portion 12 . In this case, the line connecting the boundary point between the top portion 11A and the wall portion 11B and the boundary point between the bottom portion 12 and the wall portion 11B is defined as the center line M, and the angle θ is specified.
Further, it is preferable that all of the plurality of walls 11B extend perpendicularly to the bottom 12, but some of the walls 11B may not extend perpendicularly to the bottom 12. In the latter case, the number of walls 11B perpendicular to the bottom 12 is preferably 60% or more of the total number of walls 11B from the viewpoint of functioning the ridges 11 as described above.

(Method of dividing wall portion 11B from top portion 11A and bottom portion 12)
The wall portion 11B can be divided into the top portion 11A and the bottom portion 12 in the topsheet 1 as follows.
First, a nonwoven fabric having a cross section in the thickness direction including the top portion 11A and the bottom portion 12 is placed on the pedestal of the microscope described above with the bottom portion 12 (non-skin contact side 1B) facing downward. Next, a flat plate (for example, a flat acrylic plate) is placed on the top portion 11A side (skin-contacting surface side 1T) of the nonwoven fabric, and a load of 0.05 kPa is applied. In this state, the cross section in the thickness direction is observed with the microscope at a magnification of 20. The fiber layer in contact with the pedestal is the bottom portion 12, the fiber layer in contact with the flat plate is the top portion 11A, and the fiber layer in the portion connecting the end of the top portion 11A and the end of the bottom portion 12 is the wall portion 11B.
In specifying the wall portion 11B, the thickness of each of the top portion 11A and the bottom portion 12 in the portion without the wall portion 11B is defined as the thickness of each end portion of the top portion 11A and the end portion of the bottom portion 12, and the portion excluding the thickness is defined as the wall portion 11B.

The skin-contacting surface side of the top portion 11A and the non-skin-contacting surface side of the bottom portion 12 may each have a flat surface or a curved surface. The skin-contacting surface side of the top portion 11A is preferably a dome-shaped curved surface from the viewpoint of making the feel of the wearer's skin softer. The non-skin-contacting side of the bottom portion 12 is preferably a flat surface from the viewpoint of enhancing fixability with the absorbent body 2 and enhancing transferability of excrement.

In the top sheet 1, the top portion 11A is provided with an aperture portion 13 penetrating between the skin contacting surface side 1T and the non-skin contacting surface side 1B. The apertures 13 are holes intentionally formed by processing the surface sheet 1, unlike fine holes formed between fibers, and have a hole area much larger than the fine holes formed between fibers. The size of the opening portion 13 can be appropriately selected according to the width of the top portion 11A and the like. It is preferred to have a pore area of at least 1 mm ² or more. The size of the aperture 13 can be measured using the aforementioned microscope. Specifically, the area of each opening 13 is measured at five locations with a microscope, and the average value of the measured values is taken as the hole area of each opening. The planar shape of the opening 13 can be various, and examples thereof include a rectangular shape and a circular shape.

A plurality of openings 13 are arranged at intervals along the extending direction of the ridges 11 . The area ratio of the openings 13 in the area of the top portion 11A of the ridge portion 11 when viewed in plan is preferably 5% or more, more preferably 10% or more, and still more preferably 15% or more, from the viewpoint of enhancing the effect of liquid permeability described later. Moreover, from the viewpoint of enhancing the shape retention of the ridges 11, the area ratio is preferably 30% or less, more preferably 25% or less, and even more preferably 20% or less. The area of the aperture 13 can be measured using the aforementioned microscope. In this measurement, the surface sheet 1 is placed under a load of 0.05 kPa by placing a flat plate in the same manner as described above (Method of dividing the wall portion 11B, the top portion 11A and the bottom portion 12). In this state, the top portion 11A in contact with the flat plate is viewed from the top, the area is measured, and the number of openings in the area where the area is measured is counted. Then, the ratio of the area of the opening 13 to the area of the top 11A of the ridge 11 in plan view is calculated from the following formula.
Area ratio (%) of the openings in the area of the top of the ridge when viewed in plan = (hole area of the opening × number of holes) / (area of the top of the ridge when viewed in plan) x 100

In addition, the area ratio of the open holes 13 to the area of the entire topsheet 1 when viewed in plan is preferably 5% or more, more preferably 6% or more, and even more preferably 8% or more, from the viewpoint of enhancing the liquid permeability effect described later. Moreover, from the viewpoint of enhancing the shape retention of the ridges 11, the area ratio is preferably 30% or less, more preferably 25% or less, and even more preferably 20% or less. The area of the aperture 13 can be measured using the aforementioned microscope. For this measurement, first, the surface sheet 1 is cut into a size of 50 mm×50 mm, and the number of openings in that area is counted. Then, the ratio of the area of the perforations 13 to the area of the entire surface sheet 1 in a plan view is calculated from the following formula.
Area ratio (%) of perforations in the area of the entire topsheet viewed from above = (perforation area of perforations x number of perforations)/(50 x 50) x 100
A plan view of the entire topsheet 1 is a plan view from the skin contact surface side 1T.

The openings 13 reduce the pressure loss of the excreted liquid at the top portion 11A that contacts the wearer's skin, and quickly drop the excreted liquid directly from the skin-contacting side 1T to the non-skin-contacting side 1B. That is, the liquid permeability of the topsheet 1 is increased. In addition, the ridges 11 extend (extend) in one direction (longitudinal direction Y of the diaper 10 in FIG. 2) as described above, and the excreted liquid is dispersed along this extending direction, and the plurality of openings 13 allows the excreted liquid to quickly permeate to the absorbent body 2 side at the same time. As a result, the diaper 10 has a short liquid absorption time and excellent liquid absorption. In addition, the vertical wall portion 11B that supports the top portion 11A having the openings 13 can improve the liquid flow prevention property on the surface sheet 1, thereby shortening the liquid absorption time and improving the liquid absorption property. This improvement in the prevention of liquid flow and the accompanying shortening of the liquid absorption time are particularly effective for highly viscous excretions such as loose stools. In addition, it is difficult for the liquid to remain on the skin-contacting surface side 1T of the topsheet 1, and adhesion of the excreted liquid to the wearer's skin can be reduced.
Moreover, as described above, the top sheet 1 has a characteristic well-balanced cushioning property because the top portion 11A is supported by the vertically extending wall portion 11B. Specifically, while the stress on the wearer's skin is reduced in the portion where the opening 13 is provided in the top portion 11A and elasticity accompanied by soft deformation can be felt, the vertical wall portion 11B supported by the bottom portion 12 without openings allows the amount of compressive deformation to increase in response to an increase in body pressure from the wearer, but the thickness is difficult to be flattened and the thickness is easily maintained. Therefore, the openings 13 arranged in the top portion 11A are less likely to come into contact with the absorbent body 2 side even under the body pressure, and the openings 13 are less likely to be blocked, and the liquid absorption by the openings 13 and the walls 11B is continuously exhibited.
In addition, the chances of the openings 13 coming into contact with the adhesive disposed on the non-skin-contacting surface side of the topsheet 1 (for example, the skin-contacting surface side of the absorbent body 2) are reduced, and adhesion of the adhesive to the skin is suppressed. As a result, together with the above-described air permeability in the recessed space at the position of the bottom portion 12, the stickiness of the wearer's skin is suppressed, and the feel of the wearer's skin is further improved.

Since the diaper 10 has the surface sheet 1 having the structure described above, the diaper 10 has a good cushioning property, a good touch, and an excellent liquid absorbency.

In the diaper 10, as shown in FIG. 2, the topsheet 1 preferably has hollow regions 11C on the non-skin-contacting side 1B of the ridges 11. As shown in FIG. 11 C of hollow areas are spaces which are not substantially filled with the fiber of the nonwoven fabric which comprises the surface sheet 1. FIG. Specifically, it means that the fiber density determined by the method described later is less than 10 fibers/mm ² . The lower the fiber density in the hollow region 11C, the better.

(Method for measuring fiber density)
The fiber density can be measured by observing the cross section of the surface sheet 1 and using the following method. The surface sheet 1 is cut in the thickness direction so as to pass through the site to be measured (for example, between the walls 11B). Using a scanning electron microscope (JCM-6000Plus (trade name) manufactured by JEOL Ltd.), the cut surface is magnified and observed, and the cross-sections of cut fibers within a certain area of the cut surface are counted. Magnification observation is adjusted to a magnification (150 times or more and 500 times or less) at which about 30 to 60 fiber cross sections can be measured. Next, the number of fiber cross sections per 1 mm ² is converted into the fiber density (fibers/mm ² ). The fiber density of the sample is obtained by averaging the three measurements.

Since the hollow region 11C is located on the non-skin-contacting surface side 1B of the ridges 11, the ridges 11 are further improved in softness to the touch, the cushioning property is further enhanced, and the touch of the topsheet 1 is further improved. In addition, when the hollow region 11C is continuous along the extending direction of the ridge portion 11, it acts as a flow path, further promoting transfer and absorption of the excrement to the absorbent body 2. FIG. At the same time, the interposition of the hollow region 11C cuts off the liquid return path from the absorbent body 2 to the openings 13, thereby enhancing the liquid return prevention property. In addition, the hollow region 11C serves as a primary storage space when the amount of excretion becomes excessive, and the amount of liquid remaining on the skin contact surface side 1T of the topsheet 1 can be further reduced.

In the diaper 10 of this embodiment, as shown in FIG. 2, a saddle portion 15 that connects the adjacent ridges 11, 11 is provided so as to protrude from the bottom portion 12. As shown in FIG. The saddle portion 15 is a three-dimensional fiber layer that protrudes toward the skin-contacting surface 1T of the topsheet 1 in the same manner as the ridges 11 and is erected in the thickness direction of the topsheet 1 . More specifically, the saddle portion 15 includes a top portion 15A on the skin contact surface side 1T and a wall portion 15B that supports the top portion 15A. The "vertical" is synonymous with the "perpendicular" defined for the ridge 11 described above.

The above structure makes it difficult for the ridges 11 connected by the saddle 15 to approach each other, and prevents the ridges 11 from collapsing in one direction due to an external force such as pressing. That is, the saddle portion 15 supports the ridge portion 11 from the side surface side to improve the shape retention of the ridge portion 11 . As a result, the aforementioned cushioning properties of the top sheet 1 are further enhanced. In addition, the liquid permeation effect of the openings 13 at the tops 11A of the ridges 11 is further enhanced. Furthermore, the presence of the saddle 15 acts to dam the excreted liquid between the ridges 11, 11, and the liquid flow prevention property on the skin contact surface side 1T of the topsheet 1 is enhanced. The excreted liquid, the flow of which is prevented by the damming action of the saddle 15, is passed along the fiber layer of the adjacent ridge 11 to the non-skin-contacting surface side 1T through the opening 13, and is quickly absorbed by the absorbent 2.

The saddle portion 15 extends in a direction intersecting one direction in which the ridge portion 11 extends in a plan view from the skin contact surface side 1T of the topsheet 1 . The extending direction of the saddle portion 15 can be any direction as long as it connects the adjacent ridges 11 , and is preferably perpendicular to the extending direction of the ridges 11 . In the example shown in FIG. 2, the ridges 11 extend in the longitudinal direction Y of the diaper 10, and the saddles 15 extend in the width direction X orthogonal to the longitudinal direction Y. As shown in FIG.

The saddle portions 15 are arranged in a plurality of band regions 16 extending parallel to the ridges 11 between the ridges 11 in a plan view of the skin contact surface side 1T of the topsheet 1 . In each band region 16, a plurality of saddle portions 15 are arranged at intervals along the extending direction of the parallel ridges 11 (longitudinal direction Y of the diaper 10 in the example shown in FIG. 2). Where the saddles 15 are spaced is the aforementioned bottom 12 . That is, in each band region 16, the saddle portions 15 and the bottom portions 12 are alternately arranged. The bottom 12 is thereby surrounded by the ridge 11 and the saddle 15 . More specifically, a region surrounded by a plurality of ridges 11 and a plurality of saddles 15, which are three-dimensional fiber layers erected in the thickness direction, is a box-shaped or cylindrical recess, and the bottom 12 is arranged at the bottom of the recess. In the example shown in FIG. 2, in a plan view from the skin-contacting surface side 1T of the topsheet 1, the ridges 11 and the saddles 15 are arranged in a grid pattern, and the bottoms 12 are scattered in the grid pattern and arranged in a grid pattern.

The arrangement position of the saddle portion 15 in the longitudinal direction Y of the band region 16 and the arrangement position of the opening portion 13 in the longitudinal direction Y of the ridge portion 11 can be arbitrarily set. For example, as shown in FIG. 2, the arrangement position of the saddle portion 15 in the longitudinal direction Y and the arrangement position of the opening portion 13 in the longitudinal direction Y may not overlap in the width direction X. That is, the pitch of the saddle portions 15 and the pitch of the opening portions 13 may be different in the extending direction of the band region 16 and the ridge portions 11 . Alternatively, the saddle portions 15 may be arranged at the same pitch so that the arrangement positions in the longitudinal direction Y of the saddle portions 15 and the arrangement positions of the opening portions 13 in the longitudinal direction Y overlap in the width direction X. From the viewpoint of enhancing liquid absorption, the excretion solution stopped by the saddle part 15 is transmitted smoothly by the hole 13, transmitted to the lung 11 fiber layer, and to make it easier to be absorbed quickly in the absorbent 2, and in the long -led direction Y of the saddle part 15 and the long -sided direction Y. It is preferable to place the pitch of the saddle 15 and the pitch of the hole 13 in the width direction X and the pitch of the hole 13 so that the arrangement position in the width direction X is not overlapped.

In addition, regarding the fiber structure of the saddle portion 15 and the ridge portion 11, it is preferable that the orientation direction of the fibers forming the top portion 11A of the ridge portion 11 and the orientation direction of the fibers forming the top portion 15A of the saddle portion 15 are different. This orientation direction of the fibers relates to the surface fibers of the tops 11A of the ridges 11 and the tops 15A of the saddles 15, which are specified when the skin contact surface side 1T of the topsheet 1 is viewed in plan. More specifically, the orientation direction relates to the fibers on the skin contact surface side 1T of each of the apex 11A of the ridge 11 and the apex 15A of the saddle 15 .

Since the orientation directions of the fibers are different between the tops 11A of the ridges 11 and the tops 15A of the saddles 15, the direction of the load applied to the skin contact surface side 1T of the topsheet 1 is made different between the tops 11A of the ridges 11 and the tops 15A of the saddles 15, and the load is easily dispersed over the entire topsheet 1. As a result, the saddle portion 15 and the ridge portion 11 are less likely to deform in the same direction, and the effect of supporting the ridge portion 11 from the side surfaces by the saddle portion 15 is enhanced. Due to this action and the action of the wall portion 11B described above, the surface sheet 1 is likely to be loaded perpendicularly to the compression direction. Therefore, even though the thickness of the entire surface sheet 1 remains, deformation occurs in the pressed portion, and it becomes easier to obtain a cushion feeling. In addition, the liquid permeation effect of the openings 13 at the tops 11A of the ridges 11 is further enhanced.
In addition, when the skin-contacting surface side 1T of the topsheet 1 is stroked from a certain direction, an outer surface having a fiber orientation close to or along the stroked direction exists. Therefore, it is possible to perceive a texture that is smoother when stroked, and an improvement in texture can be realized.

From the viewpoint of further enhancing the above effect, it is preferable that the direction of orientation of the fibers constituting the top portion 11A of the ridge portion 11 is the direction in which the ridge portion 11 extends, and the direction of orientation of the fibers constituting the top portion 15A of the saddle portion 15 is the direction in which the saddle portion 15 extends. In the example shown in FIG. 2, the orientation direction of the fibers forming the top portion 11A of the ridge portion 11 is the longitudinal direction Y, and the orientation direction of the fibers forming the top portion 15A of the saddle portion 15 is the width direction X. As a result, in the ridges 11, the diffusion of the excreted liquid along the direction in which the ridges 11 extend is further promoted by the orientation of the fibers, and the liquid permeation action at the openings 13 is further promoted.
The above fiber orientation direction is indicated by the degree of fiber orientation obtained by the following measuring method.

(Method of measuring orientation directions of fibers on the skin contact surface side 1T of the top portion 11A of the ridge portion 11 and the top portion 15A of the saddle portion 15)
The surface sheet is cut into a square of 2 cm×2 cm to obtain a sample, which is observed from the skin contact surface side 1T. For observation, it is preferable to use, for example, a scanning electron microscope (SEM). For the SEM, for example, JCM-6100Plus (manufactured by JEOL Ltd.) is used. For SEM observation, it is preferable to vapor-deposit the sample in advance by a recommended method. The center of the top portion 11A of the ridge portion 11 is enlarged at a magnification of 50 times and shown in the center of the observation screen. Next, a square with a side of 500 μm is drawn with the center of the screen as the intersection of the diagonal lines so as to be parallel to the ridge 11, and the number of fibers passing through the two sides parallel to the extending direction of the ridge 11 is counted (the number of fibers is N1). Similarly, the number of fibers passing through two sides perpendicular to the extending direction of the ridge 11 is counted (the number of fibers is N2). The degree of fiber orientation of the top portion 11A of the ridge portion 11 is obtained based on the following (Equation 1).

Fiber orientation degree (%) of top portion 11A of ridge portion 11
= {number of fibers N2/(number of fibers N1 + number of fibers N2)} x 100 (formula 1)

Measure this at three arbitrary locations and take the average. When the average degree of fiber orientation exceeds 50%, it is determined that the fibers in that region are oriented in the same direction as the extending direction of the ridges 11, and that direction is taken as the orientation direction. A larger value indicates that the fibers are more strongly oriented in the same direction as the extending direction of the ridges 11 .
When measuring the degree of fiber orientation at the top portion 15A of the saddle portion 15, the center of the top portion 15A of the saddle portion 15 is enlarged at a magnification of 50 times and shown in the center of the observation screen. Next, a square with a side of 500 μm is drawn with the center of the screen as the intersection of the diagonal lines so as to be parallel to the ridge 11, and the number of fibers passing through the two sides parallel to the extending direction of the ridge 11 is counted (the number of fibers is N1). Similarly, the number of fibers passing through two sides perpendicular to the extending direction of the ridge 11 is counted (the number of fibers is N2). The degree of fiber orientation of the saddle portion 15 with reference to the direction in which the ridge portion 11 extends is obtained based on the above (Equation 1).

In the surface sheet 1, in order to determine whether the fibers of the apex 15A of the saddle 15 are oriented in the same direction as the extending direction of the saddle 15, draw a square parallel to the saddle 15 instead of the square parallel to the ridges 11 as in the above method. The number of fibers passing through two sides parallel to the extending direction of the saddle portion 15 is counted (the number of fibers is N3). Similarly, the number of fibers passing through two sides perpendicular to the extending direction of the saddle portion 15 is counted (the number of fibers is N4). By this method, the degree of fiber orientation (%) along the saddle portion 15 is determined based on the following (Equation 2), and when it exceeds 50%, it is determined that the fibers are oriented in the same direction as the top portion 15A of the saddle portion 15 extends.
Degree of fiber orientation along top 15A of saddle 15 (%)
= {number of fibers N4/(number of fibers N3 + number of fibers N4)} x 100 (formula 2)

Although the saddle portion 15 has the same three-dimensional fiber structure as the ridge portion 11, it preferably has a portion whose height from the bottom portion 12 is lower than that of the ridge portion 11, as shown in FIGS. As a result, the contact area with the skin on the skin contact surface side 1T of the top sheet 1 can be reduced, the good touch can be maintained, and air permeability can be enhanced to further suppress stuffiness with the skin.
The difference (H1-H2) between the height H1 of the ridge portion 11 in the thickness direction and the height H2 of the saddle portion 15 in the thickness direction is preferably 0.5 mm or more and 7 mm or less from the viewpoint of improving the above effects. The height H1 of the ridge 11 in the thickness direction is the distance in the thickness direction from the non-skin-contacting side 1B of the bottom 12 to the skin-contacting side 1T of the top 11A of the ridge 11 . The height H2 of the saddle portion 15 in the thickness direction is the distance in the thickness direction from the non-skin-contacting surface side 1B of the bottom portion 12 to the skin-contacting surface side 1T of the top portion 15A of the saddle portion 15 at the lowest position.

(Method of measuring the difference between the height of the ridge portion 11 in the thickness direction and the height of the saddle portion 15 in the thickness direction)
As for the top sheet 1, as shown in FIG. 4, a thickness direction cross section along the extension direction of the belt regions 16 where the saddle portions 15 are arranged at the lowest position of the saddle portions 15 (thickness direction cross section at the position of line IV-IV in FIG. 2) is prepared, and placed so that the bottom portion 12 abuts on a horizontal base. A height H1 from a horizontal base to the skin contact surface side 1T of the top portion 11A of the ridge portion 11 and a height H2 from the top portion 15A of the saddle portion 15 to the skin contact surface side 1T are measured. From these measurements, the height difference (H1-H2) is calculated. The microscope described above can be used to measure the height from the horizontal table. In this measurement, a load of 0.05 kPa is applied to the surface sheet 1 having the cross section shown in FIG. In this state, the heights H1 and H2 are measured.

From the viewpoint of further improving the cushioning properties of the topsheet 1, the saddle portion 15 preferably has a hollow region 15C as shown in FIG. The definition and measurement method of this hollow region 15C are the same as those of the hollow region 11C in the ridge 11. FIG. Hollow region 15C of saddle portion 15 preferably communicates with hollow region 11C of ridge portion 11 . As a result, the diffusion of the excreted liquid on the non-skin-contacting side 1B of the topsheet 1 is promoted to suppress retention, and the liquid permeability of the perforations 13 is further increased. As a result, the liquid absorbency of the absorbent body 2 in the diaper 10 is further improved.

In the diaper 10 of the present embodiment, as shown in FIG. 6, it is preferable that the edges 13A of the openings 13 at the tops 11A of the ridges 11 have drooping ribs 17 in which fibers protrude vertically toward the non-skin-contacting surface side 1B. As a result, the fibers at the edges 13A of the openings 13 become funnel-shaped, and the ability to draw excreted fluid into the openings 13 is enhanced, thereby further improving the aforementioned liquid permeability. In particular, highly viscous liquids such as loose stools are positively guided by the hanging ribs 17 to the perforations 13, and the liquid retention property on the topsheet 1 is more effectively enhanced.

The hanging rib portion 17 can be defined as follows. That is, as shown in FIG. 6, in the cross section of the ridge 11 including the opening 13 in the thickness direction, the fiber layer present at the edge 13A of the opening 13 protrudes from the skin contact surface side of the top 11A toward the non-skin contact surface side. do. This can be measured using the aforementioned microscope.

The difference (Z1-Z2) between the protruding length Z1 of the hanging rib portion 17 and the thickness Z2 of the top portion 11A is preferably 1.0 mm or more, more preferably 1.5 mm or more, from the viewpoint of making the above-described liquid drawing property of the hanging rib portion 17 more effective.

From the same point of view, the ratio of the projecting length Z1 of the hanging ribs 17 to the thickness Z3 of the surface sheet 1 (apparent thickness between the skin-contacting side of the top portion 11A and the non-skin-contacting side of the bottom portion 12 formed by the uneven shape) is preferably 10% or more, more preferably 20% or more, and even more preferably 30% or more.
Moreover, the protruding length Z1 of the hanging rib portion 17 is preferably shorter than the thickness Z3 of the topsheet 1 from the viewpoint of enhancing the liquid return prevention property. Specifically, the ratio of the projecting length Z1 of the hanging rib portion 17 to the thickness Z3 of the topsheet 1 is preferably 70% or less, more preferably 60% or less, and even more preferably 50% or less.
The thickness Z3 of the topsheet 1 can also be measured using the microscope described above. For this measurement, a load of 0.05 kPa is applied to the surface sheet 1 having the cross section shown in FIG. In this state, the projecting length Z1 of the hanging rib portion 17 and the thickness Z3 of the surface sheet are measured.

Further, in the diaper 10 of the present embodiment, on the skin contact surface side 1T of the top portion 11A, the existence density of the constituent fibers present in the edge surrounding portion 18 of the opening portion 13 is preferably higher than the existence density of the constituent fibers present in the portion 19 other than the edge surrounding portion 18. Here, as shown in FIGS. 7 and 8, the “edge peripheral portion 18” is a region within a range of 600 μm outward from the edge 13A of the opening 13 in the planar view of the skin contact surface side 1T of the top portion 11A. That is, the edge surrounding portion 18 is a fiber layer on the skin contact surface side 1T of the top portion 11A in the above range including the fibers of the edge 13A of the opening portion 13 . The "600 μm" is the length in the direction orthogonal to the side of the edge 13A of the opening 13 when the planar shape of the opening 13 is rectangular, and the length in the direction orthogonal to the tangent line of the curve of the edge 13A of the opening 13 when the planar shape of the opening 13 is circular. The edge peripheral portion 18 exists along the edge 13A so as to surround the opening portion 13. As shown in FIG. The “portion 19 other than the peripheral edge portion 18” means a portion of the fiber layer on the skin contact surface side 1T of the top portion 11A and further away from the opening 13 than the edge peripheral portion 18 in the planar direction. The peripheral edge portion 18 of the aperture portion 13 can be specified by a method described later (Method for measuring the density of constituent fibers existing in the peripheral peripheral portion 18 and constituent fibers present in the portion 19 other than the peripheral peripheral portion 18).

By having a fiber structure with the existence density as described above on the skin contact surface side 1T of the top portion 11A, the fibers surrounding the opening portion 13 become dense and the shape of the fiber layer in that portion is easily maintained. As a result, the opening 13 is less likely to be crushed and is less likely to be closed. In addition, there is a driving force that draws the excreted liquid into the openings 13, increasing the above-described liquid permeability. In addition, the fiber structure having the above density makes the openings 13 less likely to be crushed, and the cushioning property of the topsheet 1 is further improved.

The difference (M1-M2) between the existence density M1 of the constituent fibers existing in the peripheral edge portion 18 of the aperture portion 13 and the existence density M2 of the constituent fibers existing in the portion 1 other than the peripheral edge portion 18 (M1-M2) is preferably 3% or more, more preferably 5% or more, and even more preferably 10% or more, from the viewpoint of further enhancing the above effect.
The difference (M1-M2) is preferably 40% or less, more preferably 30% or less, and even more preferably 20% or less, from the viewpoint of further improving the shape stability of the nonwoven fabric.

(Method for measuring density of constituent fibers present in peripheral portion 18 and constituent fibers present in portion 19 other than peripheral portion 18)
First, a black cardboard with a basis weight of 300 g/m ² is placed on the base of the microscope described above, and the nonwoven fabric is placed thereon so that the skin contact side 1T of the nonwoven fabric faces upward. Next, the non-woven fabric is brought into focus at a magnification of 50 times, and the presence density of the edge surrounding portion 18 and the portion 19 other than the edge surrounding portion 18 is measured using the built-in function according to the following procedure.
(1) Determining Method of Edge 13A of Opening 13 The edge 13A of the opening 13 is determined by the automatic area measurement function of the microscope described above. A threshold value of 0 is used to extract a high-brightness (white) portion, and the boundary between the non-extracted portion and the extracted portion is defined as the edge of the opening.
(2) Method for measuring the density of constituent fibers present in the peripheral edge portion 18 As shown in FIG. 9, a square 18S of 200 μm×200 μm is drawn at a position 600 μm from the determined edge of the aperture, and the amount of fibers present in that portion is measured by the automatic area measurement function of the microscope. With a threshold of 0, the area of the bright (white) part of the square is measured. As a result, the area (μm ² ) of the part where the fibers are present in the peripheral part 18 is extracted.
The fiber density is determined by dividing the resulting area by 200 x 200. This is measured at 20 points, and the average value is defined as the presence density of the constituent fibers present in the peripheral edge portion 18 of the aperture portion 13 .
(3) Method for measuring the density of constituent fibers existing in the portion 19 other than the peripheral portion 18 As shown in FIG. 10, a square 19S of 200 μm × 200 μm is drawn at the position of half the length B of the line connecting the centers 13P and 13P of the two openings 13 present in the top portion 11A, and the amount of fibers present in that portion is measured by the automatic area measurement function of the microscope. With a threshold of 0, the area of the bright (white) part of the square is measured. As a result, the area (μm ² ) of the portion where the fibers are present in the portion 19 other than the peripheral portion 18 is extracted.
The fiber density is determined by dividing the resulting area by 200 x 200. This is measured at 20 points, and the average is used as the existing density of the fibers existing in the portion 19 other than the peripheral portion 18 .

Furthermore, in the diaper 10 of this embodiment, it is preferable that the fibers of the wall portion 11B of the ridge portion 11 are oriented perpendicularly to the bottom portion 12 . This vertical orientation of the fibers enhances the effect of the vertically extending shape of the wall portion 11B. That is, the thickness of the ridges 11 tends to remain even under a high load, and together with the elasticity of the fibrous structure of the fibrous layer, the function of the walls 11B to provide excellent cushioning properties is further enhanced. As a result, the liquid permeability of the openings 13 arranged in the top portion 11A is further enhanced, and the liquid permeability is exhibited more continuously.

The vertical orientation of the fibers of the wall portion 11B is indicated as the longitudinal orientation ratio obtained by the measurement method described later. The longitudinal orientation ratio is 60% or more, more preferably 63% or more, still more preferably 65% or more, from the viewpoint of enhancing the above effects. In addition, although the upper limit of the longitudinal orientation rate is not particularly limited, it is preferably 90% or less, more preferably 85% or less, and even more preferably 80% or less from the viewpoint of creating a structure that can withstand forces by creating intersections between fibers to form fusion points and forming columns between fibers.

(Method for Measuring Vertical Orientation Ratio of Fibers in Wall Part 11B)
As shown in FIG. 3, in a cross section perpendicular to the direction in which the ridge 11 extends (in FIG. 2, the thickness direction cross section at the position of the III-III line along the width direction X), the wall portion 11B is measured in the following procedure.
That is, the fiber layer cross section of the wall portion 11B defined in the cross section in the thickness direction is observed by magnifying it by 50 times with an SEM. A square line with a side of 500 μm is attached to the observation image as a reference line. Each side (reference line) of the square is a side orthogonal to each of the thickness direction and plane direction in the cross section of the top sheet 1 . Count the total number of fibers that pass through the reference line formed by each side of the square. The number of fibers passing through a square reference line perpendicular to the plane direction of the nonwoven fabric is defined as "the number of horizontal fibers", and the number of fibers passing through the square reference line perpendicular to the thickness direction of the nonwoven fabric is defined as the "number of longitudinal fibers". The vertical orientation ratio is calculated as (number of vertical fibers)/(number of horizontal fibers+number of vertical fibers)×100=longitudinal orientation ratio (%). Each three points are measured, and the average value is taken as the value of the longitudinal orientation ratio.
The plane direction of the cross section of the topsheet 1 corresponds to the straight line L connecting the lower surfaces of the adjacent bottom portions 12 shown in FIG. The thickness direction corresponds to a direction orthogonal to the straight line L.

The cushioning property of the topsheet 1, which is enhanced by the walls 11B having a shape extending in the vertical direction and the fibers of which are vertically oriented, will be described in detail below.
First, due to the vertical orientation of the fibers of the wall portion 11B, when the skin-contacting surface side 1T of the topsheet 1 is stroked with a finger (with a force of less than 100 Pa), the fibers do not sink due to the rigidity thereof, and the elasticity is high. In the fiber structure in which the wall part 11B has a shape extending in the vertical direction and supports the thickness of the topsheet 1, a finger touching the topsheet 1 can feel that the topsheet 1 is plump and thick.
Furthermore, when a pressing force (a force of about 2.5 kPa) is applied to the skin contact surface side 1T of the topsheet 1 in the thickness direction, the pressing force tends to concentrate in the thickness direction rather than disperse in the plane direction from the vicinity of the force point. That is, the pressing force is likely to be transmitted in the vertical orientation direction of the fibers in the vertical shape of the wall portion 11B. As a result, the wall portion 11B is not deformed such that the entire wall portion 11B collapses due to the pressing force, but the wall portion 11B is gently deformed at the intermediate position, and the thickness of the topsheet 1 tends to remain. As a result, the three-dimensional structure of the topsheet 1 is prevented from being flattened (sagging), and the characteristic cushioning property described above is further improved. For example, due to the concentration of pressing force, partial sinking of the surface sheet 1 near the point of force occurs in a limited range of the surface sheet 1, and the three-dimensional structure of the entire surface sheet 1 can be maintained, and the plump softness can be maintained. In particular, around the opening 13 of the top 11A, the pad of the finger pushing in and the feeling of being wrapped around the pad are obtained, and the texture is improved. In addition, the elasticity of the vertically oriented fibers of the wall portion 11B of the topsheet 1 further enhances the thickness recoverability of the topsheet 1 . As a result, the surface sheet 1 is elastic and has a pleasant texture.
Due to the further improved cushioning properties of such a surface sheet, the openings 13 arranged at the tops 11A of the ridges 11 maintain their height and come into contact with the skin, and the liquid permeability can be exhibited more continuously.

It is preferable that the vertical orientation of the fibers of the wall portion 11B of the ridge portion 11 be the same in the wall portion 15B of the saddle portion 15 as well. Also in this case, the vertical orientation is indicated by the vertical orientation rate described above, and the above numerical values are applied. As shown in FIG. 4, the longitudinal orientation ratio is obtained on the cross section perpendicular to the direction in which the saddle portion 15 extends, based on the measurement direction described above.

Next, a preferred embodiment of the method for manufacturing the topsheet 1 will be described with reference to FIGS. 11 to 14. FIG.
In the method of manufacturing the surface sheet 1, first, as shown in FIG. 11A, a fibrous web 110 in which fibers are not fused at intersections is placed on a male supporting member 120 before being formed into a nonwoven fabric. Next, as shown in FIGS. 11(B) and 14, the fiber web 110 is pressed and sandwiched by the support female member 130 from above and shaped.
The fiber web 110 contains thermoplastic fibers. This fiber web 110 is supplied from a carding machine (not shown) to have a predetermined thickness.

As shown in FIGS. 12A and 12B, the support male member 120 has a plurality of projections 121 spaced apart in one direction (first direction D1) and a direction orthogonal thereto (second direction D2). A plurality of protrusion rows 121A each having a plurality of protrusions 121 arranged in the first direction D1 are arranged in the second direction D2 so as to be spaced apart from each other. Between the projection rows 121A, 121A, a perforated portion 124 having a height lower than that of the projection 121 and having a steeple portion 122 and a pedestal 123 is arranged at intervals in the first direction D1. A plurality of perforated portion rows 124A each having a plurality of perforated portions 124 arranged in the first direction D1 are arranged in the second direction D2 alternately with the projection rows 121A. Between the protrusion 121 and the perforated portion 124 is a recessed portion 125 extending in the front, rear, left, and right directions. Note that the perforated portion 124 may be taller than the protruding portion 121 .
The recess 125 has a first recess 125A extending in the first direction D1 between the row of perforations 124A and the row of projections 121A, a second recess 125B between the perforations 124 and 124 in the row of perforations 124A, and a third recess 125C between the projections 121 and 121 in the row of projections 121A. The third recess 125C is connected to the adjacent first recess 125A and intermittently extends in the second direction D2 via the first recess 125A and the second recess 125B.
In FIG. 12A, the arrangement position of the protrusion 121 in the first direction D1 and the arrangement position of the perforated portion 124 in the first direction D1 overlap in the second direction D2. However, the arrangement is not limited to this, and the positions of the two in the first direction D1 may be shifted from each other so that they do not overlap in the second direction D2.

In the support male member 120, a plurality of protrusions 121 are arranged corresponding to the positions where the bottom portion 12 of the top sheet 1 is shaped. A third concave portion 125C between the protrusions 121, 121 in the protrusion row 121A is located at a position where the saddle portion 15 of the topsheet 1 is formed. That is, the projection rows 121A are located at the positions of the belt regions 16 between the ridges 11, 11 of the topsheet 1. As shown in FIG.
The row of perforations 124A and the first recesses 125A, 125A on both sides thereof are located at positions where the ridges 11 of the surface sheet 1 are formed, and the perforations 124 are arranged at positions where the apertures 13 are formed.
The bottom of each concave portion 125 of the support male member 120 has a structure through which hot air blows through, and for example, a plurality of holes are arranged (not shown).

In the support male member 120, the ratio (Q1/Q2) of the height Q1 of the protrusions 121 to the height Q2 of the perforated portions 124 is preferably 0.5 or more, more preferably 0.8 or more, and even more preferably 1.0 or more, from the viewpoint of increasing the openness of the nonwoven fabric. In addition, the ratio (Q1/Q2) is preferably 2.0 or less, more preferably 1.5 or less, from the viewpoint of releasability between the nonwoven fabric and the support.
Since the height Q1 of the projections 121 is a factor that determines the thickness of the topsheet 1, it is preferably 6 mm or more, more preferably 8 mm or more. Moreover, from the viewpoint of improving the shape stability of the nonwoven fabric, the height Q1 of the projections 121 is preferably 15 mm or less, more preferably 10 mm or less.
From the viewpoint of enhancing the openness of the nonwoven fabric, the height Q2 of the perforated portion 124 is preferably 3 mm or more, more preferably 4 mm or more. Moreover, the height Q2 of the perforated portion 124 is preferably 15 mm or less, more preferably 10 mm or less, from the viewpoint of improving the peelability between the nonwoven fabric and the support.

In the second direction D2 in which the projections 121 and the perforated portions 124 are alternately arranged, the pitch P1 between the projections 121 and the perforated portions 124 is preferably 2.5 mm or more, more preferably 3.0 mm or more, from the viewpoint of ease of shaping. From the viewpoint of improving the appearance of the nonwoven fabric, the pitch P1 is preferably 6.0 mm or less, more preferably 5.0 mm or less.
A pitch P2 between the projections 121 and 121 through the perforated portion 124 is preferably 5 mm or more, more preferably 6 mm or more, and still more preferably 8 mm or more, from the viewpoint of ease of shaping. From the viewpoint of improving the appearance of the nonwoven fabric, the pitch P2 is preferably 12 mm or less, more preferably 10 mm or less.
Moreover, the pitch P3 between the protrusions 121 in the first direction D1 in the protrusion row 121A is preferably 1.5 mm or more, more preferably 2 mm or more, from the viewpoint of ease of shaping. From the viewpoint of improving the appearance of the nonwoven fabric, the pitch P3 is preferably 9 mm or less, more preferably 8 mm or less.

From the viewpoint of improving the shape stability of the nonwoven fabric, the width S1 of the protrusion 121 in the second direction D2 is preferably 1.0 mm or more, more preferably 1.5 mm or more, and even more preferably 2.0 mm or more. From the viewpoint of improving the appearance of the nonwoven fabric, the width S1 is preferably 5 mm or less, more preferably 4 mm or less.
From the viewpoint of increasing the openness of the nonwoven fabric, the width (width of the widest portion) S2 of the perforated portion 124 in the second direction D2 is preferably 1.5 mm or more, more preferably 2.0 mm or more, and even more preferably 3.0 or more. From the viewpoint of improving the appearance of the nonwoven fabric, the width S2 is preferably 5.0 mm or less, more preferably 4.0 mm or less.
The width S1 of the protrusion 121 and the width S2 of the perforated portion 124 in the second direction D2 are preferably satisfied also in the first direction D1.

The protrusion 121 may be prismatic or cylindrical. When viewed from the top, in FIGS. 12A and 12B, the shape is drawn in a quadrangular shape with respect to the first direction D1, but it may be a rhombus. From the standpoint of making it easier for the fibers to enter the male support mold 120, maintain the shape of the topsheet 1, and increase the thickness of the topsheet 1, it is preferable that the projections 121 have a prismatic shape and a square shape when viewed from above. From the viewpoint that the finished surface sheet 1 can easily retain its shape, the area of each projection 121 in plan view is preferably 3 mm ² or more, more preferably 4 mm ² or more.

The shape of the perforated portion 124 in plan view is not limited to the circular shape shown in FIGS. The area of each perforated portion 124 in plan view (area on the bottom side) is preferably 3 mm ² or more.
The steeple portion 122 of the perforated portion 124 has a tapered cross-sectional shape in the thickness direction, as shown in FIG. 12(B). However, the present invention is not limited to this, and various shapes can be employed that can perforate through the fiber web 110 and form the tops 11A of the ridges 11 and the apertures 13 satisfactorily. Moreover, the perforated portion 124 may be one without the pedestal 123 .

As shown in FIG. 13, a plurality of projections 131 continuous in the first direction D1 are arranged on the female support member 130 at intervals in the second direction D2. Between the projections 131, 131 is a recess 132 continuous in the first direction D1.
The protrusion 131 of the support female member 130 corresponds to the first recess 125A of the support male member 120 . The recesses 132 of the female support member 130 correspond to the row of projections 121 A and the row of perforations 124 A of the male support member 120 . The bottom portion of the concave portion 132 of the support female member 130 has a structure through which hot air blows through, for example, a plurality of holes are arranged (not shown).

The width S3 of the projections 131 of the female support member 130 in the second direction D2 is preferably 0.3 mm or more, more preferably 0.5 mm or more, from the viewpoint of the openness of the nonwoven fabric. Moreover, the width S3 is preferably 4.0 mm or less, more preferably 3.0 mm or less, from the viewpoint of ease of shaping.

The distance between the protrusions 131, 131 of the support female member 130 (the width of the recess 132) is wider than the width S1 of the protrusion 121 of the support male member 120 and the width S2 of the perforated portion . The distance is appropriately set so that the fibrous web 110 is sandwiched between the projections 121 of the male support member 120 and the projections 131 of the female support member 130, and the wall portions in which the fibers are oriented in the thickness direction can be formed appropriately, and the perforations 124 can form the apertures appropriately.
More specifically, as shown in FIG. 14, the ratio (S4/S1) of the distance S4 between the protrusions 131, 131 of the female support member 130 to the width S1 of the protrusion 121 of the male support member 120 is preferably 1.1 or more, more preferably 1.2 or more, and 2 or less. is preferred, and 1.5 or less is more preferred. The ratio (S5/S2) of the width S2 of the hole portion 124 to the distance S5 between the protrusions 131 and 131 is preferably 1.1 or more, more preferably 1.2 or more, more preferably 2 or less, and more preferably 2.5 or less.

Further, the projections 131 of the female support member 130 can apply a higher shearing force to the fiber web 110 as the tip of the projections 131 and 131 are needle-like and the narrower the gap between them and the perforated portion 124 is. Thereby, the moldability of the opening 13 becomes better.
From this point of view, as shown in FIG. 14, the gap S6 between the projection 131 and the perforated portion 124 of the support male member 120 is preferably 1.5 mm or less, more preferably 1.0 mm or less. From the viewpoint of ease of shaping, the gap S6 is preferably 0.1 mm or more, more preferably 0.2 mm or more. From the viewpoint of ease of shaping, the distance S4 is preferably 1.5 mm or more, more preferably 2.0 mm or more, preferably 5.0 mm or less, and more preferably 4.0 mm or less. From the viewpoint of ease of shaping, the distance S5 is preferably 1.5 mm or more, more preferably 2.0 mm or more, preferably 5.0 mm or less, and more preferably 4.0 mm or less.

The height of the protrusions 131 of the female support member 130 is preferably 1 mm or more so that the protrusions 121 of the male support member 120 can be sufficiently inserted.

The above-described first direction D1 and second direction D2 of the support male member 120 and the support member female member 130 are preferably the machine direction (MD) in the manufacturing process and the cross direction (CD) orthogonal to the machine direction. The machine flow direction and width direction in the manufacturing process preferably correspond to the longitudinal direction Y and width direction X of the topsheet 1 . However, the first direction D1 and the second direction D2 are not limited to these.

In the method of manufacturing the topsheet 1 shown in FIG. 11, the female support member 130 is pushed into the male support member 120 from above the fiber web 110 placed on the male support member 120 (FIGS. 11A and 11B). At this time, the projections 121 and the perforated portions 124 of the male support member 120 are inserted into the recesses 132 of the female support member 130 at respective positions. The protrusion 131 of the female support member 130 is inserted into the first concave portion 125A of the male support member 120 (FIGS. 11B and 14).
At the position of the first concave portion 125A of the male support member 120, the projection 131 of the female support member 130 pushes the fiber web 110 into shape. This portion becomes the ridges 11 of the topsheet 1 . At this time, the fibers of the fibrous web 110 are shaped to stand vertically along the thickness direction between the projections 121 of the male support member 120 and the projections 131 of the female support member 130 . Since the shaped fibers are not fused and have high mobility, they are oriented in the thickness direction. This portion becomes the wall portion 11B of the ridge portion 11 of the surface sheet 1. As shown in FIG. The pushing force of the pair of projections 131, 131 of the female support member 130 acts, and the fiber web 110 is pushed into the bottoms of the first and second recesses 125A and 125B while being partially perforated by the perforated portions 124 of the male support member 120. This portion becomes the top portion 11A of the surface sheet 1 including the openings 13 of the ridges 11. As shown in FIG.
On the other hand, the fibers of the fibrous web 110 are pushed up to the bottom of the recesses 132 of the female support member 130 at the positions of the projections 121 of the male support member 120 . This portion becomes the bottom portion 12 of the topsheet 1 . The bottom portion 12 is shaped as being vertically connected to the aforementioned wall portion 11B.
Since the recess 132 of the support female member 130 corresponds to the third recess 125C between the protrusions 121, 121 in the protrusion row 121A of the support male member 120, the support female member 130 does not enter. However, on both sides of the fibers of the fiber web 110 in the third recesses 125C of the row of protrusions 121A, the pushing forces of the protrusions 131, 131 of the female support member 130 act. By this action, the fibers of the fiber web 110 in the third concave portion 125C are stretched in the second direction D2 by the projections 131, 131 on both sides, pushed in the thickness direction, shaped in the thickness direction, and the orientation of the fibers is changed. This portion becomes the saddle portion 15 of the topsheet 1 . The saddle portion 15 has a top portion 15A and a wall portion 15B, and the wall portion 11B is similar to the wall portion 11B of the ridge portion 11.

Next, as shown in FIG. 11(C), the female support member 130 inserted into the male support member 120 is removed, and the fibers of the shaped fiber web 110 are heat-treated by blowing hot air W at a temperature that allows them to be appropriately fused to fuse the fibers. In this case, hot air W is blown from the side of the fiber web 110 into which the female support member 130 is pushed, and that side becomes the non-skin-contacting side 1B of the topsheet 1 . The temperature of the hot air W at this time is preferably 0° C. or more and 70° C. or less, more preferably 5° C. or more and 50° C. or less, higher than the melting point of the thermoplastic fibers forming the fiber web 110, considering common fiber materials used for this type of product.
The wind speed of the hot air W is preferably 2 m/s or more, more preferably 3 m/s or more, depending on the height of the projections 121 of the support male member 120 . As a result, heat transfer to the fibers is sufficient, and the fibers are fused to each other, so that the uneven shape can be sufficiently fixed. Moreover, the wind speed of the hot air W is preferably 100 m/s or less, more preferably 80 m/s or less. As a result, excessive heat transfer to the fibers can be suppressed, and the texture of the topsheet 1 can be improved.

Thus, the fiber web 110 is shaped and fused to form a nonwoven fabric.
As shown in FIG. 11(D), the surface of the nonwoven fabric facing the support male member 120 is turned upward to be the skin contact surface side 1T, and the nonwoven fabric for the topsheet 1 has the ridges 11 with the openings 13 at the top 11A and the bottom 12.
The non-woven fabric is cut into the size of the topsheet 1 of the diaper 10 , joined with other members, and subjected to necessary joining treatment and the like to manufacture the diaper 10 .

In the method of manufacturing the topsheet 1 described above, the female support member 130 forming the fibrous web 110 has projections 131 continuous in the first direction D1, as shown in FIG. It is not limited to this form. For example, the protrusions 131 may be formed in a grid shape, and the recesses 132 may be formed between the grid-shaped protrusions 131 . In this case, the height of the shaped saddle portion 15 becomes higher, and the unevenness becomes clearer.

Although the diaper 10 of the present embodiment has been shown as an unfolded type having a fastening tape for fastening, it is not limited to this, and may be a pants type one.

The absorbent article of the present invention is a concept including absorbent articles such as panty liners, incontinence pads, sanitary napkins, and incontinence pads, in addition to the diapers described above. In addition, other members may be appropriately incorporated into the above configuration according to the application and function.

EXAMPLES The present invention will be described in more detail below based on examples, but the present invention should not be construed as being limited thereto.

(Example 1)
A fiber web was produced using core-sheath type (polyethylene terephthalate (PET) (core): polyethylene (PE) (sheath) = 5:5 (mass ratio)) thermoplastic fibers with a fineness of 1.8 dtex. A fibrous web was arranged on the male support member 120, and as shown in FIG. Next, the female support member 130 was removed, and hot air W was blown to perform fusion bonding, thereby producing the nonwoven fabric for the topsheet 1 shown in FIG.

At this time, as the support male member 120, the height Q1 of the protrusion 121 was set to 8 mm, and the shape of a prism, which was a square of 2 mm×2 mm when viewed from above, was used. The perforated portion 124 had a height Q2 of 4 mm and a circular shape with a diameter of 3 mm when viewed from above.
A pitch P1 between the protrusions 121 and the perforated portions 124 in the second direction (CD direction) D2 was set to 3.5 mm. A pitch P2 between the projections 121, 121 via the perforated portion 124 in the second direction D2 was set to 8 mm. A pitch P3 between the projections 121, 121 in the first direction D1 was set to 8 mm. The width S1 of the protrusion 121 in the second direction D2 was set to 2 mm. The width (the width of the widest portion) S2 of the perforated portion 124 in the second direction D2 was set to 3 mm. These widths S1 and S2 are the same length in the first direction D1.

The width S3 of the projection 131 of the support female member 130 in the second direction D2 was set to 0.5 mm. The distance S4 between the projections 131, 131 at the position where the projection 121 of the male support member 120 is sandwiched between the pair of projections 131, 131 of the female support member 120 was set to 2.75 mm. The distance S5 between the projections 131, 131 was set to 3.75 mm at the position where the pair of protrusions 131, 131 of the support female member were pushed in, sandwiching the perforated portion 124 of the support male member 120. As shown in FIG. At the position where the projections 131 of the female supporting member sandwich the perforated portion 124 of the male supporting member 120, the gap S6 between the protruding portion 131 and the perforated portion 124 was set to 0.375 mm.

The blowing treatment with hot air was performed under the conditions of a temperature of 160° C., a wind speed of 4.5 m/s, and a conveying speed of 10 m/min.

As a result, a nonwoven fabric sample for the surface sheet 1 having a basis weight of 30 g/m ² and having the concave-convex structure shown in FIG. 2 was produced. The side of the support body male member 120 (the side opposite to the side to which the hot air was blown) was defined as the skin contact side 1T. The fabricated nonwoven fabric sample of Example 1 had the openings 13 at the tops 11A of the ridges 11, and the walls 11B extended perpendicularly to the bottom 12 to support the tops 11A. The details of the structure of the nonwoven fabric sample were as shown in Table 1. Various items shown in "Configuration" in Table 1 were measured by the measurement method described above.

Next, the surface sheet of a commercially available baby diaper (trade name “Merries Sarasara Air Through S Size”, manufactured by Kao Corporation, manufactured in 2020) was peeled off by cold spray, and instead, a nonwoven fabric sample cut into 100 mm × 200 mm was laminated as a surface sheet. A diaper sample of Example 1 was produced by fixing the periphery of the laminated topsheet.

(Example 2)
A nonwoven fabric sample for the topsheet 1 of Example 2 was produced in the same manner as in Example 1, except that the male support material 120 and the female support material 130 were made under the following conditions. Using this nonwoven fabric sample, a diaper sample of Example 2 was produced in the same manner as in Example 1.
Height of protrusion 121: Q1: 8 mm
Planar shape of protrusion 121 from the upper surface: 2 mm × 2 mm square Height of perforated portion 124: Q2: 10 mm
Planar view shape of perforated portion 124 from the upper surface: Φ2 mm circle Pitch P1 from protrusion 121 to perforated portion 124 in second direction D2: 3 mm
Pitch P2 between projections 121, 121 via perforated portion 124 in second direction D2: 6 mm
Pitch P3 between projections 121, 121 in first direction D1: 6 mm
Width S1 of protrusion 121 in second direction D2: 2 mm
Width S2 of perforated portion 124 in second direction D2: 2 mm
Width S3 of projection 131 in second direction D2: 0.5 mm
Distance S4 and S5 between protrusions 131, 131: 2.5 mm
Gap S6 between protrusion 131 and perforated portion 124: 0.25 mm

(Example 3)
A nonwoven fabric sample of Example 3 for the topsheet 1 was produced in the same manner as in Example 1, except that the perforated portions 124 in the perforated portion row 124A and the projections 121 in the protruded row 121A adjacent to the perforated portion row 124A were staggered so as not to overlap in the second direction D2. In this nonwoven fabric sample, the positions of the open holes 13 and the positions of the saddle portions 15 overlapped in the width direction X. As shown in FIG. Using this nonwoven fabric sample, a diaper sample of Example 3 was produced in the same manner as in Example 1.

(Comparative example 1)
A nonwoven fabric sample described in Example 1 of Patent Document 3 was produced. The details of the structure of the nonwoven fabric sample were as shown in Table 1, and the sample had openings at the bottom. A topsheet of Comparative Example 1 was prepared using the nonwoven fabric sample, and a diaper sample of Comparative Example 1 was prepared in the same manner as in Example 1.

(Comparative example 2)
A nonwoven fabric sample shown in FIG. 1 of JP-A-2013-133574 was produced using a thermoplastic fiber having a fineness of 1.8 dtex according to the manufacturing method described in the same publication. The details of the structure of the nonwoven fabric samples are shown in Table 1, and they had a perforated bottom (second protrusion), but no ridges or saddles. The first protrusion was hemispherical. As a result, the wall extends in an inclined direction rather than perpendicular to the bottom. A topsheet of Comparative Example 2 was prepared using the nonwoven fabric sample, and a diaper sample of Comparative Example 2 was prepared in the same manner as in Example 1.

[Amount of compression deformation]
With KES-FB3 (trade name) manufactured by Kato Tech Co., Ltd., compression characteristics were evaluated up to 5.0 kPa in normal mode except that the terminal speed was set to 0.1 mm/s. Thereafter, the amount of deformation from 0.15 kPa to 2.5 kPa was defined as the "compression deformation amount" of each nonwoven fabric sample. Based on the "amount of compression deformation", elasticity and cushioning properties were determined. A larger value indicates that the material is less likely to be crushed in the direction of compression under a small load, and similarly has moderate elasticity. Also, the larger the numerical value, the easier it is to be crushed before a load of 2.5 kPa is reached.

[Loose stool flow distance]
Each diaper sample was spread on the slope of an inclined table having a slope angle of 20 degrees, and at a position 30 mm rearward from the center in the longitudinal direction Y of each diaper sample, 10 g of pseudo loose stool (viscosity 40 mPa s) was injected at a flow rate of 6 g/s from a position 10 mm above the surface sheet. The simulated loose stool was prepared by dispersing bentonite in ion-exchanged water, and adjusted the bentonite concentration to have a viscosity of 40 mPa·s.
After 30 seconds, the distance that the pseudo loose stool flowed from the injection point on the surface sheet was measured, and this was defined as the loose stool flow distance.

[Absorption time of loose stool]
Each diaper sample was unfolded and flattened, and ^a cylinder with a cross-sectional area of 1000 mm2 was applied to a position 30 mm behind the center of each diaper sample in the longitudinal direction Y, and 10 g of the above-described pseudo loose stool (viscosity 40 mPa s) was injected from there at a flow rate of 6 g/s.
The time taken to completely absorb the simulated loose stool (the time required for the stool to permeate through the surface of the diaper and expose the topsheet) was measured, and this time was taken as the absorption time for loose stool.

[Presence or absence of adhesive coming off (adhesion to skin)]
Each diaper sample was unfolded and flattened, and three panelists were asked to touch the surface sheet from above to sensory evaluate the stickiness.
3 points for no stickiness, 2 points for slightly sticky feeling, and 1 point for feeling stickiness.

As shown in Table 1, the diaper samples of Examples 1 to 3 had a larger compressive deformation amount of the topsheet and superior cushioning properties than the diaper samples of Comparative Examples 1 and 2. That is, the topsheets of the diaper samples of Examples 1 to 3 were less likely to be crushed in the compression direction under a small load than the topsheets of the diaper samples of Comparative Examples 1 and 2, had moderate elasticity, and were greatly deformed until a load of 2.5 kPa was applied. Further, in the topsheets of the diaper samples of Examples 1 to 3, the ridges 11 were less likely to sag against the compressive load than the topsheets of the diaper samples of Comparative Examples 1 and 2. Thus, the diaper samples of Examples 1-3 exhibited better cushioning properties than the diaper samples of Comparative Examples 1 and 2.
In addition, the diaper samples of Examples 1 to 3 had a loose stool liquid flow distance about 30% or more shorter than the diaper samples of Comparative Examples 1 and 2, and a soft stool absorption time shortened by about 40% or more, indicating excellent liquid absorbency.
Furthermore, the diaper samples of Examples 1 to 3 felt less sticky on the surface sheet than the diaper sample of Comparative Example 1, and the adhesion of the adhesive to the skin due to the adhesive coming off from the lower layer of the surface sheet was suppressed, and a good touch was felt.

1 Top sheet 2 Absorbent body 3 Back sheet 4 Fastening tape 10 Diaper 1T Skin contact side 1B Non-skin contact side 11 Ridge 11A Top 11B Wall 11C Hollow area 12 Bottom 13 Opening 13A Edge of opening 15 Saddle 15A Top 15B Wall 15C Hollow area 16 Belt area 17 Drooping rib Z1 Projection Length Z2 Thickness Z3 of top fiber layer other than edge portion Thickness of top sheet 18 Edge peripheral portion 19 Portion other than edge peripheral portion

Claims (8)

An absorbent article comprising a liquid-permeable surface sheet on a skin-contacting side and an absorbent body disposed on the non-skin-contacting side of the surface sheet,
The surface sheet is made of a nonwoven fabric having a plurality of ridges arranged so as to protrude toward the skin contact surface and a bottom provided between adjacent ridges,
each of the plurality of ridges comprises a top and a wall supporting the top;
the wall extends perpendicular to the bottom,
The absorbent article, wherein the apex has an opening penetrating between the skin-contacting surface side and the non-skin-contacting surface side. 2. The absorbent article according to claim 1, wherein a saddle connecting said adjacent ridges is provided projecting from said bottom, said saddle comprising a top and a wall supporting said top. 3. The absorbent article according to claim 1, wherein the orientation direction of the fibers forming the top of said ridge is different from the orientation direction of the fibers forming the top of said saddle. 4. The absorbent article according to any one of claims 1 to 3, wherein the edges of the openings at the top of the ridges have hanging ribs in which fibers protrude vertically toward the non-skin-contacting surface. 5. The absorbent article according to claim 4, wherein, on the skin-contacting surface side of the apex of the ridge, the density of the constituent fibers present in the periphery of the opening is higher than the density of the constituent fibers present in portions other than the periphery. The absorbent article according to any one of the preceding claims, wherein the fibers of the walls of the ridges are oriented perpendicular to the bottom. 7. The absorbent article according to any one of claims 1 to 6, wherein the area ratio of the open holes in the area of the apex of the ridge in plan view is 5% or more and 30% or less. 8. The absorbent article according to any one of claims 1 to 7, wherein the area ratio of the open holes to the area of the entire topsheet in plan view is 5% or more and 30% or less.

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