Absorbent article and method of manufacturing absorbent article

Abstract

To provide an absorbent article that suppresses leakage of an absorbent material, and a method of manufacturing the absorbent article.SOLUTION: The absorbent article comprises: a length along a longitudinal direction corresponding to a longitudinal direction of a wearer; a length along a width direction orthogonal to the longitudinal direction; an absorption mat; a first permeable sheet that is arranged on the wearer's skin surface side of the absorption mat; a laminated part in which the plurality of first permeable sheets are stacked on a part on the skin surface side of the absorption mat; and a compression part that is provided in the laminated part.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an absorbent article and a method for manufacturing an absorbent article. [Background technology]

[0002] Absorbent articles such as disposable diapers, absorbent pads, and sanitary products have been developed. The absorbent articles include an absorbent body that absorbs liquids such as urine excreted by the wearer. For example, Patent Document 1 discloses an absorbent article that includes compressed grooves formed by compression. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-103782 Summary of the Invention [Problem to be solved by the invention]

[0004] In the manufacturing process of absorbent articles with compressed grooves, the water-permeable sheet is compressed from above to form the compressed grooves. However, compressing the water-permeable sheet from above places a load on the water-permeable sheet, which may cause the sheet to tear and the absorbent material to leak out.

[0005] SUMMARY OF THE INVENTION An object of the present invention is to provide an absorbent article that inhibits leakage of absorbent material and a method for manufacturing the absorbent article. [Means for solving the problem]

[0006] An absorbent article according to one aspect of the present invention comprises: a length along a longitudinal direction corresponding to the front-to-back direction of the wearer; a length along a width direction perpendicular to the longitudinal direction; Absorbent mat, a first water-permeable sheet disposed on the wearer's skin side of the absorbent mat; a laminated portion in which a plurality of the first water-permeable sheets are laminated on a portion of the skin-facing side of the absorbent mat; and a compression section provided on the laminated section. [Effects of the Invention]

[0007] According to the present invention, leakage of the absorbent material can be suppressed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the appearance of a diaper according to an embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the diaper according to the embodiment. [Figure 3] FIG. 3 is a plan view of the diaper according to the embodiment. [Figure 4] FIG. 4 is a cross-sectional view of a diaper according to an embodiment. [Figure 5] FIG. 5 is a diagram showing a compression portion provided on a diaper according to an embodiment. [Figure 6] FIG. 6 is an enlarged view of a laminated portion provided in a diaper according to an embodiment. [Figure 7] FIG. 7 is a cross-sectional view of the diaper according to the embodiment in a state where the leakage barrier walls are erected. [Figure 8] FIG. 8 is a diagram showing strongly adhesive portions provided on a diaper according to an embodiment. [Figure 9] FIG. 9 is a flowchart showing a method for manufacturing a diaper according to an embodiment. [Figure 10] FIG. 10 is a diagram showing a part of the diaper manufacturing apparatus according to the embodiment. [Figure 11] FIG. 11 is a diagram showing a compressing unit provided in a manufacturing apparatus for manufacturing a diaper according to an embodiment. [Figure 12] FIG. 12 is a schematic view of a manufacturing apparatus for manufacturing diapers by the diaper manufacturing method according to the embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes an embodiment of the present invention. The embodiment described below is one aspect of the present invention, and does not limit the technical scope of the present invention.

[0010] <Embodiment> In this embodiment, the longitudinal direction of a tape-type disposable diaper (an example of an "absorbent article" in the present application, hereinafter simply referred to as "diaper") is the direction connecting the front body portion, which is positioned opposite the wearer's abdomen, and the back body portion, which is positioned opposite the wearer's back. Between the front body portion (one side in the longitudinal direction) and the back body portion (the other side in the longitudinal direction) (the center in the longitudinal direction), a crotch portion, which is positioned between the wearer's crotch (facing the crotch), is located. Furthermore, when the diaper is worn by a wearer (hereinafter abbreviated as "worn state"), the side facing the wearer's skin (the inner side when worn) is the skin-facing side, and the side opposite the skin-facing side (the outer side when worn) is the non-skin-facing side. Furthermore, the direction connecting the skin-facing side and the non-skin-facing side is the thickness direction, and the direction perpendicular to both the longitudinal direction and the thickness direction is the width direction. Furthermore, a view from the thickness direction is a planar view. The left-right direction of the diaper is defined as the right side of the wearer's right hand and the left side of the wearer's left hand when the diaper is worn.

[0011] FIG. 1 is a perspective view of a diaper 1 according to this embodiment. FIG. 2 is an exploded perspective view of the diaper 1 according to this embodiment. FIG. 3 is a plan view of the diaper 1 in a stretched state, viewed from the skin-facing side. The diaper 1 has a crotch region 1B, which corresponds to the crotch area covering the wearer's genitals when worn; a front body region 1F, which is located in front of the crotch region 1B and corresponds to the wearer's front body; and a back body region 1R, which is located behind the crotch region 1B and corresponds to the wearer's back body. Tapes 2L and 2R are attached to the left and right edges of the back body region 1R, and can be attached to front patches 2F, which are provided on the non-skin-facing side of the front body region 1F. When the front body region 1F is positioned on the wearer's abdominal side and the back body region 1R is positioned on the wearer's back side, the diaper 1 is secured to the wearer's body by encircling the wearer's abdominal circumference and thighs. Since the diaper 1 is fixed to the wearer's body in this manner, the wearer can stand and walk around while wearing the diaper 1.

[0012] The diaper 1 includes an absorbent body 6, which is capable of absorbing and retaining exudates discharged by the wearer, and is located mainly near the crotch region 1B. The diaper 1 also includes leg gathers 3AL, 3AR around the wearer's legs (thighs) to prevent gaps from forming between the diaper 1 and the wearer's skin, which could serve as a path for exudates to escape. Leakage barrier walls 3BL, 3BR are provided on the inside of the leg gathers 3AL, 3AR in the width direction of the diaper 1. The leg gathers 3AL, 3AR and the leakage barrier walls 3BL, 3BR adhere closely to the wearer's skin due to the elasticity of the elastic members. Therefore, exudates discharged from the wearer's genitals are absorbed by the absorbent body 6 of the diaper 1 without leaking out. The elastic members may be selected from thread-like or strip-like rubber, as appropriate.

[0013] The diaper 1 has a cover sheet 4 that forms the outer surface when worn. The cover sheet 4 is a sheet-like member with a roughly rectangular appearance with constrictions 4KL and 4KR at the positions corresponding to the long sides, and forms the exterior surface of the diaper 1. The constrictions 4KL and 4KR are provided in the areas where the wearer's thighs are located. The cover sheet 4 is provided to reinforce the back sheet 5 (described later) and to improve the feel, and is made of a liquid-impermeable, heat-resistant material to prevent leakage of excrement, for example. A nonwoven fabric made of a thermoplastic resin can be used as the material. Examples of liquid-impermeable thermoplastic resins include polyethylene (PE) and polypropylene (PP). The cover sheet 4 is not limited to a single-layer structure, but may also have a multi-layer structure having an inner cover sheet and an outer cover sheet.

[0014] The diaper 1 has a back sheet 5, an absorbent body 6, and a top sheet 8 (an example of the "second water-permeable sheet" referred to in the present application), which are layered in this order on the wearer's skin-facing side of the cover sheet 4. The top sheet 8 may consist of a single sheet, or multiple sheets may be layered. The back sheet 5, the absorbent body 6, and the top sheet 8 are all sheet-like members having a substantially rectangular appearance, and are layered in this order on the cover sheet 4 with their longitudinal directions aligned with the longitudinal direction of the cover sheet 4. The back sheet 5, like the cover sheet 4, is a sheet made of a liquid-impermeable thermoplastic resin material to prevent leakage of excrement. The back sheet 5 is preferably made of a material that is also moisture-permeable to prevent stuffiness when worn.

[0015] The top sheet 8 is the portion that contacts the wearer's skin when the diaper 1 is worn, and is a water-permeable sheet made of a liquid-permeable material that allows excreted liquids such as urine to pass through. The top sheet 8 may be made of a woven fabric, a nonwoven fabric, a porous film, or the like. The nonwoven fabric may be made of thermoplastic resin fibers such as polypropylene, polyethylene, polyester, or nylon that have been hydrophilically treated. Alternatively, air-through nonwoven fabric, point-bonded nonwoven fabric, spun-bonded nonwoven fabric, or melt-blown nonwoven fabric may be used. When the diaper 1 is worn, excreted liquid passes through the top sheet 8, which may come into contact with the wearer's skin, into the absorbent body 6, and is absorbed therein. The longitudinal direction of the diaper 1 is the same as the longitudinal directions of the absorbent body 6 and the top sheet 8.

[0016] The back sheet 5, absorbent body 6, and top sheet 8 all extend from the front body region 1F to the back body region 1R. Therefore, when the wearer's genitals are covered with the cover sheet 4, in which the back sheet 5, absorbent body 6, and top sheet 8 are laminated, the longitudinal ends of the back sheet 5, absorbent body 6, and top sheet 8 are located on the wearer's ventral and dorsal sides. In other words, the wearer's genitals are covered by the absorbent body 6 from the ventral to dorsal sides of the wearer. Therefore, whether the wearer is in a ventral or dorsal position when excreting fluid, the fluid excreted by the wearer comes into contact with the absorbent body 6 via the top sheet 8.

[0017] The diaper 1 also includes elastic members 4SL, 4SR for forming the leg gathers 3AL, 3AR described above, which are provided between the cover sheet 4 and the back sheet 5 so as to be stretchable in the longitudinal direction of the diaper 1. The number of elastic members 4SL, 4SR (two in this embodiment) is determined based on the elastic force (contractile force) required for the design of the diaper 1. The elastic members 4SL, 4SR may not be provided.

[0018] The diaper 1 also has a pair of water-impermeable side sheets 9L, 9R (an example of the "leak-proof sheet" as used herein) arranged on both skin-facing sides of the diaper 1 in the width direction and extending longitudinally. The side sheets 9L, 9R are arranged so that their longitudinal ends coincide with the longitudinal ends of the top sheet 8. Like the cover sheet 4, the side sheets 9L, 9R have constrictions 9KL, 9KR in the areas where the wearer's thighs are located. The side sheets 9L, 9R have fixing regions 9LA, 9RA (an example of the "bonding portion" as used herein) arranged on their outer width sides. The fixing regions 9LA, 9RA are bonded to the top sheet 8, which is the component arranged on the non-skin-facing side, with a hot-melt adhesive.

[0019] Rubber threads 9EL, 9ER (an example of the "elastic member" in this application) for forming the leakage barrier walls 3BL, 3BR are arranged on the side sheets 9L, 9R along the longitudinal direction. When the diaper 1 is worn, i.e., when the diaper 1 is U-shaped in side view, the top sheets 9L, 9R are pulled longitudinally by the contractile force of the elastic threads 9EL, 9ER, and rise from the top sheet 8, forming leak-proof walls 3BL, 3BR that prevent the outflow of excreted liquid.

[0020] The side sheets 9L, 9R are bonded to the top sheet 8 with a hot melt adhesive. The widthwise inner edges of this hot melt adhesive form fold lines 3LL, 3LR (see FIG. 3), and the insides of the fold lines 3LL, 3LR form the upstanding leakage barrier walls 3BL, 3BR. That is, the fold lines 3LL, 3LR are the upstanding edges of the leakage barrier walls 3BL, 3BR. The widthwise inner edges of the side sheets 9L, 9R from the fold lines 3LL, 3LR are the leakage barrier walls 3BL, 3BR, and the widthwise inner edges of the side sheets 9L, 9R are the free edges 9LB, 9RB of the leakage barrier walls 3BL, 3BR. Two rubber threads 9EL, 9ER, which are thread-like elastic members, are arranged side by side in the width direction near the free edges 9LB, 9RB of the side sheets 9L, 9R. Note that only one rubber thread 9EL, 9ER may be arranged. The elastic threads 9EL, 9ER are fixed to the side sheets 9L, 9R with hot melt adhesive in a stretched state in the longitudinal direction of the diaper 1. The side sheets 9L, 9R have fixing portions 33L, 33R near their longitudinal ends. The fixing portions 33L, 33R fix the side sheets 9L, 9R to the top sheet 8, and serve as longitudinal starting points for the leakage barrier walls 3BL, 3BR when they rise. The side sheets 9L, 9R are also bonded to the top sheet 8 on their outer widthwise sides, but on the inner longitudinal sides of the fixing portions 33L, 33R, the inner widthwise sides of the fixing portions are not bonded with the hot melt adhesive, allowing them to rise toward the skin. When the elastic threads 9EL, 9ER contract and the leakage barrier walls 3BL, 3BR on the inner side of the fold lines 3LL, 3LR rise toward the skin, the free ends 9LB, 9RB become the tips on the skin-facing side. The upright leak-preventing walls 3BL, 3BR inhibit the movement of discharged liquid and loose stools outward in the width direction of the leak-preventing walls 3BL, 3BR, thereby suppressing lateral leakage of these.

[0021] FIG. 4 is a widthwise cross-sectional view of the diaper 1 taken along line AA in FIG. 3. The diaper 1 includes an absorbent body 6 that absorbs and retains excreted fluids such as urine. The absorbent body 6 is disposed on the non-skin-facing side of the top sheet 8, including the crotch region 1B, to absorb excreted fluids from the wearer. In this embodiment, the absorbent body 6 includes an absorbent core 6C (an example of the "absorbent mat" referred to in this application) and a core wrap sheet 7 (an example of the "first water-permeable sheet" referred to in this application) that covers part or all of the absorbent core 6C. The longitudinal direction of the absorbent body 6 coincides with the longitudinal direction of the absorbent core 6C, the longitudinal direction of the core wrap sheet 7, and the longitudinal direction of the diaper 1.

[0022] In plan view, the absorbent core 6C has a generally gourd-like shape, with the front and back body regions 1F and 1R being wider than the crotch region 1B and the crotch region 1B being narrowed. The crotch region 1B is sandwiched between the wearer's legs, so it is subjected to compressive pressure inward in the width direction. Meanwhile, the front and back body regions 1F and 1R are subjected to pressure in the thickness direction of the absorbent core 6C due to the wearer's weight. To accommodate these pressures, the absorbent core 6C is narrowed in the crotch region 1B. In the front and back body regions 1F and 1R, the width of the absorbent core 6C is increased to increase the area on which the weight is applied, thereby preventing deformation in the thickness direction. For this reason, it is preferable that the absorbent core 6C be generally gourd-shaped. The absorbent core 6C may also be generally rectangular.

[0023] The absorbent core 6C has a mat structure in which granular absorbent resin (polymeric water-absorbing material) such as SAP (Super Absorbent Polymer), a hydrophilic polymer with a cross-linked structure that can absorb and retain water, is held in the gaps between short fibers of cellulosic fibers such as pulp, rayon, or cotton, or short fibers made from synthetic fibers such as polyethylene, polypropylene, or polyethylene terephthalate that have been hydrophilically treated. These short fibers and SAP are examples of absorbent materials.

[0024] In this embodiment, SAP particles refer to a granulated resin composition containing SAP. The term "SAP-containing resin composition" as used herein encompasses both a composition consisting solely of SAP and a composition containing SAP as the main component, with other substances added to the extent that they do not adversely affect water absorption. Examples of "other substances" include additives (such as surface modifiers added to hydrophobize the particle surface) and unreacted monomers remaining during the synthesis of SAP. SAP particles can absorb approximately 10 to 100 times their own weight in liquid. The SAP particles may be, for example, granular particles with a diameter of approximately 0.1 to 0.5 mm before absorbing liquid.

[0025] While SAP particles gel and can retain liquid, it takes a certain amount of time for the liquid to be absorbed. In diaper 1, the short fibers slow down the discharged liquid while diffusing it within the absorbent core 6C until the SAP particles have absorbed the liquid, allowing the discharged liquid to be absorbed by a wide range of SAP particles, thereby preventing the liquid from flowing back.

[0026] The absorbent core 6C may have three low-bulk portions (not shown) extending in the longitudinal direction of the absorbent core 6C and spaced apart in the width direction. The low-bulk portions are portions of the absorbent material composed of the above-mentioned short fibers and SAP particles that are less bulky than the surrounding absorbent material and are formed in a concave shape from the skin-facing side to the non-skin-facing side. Urine and other excreted fluids discharged by the wearer are dispersed throughout the absorbent core 6C along the low-bulk portions provided on the skin-facing side of the absorbent core 6C. This allows the diaper 1 to efficiently absorb urine and other excreted fluids discharged by the wearer throughout the entire absorbent core 6C.

[0027] The absorbent core 6C may have an upper-layer absorbent mat arranged on the top sheet 8 side and a lower-layer absorbent mat arranged on the side not facing the wearer's skin.

[0028] The core wrap sheet 7 is a water-permeable sheet that sandwiches the absorbent core 6C, and more specifically, it covers the skin-facing side, side, and non-skin-facing side of the absorbent core 6C. The core wrap sheet 7 maintains the shape of the absorbent core 6C when not in contact with excreted liquid, preventing it from losing its shape and preventing the SAP particles contained in the absorbent core 6C from escaping. Furthermore, SAP particles when not absorbing moisture are hard and sand-like, and if these SAP particles escape from the absorbent body 6 and come into direct contact with the wearer's skin, they may cause discomfort to the wearer. For this reason, the absorbent core 6C is sandwiched between the core wrap sheets 7 to prevent the absorbent core 6C from losing its shape and to prevent the SAP particles from escaping outside the absorbent body 6.

[0029] In this embodiment, the core wrap sheet 7 is made of a pulp fiber sheet or a thin nonwoven fabric. The core wrap sheet 7 is formed from two sheets: an upper core wrap sheet 7A that is placed between the absorbent core 6C and the top sheet 8, and a lower core wrap sheet 7B that is placed on the non-skin-facing side of the absorbent core 6C. The upper core wrap sheet 7A and the lower core wrap sheet 7B of the core wrap sheet 7 are made from the same material. However, the upper core wrap sheet 7A and the lower core wrap sheet 7B may also be made from different materials. As an example, the upper core wrap sheet 7A can be made of an air-through nonwoven fabric, and the lower core wrap sheet 7B can be made of tissue paper.

[0030] In this embodiment, the core wrap sheet 7 is arranged to cover the skin-facing side, side surfaces, and non-skin-facing side of the absorbent core 6C. As shown in Fig. 4, the lower core wrap sheet 7B is arranged on the non-skin-facing side of the absorbent core 6C, covers the side surfaces of the absorbent core 6C, and is further arranged to cover the widthwise outer sides of the upper core wrap sheet 7A. Here, the upper core wrap sheet 7A and the lower core wrap sheet 7B are laminated on both widthwise sides of the skin-facing side of the absorbent core 6C, forming a laminated section 7S.

[0031] The absorbent body 6 provided in the diaper 1 according to this embodiment is formed by squeezing the absorbent body 6 from the skin-facing side. The diaper 1 has a compressed portion (an example of the "compressed groove" as referred to in the present application) formed therein. Fig. 5 is a plan view of the diaper 1 showing the compressed portion 20. For the sake of explanation, some components have been omitted from the illustration. The compressed portion 20 in this embodiment is formed of a plurality of grooves, including grooves 20A and grooves 20B that intersect with each other, as shown in Fig. 5.

[0032] As shown in Fig. 5, the groove 20A extends linearly from the front left side to the rear right side of the diaper 1, and the groove 20B extends linearly from the front right side to the rear left side of the diaper 1. The grooves 20A and 20B are formed in a lattice pattern diagonal to the long or short sides of the absorbent body 6. The extending direction of the grooves 20A and 20B is not limited to the example configuration shown in Fig. 5. For example, the groove 20A may extend from the front to the rear of the diaper 1, and the groove 20B may extend from the right to the left side of the diaper 1. The grooves 20A and 20B may also be formed in a lattice pattern parallel to the long or short sides of the absorbent body 6.

[0033] Air flows along the grooves 20A and 20B provided on the skin-facing side of the absorbent body 6, improving the breathability of the diaper 1. Liquids such as urine excreted by the wearer are dispersed throughout the absorbent body 6 along the grooves 20A and 20B provided on the skin-facing side of the absorbent body 6. This allows the diaper 1 to efficiently absorb urine excreted by the wearer throughout the absorbent body 6. Furthermore, providing the grooves 20A and 20B in the absorbent body 6 makes it easier to bend, thereby improving the comfort of the diaper 1 when worn by the wearer.

[0034] The compressed section 20 is preferably formed by compressing the laminated section 7S from the skin-facing side. When the compressed section 20 is provided on the absorbent body 6 from above the upper-layer core wrap sheet 7A, the compression load is applied to the upper-layer core wrap sheet 7A, which may tear the upper-layer core wrap sheet 7A and cause the absorbent material constituting the absorbent core 6C to leak from the absorbent body 6. When the laminated section 7S, in which the upper-layer core wrap sheet 7A and the lower-layer core wrap sheet 7B are laminated, is formed by compressing it from the skin-facing side, two or more core wrap sheets 7 are arranged on the skin-facing side of the absorbent core 6C. Therefore, even if one of the upper-layer core wrap sheet 7A or the lower-layer core wrap sheet 7B is torn when compressed from the skin-facing side of the absorbent body 6, the remaining sheet can prevent the absorbent material from leaking from the absorbent body 6.

[0035] The compressed sections 20 may also be formed by compressing the top sheet 8 and the absorbent body 6 from the skin-facing side of the top sheet 8. By compressing the top sheet 8 from the skin-facing side, the upper-layer core wrap sheet 7A, the lower-layer core wrap sheet 7B, and the top sheet 8 are laminated on the skin-facing side of the absorbent core 6C, so that even if any of the sheets are torn, leakage of the absorbent material outside the top sheet 8 can be suppressed. Furthermore, because the upper-layer core wrap sheet 7A and the top sheet 8 are laminated on the skin-facing side of the compressed sections 20 provided in the widthwise center of the absorbent body 6 where the laminate section 7S is not formed, leakage of the absorbent material outside the top sheet 8 can be suppressed even if any of the sheets is torn. Note that a sheet such as a second sheet may be laminated between the top sheet 8 and the absorbent body 6. Laminating more sheets on the skin-facing side of the absorbent core 6C can further suppress leakage of the absorbent material outside the top sheet 8.

[0036] In this embodiment, the laminated sections 7S are provided in part of the region where the compressed sections 20 are formed. More specifically, as shown in FIG. 4, the laminated sections 7S are provided on both widthwise end sides of the absorbent body 6, and the compressed sections 20 are provided over the entire skin-facing side of the absorbent core 6C. If the laminated sections 7S are provided in the widthwise central region where excreted liquid such as urine is likely to flow, it may take a long time for excreted liquid such as urine to be absorbed into the absorbent core 6C, as it must pass through the top sheet 8 and then multiple core wrap sheets 7. Therefore, the laminated sections 7S may be provided on both widthwise end sides of the region where the compressed sections 20 are formed so as not to prevent excreted liquid such as urine excreted by the wearer from being absorbed into the absorbent core 6C. Furthermore, as the number of sheets to be stacked increases, the shape of the compressed sections 20 is formed by compression. If the shape of the compressed portions 20 is not formed in the widthwise center portion of the absorbent body 6, where discharged liquids such as urine tend to flow in, there is a risk that discharged liquids such as urine will not be dispersed throughout the absorbent body 6. Therefore, the laminated portions 7S may be provided on both widthwise end sides of the area where the compressed portions 20 are formed so as not to prevent discharged liquids such as urine excreted by the wearer from being dispersed throughout the absorbent body 6. Since the top sheet 8 is disposed on top of the absorbent body 6 in the widthwise center portion of the absorbent body 6, leakage of the absorbent material to the outside of the top sheet 8 can be prevented even if the upper-layer core wrap sheet 7A is torn.

[0037] The laminated portion 7S in this embodiment may be provided over the entire area where the compressed portions 20 are formed. By providing the laminated portion 7S over the entire area where the compressed portions 20 are formed, it is possible to prevent the absorbent material from leaking out of the absorbent body 6 over the entire area where the absorbent body 6 is compressed.

[0038] At the intersections 20K of the intersecting grooves 20A and 20B, it is preferable that the number of core wrap sheets 7 laminated on the skin-facing side of the absorbent core 6C is greater than in areas where the intersections 20K are not provided. When compressed sections 20 are provided in the absorbent body 6 from above the upper-layer core wrap sheet 7A, the upper-layer core wrap sheet 7A may be torn due to the load caused by compression. Therefore, at the intersections 20K, there is a risk that the absorbent material constituting the absorbent core 6C described above may leak out from the absorbent body 6. In particular, the intersections 20K of the grooves 20A and 20B, which are formed by compression and extend in different directions, are prone to tearing because they are pulled in the directions of the grooves 20A and 20B when the compressed sections 20 are formed. By laminating multiple core wrap sheets 7 on the skin side of the intersection 20K, even if the core wrap sheet 7 laminated at the intersection 20K is torn, as long as one of the laminated core wrap sheets 7 is not torn, the leakage of the absorbent material from the absorbent core 6C can be prevented.

[0039] FIG. 6 is an enlarged view of the laminated section 7S extracted from the cross-sectional view of FIG. 4. The laminated section 7S may have a space-forming section 21A formed by a non-bonded section where the upper and lower core wrap sheets 7A and 7B are not bonded, or a weakly bonded section where the upper and lower core wrap sheets 7A and 7B are weakly bonded. Weak bonding refers to a state in which the bonded materials are bonded to a degree that allows them to be peeled apart without tearing. By providing the space-forming section 21A between the upper and lower core wrap sheets 7A and 7B, after forming the compressed section 20, the core wrap sheet 7 on the skin-facing side of the space-forming section 21A can be peeled from the compressed section 20. In this embodiment, the core wrap sheet 7 that is peelable is the lower core wrap sheet 7B. When compressed, the upper and lower core wrap sheets 7A and 7B are pulled toward the compressed section 20 and become elongated. When the core wrap sheet 7 is stretched, it becomes more prone to tearing due to the load caused by the stretching. When the lower-layer core wrap sheet 7B is peeled off from the upper-layer core wrap sheet 7A, a space is formed between the upper-layer core wrap sheet 7A and the lower-layer core wrap sheet 7B, and the stretched state of the lower-layer core wrap sheet 7B is released, making it less prone to tearing. Therefore, it is preferable to provide the space-forming portion 21A in the portion corresponding to the compressed portion 20, because the lower-layer core wrap sheet 7B is less likely to be subjected to a force pulling it toward the compressed portion 20 when it is peeled off from the compressed portion 20. In particular, the intersection 20K is more likely to be subjected to a load caused by compression, making the core wrap sheet 7 more prone to tearing, so it is preferable to form the space-forming portion 21A in the portion corresponding to the intersection 20K. The width direction of the laminated portion 7S is the same as the width direction of the absorbent body 6.

[0040] When the space forming portion 21A is a weakly bonded portion, the weak bond of the space forming portion 21A may be released by erecting the leakage preventing walls 3BL, 3BR. Fig. 7 is a cross-sectional view showing the cross section of Fig. 4 in a state in which the leakage preventing walls 3BL, 3BR are erected. The arrows in Fig. 7 indicate the direction in which the top sheet 8 is pulled by the leakage preventing walls 3BL, 3BR. When the leakage preventing walls 3BL, 3BR are erected, the top sheet 8 bonded to the side sheets 9L, 9R that form the leakage preventing walls 3BL, 3BR is pulled toward the skin side, and the weak bond of the space forming portion 21A shown in Fig. 6 can be released. Note that the weak bond of the space forming portion 21A is released before the wearer puts on the diaper 1. That's fine.

[0041] The laminated portion 7S may be formed of three or more water-permeable sheets. In this case, if at least one pair of adjacent water-permeable sheets forming the laminated portion 7S has a space-forming portion 21A between them, the space-forming portion 21A can prevent the spaced water-permeable sheets on the skin-facing side from breaking.

[0042] As shown in FIG. 6, it is preferable that the widthwise ends of the intersections 20K in the laminated section 7S have strongly bonded sections 21K between the upper-layer core wrap sheet 7A and the lower-layer core wrap sheet 7B. The strongly bonded sections 21K are areas that are strongly bonded so that the bonded materials cannot be peeled apart without tearing them. The intersections 20K are susceptible to compressive loads, making the core wrap sheet 7 prone to tearing. By providing the strongly bonded sections 21K at both widthwise ends of the intersections 20K in the laminated section 7S, even if the upper-layer core wrap sheet 7A corresponding to the intersections 20K is torn, the strongly bonded sections 21K are located at both widthwise ends of the space formed by the space-forming sections 21A, thereby retaining the absorbent material in the space formed by the space-forming sections 21A and preventing leakage of the absorbent material. The widthwise direction of the intersections 20K is the same as the widthwise direction of the absorbent body 6.

[0043] 8 is a diagram showing the positions of strong adhesive portions 21K provided in the absorbent body 6. In this embodiment, a plurality of intersections 20K are provided spaced apart from one another in the longitudinal direction of the absorbent body 6, and it is preferable that the strong adhesive portions 21K are provided continuously in the longitudinal direction of the absorbent body 6. Even if the upper-layer core wrap sheet 7A is torn in the region corresponding to the intersection 20K and its surroundings, the strong adhesive portions 21K are provided continuously at both widthwise ends of the intersection 20K, so that the absorbent material can be prevented from leaking out in the width direction of the absorbent body 6.

[0044] In this way, the diaper 1 of this embodiment prevents the absorbent material from leaking out of the absorbent body 6 by providing a laminated section 7S in which more core wrap sheets 7 are laminated in areas where multiple compressed sections 20 are formed than in areas where compressed sections 20 are not formed.

[0045] Next, a manufacturing method of the diaper 1 according to this embodiment will be described with reference to FIG. 9. FIG. 9 is a flowchart illustrating the manufacturing method of the diaper 1 according to this embodiment. First, the absorbent material constituting the absorbent core 6C described above is deposited on a hollow cylindrical forming drum having a mold frame on its outer circumferential surface to form the absorbent core 6C (step S101, absorbent core forming step). In step S102 (transfer step) following step S101, the absorbent core 6C formed in step S101 (absorbent core forming step) is fed to the conveying path 12 and transferred onto a member below the absorbent core 6C in the diaper 1 traveling on the conveying path 12. In this embodiment, this lower member is the lower-layer core wrap sheet 7B. In step S103 (absorbent body forming step (an example of the "laminate portion forming step" in this application)) following step S102, an upper-layer core wrap sheet 7A is placed on the skin-facing side of the absorbent core 6C to form the laminate portion 7S. In step S104 (compressed portion forming step) after step S103, the region including the laminated portion 7S is compressed from the upper core wrap sheet 7A side of the absorbent body 6 formed in step S103 (absorbent body forming step) to form the compressed portion 20. In step S105 (top sheet placing step) after step S104, the top sheet 8 is placed on the upper side (skin facing side) of the absorbent body 6.

[0046] FIG. 10 shows the forming drum 18D used in the absorbent core forming step (step S101) and the transfer step (step S102). FIG. 10(A) is a perspective view of the forming drum 18D seen obliquely from above. FIG. 10(B) is an exploded perspective view of the mold. The mold is formed along the entire outer periphery of the forming drum 18D to form the absorbent core 6C. The mold has a forming plate 18F that forms the bottom of the mold, and a forming plate 18S that forms the side wall of the mold and has a roughly gourd-shaped side that is the same as the outer shape of the absorbent core 6C in the width direction. The mold is formed, for example, directly on the outer periphery of the forming drum 18D. Alternatively, it may be formed by attaching a forming plate 18F and a molding plate 18S that are configured to be detachable to a cylindrical framework.

[0047] The forming plate 18F is the bottom of the formwork formed on the forming drum 18D and is made of a porous material such as a metal mesh plate. Because the forming plate 18F is made of a porous material, the bottom of the formwork is breathable, and the negative pressure generated by the forming drum 18D can suck air outside the forming drum 18D into its interior through the formwork. For example, a suction fan can be driven to create negative pressure inside and suck in outside air.

[0048] With this configuration, the absorbent material is sucked toward the forming plate 18F side of the forming drum 18D together with the air that is sucked toward the inside of the forming drum 18D. Here, although the air is sucked into the forming drum 18D through the forming plate 18F, the absorbent material cannot pass through the porous member that makes up the forming plate 18F and ends up piling up on the forming plate 18F. The accumulated absorbent material is transported by the rotation of the forming drum 18D to a position opposite the transport path 12 provided at the lower end of the forming drum 18D.

[0049] Furthermore, the forming plate 18F may have protrusions 18A, 18B, and 18C that protrude from the outer peripheral surface of the forming drum 18D and are spaced apart in the width direction extending in the longitudinal direction of the forming plate 18F (the circumferential direction of the forming drum 18D). The protrusions 18A, 18B, and 18C can form low-bulk portions where the absorbent material is less likely to accumulate and where the bulk of the absorbent material is lower than the surrounding areas, or slits where the absorbent material is not placed on the protrusions 18A, 18B, and 18C.

[0050] In step S102 (transfer process) shown in Figure 9, the absorbent material deposited on the forming plate 18F is supplied to the conveying path 12 provided opposite the lower outer peripheral surface of the forming drum 18D, and transferred onto the lower core wrap sheet 7B flowing on the conveying path 12.

[0051] In step S103 (absorbent body forming step), the upper core wrap sheet 7A is placed on the absorbent material on the side opposite to the side to which the lower core wrap sheet 7B was transferred in the transfer step (step S102), and then the lower core wrap sheet 7B is used to cover the side of the absorbent core 6C and the widthwise outer side of the upper core wrap sheet 7A to form a laminated section 7S. At this time, the upper core wrap sheet 7A and the lower core wrap sheet 7B are bonded to each other with an adhesive such as a hot melt adhesive, while providing the above-mentioned space-forming sections 21A between the upper core wrap sheet 7A and the lower core wrap sheet 7B in the laminated section 7S and strong adhesive sections 21K at both widthwise ends of the intersections 20K provided in the laminated section 7S. This results in the absorbent core 6C being covered on the skin-facing side, non-skin-facing side, and side sides with the core wrap sheets 7.

[0052] In step S104 (compressed portion forming step), the upper core wrap sheet 7A is compressed by a compressing portion provided in the diaper manufacturing apparatus to form compressed portions 20.

[0053] FIG. 11 is a diagram illustrating the compressing unit 11 used in the compressing unit forming step (step S104). FIG. 11(A) is a perspective view of the appearance of the compressing unit 11. The compressing unit 11 has a pair of rollers 11A and 11B, which rotate relative to each other with their cylindrical outer circumferential surfaces pressed against each other. The rollers 11A and 11B are made of, for example, metal. The compressing unit 11 presses the projections 11T, which are regularly arranged on the cylindrical outer circumferential surface of the upper roller 11A, against the smooth cylindrical outer circumferential surface of the lower roller 11B with a desired pressure. This compresses the absorbent body 6 on the conveying path 12.

[0054] The compressing unit 11 feeds the absorbent body 6 sandwiched between the rollers 11A and 11B in the direction of relative rotation, and compresses and bonds the absorbent body 6 at a plurality of compressing points corresponding to the positions of the protrusions 11T. The protrusions 11T formed on the cylindrical outer peripheral surface of roller 11A may be formed on the cylindrical outer peripheral surface of roller 11B as well, or may be formed on the cylindrical outer peripheral surfaces of both of these rollers, and further, they are not limited to being convex, but may be formed in a concave shape so that, for example, a continuous rib shape is pressed against the opposing cylindrical surface for compression bonding.

[0055] The protrusion 11T has a first extended protrusion 11TA extending in one direction and a second extended protrusion 11TB intersecting the first extended protrusion 11TA and extending in another direction. In this embodiment, the protrusion 11T has the first extended protrusions 11TA and the second extended protrusions 11TB intersecting each other so as to form a lattice pattern.

[0056] The absorbent body 6 has grooves 20B formed on the upper core wrap sheet 7A side of the absorbent body 6, corresponding to the first extending protrusions 11TA and the second extending protrusions 11TB provided on the roller 11A, the grooves 20B intersecting the grooves 20A extending in one direction and extending in the other direction. Note that before or after the grooves 20A and 20B are formed, the entire absorbent body 6 may be pressed to press the components within the absorbent body 6 together.

[0057] In this embodiment, the protrusions 11T are formed in a grid pattern by the first extending protrusions 11TA and the second extending protrusions 11TB as shown in Fig. 11(B), but the shape is not limited to a grid pattern as long as the protrusions 11T intersect with each other. For example, as shown in Fig. 11(C), protrusions extending in three directions may be formed so as to intersect with each other.

[0058] In step S105 (top sheet placement step) shown in Figure 9, the top sheet 8 supplied from the top sheet supply unit 16 is placed on the compression unit 20. By placing the top sheet 8 after the compression unit 20 is formed, the load caused by compression is not applied to the top sheet 8, and therefore, even if the upper-layer core wrap sheet 7A is torn, the absorbent material is prevented from leaking outward from the top sheet 8.

[0059] Here, it is preferable that the top sheet 8 and the core wrap sheet 7, which is arranged on the non-skin-facing side of the top sheet 8, are intermittently bonded. The core wrap sheet 7 is pulled and stretched when compressed. By placing the top sheet 8 along the stretched core wrap sheet 7, the space-forming section 21A peels off from the absorbent core 6C side and rises to the top sheet 8 side, forming a space between the top sheet 8 and the compressed section 20. Because the compressed section 20 is compressed, it is harder than the uncompressed area and feels uncomfortable against the skin. Therefore, when a space is formed between the top sheet 8 and the compressed section 20, the compressed section 20, which feels uncomfortable against the skin, is prevented from directly contacting the wearer's skin. Furthermore, the top sheet 8 becomes slidable relative to the core wrap sheet 7, making it less likely that the wearer will feel the hardness of the compressed section 20, improving the feel against the skin.

[0060] Next, the manufacturing apparatus for the diaper 1 according to this embodiment will be described with reference to Fig. 12. Fig. 12 is a schematic diagram showing a part of the configuration of the manufacturing apparatus for the diaper 1 according to this embodiment. The up-down direction of the manufacturing apparatus refers to the direction of gravity.

[0061] The manufacturing apparatus for diaper 1 includes a lower core wrap sheet supply section 13 that supplies a lower core wrap sheet 7B, an absorbent core manufacturing apparatus M having an absorbent core supply section 14, an upper core wrap sheet supply section 15 that supplies an upper core wrap sheet 7A, a compression section 11 that compresses the absorbent body 6, a top sheet supply section 16 that supplies a top sheet 8, and a conveying path 12 that stacks and conveys the components supplied from the supply sections for each component.

[0062] The lower core wrap sheet supply unit 13 supplies the lower core wrap sheet 7B from the lower core wrap sheet supply unit 13 to the conveying path 12 in region R1, which is the opposing region of the conveying path 12. The absorbent core manufacturing device M manufactures the absorbent core 6C and supplies the absorbent core 6C to the conveying path 12 in transfer region R2, which is the opposing region of the absorbent core supply unit 14 and the conveying path 12. The upper core wrap sheet supply unit 15 supplies the upper core wrap sheet 7A from the upper core wrap sheet supply unit 15 to the conveying path 12 in region R3, which is the opposing region of the conveying path 12. The top sheet supply unit 16 supplies the top sheet 8 from the top sheet supply unit 16 to the conveying path 12 in region R4, which is the opposing region of the conveying path 12.

[0063] The conveying path 12 is provided below the supply sections for each component, and conveys the components in the direction of arrow Y1 while stacking them. In this embodiment, the lower-layer core wrap sheet 7B, absorbent core 6C, upper-layer core wrap sheet 7A, and top sheet 8 are stacked on the conveying path 12 in this order. Therefore, the supply sections for each component that supply the components to the conveying path 12 are provided in the following order from upstream: lower-layer core wrap sheet supply section 13, absorbent core supply section 14, upper-layer core wrap sheet supply section 15, and top sheet supply section 16. In addition, the compressing section 11 is provided between the upper-layer core wrap sheet supply section 15 and the top sheet supply section 16 to compress the absorbent body 6.

[0064] The absorbent core manufacturing apparatus M has a forming drum 18D, an absorbent material supply section 17 that supplies absorbent material containing short fibers and SAP particles that constitute the absorbent core 6C to the forming drum 18D, and an absorbent core supply section 14 that deposits the absorbent material supplied from the absorbent material supply section 17 on the forming drum 18D and supplies the formed absorbent core 6C to the conveying path 12.

[0065] The forming drum 18D is provided so that its upper end is located below the absorbent material supply unit 17. The arc-shaped arrow Y2 in FIG. 12 indicates the rotation direction of the forming drum 18D. The forming drum 18D deposits the absorbent material supplied from the absorbent material supply unit 17 onto a forming plate 18F provided on the outer circumferential surface of the forming drum 18D. The deposited absorbent material is then sucked into the interior of the forming drum 18D. Thereafter, the rotation of the forming drum 18D transports the absorbent material to the absorbent core supply unit 14 located in the transfer region R2 opposite the conveying path 12, where the absorbent material is supplied to the conveying path 12 as an absorbent core 6C.

[0066] <Other embodiments> The present invention is applicable not only to tape-type diapers but also to pants-type diapers and absorbent pads.

[0067] The features included in each of the embodiments and modifications thereof disclosed above can be combined with each other. [Explanation of symbols]

[0068] 1. Diapers 1F: Front body area 1B...Inseam area 1R: Back area 2F Front patch 2L, 2R Tape 3LL, 3LR... Folded line 3BL,3BR··Leakage prevention wall 33L,33R・Fixed part 4. Cover sheet 4SL, 4SR, 9EL, 9ER... Elastic thread 5. Back seat 6. Absorber 6C··Absorbent Core 7. Core wrap sheet 7A··Upper layer core wrap sheet 7B··Lower layer core wrap sheet 7S...Laminated section 8. Top sheet 9L, 9R side seats 9LA,9RA·Fixed area 9LB,9RB··Free end 11. Compression section 11A, 11B Roller 12. Transport path 13. Lower layer core wrap sheet supply section 14. Absorbent core supply unit 15. Upper layer core wrap sheet supply section 16. Top sheet supply unit 17. Absorbent material supply section 18D forming drum 18F Forming Plate 18S··Molded Plate 20. Compression section 20K...intersection 20A,20B·Groove 21A·Space forming part 21K...strong adhesive part M··Absorbent core manufacturing equipment

Claims

1. a length along a longitudinal direction corresponding to the front-to-back direction of the wearer; a length along a width direction perpendicular to the longitudinal direction; Absorbent mat, a first water-permeable sheet disposed on the wearer's skin side of the absorbent mat; a laminated portion in which a plurality of the first water-permeable sheets are laminated on a portion of the skin-facing side of the absorbent mat; A compression section provided on the laminated section, Absorbent articles.

2. The compression sections are provided in plurality and intersect with each other, the number of the first water-permeable sheets stacked at the intersections of the compressed portions where the compressed portions intersect with each other is greater than the number of the first water-permeable sheets stacked at the areas other than the intersections; The absorbent article of claim 1.

3. At least one pair of adjacent first water-permeable sheets among the water-permeable sheets forming the laminated portion has a non-adhesive portion or a weakly adhesive portion between them. The absorbent article according to claim 1 or 2.

4. a second water-permeable sheet disposed on the wearer's skin side of the compressed portion; The absorbent article according to claim 1 or 2.

5. Among the plurality of first water-permeable sheets, the first water-permeable sheet and the second water-permeable sheet arranged on the skin side of the wearer are intermittently bonded to each other. The absorbent article of claim 4.

6. a pair of water-impermeable leak-proof sheets extending in the longitudinal direction on both sides of the second water-permeable sheet in the width direction; The leak-proof sheet is a joining portion at which one end of the outer side in the width direction is joined to the second water-permeable sheet; a free end portion that can stand up on the skin surface side at one end on the inner side in the width direction; an elastic member bonded to the free end portion so as to extend in a stretched state in the longitudinal direction; and a fixing portion connected to the second water-permeable sheet at the longitudinal end portion. The absorbent article of claim 4.

7. A method for manufacturing an absorbent article comprising: an absorbent mat; a first water-permeable sheet disposed on a wearer's skin-facing side of the absorbent mat; a laminated portion in which a plurality of the first water-permeable sheets are laminated on a part of the skin-facing side of the absorbent mat; and compressed grooves provided in the laminated portion, a laminated portion forming step of laminating the first water-permeable sheet on the absorbent mat to form the laminated portion; A compressed portion forming step of compressing the skin side of the laminate to form a compressed portion, A method for manufacturing an absorbent article.

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