JP7686909B2 - Absorbent articles - Google Patents

Description

The present invention relates to an absorbent article.

Many absorbent articles such as sanitary napkins, panty liners, and incontinence pads have grooves on the skin side to guide excreted bodily fluids and encourage the body to deform in accordance with the wearer's movements.

For example, Patent Document 1 describes an absorbent article in which a main body compression groove is provided on the surface sheet side of the main body. The document describes that the main body compression groove has an intermediate groove portion and front and rear groove portions, and each groove portion includes high-pressure compression portions that are arranged spaced apart from each other in the extension direction of each groove portion, and low-pressure compression portions interposed between the high-pressure compression portions.

JP 2021-41042 A

The compressed grooves as described in Patent Document 1 are formed using an embossing roll having a low compression section forming convex portion provided on the outer circumferential surface and a high compression section forming convex portion protruding further from the low compression section forming convex portion. For example, a laminate including a top sheet and an absorbent body is formed by pressing between a roll pair consisting of the embossing roll and a flat roll having a flat outer circumferential surface (paragraph 0030 of Patent Document 1, etc.). The roll pair is usually arranged so that its axial direction corresponds to the left-right direction of the absorbent article, and the compressed grooves are formed along the longitudinal direction. Conventionally, the high compression portions provided in each of a pair of left and right grooves such as the front and rear groove portions described in Patent Document 1 are formed at the same position in the longitudinal direction. In that case, in the process of forming the compressed grooves, a period in which the left high compression portion and the right high compression portion are simultaneously formed and a period in which the high compression portion is not formed are alternately repeated along the longitudinal direction. And, since the pressure received by the absorbent article differs when the high compression portion is formed and when the high compression portion is not formed, pressure fluctuations are repeated during the process of forming the grooves. If such pressure fluctuations are large, depending on the conditions for forming the grooves (roll pressure, conveying speed, rigidity of the absorbent before squeezing, etc.), the behavior of the roll pair may become unstable, making it impossible to form the high-pressure squeezed portion to the desired depth, or causing unevenness in the squeezing depth.

In view of the above, one aspect of the present invention aims to more reliably form high-pressure compression sections in an absorbent article in which spaced apart high-pressure compression sections are formed in a pair of left and right grooves provided on the skin side.

The first aspect of the present invention is an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body provided between the top sheet and the back sheet, and having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction, wherein grooves are formed recessed from the top sheet toward the back sheet, the grooves including a central groove extending in the longitudinal direction, and a left diagonal groove and a right diagonal groove formed in an area on the longitudinal end side from the central groove such that the distance between them increases the further away from the central groove, and within the left diagonal groove, a plurality of left high compression portions are formed spaced apart in the extension direction of the left diagonal groove, and within the right diagonal groove, a plurality of right high compression portions are formed spaced apart in the extension direction of the right diagonal groove, and when the left high compression portion and the right high compression portion are projected onto a straight line parallel to the longitudinal direction, the projected range of the left high compression portion and the projected range of the right high compression portion are at least partially staggered.

According to the first aspect, a pair of diagonal grooves (left and right diagonal grooves) are formed in the region on the longitudinal end side of the central groove, which promotes three-dimensional deformation of the absorbent article to fit the shape of the body. More specifically, the absorbent article bends around the pair of diagonal grooves as a base axis, making it easy to abut the region between the pair of left and right diagonal grooves along the front and/or rear surfaces of the body. In addition, the pair of left and right diagonal grooves are reinforced by the provision of high-pressure compression portions, which allows the left and right diagonal grooves to function better as base axes for deformation when worn, and the high-pressure compression portions are spaced apart so that the bottom and periphery of the grooves do not become excessively hard, allowing the article to naturally curve in the longitudinal direction D1 as necessary.

In addition, in this embodiment, when the left high compression portion and the right high compression portion are projected onto a straight line parallel to the longitudinal direction, the projection range of the left high compression portion and the projection range of the right high compression portion are at least partially staggered. This prevents large fluctuations in pressure during the groove formation process, and allows the device to operate more stably. Therefore, the high compression portions can be accurately formed in the desired arrangement and with the desired compression depth along the longitudinal direction. This ensures the function of the left diagonal groove and the right diagonal groove, making it easier for the absorbent article to deform to fit the shape of the body.

In a second aspect of the present invention, the distance between the projection range of the left high compression section and the projection range of the right high compression section adjacent to the projection range of the left high compression section in the longitudinal direction is zero, or the two projection ranges overlap.

According to the second aspect, there is no period during which neither the left high compression section nor the right high compression section is formed between the projection range of the left high compression section and the projection range of the right high compression section adjacent to the projection range of the left high compression section, so that pressure fluctuations in the compression groove formation process can be further suppressed and stable compression behavior of the device can be maintained. Therefore, the high compression sections can be formed in the desired arrangement and depth throughout the entire groove, and the function of the left diagonal groove and the right diagonal groove can be improved.

In a third aspect of the present invention, the distance between the left high compression portions is constant along the extension direction of the left diagonal groove, and/or the distance between the right high compression portions is constant along the extension direction of the right diagonal groove.

According to the third aspect, the spacing between the high-pressure compression parts is constant along the extension direction of the diagonal groove, so that the diagonal groove is uniformly reinforced by the high-pressure compression parts along the entire extension direction, enhancing the effect of promoting three-dimensional deformation of the front and/or rear of the absorbent article.

In the fourth aspect of the present invention, the left high compression portion in the left diagonal groove that is the furthest from the central groove and the right high compression portion in the right diagonal groove that is the furthest from the central groove are aligned in the longitudinal direction.

According to the fourth aspect, the rigidity of the tips (ends farther from the central groove) of the left and right diagonal grooves can be made symmetrical. This increases the symmetry of the left and right diagonal grooves' functions, and therefore increases the symmetry of deformation of the absorbent article, improving leakage prevention and fit.

In the fifth aspect of the present invention, a plurality of first highly compressed portions are formed in the central groove, spaced apart in the longitudinal direction along a first imaginary wavy line extending in the longitudinal direction, and a plurality of second highly compressed portions are formed in the central groove, spaced apart in the longitudinal direction along a second imaginary wavy line extending in the longitudinal direction and intersecting the first imaginary wavy line, and when the first highly compressed portions and the second highly compressed portions are projected onto a straight line parallel to the longitudinal direction, the projected ranges of the first highly compressed portions and the projected ranges of the second highly compressed portions are positioned alternately.

According to the fifth aspect, by forming high-pressure compression sections in a predetermined arrangement also in the central groove, large fluctuations in the pressure received by the absorbent article can be suppressed even when the central groove is formed, so stable operation of the roll pair can be maintained and high-pressure compression sections can be accurately formed throughout the diagonal grooves and the central groove. This improves the function of the central groove, particularly in promoting deformation of the absorbent article when worn. In addition, because the high-pressure compression sections in the central groove are discontinuous in the longitudinal direction, the central groove portion does not become excessively hard, and it becomes easier to curve the absorbent article to follow the curvature of the body in the front-to-back direction when worn.

In a sixth aspect of the present invention, a method for manufacturing an absorbent article is provided with a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body provided between the top sheet and the back sheet, the method having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction, and grooves recessed from the top sheet toward the back sheet, the method comprising forming a central groove extending in the longitudinal direction, forming left and right oblique grooves in an area on the longitudinal end side from the central groove such that the distance between the left and right oblique grooves increases the further away from the central groove, forming a plurality of left high compression portions in the left oblique groove so as to be spaced apart in the extension direction of the left oblique groove, forming a plurality of right high compression portions in the right oblique groove so as to be spaced apart in the extension direction of the right oblique groove, and when the left high compression portion and the right high compression portion are projected onto a straight line parallel to the longitudinal direction, the projected range of the left high compression portion and the projected range of the right high compression portion are at least partially staggered.

According to the sixth aspect, a method for manufacturing an absorbent article can be provided that achieves the same effect as the first aspect.

In view of the above, one aspect of the present invention makes it possible to more reliably form the high-pressure compression portions in an absorbent article in which spaced apart high-pressure compression portions are formed in a pair of left and right grooves provided on the skin side.

FIG. 1 is a plan view of an absorbent article according to one embodiment. 2 is a cross-sectional view taken along line II in FIG. 1. 2 is a cross-sectional view taken along line II-II of FIG. 1. FIG. 4 is an enlarged view of a portion including a left oblique groove and a right oblique groove. 11 shows left and right oblique grooves according to a modified example. 13 shows left and right oblique grooves according to another modified example. 13 shows left and right oblique grooves according to yet another modified example.

The following describes an embodiment of the present invention with reference to the drawings. In each drawing, unless otherwise specified, the same or corresponding configurations may be denoted by the same reference numerals and the description may be omitted.

<Basic structure of absorbent article>
FIG. 1 shows a plan view of an absorbent article 1 according to an embodiment. FIG. 2 shows a cross-sectional view taken along line II of FIG. 1, and FIG. 3 shows a cross-sectional view taken along line II-II of FIG. 1. As shown in FIGS. 1 to 3, the absorbent article 1 includes a liquid-permeable top sheet 3, a liquid-impermeable back sheet 2, and an absorbent body 4 disposed between the two sheets, and has a generally flat shape as a whole before being worn (FIGS. 2 and 3). When the absorbent article 1 is worn, the top sheet 3 side is the side that comes into contact with the skin (skin side or front side), and the back sheet 2 side is the side that is fixed to an underwear (underwear side or back side). FIG. 1 shows the absorbent article 1 as viewed from the skin side.

The absorbent article 1 has an elongated shape in a plan view, and has a longitudinal direction (front-rear direction) D1 and a lateral direction (width direction or left-right direction) D2 perpendicular to the longitudinal direction D1. When the absorbent article 1 is worn, the longitudinal direction D1 corresponds to the front-rear direction of the wearer's body, and the lateral direction D2 corresponds to the left-right direction of the wearer's body. In the form shown in FIG. 1, the absorbent article 1 has a shape that is approximately line-symmetrical with respect to a center line (a center line that divides the absorbent article 1 in the lateral direction D2, or a longitudinal center line) CL extending along the longitudinal direction D1 in a plan view, but the shape does not have to be line-symmetrical. In addition, the configuration other than the shape of the absorbent article 1 (including the density, material, and size of the compressed portion of the absorbent body 4) may also be approximately symmetrical or asymmetrical with respect to the center line CL as an axis of symmetry.

The back sheet 2 may be a sheet that is at least water-proof, and may be, for example, a sheet made of an olefin resin such as polyethylene or polypropylene. Alternatively, a laminated nonwoven fabric in which a nonwoven fabric is laminated on a polyethylene sheet or the like, or a laminated sheet of nonwoven fabric in which a waterproof film is interposed to ensure substantial liquid impermeability, may be used. From the viewpoint of preventing stuffiness, it is more preferable to use a sheet that has moisture permeability. As such a water-proof/moisture-permeable sheet material, a microporous sheet obtained by melt-kneading an inorganic filler in an olefin resin such as polyethylene or polypropylene to form a sheet and then stretching the sheet in a uniaxial or biaxial direction may be used.

The top sheet 3 can be a sheet that is permeable to bodily fluids such as urine, menstrual blood, and vaginal discharge. As the top sheet 3, a nonwoven fabric with or without holes, a porous plastic sheet, or the like is preferably used. As the material fiber constituting the nonwoven fabric, for example, olefins such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cupra, and blended fibers thereof, and natural fibers such as cotton can be used alone or in combination of two or more kinds. In addition, examples of processing methods for nonwoven fabric include the spunlace method, the spunbond method, the thermal bond method, the meltblown method, and the needle punch method. Among these processing methods, the spunlace method is preferred in that it can produce a nonwoven fabric that is flexible, and the spunbond method is preferred in that it can produce a nonwoven fabric that is rich in drapeability, and the thermal bond method is preferred in that it can produce a nonwoven fabric that is bulky and soft. In addition, composite fibers such as core-sheath type fibers, side-by-side type fibers, and split type fibers, which have a fiber with a high melting point as the core and a fiber with a low melting point as the sheath, can also be used.

The absorbent body 4 is not limited to any material that can absorb and retain bodily fluids, but preferably contains cotton-like pulp and a water-absorbing polymer. As the water-absorbing polymer, superabsorbent polymer granular powder (superabsorbent polymer (SAP)), superabsorbent polymer fiber (superabsorbent fiber (SAF)), and combinations thereof can be used. As the pulp, chemical pulp obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate can be used. As the raw material for chemical pulp, broadleaf wood and softwood are used, but softwood is preferably used because of its long fiber length.

Synthetic fibers may be mixed into the absorbent 4. Examples of synthetic fibers that can be used include polyolefins such as polyethylene and polypropylene, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamides such as nylon, and copolymers of these. Two of these can also be mixed and used. Composite fibers such as core-sheath fibers with a high melting point fiber as the core and a low melting point fiber as the sheath, side-by-side fibers, and split fibers can also be used. Hydrophobic fibers can also be surface-treated with a hydrophilizing agent to give them affinity for body fluids. The absorbent 4 is preferably manufactured by stacking or air-laid methods.

The absorbent body 4 may be a body portion wrapped in an envelope sheet made of crepe paper, nonwoven fabric, or the like. By providing the absorbent body 4 with an envelope sheet, it is possible to prevent the absorbent body 4 from twisting or cracking and to maintain its shape. The envelope sheet may be uncolored (i.e., white) crepe paper or nonwoven fabric, or it may be colored (for example, colored in a similar color to the color of the body fluid or a color complementary to the color of the body fluid).

The absorbent body 4 may have a planar shape, as shown in FIG. 1, that is elongated and has a substantially constant width, but the width of the absorbent body 4 may vary along the longitudinal direction D1. The absorbent body 4 may have a uniform thickness over the entire surface, but the thickness of the absorbent body 4 does not have to be uniform, and may be locally thinner or thicker.

At both ends of the absorbent body 4 in the longitudinal direction D1, the edge of the back sheet 2 and the edge of the top sheet 3 may be joined by adhesive, heat sealing, or the like (shown by hatching in FIG. 1). In addition, a pair of side sheets 7, 7 may be arranged on the front side (top sheet 3 side) of both sides of the absorbent article 1, i.e., on both sides in the lateral direction D2, along the longitudinal direction D1.

The side sheet 7 may be made of a nonwoven material that has been treated for water repellency or hydrophilicity depending on the purpose of preventing penetration of bodily fluids or improving the texture. The material of the side sheet 7 may be natural fibers, synthetic fibers, regenerated fibers, etc. In addition, when the side sheet 7 is treated for water repellency, a silicone-based, paraffin-based, or other water repellent agent may be used for the treatment. The absorbent article may have a configuration in which the top sheet 3 extends to the end of the absorbent article 1 in the lateral direction D2 and is joined to the back sheet 2 without using the side sheet 7. The side sheet 7 may be made into two layers by folding back on each side or by stacking a separate side sheet on top of each other, and a stretchable member such as thread rubber may be arranged between the two layers so as to extend along the longitudinal direction in a stretched state and fixed intermittently to form a standing gather portion. For example, by fixing the gather sheet 7 at the inner or outer end in the width direction D2, the outer or inner end of the rising gathers on both sides can rise up toward the skin when the stretch of the elastic member is relaxed.

The absorbent article 1 has an intermediate region M that mainly corresponds to the wearer's crotch when worn, a front region F that is adjacent to the intermediate region M at the front and extends to the front end of the absorbent article 1, and a rear region R that is adjacent to the rear of the intermediate region M and extends to the front end of the absorbent article 1. The intermediate region M includes a body fluid discharge port facing region Q. The body fluid discharge port facing region Q is a region that faces the body fluid discharge port of the wearer when worn, such as the urethral opening or vaginal opening, and its center is located on the longitudinal centerline CL. In the example shown in FIG. 1, the body fluid discharge port facing region Q is drawn in an elliptical shape as a region corresponding to the urethral opening, but the size and shape of the body fluid discharge port facing region Q shown in the figure are merely examples for explaining the absorbent article according to this embodiment.

When the absorbent article is individually packaged, the front region F and the rear region R can be folded back toward the skin in the longitudinal direction D1. In the example of FIG. 1, the front region F can be folded back along a fold line along the boundary line between the front region F and the middle region M, and the rear region R can be folded back along a fold line along the boundary line between the rear region R and the middle region M. Either the front region F or the rear region R can be folded back first. By folding in this way, the absorbent article 1 can be folded in thirds or more.

The overall length (total length) of the absorbent article 1 in the longitudinal direction D1 may be preferably 170 to 360 mm, and more preferably 200 to 270 mm. The length of the absorbent article 1 in the lateral direction D2 (the width of the body excluding the wing portions if wings are provided) may be preferably 50 to 150 mm, and more preferably 70 to 120 mm. The width of the absorbent body 4 sandwiched between the top sheet 3 and the back sheet 2 may be 50 to 100 mm. Furthermore, the overall thickness of the absorbent article 1 may be preferably 1 to 30 mm, and more preferably 2 to 15 mm.

The absorbent article 1 shown in Figures 1 to 3 does not have wings, but the absorbent article 1 may have a pair of wings extending laterally from both side edges of the middle region M. The wings can be formed by joining the extending portions of the side sheets 7 and the extending portions of the back sheet 2.

A slip prevention part may be formed on the back sheet 2 side of the absorbent article 1 to reliably fix the absorbent article 1 to the underwear when worn and prevent the absorbent article 1 from slipping (not shown). The slip prevention part is preferably an adhesive slip prevention part. The adhesive slip prevention part is formed, for example, by applying a liquid adhesive or by applying a preformed adhesive layer (adhesive tape, etc.). The adhesive used as the slip prevention part may be a known adhesive, for example a hot melt type adhesive. The main components include a styrene polymer, a tackifier, and a plasticizer, and combinations of these.

<Groove on the skin side>
The skin side of the absorbent article 1 is provided with grooves that are recessed from the skin side to the non-skin side (i.e., recessed from the top sheet 3 toward the back sheet 2). In the example shown in Fig. 1, the grooves include a central groove 11, a pair of diagonal grooves 12Lf, 12Rf formed in front of the central groove 11, and a pair of diagonal grooves 12Lr, 12Rr formed behind the central groove 11, but any one of the front pair of diagonal grooves 12Lf, 12Rf and the rear pair of diagonal grooves 12Lr, 12Rr may be omitted.

The grooves are preferably compressed grooves formed by compression. Compressed grooves can be formed by pressing a laminate including at least the top sheet and absorbent body between a pair of rolls: an embossing roll having convex portions on its outer circumferential surface corresponding to the shape of the compressed grooves, and a flat roll having a flat outer circumferential surface. When the bottom of the groove has a high-pressure compressed portion, the outer circumferential surface of the embossing roll may have a convex portion for forming a low-pressure compressed portion corresponding to the low-pressure compressed portion, which is a portion other than the high-pressure compressed portion, and a convex portion for forming a high-pressure compressed portion that protrudes further than the convex portion for forming the low-pressure compressed portion. The area on the skin side of the absorbent article 1 where no compressed grooves are formed is shown as a non-compressed portion 14.

<Central groove>
The central groove 11 is a groove formed along the longitudinal direction D1 at the center of the lateral direction D2 of the absorbent article 1. Since the central groove 11 is a groove recessed from the top sheet 3 side to the back sheet 2 side, when the absorbent article 1 receives force from both sides in the lateral direction D2 during wearing, the central part in the lateral direction D2 is easily deformed so as to protrude toward the back sheet 2 side (non-skin side). Body fluids can be at least temporarily stored in the depression on the skin side formed by the protrusion. Furthermore, when the central groove 11 is formed by compression, the area of the central groove 11 has a higher density than the uncompressed areas surrounding the central groove 11, so that body fluids are easily retained in the central groove 11.

The central groove 11 extends along the longitudinal direction D1, and therefore not only receives and temporarily stores bodily fluids as described above, but also has the function of guiding the bodily fluids in the longitudinal direction D1. In particular, when the central groove 11 is formed by compression, the density of the area in which the central groove 11 is formed is greater than the density of the uncompressed areas on either side of it in the lateral direction D2, making it easier to guide the bodily fluids in the longitudinal direction D1 than in the lateral direction D2. By guiding the bodily fluids along the longitudinal direction D1, leakage of the bodily fluids in the lateral direction D2 can be prevented.

The central groove 11 is formed so as to overlap the bodily fluid discharge outlet facing region Q at the center in the lateral direction D2, preferably so as to overlap the longitudinal centerline CL of the absorbent article 1. In the illustrated example, the centerline extending along the longitudinal direction D1 of the central groove 11 (the line passing through the center of the width of the central groove 11) coincides with the longitudinal centerline CL of the absorbent article 1.

The central groove 11 is preferably formed to include the middle region M of the absorbent article 1, and more preferably formed to include the bodily fluid discharge port facing region Q in the longitudinal direction D1. The central groove 11 is also preferably formed within the middle region M. This makes it easier to fit the front region F and rear region R of the absorbent article 1 along the curves of the front and rear surfaces of the body.

The length of the central groove 11 in the longitudinal direction D1 (the length from the front end 11f to the rear end 11r) is preferably 50 to 160 mm, and more preferably 55 to 80 mm. By setting the length within the above range, bodily fluids can be sufficiently guided along the longitudinal direction D1, and grooves can be avoided from being formed near the center of the width direction D2 of the front region F and rear region R, making it easier for the front region F and rear region R to fit the front and rear surfaces of the wearer's body better.

The length (width) of the central groove 11 in the horizontal direction D2 is preferably 3 to 15 mm, and more preferably 4 to 8 mm. By setting the length (width) within the above range, even a large amount of body fluid can be easily stored in the central groove 11, and even if the central groove 11 is slightly deformed due to the application of strong forces from both sides in the horizontal direction D2, the shape and function of the central groove 11 as a groove can be maintained.

<Diagonal groove>
In this embodiment, a pair of diagonal grooves (left diagonal groove and right diagonal groove) is formed on the end side in the longitudinal direction D1 from the central groove 11. More specifically, a pair of left diagonal groove 12Lf and right diagonal groove 12Rf is formed in front of the central groove 11, and/or a pair of left diagonal groove 12Lr and right diagonal groove 12Rr is formed behind the central groove 11. The pair of diagonal grooves extends from the end of the longitudinal direction D1 of the central groove 11 outward in the longitudinal direction D1 (toward the end of the longitudinal direction D1 of the absorbent article 101), and is formed so that the distance between them increases as they move away from the central groove 11. For example, the front left diagonal groove 12Lf and right diagonal groove 12Rf are formed so that the distance between them increases as they move forward. It is preferable that the pair of left and right diagonal grooves are symmetrical with respect to the longitudinal center line CL.

The formation of paired left and right oblique grooves in front and/or behind the central groove 11 can promote three-dimensional deformation of the absorbent article to fit the shape of the wearer's body. For example, the left and right oblique grooves 12Lf and 12Rf in the front become wider as the area between the left and right oblique grooves 12Lf and 12Rf becomes wider toward the front, so that the absorbent article can be made to conform to the curved surface extending from left to right near the pubic bone in the front of the body. The left and right oblique grooves 12Lf and 12Rf in the front become narrower as they approach the central groove 11, and gradually approach the central groove 11 in the lateral direction D2, so that the paired left and right oblique grooves 12Lf and 12Rf naturally continue to the central groove 11, facilitating deformation from the front region F to the middle region M. The left and right oblique grooves 12Lr and 12Rr in the rear have the same effect. In the case of the rear left diagonal groove 12Lr and right diagonal groove 12Rr, the area between the left diagonal groove 12Lr and the right diagonal groove 12Rr can be aligned to the curve of the wearer's buttocks.

In the illustrated example, the left and right diagonal grooves 12Lf and 12Rf formed forward of the central groove 11 each extend continuously from the front end 11f of the central groove 11, but they do not necessarily have to be continuous. However, if the central groove 11 is continuous with the left and right diagonal grooves 12Lf and 12Rf, a more clearly Y-shaped groove can be formed by the combination of grooves, and the absorbent article 1 can be deformed using this Y-shaped groove as the base axis (base axis for folding) to more easily achieve three-dimensional deformation that fits the shape of the wearer's body. The same is true for the left and right diagonal grooves 12Lr and 12Rr formed rearward of the central groove 11.

The groove width of each diagonal groove may be 1 to 4 mm. Furthermore, the length of the diagonal groove in the longitudinal direction D1 may be 30 to 60% of the length of the central groove 11 in the longitudinal direction D1.

<High pressure compression section>
In this embodiment, at least in the diagonal groove, a high compression portion is formed which is a portion compressed deeper than the bottom surface of the groove. The high compression portion is shown in black in the drawing. When the diagonal groove is formed by compression, the bottom surface of the diagonal groove becomes a low compression portion. The low compression portion is a portion recessed by 1 to 10 mm, preferably 2 to 5 mm, from the non-compressed region (non-compressed portion 14), and the high compression portion may be a portion compressed 0.2 to 1 mm deeper than the low compression portion in the diagonal groove. In the following, the pair of diagonal grooves (left diagonal groove 12Lf and right diagonal groove 12Rf) in front of the central groove 11 will be mainly described, but the configuration and effect of the pair of diagonal grooves (left diagonal groove 12Lr and right diagonal groove 12Rr) behind the central groove 11 are also similar.

4 shows an enlarged view of the portion of the absorbent article 1 in FIG. 1 from the front diagonal grooves (left diagonal groove 12Lf and right diagonal groove 12Rf) to the central groove 11. As shown in FIG. 4, in a plan view, a plurality of left high compression portions 25Lf, 25Lf, ... are formed in the left diagonal groove 12Lf, which are spaced apart in the extension direction or longitudinal direction D1 of the left diagonal groove 12Lf, and a plurality of right high compression portions 25Rf, 25Rf, ... are formed in the right diagonal groove 12Rf, which are spaced apart in the extension direction or longitudinal direction D1 of the right diagonal groove 12Rf. The formation of the high compression portions in the diagonal grooves reinforces the grooves, and when the absorbent article 1 is deformed when worn, the left diagonal groove 12Lf and the right diagonal groove 12Rr can function well as a base axis for deformation. In addition, the high-pressure compression portions are formed discontinuously within the diagonal groove, i.e., spaced apart along the extension direction of the diagonal groove, so that the groove portion does not become excessively hard, ensuring flexibility, and allowing the front region F to naturally curve in the longitudinal direction D1.

The left diagonal groove 12Lf with the left high compression portions 25Lf, 25Lf, ... and the diagonal groove 12Rf with the right high compression portions 25Rf, 25Rf, ... can be formed by a roll pair of an embossing roll and a flat roll as described above. It is preferable that the roll pair is arranged so that its axial direction corresponds to the lateral direction (left-right direction) D2 of the absorbent article 1, and the absorbent article 1 is transported in the longitudinal direction D1. In that case, the left diagonal groove 12Lf and the right diagonal groove 12Rf are formed along the longitudinal direction D1.

Furthermore, in this embodiment, when the left high compression portion and the right high compression portion are projected onto a straight line parallel to the longitudinal direction D1, the projection range of the left high compression portion and the projection range of the right high compression portion are at least partially staggered. For example, as shown in FIG. 4, the projection range 26Lf, 26Lf, ... of the left high compression portion 25Lf, 25Lf, ... projected onto the longitudinal center line CL and the projection range 26Rf, 26Rf, ... of the right high compression portion 25Rf projected onto the longitudinal center line CL are staggered. Therefore, in the groove formation process along the longitudinal direction D1, large fluctuations in pressure, for example, fluctuations that may occur when a period in which the left high compression portion 25Lf and the right high compression portion 25Rf are formed simultaneously and a period in which the high compression portion is not formed are repeated, are suppressed. Therefore, stable operation of the device (roll pair) can be maintained even under various groove formation conditions (roll pressure, conveying speed, rigidity of the absorbent before compression, etc.). This allows the high compression portions 25Lf, 25Lf, ... and 25Rf, 25Rf, ... to be accurately formed in the desired arrangement and with the desired compression depth along the longitudinal direction D1. By forming the high compression portions in the desired arrangement and depth, the left diagonal groove 12Lf and the right diagonal groove 12Rf function more reliably, and the absorbent article 1 can more easily deform to conform to the shape of the body, preventing leakage and improving the fit.

In the example shown in FIG. 4, for all the left high compression portions 25Lf, 25Lf, ... and the right high compression portions 25Rf, 25Rf, ..., the projection ranges 26Lf, 26Lf, ... and the projection ranges 26Rf, 26Rf, ... are staggered. However, in this embodiment, it is sufficient that the projection ranges 26Lf, 26Lf, ... and the projection ranges 26Rf, 26Rf, ... are staggered in at least a portion of the entire diagonal groove. For example, in the left diagonal groove 12Lf and the right diagonal groove 12Rf, the number of high compression portions in which the projection ranges 26Lf, 26Lf, ... and the projection ranges 26Rf, 26Rf, ... are staggered may be 80% or more, preferably 90% or more, of the total number of high compression portions.

In addition, in a configuration in which the projection ranges 26Lf, 26Lf, ... and the projection ranges 26Lf, 26Lf, ... are staggered, the pressing force of the roll pair is less likely to be dispersed to the left and right when the high-pressure compression section is formed. Therefore, compared to a configuration in which the left high-pressure compression section and the right high-pressure compression section are formed at the same position in the longitudinal direction D1, the linear pressure for forming the high-pressure compression section is higher, and each high-pressure compression section can be clearly formed.

The distance between the projection range 26Lf of the left high compression portion 25Lf and the projection range 26Rf of the right high compression portion 25Rf is preferably zero or the projection ranges 26Lf, 26Rf overlap. In other words, it is preferable that the projection range 26Lf of the left high compression portion 25Lf and the projection range 26Rf of the right high compression portion 25Rf are not separated from each other. This eliminates a period during which the high compression portions are not formed in the process of forming the left diagonal groove 12Lf and the right diagonal groove 12Rf, so that the pressure received by the absorbent article 1 becomes more uniform in the longitudinal direction D1, and the high compression portions 25Lf, 25Lf, ... and 25Rf, 25Rf, ... can be formed stably and reliably.

The left high compression portions 25Lf, 25Lf, ... may be arranged at equal intervals along the extension direction of the left diagonal groove 12Lf, and similarly, the right high compression portions 25Rf, 25Rf, ... may be arranged at equal intervals along the extension direction of the right diagonal groove 12Rf. In the example shown in FIG. 4, the distance d2 between the right high compression portions 25Rf, 25Rf along the center line (partial arc-shaped curve) L of the groove width of the right diagonal groove 12Rf is equal throughout the right diagonal groove 12Rf. The same is true for the distance between the left high compression portions 25Lf, 25Lf. As a result, the diagonal grooves 12Lf, 12Rf can obtain a reinforcing effect of the high compression portions over the entire extension direction of the diagonal grooves, and the flexibility of the diagonal grooves can be ensured over the entire extension direction. d2 may be 1.5 to 2.5 mm, preferably 2.0 to 2.3 mm.

When the high-pressure compression portions are arranged at equal intervals along the extension direction of the diagonal groove, the intervals between the high-pressure compression portions along the longitudinal direction D1 are not necessarily uniform along the longitudinal direction D1. This is because the diagonal groove curves outward in the lateral direction D2 toward the end of the longitudinal direction D1. For example, the right diagonal groove 12Rf curves outward in the lateral direction D2 toward the front in a plan view, so the interval d1 between the right high-pressure compression portions 25Rf, 25Rf along the longitudinal direction D1 is not uniform along the entire right diagonal groove 12Rf, but becomes smaller toward the front. In this case, the projection range 26Lf of the left high-pressure compression portion 25Lf and the projection range 26Rf of the right high-pressure compression portion 25Rf are in contact with each other near the central groove 11, but as they move away from the central groove 11, the two projection ranges 26Lf, 26Rf begin to overlap in the longitudinal direction D1, and the overlap increases.

The above embodiment has an advantage when a positional deviation error occurs in the lateral direction D2 of the absorbent article 1 during the groove formation process. The positional deviation error of the absorbent article 1 is likely to occur in the lateral direction D2 and the longitudinal direction D1, for example, when the absorbent article 1 rotates slightly, but the positional deviation is particularly large in the region near the end of the longitudinal direction D1. Therefore, since the projection range 26Lf of the left high compression portion 25Lf and the projection range 26Rf of the right high compression portion 25Rf overlap at a position near the end of the longitudinal direction D1 of the absorbent article 1, even if a positional deviation error occurs in the absorbent article 1, a gap is unlikely to occur between the projection range 26Lf of the left high compression portion 25Lf and the projection range 26Rf of the right high compression portion 25Rf, or even if a gap occurs, it can be kept small. In other words, this embodiment is suitable for absorbent articles with a long length in the longitudinal direction D1, in which a positional deviation error is likely to occur during the groove formation process.

In the example shown in FIG. 4, the left high compression portions 25Lf, 25Lf, ... are formed to have the same shape and size, the right high compression portions 25Rf, 25Rf, ... are also formed to have the same shape and size, and the left high compression portion 25Lf and the right high compression portion 25Rf are also formed to have the same shape and size. However, the shapes and sizes of the high compression portions may be different from each other within the left diagonal groove 12Lf and/or within the right diagonal groove 12Rf, or may be different between the left and right.

The left high compression portions 25Lf, 25Lf, ... and the right high compression portions 25Rf, 25Rf, ... are formed in a dot pattern, and the shape of each high compression portion in a plan view is circular, but the shape in a plan view is not limited to circular, and may be elliptical, polygonal, or any other shape. The size of each of the left high compression portions 25Lf, 25Lf, ... and the right high compression portions 25Rf, 25Rf, ... may be a diameter of 1.2 to 2 mm if the shape in a plan view is circular, and may be a size having the same area if the shape in a plan view is other than circular.

<Modification>
6 shows a modified example of the high compression portion. In the example shown in FIG. 6, the left high compression portions 25Lf, 25Lf, ... of the left oblique groove 12Lf and the right high compression portions 25Rf, 25Rf, ... of the right oblique groove 12Rf are formed at equal intervals along the longitudinal direction D1. That is, the interval d1 between the right high compression portions 25Rf, 25Rf along the longitudinal direction D1 is constant throughout the right oblique groove 12Rf. On the other hand, the interval d2 between the right high compression portions 25Rf, 25Rf along the extension direction of the right oblique groove 12Rf is not constant within the right oblique groove 12Rf. The interval between the left high compression portions 25Lf, 25Lf, ... of the left oblique groove 12Lf is also the same as that of the right oblique groove 12Rf.

In the modified example shown in FIG. 6, the projection ranges 26Lf, 26Lf, ... of the left high compression portions 25Lf, 25Lf, ... of the left diagonal groove 12Lf on a straight line parallel to the longitudinal direction D1 and the projection ranges 26Rf, 26Rf, ... of the right high compression portions 25Rf, 25Rf, ... of the right diagonal groove 12Rf on a straight line parallel to the longitudinal direction D1 are staggered. Furthermore, in this modified example, the projection range 26Lf of the left high compression portion 25Lf is in contact with the projection range 26Rf of the adjacent right high compression portion 25Rf in the longitudinal direction D1, and there is no range in the longitudinal direction D1 where a high compression portion is not formed. Therefore, in the groove formation process, the pressure is uniform throughout the entire longitudinal direction D1, which is preferable in that the behavior of the roll pair is stable. Therefore, this embodiment is suitable for absorbent articles with a short length in the longitudinal direction D1, which is less likely to cause positional deviation errors in the groove formation process.

Furthermore, Figs. 6 and 7 show modified examples of the tip portions of the diagonal grooves 12Lf, 12Rf (the ends on the end side of the longitudinal direction D1 of the absorbent article). The left diagonal groove 12Lf and the right diagonal groove 12Rf shown in Figs. 6 and 7 have the same basic configuration as those shown in Fig. 4, but the left high compression portion 25LfT, which is the most distal end of the left high compression portions 25Lf, 25Lf, ..., and the right high compression portion 25RfT, which is the most distal end of the right high compression portions 25Rf, 25Rf, ..., are aligned. More specifically, the left high compression portion 25LfT and the right high compression portion 25RfT are formed so that the front edge of the most distal left high compression portion 25LfT and the front edge of the right high compression portion 25RfT are located on a line EL parallel to the width direction D2.

As shown in the example in Figures 6 and 7, by aligning the positions of the most distal left high compression portion 25LfT and the most distal right high compression portion 25RfT, the rigidity of the left diagonal groove 12Lf and the right diagonal groove Rf can be made more symmetrical, and the symmetry of deformation of the absorbent article 1 when worn can also be improved.

In the example shown in FIG. 6, in the left high compression portions 25Lf, 25Lf, ... and right high compression portions 25Rf, 25Rf, ... formed in the same manner as in the example shown in FIG. 4, a right high compression portion 25RfT having the same shape and size as the right high compression portion 25Rf shown in FIG. 4 is added to the tip of the right diagonal groove 12Rf. In the example shown in FIG. 6, the left high compression portions 25Lf, 25Lf, ... including the left high compression portion 25LfT at the tip, and the right high compression portions 25Rf, 25Rf, ... including the right high compression portion 25RfT at the tip, have the same shape and size.

The high-pressure compression portions formed at the tips of the diagonal grooves 12Lf, 12Rf tend to be formed deeper than other high-pressure compression portions, for example, when the absorbent has a large thickness and is soft before compression, because the non-compressed portions are close to each other in the longitudinal direction D1. In contrast, in the example shown in FIG. 6, the force of the roll pair can be distributed to the left and right when forming the high-pressure compression portion at the very tip of the diagonal groove. This makes it possible to prevent the very tip left high-pressure compression portion 25LfT and the very tip right high-pressure compression portion 25RfT from being formed excessively deep relative to the high-pressure compression portions at other positions.

In the example shown in Figure 7, the left high compression portion 25LfT at the tip has a different shape from the other left high compression portions 25Lf, 25Lf, ..., and the right high compression portion 25RfT at the tip also has a different shape from the other right high compression portions 25Rf, 25Rf, .... While the left high compression portions 25Lf, 25Lf, ... and the right high compression portions 25Rf, 25Rf, ... are circular, the left high compression portion 25LfT at the tip and the right high compression portion 25RfT at the tip are both elliptical. Also, the right high compression portion 25RfT at the tip is a longer ellipse that runs along the extension direction of the right diagonal groove 12Rf. Furthermore, in the example shown in FIG. 7, the widths of the leading left high compression portion 25LfT and the leading right high compression portion 25RfT (the widthwise lengths of the diagonal grooves 12Lf, 12Rf) are both narrower than the other left high compression portions 25Lf, 25Lf, ... and the other right high compression portions 25Rf, 25Rf, .... If the leading left high compression portion 25LfT and the leading right high compression portion 25RfT are less likely to be formed deeper than the other high compression portions, as shown in FIG. 7, the widths in the width direction D2 of the leading left high compression portion 25LfT and the leading right high compression portion 25RfT can be narrowed, and the line pressure when the leading left high compression portion 25LfT and the leading right high compression portion 25RfT are formed can be made approximately the same as the line pressure when the other left high compression portions 25Lf, 25Lf, ... and the other right high compression portions 25Rf, 25Rf, ... are formed.

<High pressure compression area in the central groove>
In this embodiment, as shown in Fig. 1 and Fig. 4, a highly compressed portion may also be formed in the central groove 11. This increases the rigidity of the central groove 11 and its surroundings, and prevents the central groove 11 from being crushed even when the central groove 11 is subjected to leg forces from both sides when worn. The form of the highly compressed portion in the central groove 11 is not particularly limited, but as shown in Fig. 4, the highly compressed portion in the central groove 11 may have discontinuous first highly compressed portions 31, 31, ... along a first imaginary wavy line WL1 extending in the longitudinal direction D1, and discontinuous second highly compressed portions 32, 32, ... along a second imaginary wavy line WL2. The first imaginary wavy line WL1 and the second imaginary wavy line WL2 may have a regular pattern and be formed in line symmetry with respect to the longitudinal center line CL.

The arrangement of the first high-squeezing portion 31, 31, ... and the second high-squeezing portion 32, 32, ... in the longitudinal direction D1 in the central groove 11 is not particularly limited. However, as shown in FIG. 4, it is preferable that the projection range of the first high-squeezing portion 31, 31, ... projected onto a straight line parallel to the longitudinal direction D1 (the longitudinal center line CL in the illustrated example) and the projection range of the first high-squeezing portion 31, 31, ... are staggered. This reduces the fluctuation of the pressure received from the roll pair in the groove formation process, so that the high-squeezing portion can be formed stably. In addition, since the pressing force of the roll pair is not easily distributed to the left and right, the line pressure for forming the high-squeezing portion is higher than that in a form in which the first high-squeezing portion 31, 31, ... and the second high-squeezing portion 32, 32, ... are formed at the same position in the longitudinal direction D1, and each high-squeezing portion can be clearly formed.

The central groove 11 may include an area where the above-mentioned projected range of the first high-pressure compression portion 31, 31, ... and the above-mentioned projected range of the first high-pressure compression portion 31, 31, ... are in contact with each other, an area where they overlap with each other, and an area where they are spaced apart from each other.

In the illustrated example, the first high-pressure compressed portions 31, 31, ... and the second high-pressure compressed portions 32, 32, ... are formed in the same circular shape. Furthermore, the size of one of the high-pressure compressed portions 25Lf, 25Lf, ... and 25Rf, 25Rf, ... in the diagonal grooves 12Lf, 12Rf may be larger than the size of one of the first high-pressure compressed portions 31, 31, ... and the second high-pressure compressed portions 32, 32, ... in the central groove 11. This can promote deformation of the front and rear regions that need to be bent significantly when the absorbent article 1 is worn. When the size of the highly compressed portion in the central groove 11 is made smaller than that of the highly compressed portion in the diagonal grooves 12Lf, 12Rf, 12Lr, 12Rr, by providing an area in the central groove 11 where the projected range of the first highly compressed portion 31, 31, ... overlaps with the projected range of the first highly compressed portion 31, 31, ..., the difference in the line pressure when the highly compressed portion in the diagonal groove is formed and the line pressure when the highly compressed portion in the central groove 11 is formed can be reduced in the groove forming process. This makes it possible to reduce the difference in the depth of the highly compressed portion between the central groove 11 and the diagonal grooves 12Lf, 12Rf, 12Lr, 12Rr, which is preferable.

The present invention has been described above based on the embodiments, but the present invention is not limited to these embodiments. Furthermore, the above embodiments can be modified, altered, substituted, added, deleted, and combined in various ways within the scope of the claims, and these also fall within the technical scope of the present invention.

1 Absorbent article 2 Back sheet 3 Top sheet 4 Absorbent body 7 Side sheet 11 Central groove 11f Front end 11r of central groove Rear end 12Lf of central groove Front left diagonal groove 12Rf Front right diagonal groove 12Lr Rear left diagonal groove 12Rr Rear right diagonal groove 14 Non-compressed portion 25Lf Front left compressed portion 25LfT Front (forwardmost) left compressed portion 25Rf Front right compressed portion 25RfT Front (forwardmost) right compressed portion 26Lf Projected range 26Rf of front left compressed portion Projected range 31 of front right compressed portion First compressed portion 32 Second compressed portion CL Longitudinal center line D1 First direction (longitudinal direction)
D2 Second direction (horizontal direction)
F: front region M: middle region R: rear region Q: body fluid outlet facing region WL1: first imaginary wavy line WL2: second imaginary wavy line

Claims (5)

An absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body provided between the top sheet and the back sheet, the absorbent article having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction,
A groove is formed extending from the top sheet toward the back sheet,
The groove is
a central groove extending in the longitudinal direction;
a left oblique groove and a right oblique groove formed in an area closer to the end in the longitudinal direction than the central groove so that the distance between them increases as the area moves away from the central groove,
A plurality of left high compression portions are formed in the left oblique groove and spaced apart in the extension direction of the left oblique groove, and a plurality of right high compression portions are formed in the right oblique groove and spaced apart in the extension direction of the right oblique groove,
When the left high compression portion and the right high compression portion are projected onto a straight line parallel to the longitudinal direction, the projected range of the left high compression portion and the projected range of the right high compression portion are at least partially alternately positioned ,
A left high compression portion at a tip end of the left oblique groove furthest from the central groove and a right high compression portion at a tip end of the right oblique groove furthest from the central groove are aligned in the longitudinal direction,
The left high-compression portion at the tip is formed longer along the left diagonal groove than the left high-compression portion other than the left high-compression portion at the tip, and/or the right high-compression portion at the tip is formed longer along the right diagonal groove than the right high-compression portion other than the right high-compression portion at the tip,
an absorbent article in which the width of the left high compression portion at the tip is smaller than the width of the left high compression portion other than the left high compression portion at the tip, and the width of the right high compression portion at the tip is smaller than the width of the right high compression portion other than the right high compression portion at the tip . The absorbent article according to claim 1 , wherein the distance between the projected range of the left high compression portion and the projected range of the right high compression portion adjacent to the projected range of the left high compression portion in the longitudinal direction is zero, or the two projected ranges overlap. The absorbent article according to claim 1 or 2, wherein the distance between the left high compression parts is constant along the extension direction of the left diagonal groove, and/or the distance between the right high compression parts is constant along the extension direction of the right diagonal groove. A plurality of first compressed portions are formed in the central groove and are spaced apart in the longitudinal direction along a first imaginary wavy line extending in the longitudinal direction, and a plurality of second compressed portions are formed in the central groove and are spaced apart in the longitudinal direction along a second imaginary wavy line extending in the longitudinal direction and intersecting the first imaginary wavy line,
4. The absorbent article according to claim 1, wherein when the first highly compressed portion and the second highly compressed portion are projected onto a straight line parallel to the longitudinal direction, the projected range of the first highly compressed portion and the projected range of the second highly compressed portion are staggered. A method for manufacturing an absorbent article comprising a liquid-permeable top sheet, a liquid-impermeable back sheet, and an absorbent body provided between the top sheet and the back sheet, the absorbent article having a longitudinal direction and a lateral direction perpendicular to the longitudinal direction, and a groove recessed from the top sheet toward the back sheet, comprising:
forming a central groove extending in the longitudinal direction;
a left oblique groove and a right oblique groove are formed in an area closer to the end portion in the longitudinal direction than the central groove, the distance between the left oblique groove and the right oblique groove increasing as the area moves away from the central groove;
In forming the left oblique groove, a plurality of left high compression portions are formed in the left oblique groove at intervals in the extension direction of the left oblique groove, and in forming the left oblique groove, a plurality of right high compression portions are formed in the right oblique groove at intervals in the extension direction of the right oblique groove,
When the left high compression portion and the right high compression portion are projected onto a straight line parallel to the longitudinal direction, the projected range of the left high compression portion and the projected range of the right high compression portion are at least partially alternately positioned ,
A left high compression portion at a tip end of the left oblique groove furthest from the central groove and a right high compression portion at a tip end of the right oblique groove furthest from the central groove are aligned in the longitudinal direction,
The left high-compression portion at the tip is formed longer along the left diagonal groove than the left high-compression portion other than the left high-compression portion at the tip, and/or the right high-compression portion at the tip is formed longer along the right diagonal groove than the right high-compression portion other than the right high-compression portion at the tip,
A method for manufacturing an absorbent article, wherein the width of the left high compression portion at the tip is smaller than the width of the left high compression portion other than the left high compression portion at the tip, and the width of the right high compression portion at the tip is smaller than the width of the right high compression portion other than the right high compression portion at the tip .

Images