Absorbent article

By integrating a low-rigidity region with guide marks in the SAP sheet, the absorbent article addresses discomfort issues caused by superabsorbent polymer expansion, ensuring flexible deformation and improved comfort.

WO2026141400A1PCT designated stage Publication Date: 2026-07-02UNI CHARM CORP

Patent Information

Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
UNI CHARM CORP
Filing Date
2025-12-23
Publication Date
2026-07-02

AI Technical Summary

Technical Problem

Existing absorbent articles fail to adequately reduce wearer discomfort, particularly due to the expansion of superabsorbent polymer sheets after urine absorption, which can cause discomfort and hinder flexible deformation.

Method used

Incorporating a low-rigidity region in the absorbent article's SAP sheet, specifically designed to have a lower basis weight of superabsorbent polymer, and providing guide marks to facilitate proper body positioning, allowing for flexible deformation even after absorption.

Benefits of technology

The combination of guide marks and low-rigidity regions effectively reduces wearer discomfort by enabling flexible deformation and appropriate urine distribution, enhancing comfort during use.

✦ Generated by Eureka AI based on patent content.

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Abstract

This diaper comprises an absorbent body including: a front surface sheet disposed on a skin surface side of a wearer; a back surface sheet disposed on a non-skin surface side opposite to the skin surface side; and an absorber having an SAP sheet including a superabsorbent polymer, the absorber being disposed between the front surface sheet and the back surface sheet. A guide mark for guiding a position at which a part of the body of the wearer is to be placed is formed on the absorbent body. The SAP sheet has a low-rigidity region extending in a longitudinal direction at least on a center side of the absorbent body in the longitudinal direction relative to the guide mark.
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Description

Absorbent article

[0008]

[0001] The present disclosure relates to an absorbent article.

[0002] In Patent document 1, a marked diaper is described which includes a top sheet on which a guiding mark for guiding the position of the wearer's buttocks is displayed, a back sheet (cover sheet), and an absorbent core (absorbent body) disposed between the top sheet and the back sheet.

[0003] Japanese Unexamined Patent Application Publication No. 2014 - 230716

[0004] In the absorbent article as described above, the guiding mark can allow the user to recognize the position where a part of the wearer's body should be placed. Thereby, by wearing the absorbent article on the wearer so that a part of the wearer's body fits at the appropriate position indicated by the guiding mark, the discomfort of the wearer can be reduced. However, in the absorbent article, it is required to further improve the effect of reducing the discomfort of the wearer.

[0005] An object of the present disclosure is to provide an absorbent article that can effectively reduce the discomfort of the wearer.

[0006] An absorbent article according to one embodiment is an absorbent article extending in a longitudinal direction connecting the ventral side to the dorsal side of the wearer and a transverse direction perpendicular to the longitudinal direction, and includes an absorbent main body including a top sheet disposed on the skin side of the wearer, a back sheet disposed on the non - skin side opposite to the skin side, and an absorber having a SAP sheet containing a superabsorbent polymer disposed between the top sheet and the back sheet, and a guiding mark for guiding the position where a part of the wearer's body should be placed is formed on the absorbent main body. The SAP sheet has a low - rigidity region extending in the longitudinal direction at least on the central side of the absorbent main body in the longitudinal direction rather than the guiding mark, and the low - rigidity region is a portion where the basis weight of the superabsorbent polymer is lower than that of the portion adjacent to the low - rigidity region of the SAP sheet when viewed from the thickness direction perpendicular to the longitudinal direction and the transverse direction.<​​​​This is a plan view of the diaper according to the embodiment, seen from the skin side. This is a plan view of the diaper in Figure 1, seen from the non-skin side. This is a cross-sectional view of the diaper along line III-III in Figure 1. This figure shows a modified example of the absorbent material. This is a plan view of the diaper according to the first modified example, seen from the non-skin side. This is a plan view of the diaper according to the second modified example, seen from the non-skin side. This figure shows a modified example of the absorbent material (SAP sheet).

[0009] At least [1] to

[12] embodiments are disclosed in this specification and the accompanying drawings.

[0010] [1] An absorbent article extending in a longitudinal direction connecting the ventral side to the dorsal side of a wearer, and in a transverse direction perpendicular to the longitudinal direction, comprising an absorbent body having a surface sheet disposed on the skin side of the wearer, a back sheet disposed on the non-skin side opposite to the skin side, and an absorbent body having an SAP sheet containing a superabsorbent polymer disposed between the surface sheet and the back sheet, wherein the absorbent body has guide marks formed on it for guiding the position where a part of the wearer's body should be placed, the SAP sheet has a low-rigidity region extending in the longitudinal direction at least on the central side of the absorbent body in the longitudinal direction from the guide marks, and the low-rigidity region is a portion of the SAP sheet with a lower basis weight of the superabsorbent polymer than the portion adjacent to the low-rigidity region when viewed from the thickness direction perpendicular to the longitudinal and transverse directions.

[0011] In the absorbent article described above, the guide marks allow the user to understand where to position a part of their body, thereby reducing discomfort for the wearer. Furthermore, by using an SAP sheet that can be made relatively thin before use, the aforementioned effect of reducing discomfort can be improved. However, when an SAP sheet is used as the absorbent material, the expansion rate after use (after absorbing the wearer's urine, etc.) is relatively large compared to the state before use, which can easily cause discomfort for the wearer. Therefore, in the absorbent article described above, a low-rigidity region extending vertically is provided at least towards the center of the absorbent body from the guide marks (i.e., towards the crotch when worn). As a result, even after the SAP sheet has absorbed the wearer's urine and expanded, the SAP sheet can maintain a state in which it can be flexibly deformed starting from the low-rigidity region, thereby reducing discomfort. Thus, the absorbent article described above, by combining guide marks and a low-rigidity region provided in the SAP sheet, can effectively reduce discomfort for the wearer.

[0012] [2] The absorbent article of [1], in which the low-rigidity region, when viewed from the thickness direction, traverses the guide mark in the vertical direction.

[0013] The locations where guide marks are present, which serve as markers for aligning with parts of the wearer's body, may be areas where the wearer's body parts and the absorbent material are likely to come into close contact when worn. By providing low-rigidity areas that cross these guide marks, discomfort for the wearer can be effectively reduced.

[0014] [3] The absorbent article according to [1] or [2], wherein the low-rigidity region has a first region extending in the vertical direction at the center of the absorbent body in the lateral direction.

[0015] According to the above configuration, by providing a low-rigidity area (first area) in the part that faces the center of the wearer's crotch (the line along the crease of the buttocks) when worn, the wearer's discomfort can be effectively reduced.

[0016] [4] The guide mark is a mark that indicates the position where the wearer's buttocks should be placed, and is an absorbent article of any of [1] to [3].

[0017] According to the above configuration, a low-rigidity area can be provided in the crotch area between the position where the wearer's buttocks should be placed (a position further back than the vertical center of the absorbent body) and the vertical center of the absorbent body, in a location that has a significant impact on the wearer's comfort. As a result, the wearer's comfort can be pleasantly improved.

[0018] [5] The absorbent article according to [4], wherein the low-rigidity region extends in the longitudinal direction from the center of the absorbent body in the transverse direction and has a first low-rigidity region that passes through the center of the absorbent body in the longitudinal direction and crosses a center line that extends in the transverse direction.

[0019] In the above configuration, at least the first low-rigidity region is provided so as to extend to the vicinity of the urinary opening. Through this first low-rigidity region, the urine excreted by the wearer can be appropriately diffused vertically.

[0020] [6] The absorbent article according to any one of [1] to [5], wherein the absorbent body further comprises an intermediate sheet disposed between the surface sheet and the absorbent, and the low-rigidity region has a portion that does not overlap with the intermediate sheet in the thickness direction.

[0021] If an intermediate sheet is placed over a low-rigidity region in an SAP sheet, which is a region with lower rigidity than adjacent parts and therefore more easily deformable, the rigidity of the part of the absorbent body where the low-rigidity region is located will increase by the amount of the increased thickness of the intermediate sheet, which may hinder flexible deformation. With the above configuration, by arranging the low-rigidity region so that it does not overlap with the intermediate sheet, an appropriate rigidity difference can be ensured between the low-rigidity region and its adjacent regions. As a result, flexible deformation starting from the low-rigidity region is made possible, and discomfort during wear can be effectively reduced.

[0022] [7] The absorbent article of [4], wherein the low-rigidity region has a plurality of second regions arranged in the lateral direction and extending in the vertical direction, within the range in which the guide marks are arranged in the lateral direction.

[0023] According to the above configuration, multiple low-rigidity regions (second region) are arranged within the range where the guide marks are placed in the lateral direction, thereby suitably obtaining the effects of the low-rigidity regions described above (reduction of discomfort when worn by enabling flexible deformation starting from the low-rigidity regions).

[0024] [8] The SAP sheet is a sheet in which the superabsorbent polymer is packed in a bag shape, and the low-rigidity region is composed of a region of the SAP sheet in which the superabsorbent polymer is not arranged when viewed from the thickness direction, according to any of [1] to [7].

[0025] According to the above configuration, an SAP sheet having a low-rigidity region can be suitably obtained.

[0026] [9] The SAP sheet comprises a base sheet made of a nonwoven fabric and the superabsorbent polymer held on at least one of the skin-facing side and the non-skin-facing side of the base sheet, wherein the low-rigidity region is composed of a region in which the base sheet and the superabsorbent polymer are not arranged when viewed from the thickness direction, and the absorbent article is one of [1] to [7].

[0027] According to the above configuration, an SAP sheet having a low-rigidity region can be suitably obtained.

[0028]

[10] The absorbent article of any of [1] to [9], comprising the SAP sheet and another absorbent core disposed so as to overlap the SAP sheet in the thickness direction, wherein the absorbent core has a uniform thickness or has a low-rigidity portion at a position that overlaps the low-rigidity region of the SAP sheet in the thickness direction, and the low-rigidity portion is a portion of the absorbent core in which the basis weight of the absorbent material constituting the absorbent core is lower than that of the portion of the absorbent core adjacent to the low-rigidity portion when viewed from the thickness direction.

[0029] According to the above configuration, the absorber employs a structure in which an SAP sheet and other absorbent cores are laminated, while the portion of the absorber with low rigidity in the SAP sheet, when viewed from the thickness direction, becomes the low rigidity region (the part that serves as the starting point for deformation) of the absorber as a whole. As a result, the aforementioned effect of the low rigidity region (reduction of discomfort when worn by enabling flexible deformation starting from the low rigidity region) can be suitably obtained.

[0030]

[11] The absorbent article of [4], wherein the absorbent body further comprises a liquid diffusion sheet disposed between the surface sheet and the absorbent, the liquid diffusion sheet being arranged to overlap with the guide mark in the thickness direction.

[0031] According to the above configuration, by placing the liquid diffusion sheet in the area where the guide mark is provided (the area where body pressure is likely to be applied due to the wearer's buttocks), the liquid (urine) can be effectively diffused in the above area even when body pressure is applied by the wearer.

[0032]

[12] The SAP sheet has a low basis weight region different from the low rigidity region at a position overlapping with the guide mark or on the back side of the guide mark, wherein the low basis weight region is a region with a relatively low basis weight in the part of the SAP sheet excluding the low rigidity region, the absorbent article of [4].

[0033] According to the above configuration, by providing a low-weight area in the SAP sheet near the part where the wearer's buttocks are positioned, the volume difference of the SAP sheet before and after use in that area can be reduced, thereby reducing discomfort for the wearer.

[0034] [Embodiments] Embodiments of the present disclosure will be described below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will not be repeated. The dimensional ratios in the drawings do not necessarily match those described.

[0035] Referring to Figures 1 to 3, the structure of a diaper 1, which is an example of an absorbent article according to the embodiment, will be described. Figure 1 is a plan view of the diaper 1 as seen from the skin side Z1. Figure 2 is a plan view of the diaper 1 as seen from the non-skin side Z2. Figure 3 is a schematic cross-sectional view of the diaper 1 along the line III-III shown in Figure 1. Figures 1 and 2 show the diaper 1 in an unfolded state, stretched to a state where no wrinkles are formed. In the following description, unless otherwise specified, the positional relationships will be described in the unfolded state. Note that in the cross-sectional view of Figure 3, for the sake of explanation, each member is shown spaced apart in the thickness direction Z, but in the actual product, they are in contact in the thickness direction Z.

[0036] Diaper 1 is a tape-type disposable diaper. Diaper 1 may be a child's diaper or an adult's diaper. In the following description, the person wearing Diaper 1 is referred to as the "wearer," and the person who puts Diaper 1 on the wearer is referred to as the "user." Typically, the wearer is a child or a person receiving care, and the user is a parent or caregiver.

[0037] As shown in Figure 1, the diaper 1 extends in the transverse direction X, which is aligned with the wearer's waist, and in the longitudinal direction Y, which connects the wearer's ventral side to their back. The transverse direction X corresponds to the width direction of the diaper 1, and the longitudinal direction Y corresponds to the length direction of the diaper 1. The transverse direction X and the longitudinal direction Y are perpendicular to each other. The thickness direction Z is perpendicular to the transverse direction X and the longitudinal direction Y, and includes a skin-facing side Z1 that faces the wearer's skin when worn, and a non-skin-facing side Z2 that faces away from the wearer's skin when worn. The diaper 1 is worn so as to cover the wearer's abdomen, crotch, and back.

[0038] The diaper 1 comprises an absorbent body 2 and a pair of fastening tabs 90. The absorbent body 2 has a ventral edge 2F located on one side in the longitudinal direction Y and a dorsal edge 2R located on the other side in the longitudinal direction Y. When worn, the ventral edge 2F is positioned on the ventral side in the direction of the wearer's waist, and the dorsal edge 2R is positioned on the dorsal side in the direction of the wearer's waist. The distance in the longitudinal direction Y between the ventral edge 2F and the dorsal edge 2R is the total length (maximum length) L1 of the absorbent body 2. In the following description, the side on which the ventral edge 2F is located relative to the dorsal edge 2R in the longitudinal direction Y is referred to as the ventral side, and the opposite side is referred to as the dorsal side.

[0039] The absorbent body 2 has a dorsal region 51 located on the dorsal side, a ventral region 52 located on the ventral side, and an intermediate region 53 located between the dorsal region 51 and the ventral region 52. The width of the intermediate region 53 in the lateral direction X is smaller than the width of the dorsal region 51 and the ventral region 52 in the lateral direction X.

[0040] A pair of flap portions 15 are formed on the dorsal region 51 of the absorbent body 2, extending outward in the lateral direction X from the absorbent body 2. The width of the pair of flap portions 15 in the lateral direction X corresponds to the maximum width of the absorbent body 2.

[0041] Each of the pair of flap portions 15 is provided with a pair of fastening tabs 90. The pair of fastening tabs 90 extend outward in the lateral direction X from the side edge 2S of the absorbent body 2. Each of the pair of fastening tabs 90 has a base sheet 91 joined to the flap portion 15 and a joining portion 92 provided on the base sheet 91. The joining portion 92 is located on the skin-side Z1 surface of the base sheet 91. The joining portion 92 is, for example, a mechanical fastener and is configured to be joined to a target portion 48 formed on the non-skin-side Z2 of the absorbent body 2.

[0042] As shown in FIG. 2, the target portion 48 is provided on the non-skin surface side Z2 of the ventral region 52 of the absorbent body 2. The target portion 48 has a strip shape extending in the lateral direction X. The target portion 48 is disposed ventral to the pair of fastening tabs 90 and engages with the pair of fastening tabs 90. Note that the absorbent body 2 may be configured without the target portion 48, and the joint portion 92 of the pair of fastening tabs 90 may be directly joined to the backsheet 20 of the absorbent body 2 described later.

[0043] As shown in FIGS. 1 to 3, the absorbent body 2 includes a topsheet 10, a backsheet 20, and an absorber 30. The topsheet 10 constitutes the surface of the absorbent body 2 that is applied to the wearer and is disposed on the skin surface side Z1. The topsheet 10 includes a center sheet 11 disposed at the center in the lateral direction X and covering the absorber 30, and a pair of side sheets 12 covering both sides of the center sheet 11 in the lateral direction X. The center sheet 11 is made of, for example, a liquid-permeable nonwoven fabric that allows the urine of the wearer to permeate toward the absorber 30 side, and the side sheet 12 is made of, for example, a liquid-impermeable nonwoven fabric.

[0044] As shown in FIG. 3, the inner portions of the pair of side sheets 12 in the lateral direction X are folded back to the non-skin surface side Z2. A pair of elastic members 13 extending in the longitudinal direction Y are disposed between the folded pair of side sheets 12. The pair of side sheets 12 and the pair of elastic members 13 constitute a pair of leak-proof gathers 80. The pair of leak-proof gathers 80 are upright leak-proof gathers and are disposed on the skin surface side Z1 relative to the absorber 30.

[0045] As shown in FIG. 1, the pair of leak-proof gathers 80 are disposed outside the absorber 30 in the lateral direction X to suppress leakage of urine excreted into the absorber 30 in the lateral direction X. Each of the pair of leak-proof gathers 80 includes an elastic member 13 extending in the longitudinal direction Y, a standing portion 81 that stands up due to the contraction of the elastic member 13, a horizontal fixing portion 82 that serves as a standing fulcrum of the standing portion 81 in the lateral direction X, and a vertical fixing portion 83 that serves as a standing fulcrum of the standing portion 81 in the longitudinal direction Y.

[0046] The elastic member 13 extends along the thickness range of the side sheet 12 in the vertical direction Y. The elastic member 13 is made of a stretchable material such as rubber or spandex that can contract in the length direction, for example. The elastic members 13 of the pair of leak-proof gathers 80 are spaced apart from each other across the longitudinal center line CW passing through the center of the absorbent body 2 in the lateral direction X, and are fixed to the side sheet 12 in a state of being extended in the vertical direction Y. The end on the back side of the elastic member 13 is disposed in the back side region 51, and the end on the ventral side of the elastic member 13 is disposed in the ventral side region 52.

[0047] The lateral fixing portion 82 is formed over substantially the entire vertical range of the absorbent body 2 at a position outside the side sheet 12 in the lateral direction X of the standing portion 81. As an example, the lateral fixing portion 82 is disposed outside the absorbent layer 31 (described later) in the lateral direction X. The lateral fixing portion 82 is a part of the side sheet 12 and is fixed to the center sheet 11. The lateral fixing portion 82 serves as a standing fulcrum of the standing portion 81 in the lateral direction X.

[0048] The longitudinal fixing portion 83 is formed inside the lateral fixing portion 82 in the lateral direction X. The longitudinal fixing portion 83 includes a back side fixing portion 84 disposed in the back side region 51 and a ventral side fixing portion 85 disposed in the ventral side region 52. The back side fixing portion 84 and the ventral side fixing portion 85 are parts of the side sheet 12 and are fixed to the center sheet 11. The back side fixing portion 84 and the ventral side fixing portion 85 serve as the back side and ventral side standing fulcrums of the standing portion 81, respectively.

[0049] The standing portion 81 is formed between the back side fixing portion 84 and the ventral side fixing portion 85. That is, the standing portion 81 is disposed at a position inside the lateral fixing portion 82 in the lateral direction X and at a position inside the longitudinal fixing portion 83 in the vertical direction Y. The standing portion 81 is a part of the side sheet 12 that is not fixed to the center sheet 11. The elastic member 13 is connected to the standing portion 81 in a state of being extended in the vertical direction Y. When the elastic member 13 contracts in the vertical direction Y, the absorbent body 2 is deformed in the closing direction, and the standing portion 81 rises starting from the lateral fixing portion 82. In this way, when the standing portion 81 rises at a position where it sandwiches the absorbent layer 31 from the lateral direction X, urine leakage is prevented.

[0050] The backing sheet 20 constitutes the outer surface of the absorbent body 2 when worn, and is positioned on the non-skin side Z2. The backing sheet 20 includes a liquid-impermeable backing film 21 and a backing nonwoven fabric 22 located on the non-skin side Z2 than the backing film 21. The width of the backing film 21 in the lateral direction X is formed to be shorter than the width of the backing nonwoven fabric 22 in the lateral direction X, and the backing nonwoven fabric 22 may extend beyond the backing film 21 on both sides in the lateral direction X. The backing nonwoven fabric 22 constitutes the outermost layer of the diaper 1.

[0051] The absorbent body 30 is positioned between the surface sheet 10 and the back sheet 20. The absorbent body 30 includes, for example, an absorbent material having water-absorbing properties, and absorbs the wearer's urine. The absorbent material is composed of, for example, pulp fibers and superabsorbent polymer (SAP). In this embodiment, the absorbent body 30 is configured as an SAP sheet containing a superabsorbent polymer. The absorbent body 30 is positioned approximately in the center of the absorbent body 2 in the lateral direction X.

[0052] The absorbent body 30 has a dorsal edge 30R and a ventral edge 30F. The dorsal edge 30R of the absorbent body 30 has a width W1 in the lateral direction X. The width W1 is the maximum width of the absorbent body 30. For example, the width W1 of the dorsal edge 30R is greater than the distance d between a pair of leak-proof gathers 80 in a non-upright state. The ventral edge 30F of the absorbent body 30 has, for example, the same width as the dorsal edge 30R. In this embodiment, the absorbent body 30 has a vertically elongated rectangular shape when viewed from the thickness direction Z.

[0053] As shown in Figure 1, the diaper 1 further includes an elastic member 40 that is expandable in the longitudinal direction Y. The elastic member 40 is positioned outside the elastic member 13 in the transverse direction X. The dorsal end of the elastic member 40 is positioned in the dorsal area 51, and the ventral end of the elastic member 40 is positioned in the ventral area 52. The elastic member 40 is made of an elastic material such as rubber or spandex that is contractible in the longitudinal direction Y, and extends in the longitudinal direction Y between the surface sheet 10 and the back sheet 20 of the absorbent body 2. When the diaper 1 is worn, the elastic member 40 contracts in the longitudinal direction Y, causing the side edge 2S of the absorbent body 2 to fit around the wearer's legs. That is, the elastic member 40 forms a leg-lengthening gather that expands and contracts along the wearer's legs. Note that the diaper 1 may include multiple elastic members 40. As shown in Figure 1, multiple elastic members 40 are arranged in the transverse direction X outside the elastic member 13 and extend in the longitudinal direction Y parallel to each other.

[0054] The absorbent body 2 has guide marks 60 formed on it to indicate the position where a part of the wearer's body (in this example, the wearer's buttocks) should be placed. In this embodiment, the guide marks 60 are colored on an intermediate sheet 71, which is a sheet material placed between the center sheet 11 and the absorbent body 30. The intermediate sheet 71 is, for example, tissue containing pulp. In this embodiment, the intermediate sheet 71 functions as a printed sheet on which the guide marks 60 are colored, and also functions as a liquid diffusion sheet that diffuses liquid (such as urine) that has migrated from the center sheet 11. For example, the skin-facing side Z1 of the intermediate sheet 71 is adhered to the center sheet 11, and the non-skin-facing side Z2 of the intermediate sheet 71 is adhered to the core wrap 32 (skin-facing nonwoven fabric 32A) of the skin-facing side Z1 of the absorbent body 30. For example, a hot melt adhesive is used to adhere the intermediate sheet 71. Note that only one of the skin-facing side Z1 or non-skin-facing side Z2 of the intermediate sheet 71 may be adhered to an adjacent sheet.

[0055] The guide mark 60 may be printed on the skin-facing side Z1 of the intermediate sheet 71, or on the non-skin-facing side Z2 (absorbent side 30). The guide mark 60 printed on the non-skin-facing side Z2 of the intermediate sheet 71 is visible from the skin-facing side Z1 through the center sheet 11 and the intermediate sheet 71. To prevent misidentification as blood or stool, the guide mark 60 may be printed in ink of a color other than red and yellow. For example, the guide mark 60 may be printed in blue or green. More specifically, the guide mark 60 may be printed in a color that falls within the range of 5GY to 10RP on the Munsell color circle, for example.

[0056] As shown in Figures 1 and 2, for example, the guide mark 60 has a horizontally elongated shape that is long in the horizontal direction X, and has a shape that resembles the inverted M shape of the buttocks. For example, the guide mark 60 is formed in the second region from the dorsal side (buttock region) when the absorbent body 2 is divided into four sections in the vertical direction Y. The buttock region is located between the transverse center line CL1 of the absorbent body 2 and the center line between the transverse center line CL1 and the dorsal edge 2R. The transverse center line CL1 is the center line between the ventral edge 2F and the dorsal edge 2R in the vertical direction Y, and is the part where a fold is formed when the diaper 1 is folded in half in the vertical direction Y. The intermediate sheet 71 on which the guide mark 60 is printed is formed in a rectangular shape that includes the guide mark 60. For example, the intermediate sheet 71 is positioned approximately in the center (slightly dorsal) of the vertical direction Y of the absorbent body 2 so as to cross the transverse center line CL1. As an example, the width of the intermediate sheet 71 in the lateral direction X is smaller than the width of the absorbent 30 in the lateral direction X. Also, the dorsal end of the intermediate sheet 71 is located ventrally to the dorsal edge 30R of the absorbent 30. The ventral end of the intermediate sheet 71 is located dorsal to the ventral edge 30F of the absorbent 30. In other words, when viewed from the thickness direction Z, the intermediate sheet 71 is contained within the region where the absorbent 30 is located.

[0057] As shown in Figures 1 to 3, the absorber 30 has a low-rigidity region R extending in the longitudinal direction Y, at least on the side of the absorbent body 2 in the longitudinal direction Y that is closer to the transverse center line CL1 in the longitudinal direction Y than the guide mark 60. In this embodiment, two low-rigidity regions R are arranged on both sides of the transverse direction X of the longitudinal center line CW and extend in the longitudinal direction Y over the entire length of the absorber 30 in the longitudinal direction Y. That is, as shown in Figures 1 and 2, each low-rigidity region R extends from the ventral edge 30F to the dorsal edge 30R of the absorber 30. The low-rigidity region R has a certain width in the transverse direction X.

[0058] The low-rigidity region R is the portion of the SAP sheet (absorbent 30) with a lower basis weight of the superabsorbent polymer than the portion adjacent to the low-rigidity region R, when viewed from the thickness direction Z. In this embodiment, the absorbent 30 has an absorbent layer 31 made of an absorbent polymer and a core wrap 32 covering the absorbent layer. The core wrap 32 is made of, for example, a nonwoven fabric.

[0059] As shown in Figure 3, in this embodiment, the absorbent 30 is configured as a sheet in which an absorbent layer 31 containing a superabsorbent polymer is packed into a bag shape by a core wrap 32. Furthermore, the low-rigidity region R is composed of the region of the absorbent 30 in which the superabsorbent polymer (absorbent layer 31) is not arranged when viewed from the thickness direction Z.

[0060] The core wrap 32 has a skin-side nonwoven fabric 32A and a non-skin-side nonwoven fabric 32B. The skin-side nonwoven fabric 32A is positioned on the skin-side Z1 of the absorbent layer 31 so as to cover the skin-side Z1 of the absorbent layer 31. The non-skin-side nonwoven fabric 32B is positioned on the non-skin-side Z2 of the absorbent layer 31 so as to cover the non-skin-side Z2 of the absorbent layer 31. As an example, the skin-side nonwoven fabric 32A is provided so as to overlap the non-skin-side nonwoven fabric 32B on the side of the absorbent body 30 in the lateral direction X. This realizes a structure in which the absorbent layer 31 is enclosed between the skin-side nonwoven fabric 32A and the non-skin-side nonwoven fabric 32B.

[0061] The absorption layer 31 comprises a central absorption layer 31A and a pair of lateral absorption layers 31B. The central absorption layer 31A is the portion of the absorption layer 31 that extends in the vertical direction Y from the center in the lateral direction X. The pair of lateral absorption layers 31B are located on both sides of the central absorption layer 31A in the lateral direction X, spaced apart from the central absorption layer 31A, and each extends in the vertical direction Y. A low-rigidity region R is provided between the central absorption layer 31A and each of the lateral absorption layers 31B.

[0062] The low-rigidity region R is a closed region between the central absorption layer 31A and the lateral absorption layer 31B, where opposing portions of the skin-side nonwoven fabric 32A and the non-skin-side nonwoven fabric 32B in the thickness direction Z are bonded together, preventing the superabsorbent polymer contained in the central absorption layer 31A and the superabsorbent polymer contained in the lateral absorption layer 31B from moving back and forth. In other words, the absorption layer 31 is separated by each low-rigidity region R, so that the central absorption layer 31A and the pair of lateral absorption layers 31B are arranged in the lateral direction X.

[0063] As an example, the central absorption layer 31A and the pair of lateral absorption layers 31B extend from the dorsal edge 30R to the ventral edge 30F of the absorber 30. That is, the central absorption layer 31A is located in a rectangular region enclosed by two low-rigidity regions R and edges 30R and 30F. Each lateral absorption layer 31B is located in a rectangular region enclosed by the low-rigidity region R and the lateral X end and edges 30R and 30F of the absorber 30. In this embodiment, the central absorption layer 31A and the pair of lateral absorption layers 31B are formed symmetrically with respect to the longitudinal centerline CW, and the width of the central absorption layer 31A in the lateral X direction is smaller than the width of each lateral absorption layer 31B in the lateral X direction.

[0064] [Function and Effects] In diaper 1, the guide mark 60 allows the user to understand where to position a part of the wearer's body (buttocks), and by positioning the part of the wearer's body in the appropriate location, discomfort during wear can be reduced. Furthermore, in diaper 1, the absorbent material 30, which is an SAP sheet that can be made relatively thin in its pre-use state, can improve the effect of reducing the aforementioned discomfort during wear. However, when an SAP sheet is used as the absorbent material 30, the expansion rate after use (after absorbing the wearer's urine, etc.) is relatively large compared to the pre-use state, which can easily cause discomfort during wear. Therefore, in diaper 1, a low-rigidity region R extending in the vertical direction Y is provided at least on the central side of the absorbent body 2 (i.e., the crotch side when worn) from the guide mark 60. That is, the low-rigidity region R is provided so as to extend for a certain length or more in the vertical direction Y in at least a part of the area (in this embodiment, the entire area) between the guide mark 60 and the transverse center line CL1 in the vertical direction Y. As a result, even after the absorbent material 30 absorbs the wearer's urine and the absorbent layer 31 (i.e., the superabsorbent polymer contained in the absorbent layer 31) expands, the absorbent material 30 can maintain a state in which it can be flexibly deformed starting from the low-rigidity region R, thereby reducing discomfort when wearing the diaper. Thus, with the diaper 1, by having both the guide mark 60 and the low-rigidity region R provided in the absorbent material 30, discomfort when wearing the diaper can be effectively reduced. In order to obtain the above effect, the low-rigidity region R only needs to be provided in at least a part between the guide mark 60 and the transverse center line CL1, and does not necessarily need to be provided over the entire length Y of the absorbent material 30.

[0065] In diaper 1, when viewed from the thickness direction Z, the low-rigidity region R crosses the guide mark 60 in the vertical direction Y. As shown in Figures 1 and 2, in this embodiment, each of the two low-rigidity regions R, having a certain width on both sides of the longitudinal center line CW in the lateral direction X, crosses the guide mark 60 in the vertical direction Y. The location of the guide mark 60, which serves as a marker for aligning a part of the wearer's body (in this embodiment, the buttocks), may be a location where the part of the wearer's body and the absorbent body 2 are likely to come into close contact when worn. By providing such a low-rigidity region R that crosses the guide mark 60, the wearer's discomfort from wearing the diaper can be effectively reduced.

[0066] In diaper 1, the guide mark 60 is a mark that guides the wearer's buttocks to the correct position. With the above configuration, a low-rigidity area R can be provided in the crotch area (buttock area) between the position where the wearer's buttocks should be placed (a position dorsal to the center of the absorbent body 2 in the vertical direction Y (transverse center line CL1)) and the transverse center line CL1, in a location that has a significant impact on the wearer's comfort. As a result, the wearer's comfort can be pleasantly improved.

[0067] The absorbent body 2 further includes an intermediate sheet 71 positioned between the surface sheet 10 (center sheet 11) and the absorbent body 30. The low-rigidity region R has a portion in the thickness direction Z that does not overlap with the intermediate sheet 71. In this embodiment, the low-rigidity regions R on both the left and right sides have portions that overlap with the intermediate sheet 71, but also have portions that extend dorsally beyond the dorsal end of the intermediate sheet 71 and portions that extend ventrally beyond the ventral end of the intermediate sheet 71 (i.e., portions that do not overlap with the intermediate sheet 71). If the intermediate sheet 71 is superimposed over the entire low-rigidity region R, which is a portion of the absorbent body 30 (SAP sheet) that has lower rigidity than other adjacent portions to make it easier to deform, the rigidity of the portion of the absorbent body 2 where the low-rigidity region R is provided will increase by the amount of the increased thickness of the intermediate sheet 71, which may hinder flexible deformation. In contrast, as in this embodiment, by arranging the low-rigidity region R so as to have a portion that does not overlap with the intermediate sheet 71, an appropriate difference in rigidity can be secured between the low-rigidity region R and its adjacent region (central absorption layer 31A or lateral absorption layer 31B). As a result, flexible deformation starting from the low-rigidity region R is made possible, and discomfort during wear can be effectively reduced.

[0068] From the viewpoint of suitably obtaining the effects of the low-rigidity region R described above, it is preferable that 1 / 3 or more of the low-rigidity region R is formed so as not to overlap with the intermediate sheet 71, more preferably that 1 / 2 or more of the low-rigidity region R is formed so as not to overlap with the intermediate sheet 71, and even more preferably that the entire low-rigidity region R is formed so as not to overlap with the intermediate sheet 71. As an example of a configuration in which the entire low-rigidity region R does not overlap with the intermediate sheet, in the diaper 1, the intermediate sheet 71 itself may be omitted by coloring the guide mark 60 on the center sheet 11. As another example, the intermediate sheet may be placed in a position that does not overlap with the low-rigidity region R (for example, the area between the two low-rigidity regions R on the left and right).

[0069] As shown in Figures 1 and 2, the low-rigidity region R has multiple regions (i.e., two low-rigidity regions R formed on both sides of the central absorption layer 31A) (second region) arranged in the lateral direction X within the range where the guide marks 60 are positioned in the lateral direction X, and each region extending in the vertical direction Y. With the above configuration, by arranging multiple (two in this embodiment) low-rigidity regions R within the range where the guide marks 60 are positioned in the lateral direction X, the above-mentioned effect of the low-rigidity region R (reduction of discomfort when worn by enabling flexible deformation starting from the low-rigidity region R) can be suitably obtained.

[0070] As shown in Figure 3, the absorbent body 30 (SAP sheet) is a sheet in which a superabsorbent polymer is packed into a bag shape, and the low-rigidity region R is composed of a region of the absorbent body 30 in which the superabsorbent polymer is not arranged when viewed from the thickness direction Z (in this embodiment, the region where the skin-side nonwoven fabric 32A and the non-skin-side nonwoven fabric 32B are joined). That is, in the absorbent body 30, the absorbent layer 31 made of the superabsorbent polymer is composed of a plurality (for example, three) bag-shaped divided areas (a central absorbent layer 31A and two lateral absorbent layers 31B). With the above configuration, an SAP sheet having a low-rigidity region R, which is the boundary of each area (i.e., the part in which the superabsorbent polymer is not arranged), can be suitably obtained.

[0071] The absorbent body 2 has a liquid diffusion sheet positioned between the surface sheet 10 (center sheet 11) and the absorbent body 30. In this embodiment, the intermediate sheet 71 described above functions as the liquid diffusion sheet. The liquid diffusion sheet is positioned so as to overlap with the guide mark 60 in the thickness direction Z. In this embodiment, the intermediate sheet 71 overlaps with both the central absorbent layer 31A and each of the lateral absorbent layers 31B in the thickness direction Z. Also, as shown in Figures 1 and 2, each of the lateral absorbent layers 31B overlaps with both sides of the guide mark 60 in the lateral direction X in the thickness direction Z. With the above configuration, by positioning the liquid diffusion sheet (intermediate sheet 71) in the area where the guide mark 60 is provided (the area where body pressure is likely to be applied due to the wearer's buttocks), the liquid (urine) can be appropriately diffused in the above area even when body pressure is applied by the wearer.

[0072] [Variations] The form of the absorbent article of this disclosure is not limited to the embodiments described above. Various materials and shapes can be used for the materials and shapes of each component, not limited to those described above. In addition, some of the components included in the embodiments described above may be changed or omitted, or other components may be added. Several variations of the absorbent article will be described below. The components of the embodiments described above and the various variations described thereafter can be combined as appropriate to the extent that they do not contradict each other.

[0073] Figure 4 shows modified examples (absorbents 30A to 30D) of an absorbent including an SAP sheet. Figure 4(A) schematically shows the first modified example of the absorbent (absorbent 30A). The absorbent 30A (SAP sheet) has a base sheet 33 made of nonwoven fabric and a superabsorbent polymer 31a held on at least one of the skin-facing and non-skin-facing sides (both in the example of Figure 4(A)) of the base sheet 33. The base sheet 33 is divided into a plurality of parts 33A (three in one example) in the lateral direction X. Adjacent parts 33A are spaced apart from each other in the lateral direction X. The absorbent 30A is formed by covering the plurality of parts 33A arranged in this manner with a core wrap 34.

[0074] In the absorbent 30A, the low-rigidity region R is composed of areas where the base sheet 33 and the superabsorbent polymer 31a are not arranged when viewed from the thickness direction Z. As shown in Figure 4(A), in this example, the region between adjacent portions 33A functions as the low-rigidity region R where the base sheet 33 and the superabsorbent polymer 31a are not arranged. By configuring the absorbent 30A as described above, a suitable SAP sheet having a low-rigidity region R can be obtained.

[0075] Figure 4(B) schematically shows a second modified example of the absorbent (absorbent 30B). Absorbent 30B (SAP sheet) differs from the absorbents 30 and 30A described above (i.e., absorbents configured so that the region where no superabsorbent polymer exists functions as the low-rigidity region R) in that the superabsorbent polymer is present even in the low-rigidity region R and has a certain thickness. In this example, the low-rigidity region R is composed of a portion of absorbent 30B where a recess is formed by making the basis weight of the superabsorbent polymer lower than in other parts. Thus, the low-rigidity region R is a region in which, when viewed from the thickness direction Z, the basis weight of the superabsorbent polymer is smaller than the basis weight in the adjacent region.

[0076] Figure 4(C) schematically shows a third modified example of the absorbent (absorbent 30C). Absorbent 30C includes an SAP sheet 301 having the same structure as absorbent 30B, and another absorbent core 302 arranged to overlap the SAP sheet 301 in the thickness direction Z. The absorbent core 302 contains an absorbent material such as pulp fibers or superabsorbent polymer (SAP). That is, absorbent 30C has a two-stage structure consisting of an SAP sheet 301 and an absorbent core 302. The absorbent core 302 has a uniform thickness in the portion that overlaps with the SAP sheet 301.

[0077] Figure 4(D) schematically shows a fourth modified example of the absorbent (absorbent 30D). The absorbent 30D includes an SAP sheet 301 and another absorbent core 303 arranged to overlap the SAP sheet 301 in the thickness direction Z. That is, the absorbent 30D has a two-stage structure consisting of an SAP sheet 301 and an absorbent core 303. The absorbent core 303 is similar to the absorbent core 302 in that it contains an absorbent material such as pulp fibers or superabsorbent polymer (SAP), but differs from the absorbent core 302 in that it has a low-rigidity portion 303a at a position that overlaps with the low-rigidity region R of the SAP sheet 301 in the thickness direction Z. The low-rigidity portion 303a is a portion of the absorbent core 303 where the basis weight of the absorbent material is lower than the portion of the absorbent core 303 adjacent to the low-rigidity portion 303a when viewed from the thickness direction Z.

[0078] In both the third and fourth modifications, the absorbers 30C and 30D employ a structure in which the SAP sheet 301 and other absorbent cores 302 and 303 are laminated, while being configured such that the portion of the SAP sheet 301 with a low-rigidity region R, viewed from the thickness direction Z, becomes the low-rigidity region (the portion that serves as the deformation initiation point) for the absorbers 30C and 30D as a whole. For example, if a portion of the other absorbent core with a relatively large basis weight of absorbent material is arranged to overlap with the low-rigidity region R of the SAP sheet 301, the portion with the low-rigidity region R will not become the portion with a relatively small basis weight of absorbent material within the entire absorber, and there is a risk that the portion with the low-rigidity region R will not function as the deformation initiation point. On the other hand, the structure of the absorbers 30C and 30D avoids the above-mentioned problem and allows for the favorable acquisition of the effect of the low-rigidity region R (reduction of discomfort when worn by enabling flexible deformation starting from the low-rigidity region R).

[0079] Figure 5 is a plan view of the diaper 1A according to the first modified example, as seen from the non-skin side Z2. Diaper 1A differs from diaper 1 in that it has an absorbent 30E instead of an absorbent 30. The absorbent 30E (SAP sheet) differs from absorbent 30 in that it has a low basis weight region R1 that is different from the low rigidity region R, at a position that overlaps with the guide mark 60 or dorsal to the guide mark 60. In this example, the low basis weight region R1 is provided in the portion of the absorbent 30E dorsal to the guide mark 60. The low basis weight region R1 is a region with a relatively low basis weight in the portion of the absorbent 30E excluding the low rigidity region R. That is, the basis weight of the absorbent material (SAP constituting the absorbent layer 31) in the low basis weight region R1 is smaller than the basis weight of the absorbent material in the region ventral to the low basis weight region R1 excluding the low rigidity region R. According to the above configuration, by providing a low-weight area R1 in the absorbent material 30E near the part where the wearer's buttocks are positioned, the volume difference of the SAP sheet before and after use in that area can be reduced, thereby reducing discomfort for the wearer. The low-weight area R1 may also be provided in the part that overlaps with the guide mark 60. Even in this case, the above-mentioned effects can be obtained.

[0080] Figure 6 is a plan view of diaper 1B according to the second modified example, as seen from the non-skin side Z2. Diaper 1B differs from diaper 1 in that it has an absorbent 30G instead of absorbent 30. Absorbent 30G (SAP sheet) differs from absorbent 30 in that it has a low-rigidity region RA (first region) that extends in the vertical direction Y at the center of the absorbent body 2 in the horizontal direction X. That is, absorbent 30G has one low-rigidity region RA that extends in the vertical direction Y along the longitudinal center line CW. With the above configuration, by providing a low-rigidity region RA in the part that faces the center of the wearer's crotch (the line along the crease of the buttocks) when worn, the discomfort of wearing the diaper can be effectively reduced.

[0081] Furthermore, in diaper 1B, the low-rigidity region RA (first low-rigidity region) crosses the transverse centerline CL1. In the above configuration, the low-rigidity region RA is provided to extend at least to the vicinity of the urinary opening (slightly ventrally from the intersection of the longitudinal centerline CW and the transverse centerline CL1). Through such a low-rigidity region RA, the urine excreted by the wearer can be appropriately diffused in the longitudinal direction Y.

[0082] Figure 7 shows a modified example of a configuration in which an absorbent layer 31 made of a superabsorbent polymer is divided into multiple areas in a bag-like shape. In Figure 7, (A) is a plan view showing a part of the absorbent body 30 as seen from the thickness direction Z, and (B) is a cross-sectional view along the line B-B in (A). Thus, the absorbent body 30 may be configured to include multiple absorbent layers 31 divided into cells of the same shape (for example, a regular hexagon). In this configuration, the skin-side nonwoven fabric 32A and the non-skin-side nonwoven fabric 32B are bonded (adhered) at the boundaries between adjacent cells. In this configuration, similar to the configuration of the above embodiment (see Figure 3), a low-rigidity region R is formed by the bonding portion between the skin-side nonwoven fabric 32A and the non-skin-side nonwoven fabric 32B (i.e., the region where the superabsorbent polymer is not placed). Note that the shape of the multiple areas divided into bag-like shapes is not limited to the shapes shown in the above embodiment (rectangular) or the modified example in Figure 7 (regular hexagon), but may be other polygonal shapes (for example, triangular) or approximately circular.

[0083] In this disclosure, an example of a guide mark is described as a mark that guides the wearer's buttocks to the position where they should be placed. However, the shape of the guide mark is not limited to the above embodiment (the inverted M-shaped guide mark 60 that resembles the buttocks). The guide mark may also guide the wearer to the position where they should be placed on a part of their body other than their buttocks. For example, the guide mark may be a mark that guides the wearer to the position where they should be placed on their groin or urinary opening. The shape and position of the guide mark may be appropriately changed depending on the position that the guide mark guides. In addition, the diaper may be provided with multiple guide marks (for example, a guide mark 60 for the buttocks and a guide mark for the groin). Furthermore, the guide mark 60 may be colored on the surface sheet 10 (for example, the non-skin side Z2 of the center sheet 11). In this case, the intermediate sheet 71 (i.e., the sheet for printing the guide mark 60) in the above embodiment may be omitted. Alternatively, even if the guide mark 60 is colored on the center sheet 11, an intermediate sheet 71 for liquid diffusion may be provided.

[0084] Furthermore, although this disclosure describes diapers as an example of an absorbent article, the absorbent article having the above-described configuration may be an absorbent article other than a diaper, such as an absorbent pad used in combination with a diaper.

[0085] 1, 1A, 1B... Diaper (absorbent material), 2... Absorbent body, 10... Surface sheet, 20... Back sheet, 30, 30A, 30B, 30E, 30G... Absorbent material, 31a... Superabsorbent polymer, 33... Base sheet, 60... Guide mark, 71... Intermediate sheet, 301... SAP sheet, 302, 303... Absorbent core, 303a... Low rigidity part, R... Low rigidity region, R1... Low basis weight region, RA... Low rigidity region (first region, first low rigidity region), X... Lateral direction, Y... Vertical direction, Z... Thickness direction, Z1... Skin side, Z2... Non-skin side.

Claims

1. An absorbent article extending in a longitudinal direction connecting the ventral side to the dorsal side of a wearer, and in a transverse direction perpendicular to the longitudinal direction, comprising an absorbent body having a surface sheet disposed on the skin side of the wearer, a back sheet disposed on the non-skin side opposite to the skin side, and an absorbent body having an SAP sheet containing a superabsorbent polymer disposed between the surface sheet and the back sheet, wherein the absorbent body has guide marks formed on it for guiding the position where a part of the wearer's body should be placed, the SAP sheet has a low-rigidity region extending in the longitudinal direction at least on the central side of the absorbent body in the longitudinal direction from the guide marks, and the low-rigidity region is a portion of the SAP sheet with a lower basis weight of the superabsorbent polymer than the portion adjacent to the low-rigidity region when viewed from the thickness direction perpendicular to the longitudinal and transverse directions.

2. The absorbent article according to claim 1, wherein, when viewed from the thickness direction, the low-rigidity region traverses the guide mark in the longitudinal direction.

3. The absorbent article according to claim 1, wherein the low-rigidity region has a first region extending in the vertical direction at the center of the absorbent body in the lateral direction.

4. The absorbent article according to claim 1, wherein the guide mark is a mark that guides the position where the wearer's buttocks should be placed.

5. The absorbent article according to claim 4, wherein the low-rigidity region extends in the longitudinal direction from the center of the absorbent body in the transverse direction and has a first low-rigidity region that passes through the center of the absorbent body in the longitudinal direction and crosses a center line extending in the transverse direction.

6. The absorbent article according to claim 1, wherein the absorbent body further comprises an intermediate sheet disposed between the surface sheet and the absorbent, and the low-rigidity region has a portion that does not overlap with the intermediate sheet in the thickness direction.

7. The absorbent article according to claim 4, wherein the low-rigidity region has a plurality of second regions arranged in the lateral direction and extending in the vertical direction, within the range in which the guide marks are arranged in the lateral direction.

8. The absorbent article according to claim 1, wherein the SAP sheet is a sheet in which the superabsorbent polymer is packed in a bag-like shape, and the low-rigidity region is composed of a region of the SAP sheet in which the superabsorbent polymer is not arranged when viewed from the thickness direction.

9. The absorbent article according to claim 1, wherein the SAP sheet comprises a base sheet made of a nonwoven fabric and the superabsorbent polymer held on at least one of the skin-facing side and the non-skin-facing side of the base sheet, and the low-rigidity region is composed of a region in which the base sheet and the superabsorbent polymer are not arranged when viewed from the thickness direction.

10. The absorbent article according to claim 1, wherein the absorbent comprises the SAP sheet and another absorbent core disposed so as to overlap the SAP sheet in the thickness direction, the absorbent core having a uniform thickness or having a low-rigidity portion at a position overlapping the low-rigidity region of the SAP sheet in the thickness direction, the low-rigidity portion being a portion of the absorbent core with a lower basis weight of the absorbent material constituting the absorbent core than the portion of the absorbent core adjacent to the low-rigidity portion when viewed from the thickness direction.

11. The absorbent article according to claim 4, wherein the absorbent body further comprises a liquid diffusion sheet disposed between the surface sheet and the absorbent, and the liquid diffusion sheet is arranged to overlap with the guide mark in the thickness direction.

12. The absorbent article according to claim 4, wherein the SAP sheet has a low basis weight region different from the low rigidity region at a position overlapping with the guide mark or on the back side of the guide mark, and the low basis weight region is a region with a relatively low basis weight within the portion of the SAP sheet excluding the low rigidity region.