METHOD OF PRODUCING ABSORBENT BODIES

Abstract

To facilitate the production of superabsorbent polymers containing absorbent bodies (SAP sheets) that are kept thin and ensure a good fit when worn, the invention proposes a method for producing superabsorbent polymers containing absorbent bodies, which includes: a transport step to transport the substrate with one surface of the substrate supported by a support unit; and a particle feeding step to feed superabsorbent polymer particles toward the other surface of the substrate. The support unit has numerous openings. In the figure, the diameter of the inscribed circle in each opening is equal to or greater than the average particle diameter of the superabsorbent polymer particles. In the particle feeding step, the substrate is attracted by the suction force through the openings from one side of the substrate.

Description

Method for manufacturing an absorbent body

[0001] The present invention relates to a method for producing an absorbent article.

[0002] Conventionally, there are absorbent articles such as disposable diapers that include a liquid-absorbing absorbent body. As such an absorbent body, a SAP sheet containing a superabsorbent polymer (so-called SAP) but not containing a fibrous material such as pulp is known. Such an SAP sheet is suitable for forming a thin absorbent body because it is easier to reduce the thickness compared to absorbents containing fibrous materials. For example, Patent Document 1 discloses an absorbent body in which a superabsorbent polymer is disposed on a sheet.

[0003] Japanese Patent Application Laid-Open No. 2023-122342

[0004] In the SAP sheet (absorbent) described in Patent Document 1, a large number of SAP particles are laminated to a material sheet (base sheet) so as to have a uniform thickness. However, with such an SAP sheet, when it is placed between the legs of a wearer (i.e., in the groin area) during wear, it is difficult for the sheet to deform along the contours of the wearer's body, which may result in poor fit.

[0005] The present invention has been made in consideration of the above-mentioned conventional problems, and its purpose is to easily manufacture an absorbent body (SAP sheet) having a superabsorbent polymer that has a good fit when worn while maintaining a thinness.

[0006] The main invention for achieving the above object is a method for producing an absorbent body containing a superabsorbent polymer, comprising: a conveying step of conveying a base sheet while supporting one side of the base sheet with a support part; and a particle supplying step of supplying superabsorbent polymer particles toward the other side of the base sheet, wherein the support part has a plurality of openings, and in a planar view, the diameter of the inscribed circle inscribed in the openings is equal to or greater than the average particle size of the superabsorbent polymer particles, and in the particle supplying step, the base sheet is sucked through the openings from the side of the one side of the base sheet.

[0007] Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[0008] According to the present invention, it is possible to easily produce an absorbent body containing a highly absorbent polymer that maintains a thin profile and provides a good fit when worn.

[0009] 1 is a schematic perspective view of a diaper 1; FIG. 2 is a plan view of the diaper 1 in an unfolded and stretched state, viewed from the skin side; FIG. 3 is a schematic cross-sectional view taken along the center line CL of FIG. 2; FIG. 4A is a schematic cross-sectional view of an absorbent body 20; FIG. 4B is a schematic cross-sectional view of an absorbent body 20A, showing details of an SAP layer 27; FIG. 5 is a schematic plan view of an absorbent body 20A; FIG. 6A is a schematic cross-sectional view showing how a superabsorbent polymer is laminated on a base sheet 14; FIG. 6B is a schematic plan view showing the state of a recessed region 214F on one surface of the base sheet 14; FIG. 7A is a schematic cross-sectional view showing the absorbent body 20A before absorbing moisture; FIG. 7B is a schematic cross-sectional view showing the absorbent body 20A after absorbing moisture; FIG. 8 is a schematic plan view of an absorbent body 20B of a modified example; FIG. 9 is a schematic diagram showing an overview of an absorbent body manufacturing apparatus 50; FIG. 10 is a diagram illustrating a suction opening 11su of a suction unit 11P. 11A is a cross-sectional schematic diagram showing a portion of the conveyor belt 11cn. FIG. 11B is a plan schematic diagram showing a portion of the conveyor belt 11cn. FIG. 11B is a plan schematic diagram showing another example of the suction opening su of the suction unit 11P. FIG. 11C is a diagram explaining the supply of SAP particles and the discharge of adhesive in the absorbent body manufacturing apparatus 50. FIG. 11D is a diagram explaining the suction opening 11su in the absorbent body manufacturing apparatus 50A of the first modified example. FIG. 11E is a schematic diagram showing an overview of the absorbent body manufacturing apparatus 60. FIG. 11F is a diagram explaining the plate unit 11pt of the conveying unit 11y. FIG. 11G is a plan schematic diagram showing another example of the plate unit 11pt. ​​FIG. 11H is a diagram explaining the supply of SAP particles and the discharge of adhesive in the absorbent body manufacturing apparatus 60. FIG. 11H is a perspective view of the absorbent body manufacturing apparatus 60A of the second modified example. FIG. 11H is a plan schematic diagram showing another example of the substrate 118 of the plate unit 11pt. ​​FIG. 11H is a perspective view of the absorbent body manufacturing apparatus 60B of the third modified example.

[0010] At least the following matters will become clear from the description of this specification and the accompanying drawings.

[0011] (Aspect 1) A method for producing an absorbent body containing a superabsorbent polymer, comprising: a conveying step of conveying a base sheet while supporting one side of the base sheet with a support part; and a particle supplying step of supplying superabsorbent polymer particles toward the other side of the base sheet, wherein the support part has a plurality of openings, and in a plan view, the diameter of an inscribed circle inscribed in the openings is equal to or greater than the average particle size of the superabsorbent polymer particles, and wherein the particle supplying step involves suctioning the base sheet from the side of the one side of the base sheet through the openings.

[0012] According to Aspect 1, an absorbent body having a superabsorbent polymer laminated on a base sheet can be manufactured by including a conveying step of conveying the base sheet while supporting one side of the base sheet with a support portion and a particle supplying step of supplying superabsorbent polymer particles toward the other side of the base sheet. The support portion has multiple openings, and by suctioning the base sheet from one side of the base sheet through the multiple openings in the particle supplying step, an absorbent body can be manufactured in which high basis weight regions and low basis weight regions are formed around each high basis weight region. The low basis weight regions serve as folding points, making the absorbent body more easily deformable to conform to the contours of the wearer's body, improving fit. In a plan view, the diameter of the inscribed circle inscribed in each of the multiple openings is equal to or greater than the average particle size of the superabsorbent polymer particles, allowing for the arrangement of multiple high basis weight regions and low basis weight regions while maintaining the absorbent body's thinness. Therefore, Aspect 1 makes it possible to easily manufacture an absorbent body having a superabsorbent polymer that maintains a thin profile and provides a good fit when worn.

[0013] (Aspect 2) The method for producing the absorbent body according to aspect 1, wherein in the conveying step, the support part is a conveying belt that conveys the base sheet.

[0014] According to aspect 2, even with an absorbent body manufacturing apparatus using a conveyor belt, it is possible to easily manufacture an absorbent body having a superabsorbent polymer that maintains a thinness and provides a good fit when worn.

[0015] (Aspect 3) A method for producing the absorbent body according to Aspect 2, characterized in that a suction section is provided on the opposite side of the support section from the side on which the base sheet is located, and another conveyor belt having a suction opening is provided, and the other conveyor belt is positioned between the conveyor belt and the suction section and moves in the same direction as the conveying direction of the conveyor belt.

[0016] According to aspect 3, another conveying belt is positioned between the conveying belt and the suction section and moves in the same direction as the conveying direction of the conveying belt, thereby suppressing wear of the conveying belt due to the conveying belt rubbing against the edge of the suction opening and extending the life of the conveying belt.

[0017] (Aspect 4) A method for producing an absorbent body according to Aspect 2 or 3, characterized in that a suction section is provided on the opposite side of the support section from the side on which the base sheet is located, and the suction port of the suction section has, in a cross direction crossing the conveyance direction of the base sheet, a first opening region and a second opening region adjacent to the first opening region and having a lower opening ratio than the first opening region, and in the particle supply step, the suction section sucks the base sheet from the side of the one surface of the base sheet through the openings, the first opening region, and the second opening region.

[0018] According to Aspect 4, an absorbent body having a channel region can be formed. The absorbent body having a channel region is more likely to deform in the width direction under the crotch of the wearer, increasing the storage capacity under the crotch and improving the fit.

[0019] (Aspect 5) A method for manufacturing the absorbent body according to Aspect 4, characterized in that the opening ratio of the first opening region is equal to or greater than the opening ratio of the openings in the region where the openings of the support section are provided.

[0020] According to the fifth aspect, an absorber having a channel region can be appropriately formed.

[0021] (Aspect 6) A method for manufacturing the absorbent body according to Aspect 4 or 5, characterized in that the aperture ratio of the second opening region is equal to or less than the aperture ratio of the openings in the region where the openings of the support section are provided.

[0022] According to the sixth aspect, an absorber having a channel region can be appropriately formed.

[0023] (Aspect 7) A method for producing the absorbent body according to any one of Aspects 4 to 6, characterized in that a plurality of the second opening regions are provided in the crossing direction.

[0024] According to aspect 7, an absorbent body having a plurality of channel regions can be formed. In an absorbent body having a plurality of channel regions, the storage capacity in the crotch area is further increased, and the fit is further improved.

[0025] (Aspect 8) A method for manufacturing an absorbent body according to any one of Aspects 4 to 7, wherein the suction section comprises a third opening region and a non-opening region, the third opening region is located downstream of the first opening region in the conveying direction and has a portion that overlaps with the first opening region in the crossing direction, the third opening region has a lower opening rate than the first opening region, the non-opening region is located downstream of the second opening region in the conveying direction and has a portion that overlaps with the second opening region in the crossing direction, and the suction section sucks the base sheet from the side of the one surface of the base sheet via the third opening region downstream of a position where the superabsorbent polymer particles are supplied to the base sheet in the conveying direction of the base sheet.

[0026] According to the eighth aspect, it is possible to prevent the superabsorbent polymer particles that have rebounded at the position where the superabsorbent polymer particles are supplied from being disposed in the channel region downstream.

[0027] (Aspect 9) A method for manufacturing the absorbent body described in Aspect 8, wherein the suction section has a fourth opening area that is located outside the first opening area and the third opening area in the cross direction in a plan view and overlaps with an end of the base sheet in the cross direction, and wherein in the conveying step, the suction section sucks the end from the side of the one surface of the base sheet through the fourth opening area.

[0028] According to Aspect 9, it is possible to prevent the base sheet from curling up during transport.

[0029] (Aspect 10) A method for producing an absorbent body according to any one of Aspects 1 to 9, characterized in that in the conveying step, the support part is a rotating body that conveys the base sheet.

[0030] According to aspect 10, even with an absorbent body manufacturing apparatus using a rotating body, it is possible to easily manufacture an absorbent body having a highly absorbent polymer that maintains a thinness and provides a good fit when worn.

[0031] (Aspect 11) A method for manufacturing an absorbent body according to Aspect 10, characterized in that a suction section is provided on the side of the support section opposite to the side on which the base sheet is located, the support section having first openings and second openings having a lower opening rate than the first openings among the plurality of openings, the region in which the first openings are provided and the region in which the second openings are provided being adjacent to each other in a cross direction intersecting with the conveyance direction of the base sheet, and in the particle supply step, the suction section sucks the base sheet from the side of the one surface of the base sheet through the first openings and the second openings.

[0032] According to Aspect 11, an absorbent body having a channel region can be formed. The absorbent body having a channel region is more likely to deform in the width direction under the crotch of the wearer, increasing the storage capacity under the crotch and improving the fit.

[0033] (Aspect 12) A method for producing the absorbent body according to aspect 11, characterized in that a plurality of regions in which the second openings are provided are provided in the cross direction.

[0034] According to aspect 12, an absorbent body having a plurality of channel regions can be formed. In an absorbent body having a plurality of channel regions, the storage capacity in the crotch area is further increased, and the fit is further improved.

[0035] (Aspect 13) A method for producing an absorbent body according to any one of aspects 1 to 12, characterized in that the method includes an upstream adhesive application step of applying adhesive toward the other surface of the base sheet upstream of the position where the superabsorbent polymer particles are supplied to the base sheet in the conveying direction of the base sheet.

[0036] According to Aspect 13, the superabsorbent polymer particles can be made to easily stick to the base sheet.

[0037] (Aspect 14) A method for producing the absorbent body according to Aspect 13, comprising: a separate sheet supplying step of supplying another sheet so as to cover the superabsorbent polymer particles from the other side of the base sheet downstream in the conveying direction of the base sheet from the position where the superabsorbent polymer particles are supplied to the base sheet; and a joint forming step of joining the other sheet and the base sheet in the thickness direction in an area of ​​the other side of the base sheet where the adhesive is not applied, along a cross direction that intersects with the conveying direction of the base sheet.

[0038] According to Aspect 14, it is possible to suppress the opening between the base sheet and the other sheet.

[0039] (Aspect 15) A method for producing an absorbent body according to any one of aspects 1 to 14, wherein the diameter of an inscribed circle inscribed in the opening is 2 mm or more and 4 mm or less.

[0040] According to aspect 15, by reducing the size of each of the multiple high basis weight regions in a planar view, a large number of high basis weight regions and low basis weight regions can be arranged on the base sheet, making it easier for the absorbent body to deform in accordance with the contours of the wearer's body, thereby improving fit.

[0041] (Aspect 16) A method for manufacturing the absorbent body according to Aspect 15, characterized in that in the support section, the opening ratio of the openings in the region where the openings are provided is 40% or more and 60% or less.

[0042] According to Aspect 16, a high basis weight region can be appropriately formed in the absorbent body.

[0043] (Aspect 17) A method for producing an absorbent body according to any one of aspects 1 to 16, comprising a downstream adhesive discharge step of discharging adhesive together with an air flow toward the other surface of the base sheet downstream in the conveying direction of the base sheet from the position where the superabsorbent polymer particles are supplied to the base sheet, and wherein the discharged adhesive pushes back toward the base sheet at least a portion of the superabsorbent polymer particles that have rebounded from the base sheet.

[0044] According to Aspect 17, it is possible to reduce the possibility of the superabsorbent polymer particles being disposed in unintended positions on the base sheet.

[0045] (Aspect 18) A method for manufacturing an absorbent body according to Aspect 17, characterized in that in the conveying step, the base sheet is conveyed by a conveying conveyor, and the conveying surface of the conveying conveyor is inclined with respect to a horizontal plane so that the downstream side faces downward.

[0046] According to Aspect 18, it is possible to further reduce the possibility of the superabsorbent polymer particles being disposed in unintended positions on the base sheet.

[0047] (Aspect 19) A method for manufacturing an absorbent body according to Aspect 17, characterized in that in the conveying step, the base sheet is conveyed by a rotating body, the adhesive is discharged in a predetermined discharge direction, and the upstream side of the discharge direction is inclined toward the downstream side of the conveying direction so that the angle formed by an imaginary line extending the discharge direction and a tangent to the rotating body at the intersection of the imaginary line and the outer peripheral surface of the rotating body is greater than 90 degrees.

[0048] According to Aspect 19, it is possible to reduce the possibility of the superabsorbent polymer particles being disposed in unintended positions on the base sheet.

[0049] (Aspect 20) A method for manufacturing an absorbent body according to any one of aspects 1 to 19, characterized in that the method for manufacturing an absorbent body includes a fibrous material supplying step of supplying a fibrous material containing pulp from above the superabsorbent polymer laminated on the base sheet downstream in the conveying direction of the base sheet from the position where the superabsorbent polymer particles are supplied to the base sheet.

[0050] According to Aspect 20, it is possible to easily manufacture an absorbent body that can quickly and temporarily absorb excreted liquid and can prevent overflow and leakage of excreted liquid during excretion.

[0051] Absorbent Article and Absorbent Body The absorbent article according to the present invention will be described using a pants-type disposable diaper 1 for infants (hereinafter also referred to as "diaper 1") as an example. However, the absorbent article according to the present invention also includes tape-type disposable diapers, shorts-type napkins, absorbent pads, sanitary napkins, and other absorbent articles. Furthermore, the wearer of the absorbent article is not limited to infants, but may also be an adult, an animal, or other living being.

[0052] <<Configuration of absorbent article (diaper 1)>> Fig. 1 is a schematic perspective view of the diaper 1. Fig. 2 is a plan view of the diaper 1 in an unfolded and stretched state, as seen from the skin side. Fig. 3 is a schematic cross-sectional view taken along the center line CL of Fig. 2 .

[0053] The "unfolded state" of the diaper 1 refers to the state in which the pair of side seam regions 2 provided on both sides of the diaper 1 shown in Fig. 1 are separated, and the diaper 1 is opened and unfolded in a flat plane as shown in Fig. 2. The "stretched state" of the diaper 1 refers to the state in which the entire diaper 1 is stretched without wrinkles, specifically, the state in which the dimensions of each component constituting the diaper 1 (e.g., the absorbent main body 10 and waist-lined regions 30, 40, etc., described below) are stretched to the same dimensions as or close to the dimensions of the individual components.

[0054] As shown in Fig. 1, the diaper 1 has a vertical direction, a width direction, and a front-to-rear direction that are perpendicular to each other, and has a waist opening BH and a pair of leg openings LH. The upper side in the vertical direction corresponds to the waist opening BH side, and the lower side corresponds to the crotch side. The front side in the front-to-rear direction corresponds to the wearer's abdomen side, and the rear side corresponds to the wearer's back side. As shown in Fig. 2, the width direction is a direction along the stretch direction of waist elastic members 33, 43 such as rubber thread provided in the front waist portion 30 and the rear waist portion 40. The vertical direction is a direction perpendicular to the stretch direction.

[0055] The diaper 1 is a so-called three-piece pants-type diaper having a liquid-absorbent main body 10 and a pair of waist-surrounding sections 30, 40. Of the pair of waist-surrounding sections, the one covering the wearer's abdominal region is also referred to as the front waist-surrounding section 30, and the other covering the wearer's dorsal region is also referred to as the rear waist-surrounding section 40.

[0056] In the unfolded state shown in Fig. 2, the diaper 1 has a longitudinal direction, a width direction, and a thickness direction which are perpendicular to one another. The longitudinal direction is along the longitudinal direction of the absorbent body 10 and along the vertical direction of the pants-type diaper 1. The thickness direction is the direction in which the materials constituting the diaper 1 are layered, as shown in Fig. 3. In the thickness direction, the side that comes into contact with the wearer's skin is referred to as the skin side, and the opposite side is referred to as the non-skin side.

[0057] 2 , the front waistline section 30 and the rear waistline section 40 are aligned parallel to each other with a gap in the longitudinal direction, with the absorbent main body 10 suspended between them, with each longitudinal end of the absorbent main body 10 joined and fixed to the skin side of the nearest waistline section 30, 40, resulting in an external shape that is generally H-shaped in plan view. From this state, the absorbent main body 10 is then folded in half along the longitudinal center line CL. In this folded state, the opposing front waistline section 30 and rear waistline section 40 are joined and connected at both widthwise sides to form a pair of side joint sections 2. The side joint sections 2 are formed by known joining means such as welding or adhesive bonding.

[0058] As shown in Figure 3, the absorbent body 10 has an absorbent body 20 (details will be described later), a liquid-permeable top sheet 12 arranged closer to the skin than the absorbent body 20, and a back sheet 13 arranged closer to the skin than the absorbent body 20. The back sheet 13 has a two-layer structure consisting of a liquid-impermeable sheet 13a and a hydrophobic exterior sheet 13b arranged on the far side of the liquid-impermeable sheet 13a. However, the absorbent body 10 may also include sheet members other than these. For example, a second sheet (not shown) may be provided between the top sheet 12 and the absorbent body 20 in the thickness direction.

[0059] A pair of leakage preventing walls 15 is provided along the longitudinal direction of the absorbent main body 10 on both widthwise sides of the absorbent main body 10. In Figure 3, a part of the exterior sheet 13b extends outward from both ends of the absorber 20 in the widthwise direction and is folded toward the skin at multiple locations to form the pair of leakage preventing walls 15. A leakage preventing wall elastic member 16 such as rubber thread is attached to the tip of the leakage preventing wall 15 in a state stretched along the longitudinal direction of the absorbent main body 10, so that the leakage preventing wall 15 can stand up toward the skin. In addition, leg elastic members 17 such as rubber thread are attached to both widthwise sides of the absorbent main body 10 in a state stretched along the longitudinal direction of the absorbent main body 10.

[0060] As shown in FIG. 2 , the front waistline portion 30 and the rear waistline portion 40 each include a skin-side sheet 31, 41, a non-skin-side sheet 32, 42, and multiple waistline elastic members 33, 43 such as rubber threads. The multiple waistline elastic members 33, 43 are arranged vertically between the skin-side sheet 31, 41 and the non-skin-side sheet 32, 42 and are attached in a stretched state in the width direction. The stretchability of the waistline elastic members 33, 43 allows the front waistline portion 30 and the rear waistline portion 40 to fit the wearer's waist. Cover sheets 34, 44 may also be provided to cover the upper end of the absorbent main body 10 from the skin side. The cover sheets 34, 44 can prevent the absorbent main body 10 from opening.

[0061] 2, the front waistline portion 30 and the rear waistline portion 40 have different planar shapes in the unfolded and stretched state. The front waistline portion 30 has a vertical length that is roughly the same as that of the side joint portion 2 and a rectangular shape that is long in the width direction. The rear waistline portion 40 has a rectangular portion that overlaps with the front waistline portion 30 and a generally trapezoidal portion 40E that extends downward from the rectangular portion 30. The extending portion 40E can cover the wearer's buttocks.

[0062] The basic configuration of the diaper 1 has been described above, but the above configuration is merely an example and is not intended to be limiting. For example, the front waistline portion 30 and the rear waistline portion 40 may be formed from a single continuous member, or an outer member may be provided in the crotch area connecting the front waistline portion 30 and the rear waistline portion 40. Furthermore, the elastic members such as the waistline elastic members 33, 43 may be sheet-like elastic members instead of rubber threads.

[0063] <<Configuration of Absorbent Body>> Next, the absorbent body 20 of the above-described absorbent article (diaper 1) will be described in detail with reference to FIGS. 4A, 4B and 5. FIG.

[0064] Fig. 4A is a schematic cross-sectional view of the absorbent body 20. Fig. 4B is a schematic cross-sectional view of the absorbent body 20A showing details of the SAP layer 27. Fig. 5 is a schematic plan view of the absorbent body 20A.

[0065] 4A, the absorbent body 20 of the absorbent article (diaper 1) described above has absorbent cores 21 to 23 between a skin-side core wrap sheet 24 and a non-skin-side core wrap sheet 25. Each of the absorbent cores 21 to 23 is a member that absorbs and retains excretory fluids such as urine, and includes at least one of a fibrous material and a super absorbent polymer (hereinafter also referred to as SAP).

[0066] The fibrous material and superabsorbent polymer are not particularly limited as long as they can be used as an absorbent core for an absorbent article. The fibrous material is a fibrous material with liquid absorbency, such as wood pulp fiber, non-wood pulp fiber such as bagasse, kenaf, bamboo, hemp, or cotton, regenerated cellulose fiber such as rayon fiber, semi-synthetic fiber such as acetate fiber, or a mixture thereof. Examples of SAP include starch-based, cellulose-based, and synthetic polymer-based polymer absorbents, or a mixture thereof. The core wrap sheets 24 and 25 are liquid-permeable sheets, such as nonwoven fabrics and tissues.

[0067] The absorbent cores 21-23 may be referred to as the skin-side layer 21, the intermediate layer 22, and the non-skin-side layer 23, in that order from the skin side in the thickness direction. In the absorbent body 20 shown in Fig. 4A , the skin-side layer 21 is not formed integrally with the intermediate layer 22, which is located closer to the skin than the skin-side layer 21, but is laminated adjacent to the intermediate layer 22 in the thickness direction via a sheet 26 made of nonwoven fabric, tissue, or the like. In addition, in the absorbent body 20 shown in Fig. 4A , the intermediate layer 22 and the non-skin-side layer 23 are formed integrally. In other words, the non-skin-side layer 23 is laminated directly on the non-skin side of the intermediate layer 22 without an intervening sheet of nonwoven fabric, adhesive HMA, or the like.

[0068] The volume occupancy of the fibrous material or SAP in the absorbent cores 21-23 can be varied for each absorbent core 21-23 depending on the purpose. For example, the volume occupancy of SAP may be high in the skin-side layer 21, the volume occupancy of the fibrous material may be high in the intermediate layer 22, and the volume occupancy of SAP may be high in the non-skin-side layer 23. Furthermore, the skin-side layer 21 may contain only SAP without any fibrous material, the intermediate layer 22 may contain only fibrous material without any SAP, and the non-skin-side layer 23 may contain only SAP without any fibrous material. Because SAP absorbs liquids slowly and fibrous material absorbs liquids faster than SAP, excreted liquids tend to migrate to the intermediate layer 22 before being absorbed by the SAP in the skin-side layer 21. Excreted liquid absorbed between the fibers of the fibrous material in the intermediate layer 22 gradually migrates by gravity to the non-skin-side layer 23, where it is firmly absorbed and retained by the SAP in the non-skin-side layer 23.

[0069] This makes it easier for excreted liquid to be drawn all the way to the non-skinside layer 23, allowing the absorbent cores 21-23 to be effectively utilized in the thickness direction. This increases the absorbent cores' absorbing and holding capacity, preventing excreted liquid from leaking even with repeated excretion. This also ensures that the skin-side surfaces of the absorbent cores 21-23 remain dry, improving the comfort of the diaper 1. Furthermore, even if excreted liquid in the intermediate layer 22 or the non-skinside layer 23 attempts to return to the skin side, the SAP in the skin-side layer 21 absorbs and retains the excreted liquid. This also helps to prevent rewetting of excreted liquid. This also ensures that the skin-side surfaces of the absorbent cores 21-23 remain dry.

[0070] As shown in FIG. 4A , the sheet 26 is located closer to the skin side than the intermediate layer 22 in the thickness direction (the side where the skin side layer 21 is located), and an adhesive HMA is provided between the intermediate layer 22 and the sheet 26. The adhesive HMA is a hot melt adhesive. In other words, the adhesive HMA is provided between the fibrous material (intermediate layer 22) and the SAP (skin side layer 21). Furthermore, the core wrap sheet 25 is located closer to the skin side than the non-skin side layer 23, and an adhesive HMA is provided between the non-skin side layer 23 and the core wrap sheet 25. The adhesive HMA provided between the intermediate layer 22 and the sheet 26 and the adhesive HMA provided between the non-skin side layer 23 and the core wrap sheet 25 bond the sheet 26 and the core wrap sheet 25, and fix the intermediate layer 22 and the non-skin side layer 23 to the sheet 26 and the core wrap sheet 25.

[0071] Here, the absorbent body 20 is not limited to the embodiment shown in Fig. 4A . In the absorbent body 20 shown in Fig. 4A , the following layers are laminated in order from the skin side in the thickness direction: a sheet (core wrap sheet 24), a skin-side layer 21, a sheet 26, an integrally formed intermediate layer 22 and non-skin-side layer 23, and a sheet (core wrap sheet 25). However, the sheet 26 may be located between the intermediate layer 22 and the non-skin-side layer 23, rather than between the skin-side layer 21 and the intermediate layer 22. In this case, the skin-side layer 21 (a layer with a high volume occupancy rate of SAP) and the intermediate layer 22 (a layer with a high volume occupancy rate of fibrous material) may be integrally formed. In other words, the intermediate layer 22 (a layer with a high volume occupancy rate of fibrous material) may be laminated directly on the non-skin side of the skin-side layer 21 (a layer with a high volume occupancy rate of SAP) without the interposition of a sheet such as a nonwoven fabric or an adhesive such as an HMA. In this case, the absorbent body 20 has a pulp-containing fibrous material adjacent to the SAP in the thickness direction. This allows for rapid, temporary absorption of excreted fluid and prevents overflow and leakage of excreted fluid during excretion. The non-skin-side layer 23 (a layer having a high volume occupancy rate of SAP) may be laminated adjacently in the thickness direction with the sheet 26 interposed therebetween.

[0072] Furthermore, without being limited to the above, the skin side layer 21 that is not integrally formed with the intermediate layer 22 may be laminated to the intermediate layer 22 without an intervening sheet of nonwoven fabric or adhesive HMA. Similarly, the non-skin side layer 23 that is not integrally formed with the intermediate layer 22 may be laminated to the intermediate layer 22 without an intervening sheet of nonwoven fabric or adhesive HMA. Furthermore, the intermediate layer 22 is not limited to being formed integrally with only one of the skin side layer 21 and the non-skin side layer 23, but may be formed integrally with both the skin side layer 21 and the non-skin side layer 23. A sheet of nonwoven fabric or adhesive HMA may or may not be provided between the skin side layer 21 and the intermediate layer 22, and between the intermediate layer 22 and the non-skin side layer 23, respectively.

[0073] The absorbent body 20 is not limited to a configuration in which three absorbent core layers, i.e., the skin side layer 21, the intermediate layer 22, and the non-skin side layer 23, are laminated. Two absorbent core layers may be laminated, or only one absorbent core layer may be laminated. In the following, the description will be continued using an absorbent body in which SAP is laminated on a sheet of nonwoven fabric or the like (hereinafter referred to as an SAP sheet) as a configuration in which only one absorbent core layer is laminated.

[0074] As shown in FIG. 4B , the absorbent body 20A includes a base sheet 14, an SAP layer 27, and another sheet 14S. The combination of the base sheet 14, the SAP layer 27, and the another sheet 14S in the absorbent body 20A corresponds, for example, to the combination of the core wrap sheet 24, the skin-side layer 21, and the sheet 26 in the absorbent body 20, or the combination of the core wrap sheet 25, the non-skin-side layer 23, and the sheet 26 when the sheet 26 is positioned between the intermediate layer 22 and the non-skin-side layer 23. The SAP layer 27 (high basis weight regions 211 and low basis weight regions 212, described below) contains only SAP and does not contain any fibrous material other than SAP. This allows the absorbent body 20A to be thinner than absorbents that do not contain fibrous materials. The SAP in the SAP layer 27 is fixed to the base sheet 14 or the another sheet 14S by an adhesive HMA. This ensures reliable fixation of the SAP to the base sheet 14 or the another sheet 14S.

[0075] Hereinafter, "particles" when used in conjunction with the term "superabsorbent polymer (SAP)" encompass any individual shape or form, and can include granules, agglomerates, flakes, fibers, spheres, and the like, and combinations thereof. Also, particles can have any desired shape, such as, for example, spherical, polygonal, rod-like, polyhedral, or other circular or angular regular or irregular shapes.

[0076] As shown in Fig. 4B , the SAP layer 27 has high basis weight regions 211 in which the basis weight of the SAP is higher than that of the surrounding areas. Furthermore, as shown in Fig. 5 , within the high basis weight regions 211, points S of maximum thickness in the thickness direction are located intermittently in the longitudinal and width directions. As a result, the high basis weight regions 211 shown in Fig. 5 are arranged intermittently in the longitudinal and width directions. Furthermore, between adjacent points S of maximum thickness (i.e., around the high basis weight regions 211), low basis weight regions 212 in which the basis weight of the SAP is lower than that of the high basis weight regions 211 are formed.

[0077] However, as long as the points S of maximum thickness are located intermittently in the longitudinal direction and the width direction, a portion of the space between adjacent points S of maximum thickness may be formed by the high basis weight region 211. In other words, a portion of the space between adjacent points S of maximum thickness may be connected by the high basis weight region 211. In Figure 5, the range of the high basis weight region 211 in a plan view is represented by a solid line, and the range of the low basis weight region 212 is represented by a dashed dotted line. The ranges of the high basis weight region 211 and the low basis weight region 212 shown in Figure 5 are represented schematically for convenience.

[0078] 4B and 5, the low basis weight region 212 has a low basis weight laminated region 212E where SAP is laminated, and a non-laminated region 212N where no SAP is present. Here, "no SAP" not only means that no SAP particles are present, but also includes a situation where there are only a small number of laminated SAP particles and no SAP particles are substantially present. In FIG. 5, a triangle mark is placed at the center of the low basis weight laminated region 212E, and an x ​​mark is placed at the center of the non-laminated region 212N.

[0079] In the absorbent body 20A of this embodiment, the low basis weight regions 212 (low basis weight laminated regions 212E and non-laminated regions 212N) serve as folding points, allowing the absorbent body 20A to easily deform along the contours of the wearer's body, improving fit. Furthermore, the low basis weight regions 212 that serve as folding points include the low basis weight laminated regions 212E that can absorb and retain excrement, and the non-laminated regions 212N that are more easily bent due to the absence of SAP. As a result, even in the low basis weight regions 212 where the basis weight of SAP is lower than that of the high basis weight regions 211, it is possible to achieve both ease of deformation along the contours of the wearer's body and the ability to absorb and retain excrement.

[0080] As described above, the low basis weight regions 212 are formed between points S of maximum thickness that are arranged intermittently in the longitudinal and width directions. Therefore, the low basis weight regions 212 are also arranged intermittently in the longitudinal and width directions, as shown in Fig. 5. That is, the low basis weight laminated regions 212E are arranged intermittently in the longitudinal and width directions, and similarly, the non-laminated regions 212N are also arranged intermittently in the longitudinal and width directions. By sparsely arranging the low basis weight laminated regions 212E and non-laminated regions 212N in this way in a plane, the absorbent body 20A can easily deform to conform to the contours of the wearer's body and can absorb and retain excrement in a planar manner.

[0081] In the absorbent body 20A of this embodiment, for example, in the plan view shown in Fig. 5, the number of low basis weight laminated regions 212E varies among the regions obtained by dividing the absorbent body 20A into three equal parts in the longitudinal direction. The number of non-laminated regions 212N also varies among the regions obtained by dividing the absorbent body 20A into three equal parts in the longitudinal direction. As will be described in detail later, when SAP particles are supplied toward a base sheet to manufacture an absorbent body, regions to which no SAP particles adhere become non-laminated regions 212N, and regions to which some SAP particles adhere become low basis weight laminated regions 212E. The non-laminated regions 212N and the low basis weight laminated regions 212E are each generated randomly in a plan view, and therefore, as described above, the number of low basis weight laminated regions 212E and the number of non-laminated regions 212N vary among the regions obtained by dividing the absorbent body 20A into three equal parts in the longitudinal direction in a plan view. In this way, by randomly arranging the low basis weight laminated regions 212E and non-laminated regions 212N in a plane, the absorbent body 20A becomes more likely to deform along the contours of the wearer's body, thereby improving fit.

[0082] Furthermore, in the absorbent body 20A of this embodiment, the low basis weight region 212 surrounding the high basis weight region 211 facilitates diffusion of excrement in the planar direction. If the basis weight of the SAP were constant in a planar direction, adjacent SAP particles would likely stick together when they absorb moisture, forming clumps that could inhibit further diffusion of excrement. In other words, if the basis weight of the SAP were constant in a planar direction, there is a risk of so-called gel blocking occurring.

[0083] Therefore, in the absorbent body 20A of this embodiment, the absorbent body 20A has a low basis weight region 212 around the high basis weight region 211, which makes it easier for the excreted liquid to spread along the low basis weight region 212 even after absorbing a certain amount of excreted liquid, thereby suppressing the occurrence of the above-mentioned gel blocking.

[0084] The non-laminated regions 212N are arranged so that there are more of them on the widthwise side than on the longitudinal side when viewed from a certain high basis weight region 211. In other words, among the points S of maximum thickness, the number of points S at which non-laminated regions 212N are adjacent on one or both sides in the widthwise direction is greater than the number of points S at which non-laminated regions 212N are adjacent on one or both sides in the longitudinal direction. As a result, the low basis weight laminated regions 212E are arranged so that there are more of them on the longitudinal side than on the widthwise side when viewed from the high basis weight region 211. In this case, when the absorbent body 20A has absorbed excrement, that is, when it is in a swollen state, more SAPs will stick together in the longitudinal direction where there are more low basis weight laminated regions 212E. Therefore, it is possible to prevent the absorbent body 20A from losing flexibility in the widthwise direction when it is in a swollen state.

[0085] The absorbent body 20A shown in Fig. 5 may further be provided with a channel region 215 shown in Fig. 8, which will be described later. The channel region 215 will be described in detail later. Having the channel region 215, for example, when the absorbent body 20A is held between the wearer's legs (i.e., the groin area) during wear, makes it easier for the absorbent body 20A to deform in the width direction under the wearer's crotch, increasing storage capacity under the crotch area and further improving fit. In this case, the channel region 215 itself serves as a folding starting point, thereby contributing to improved fit. However, the channel region 215 does not necessarily have to be provided in the absorbent body 20A.

[0086] Furthermore, as shown in FIG. 4B , in the absorbent body 20A of this embodiment, it is preferable that the maximum thickness T is 3 mm or less, and the distance between adjacent maximum thickness points S is 5 times or less the maximum thickness T. This allows for the arrangement of multiple high and low basis weight regions while maintaining the thinness of the absorbent body 20A. Therefore, the absorbent body 20A containing a superabsorbent polymer can maintain its thinness while improving its fit when worn. It is even more preferable that the maximum thickness T is 2 mm or less, and the distance between adjacent maximum thickness points S is 4 times or less the maximum thickness T. This allows for the absorbent body 20A containing a superabsorbent polymer to maintain its thinness while improving its fit when worn.

[0087] 5, the diameter of a circumscribing circle CC circumscribing each of the plurality of high basis weight regions 211 is preferably 2 mm or more and 4 mm or less. This allows the size of each of the plurality of high basis weight regions 211 to be reduced, and allows a large number of high basis weight regions 211 and low basis weight regions 212 to be arranged on the base sheet 14. This makes it easier for the absorbent body 20A to deform along the contours of the wearer's body, improving fit.

[0088] 5, it is preferable that the largest diameter of the inscribed circles IC inscribed in each of the plurality of non-laminated regions 212N is equal to or smaller than the maximum thickness T. In this way, by reducing the size of the non-laminated regions 212N without SAP in plan view, leakage of excrement through the non-laminated regions 212N can be suppressed.

[0089] Furthermore, in the plan view shown in Fig. 5, a joint 213 is provided longitudinally outward of the regions where SAP is provided (i.e., the high basis weight region 211 and the low basis weight region 212). The joint 213 is a portion where the base sheet 14 and the separate sheet 14S are joined in the thickness direction. The joint 213 is formed by a known joining method such as embossing, welding, or adhesion. This makes it possible to prevent the base sheet 14 and the separate sheet 14S from opening open.

[0090] The region of the base sheet 14 where the bonding portion 213 is formed is a region where no SAP is provided and no adhesive for fixing the SAP is provided. Here, the region where no SAP is provided is a region where substantially no SAP is provided (for example, the weight of SAP provided in this region is 10% or less of the weight of SAP provided in the entire base sheet 14). Also, the bonding portion 213 does not have to be provided.

[0091] Fig. 6A is a schematic cross-sectional view showing how a superabsorbent polymer is laminated on a base sheet 14. Fig. 6B is a schematic plan view showing how a recessed region 214F appears on one surface of the base sheet 14.

[0092] 6A , recessed regions 214 are formed on both one surface and the other surface of the base sheet 14 in the thickness direction. Specifically, recessed region 214F is formed on one surface of the base sheet 14, and recessed region 214B is formed on the other surface. On one surface of the base sheet 14 in the thickness direction, a large amount of SAP is disposed in recessed region 214F, forming a high basis weight region 211. On the other hand, in regions other than recessed region 214F, no SAP is disposed, or even if SAP is disposed, it is disposed in a smaller amount than in recessed region 214F, thereby forming a low basis weight region 212 (low basis weight laminated region 212E or non-laminated region 212N).

[0093] 6B , the recessed regions 214F are arranged intermittently in the longitudinal and width directions on one side of the base sheet 14. This results in the high basis weight regions 211 being arranged so that points S at which the high basis weight regions 211 have the maximum thickness in the thickness direction are located intermittently in the longitudinal and width directions. Similarly, the low basis weight regions 212 (low basis weight laminated regions 212E and non-laminated regions 212N) are also arranged intermittently in the longitudinal and width directions.

[0094] Furthermore, the difference SB1 between the highest point H1 and the lowest point L1 in the thickness direction on one surface of the base sheet 14 is different from the difference SB2 between the highest point H2 and the lowest point L2 in the thickness direction on the other surface of the base sheet 14. In other words, the depth of the recessed region 214 where the SAP is arranged can be made different between the recessed region 214F on one surface of the base sheet 14 and the recessed region 214B on the other surface. In other words, in the base sheet 14 shown in Fig. 6B, the recess in the recessed region 214F on one surface is shallow, and the recess in the recessed region 214B on the other surface is deep.

[0095] In the base sheet 14 shown in FIG. 6A , the absorbent body 20A is formed by disposing SAP in the recessed region 214F on the shallower recess side. However, the absorbent body 20A may also be formed by disposing SAP in the recessed region 214B on the deeper recess side. For example, more SAP can be disposed in the recessed region 214B on the deeper recess side than in the recessed region 214F on the shallower recess side, thereby improving the absorption and retention of excreted liquid. Conversely, disposing SAP in the recessed region 214F on the shallower recess side can improve liquid diffusibility compared to the recessed region 214B. Therefore, by making the depths of the recessed region 214F and the recessed region 214B different as described above, it is possible to select which recessed region 214 the SAP is disposed in, and an absorbent body with properties tailored to the intended purpose can be formed.

[0096] However, the difference SB1 between the highest point H1 and the lowest point L1 in the thickness direction on the front surface side of the base sheet 14 may be the same as the difference SB2 between the highest point H2 and the lowest point L2 in the thickness direction on the back surface side of the base sheet 14. In other words, the depth of the recessed region 214 where the SAP is arranged may be the same on one surface of the base sheet 14 and the other surface.

[0097] 6A , on the front surface side of the base sheet 14, the weight of the SAP layered below the highest point H1 is 50% or more of the weight of the SAP layered over the entire base sheet 14. This allows a desired weight of SAP to be layered in the recessed regions of the base sheet 14, thereby forming high basis weight regions 211 at appropriate positions.

[0098] 6B , the largest diameter of the inscribed circles IC inscribed in each of the non-laminated regions 212N is equal to or smaller than the difference SB1 on the front surface side. This reduces the size of the non-laminated regions 212N without SAP in the plan view, thereby suppressing leakage of excretory fluid through the non-laminated regions 212N.

[0099] 6B, the area below the midpoint M1 between the highest point H1 and the lowest point L1 shown in Fig. 6A is represented as the range of the recessed region 214F. In this case, the total length LG1 of the multiple recessed regions 214F on an imaginary line V1 that passes through the center C of the multiple recessed regions 214F in the longitudinal direction is preferably 50% or more of the overall length of the base sheet 14. This allows the high basis weight region 211 and the low basis weight region 212 to be formed in appropriate positions by layering the SAP in desired regions of the base sheet 14.

[0100] Similarly, it is preferable that the total length LG2 of the multiple recessed regions 214F on an imaginary line V2 passing through the centers of the multiple recessed regions 214F in the width direction be 50% or more of the overall length of the base sheet 14. This allows the SAP to be laminated in desired regions of the base sheet 14, thereby forming high basis weight regions 211 and low basis weight regions 212 in appropriate positions.

[0101] Fig. 7A is a schematic cross-sectional view showing the absorber 20A before it absorbs moisture, and Fig. 7B is a schematic cross-sectional view showing the absorber 20A after it has absorbed moisture.

[0102] The absorbent body 20A of this embodiment has a bonded region 28 where the base sheet 14 and another sheet 14S are bonded between adjacent maximum thickness points S, and a non-bonded region 29 where the base sheet 14 and another sheet 14S are not bonded between adjacent maximum thickness points S. By having the bonded region 28 that serves as the folding start point and the non-bonded region 29 where SAP can be arranged between the base sheet 14 and another sheet 14S, it is possible to achieve both ease of deformation to follow the irregularities of the wearer's body and the ability to absorb and retain excrement.

[0103] In the bonded regions 28, the base sheet 14 and the separate sheet 14S are bonded together in the non-laminated regions 212N via the adhesive HMA. When the absorbent 20A absorbs moisture, the SAP swells, as shown in Fig. 7B, and the bonded portions of the bonded regions 28 between the base sheet 14 and the separate sheet 14S come apart. In this way, as the absorbent 20A absorbs moisture, the bonded portions of the bonded regions 28 come apart, thereby preventing the bonded regions 28 from interfering with the swelling of the SAP.

[0104] FIG. 8 is a schematic plan view of an absorbent body 20B of a modified example.

[0105] The modified absorbent body 20B has a channel region 215 in which the basis weight of the SAP is lower than that of the high basis weight region 211. As shown in FIG. 8 , the channel region 215 extends in the longitudinal direction, and the width of the channel region 215 in the width direction is greater than the distance between adjacent maximum thickness points S. In other words, the width of the channel region 215 is greater than the width of the low basis weight region 212 formed between adjacent high basis weight regions 211 (i.e., around the high basis weight region 211). When the modified absorbent body 20B is sandwiched between the wearer's legs (i.e., in the groin area) during wear, for example, the channel region 215 becomes a folding point, making it easier to deform in the width direction under the wearer's crotch, increasing storage capacity in the crotch area and improving fit. In addition, excrement is more easily dispersed in the longitudinal direction.

[0106] A plurality of channel regions 215 are provided in the width direction. Specifically, as shown in Fig. 8, two channel regions 215 are provided. This further increases the storage capacity in the crotch area and improves the fit. However, only one channel region 215 may be provided in the width direction.

[0107] ===Absorbent Body Manufacturing Apparatus and Absorbent Body Manufacturing Method=== Hereinafter, an absorbent body manufacturing apparatus and an absorbent body manufacturing method will be described with respect to the absorbent body 20A described above.

[0108] <<Configuration of the absorbent body manufacturing apparatus 50 >> FIG. 9 is a schematic diagram showing an overview of the absorbent body manufacturing apparatus 50 .

[0109] The absorbent body manufacturing apparatus 50 is an apparatus for manufacturing absorbent bodies containing superabsorbent polymer (SAP), and includes a conveying section 11x, an upstream adhesive applying section 18, a particle supplying section 19, a suction section 11P, an adhesive discharging section 15D, and a bond forming section 11em.

[0110] The conveying section 11x is a member that conveys the base sheet 14 in the conveying direction. In the absorbent body manufacturing apparatus 50 shown in Fig. 9, the conveying section 11x has a conveying belt 11cn and a plurality of conveying rollers 11rn. The conveying belt 11cn is an endless belt that is driven to rotate, and the upper surface of the conveying belt 11cn serves as the conveying surface of the base sheet 14. In other words, the conveying belt 11cn conveys the base sheet 14 while supporting the lower surface (hereinafter sometimes referred to as "one surface") of the base sheet 14. Therefore, the conveying belt 11cn may be referred to as a supporting section.

[0111] 9, the conveying section 11x is a suction belt conveyor that conveys the base sheet 14 while sucking it with a suction section 11P through a plurality of openings 11pn (described later) provided on the conveying surface of the conveying belt 11cn. The conveying roller 11rn may be a driving roller that is driven to rotate by a driving source such as a motor, or may be a driven roller that is driven to rotate without a driving source.

[0112] The upstream adhesive applicator 18 is a member that applies an adhesive to the base sheet 14 before the SAP particles 19S are supplied to the base sheet 14. As shown in FIG. 9 , the upstream adhesive applicator 18 is provided upstream in the conveyance direction from the particle supplying unit 19 that supplies the SAP particles 19S. In this example, the adhesive applied by the upstream adhesive applicator 18 is a hot melt adhesive. By applying an adhesive to the base sheet 14 before the particle supplying unit 19 supplies the SAP particles 19S to the base sheet 14, the SAP particles 19S can be more easily attached to the base sheet 14, and the amount of rebound of the SAP particles 19S can be reduced. This prevents the SAP particles 19S from being placed in unintended positions. However, the absorbent body manufacturing apparatus 50 does not necessarily have to have the upstream adhesive applicator 18.

[0113] The particle supply unit 19 is a member that supplies the SAP particles 19S toward the upper surface (hereinafter, sometimes referred to as the "other surface") of the base sheet 14. When the particle supply unit 19 releases the SAP particles 19S, the SAP particles 19S are supplied by gravity or ejected together with pressurized air toward the base sheet 14 arranged on the conveying surface of the conveying unit 11x.

[0114] The suction section 11P is a member that sucks the base sheet 14 from one surface (lower surface) of the base sheet 14 through a plurality of openings 11pn of the conveyor belt 11cn. Details of the suction section 11P will be described later.

[0115] The adhesive discharge unit 15D is a member that discharges adhesive together with an air flow toward the base sheet 14. The adhesive discharge unit 15D is arranged downstream in the conveyance direction from the particle supply unit 19. In the absorbent body manufacturing apparatus 50 shown in Fig. 9, the adhesive discharge unit 15D has two adhesive discharge units 15D: a first adhesive discharge unit 15x1 and a second adhesive discharge unit 15x2 that is arranged downstream in the conveyance direction from the first adhesive discharge unit 15x1. Details of the adhesive discharge unit 15D will be described later.

[0116] The joint forming portion 11em is a member that joins the base sheet 14 and the separate sheet 14S in the thickness direction after they are joined to form a joint. The joint forming portion 11em may, for example, emboss the base sheet 14 and the separate sheet 14S, or may use other known joining means such as welding or adhesion. The joint forming portion 11em can form the joint 213 in the absorbent body 20A shown in FIG. 5 described above.

[0117] In this embodiment, the absorbent body containing the above-described superabsorbent polymer is manufactured by the absorbent body manufacturing apparatus 50 having the above-described configurations. The method for manufacturing the absorbent body containing the superabsorbent polymer first includes at least a conveying step of conveying the base sheet 14 while supporting one surface (lower surface) of the base sheet 14 with a support section (conveyor belt 11cn), and a particle supplying step of supplying SAP particles 19S toward the other surface (upper surface) of the base sheet 14. This makes it possible to manufacture an absorbent body having a superabsorbent polymer laminated on the base sheet 14.

[0118] In this embodiment, the method for producing an absorbent body containing a superabsorbent polymer may involve applying adhesive to the other surface (upper surface) of the base sheet 14 by the upstream adhesive applicator 18, upstream in the conveyance direction of the base sheet 14 from the position where the SAP particles 19S are supplied to the base sheet 14 (upstream adhesive application step). This makes it easier for the SAP particles 19S to adhere to the base sheet 14. However, the method for producing an absorbent body containing a superabsorbent polymer does not necessarily have to include the upstream adhesive application step.

[0119] In addition, in the method for producing an absorbent body containing a superabsorbent polymer, in this embodiment, another sheet 14S may be supplied from the other surface (upper surface) of the base sheet 14 downstream in the conveying direction of the base sheet 14 from the position where the SAP particles 19S are supplied to the base sheet 14 so as to cover the SAP particles 19S (separate sheet supplying step). Furthermore, in this embodiment, in an area of ​​the other surface (upper surface) of the base sheet 14 where no adhesive is applied, the other sheet 14S and the base sheet 14 may be joined in the thickness direction along a direction intersecting the conveying direction of the base sheet 14 (joint forming step). This makes it possible to suppress an opening between the base sheet 14 and the other sheet 14S. However, the method for producing an absorbent body containing a superabsorbent polymer does not necessarily have to include the separate sheet supplying step or the joint forming step.

[0120] In this embodiment, the absorbent body is formed by cutting the SAP particles to a desired size further downstream of the bond forming process. In this embodiment, after the SAP particles are supplied onto the base sheet 14, another sheet 14S is laminated thereon, but this is not limiting. For example, the absorbent body can be formed simply by laminating the SAP particles on the base sheet 14 and then cutting the base sheet 14 to a desired size. Alternatively, the absorbent body can be formed by laminating the SAP particles on the base sheet 14 and then laminating a pulp-containing fibrous material thereon. This makes it possible to easily manufacture an absorbent body that can quickly and temporarily absorb excreted liquid and prevent overflow and leakage of excreted liquid during excretion. Furthermore, if a pulp-containing fibrous material is mixed in addition to the SAP particles as the material for the absorbent body, the fibrous material can be supplied to the base sheet 14 before or after the particle supply unit 19 supplies the SAP particles 19S.

[0121] As described above, the conveying section 11x of the absorbent body manufacturing apparatus 50 is a suction belt conveyor that conveys the base sheet 14 while sucking it with the suction section 11P through a plurality of openings 11pn provided on the conveying surface of the conveying belt 11cn. In this regard, the suction section 11P and the conveying belt 11cn will be described in detail.

[0122] Fig. 10 is a diagram illustrating the suction opening 11su of the suction unit 11P. Fig. 11A is a schematic cross-sectional view showing a portion of the conveyor belt 11cn. Fig. 11B is a schematic plan view showing a portion of the conveyor belt 11cn. For reference, in Fig. 10 and Fig. 11A, the outline of the base sheet 14 is shown by a dashed line.

[0123] As shown in Fig. 10, the suction unit 11P is provided on the opposite side of the conveyor belt 11cn (support unit) from the side where the base sheet 14 is located. A suction opening 11su is provided on the suction unit 11P on the side where the base sheet 14 is located. The suction unit 11P performs suction through the suction opening 11su. The conveyor belt 11cn is located between the suction unit 11P and the base sheet 14 as viewed from the suction opening 11su, and conveys the base sheet 14 in the conveyance direction.

[0124] The conveyor belt 11cn is, for example, a mesh belt, and a conveying surface 11m of the conveyor belt 11cn is provided with a plurality of openings 11pn. Specifically, as shown in Figures 11A and 11B, the conveying surface 11m of the conveyor belt 11cn is formed by weaving thread-like members using fibers made from synthetic resin such as nylon. However, the thread-like members may also be formed from metal such as wire. The thread-like members are, for example, composed of vertical members 116 and horizontal members 117, and the openings defined by the vertical members 116 and horizontal members 117 become the openings 11pn when the base sheet 14 is sucked.

[0125] 11A, in the particle supplying step described above, the suction unit 11P sucks the base sheet 14 from one side (the lower surface) of the base sheet 14 through a plurality of openings 11pn provided in the conveying surface 11m of the conveying belt 11cn. Because the base sheet 14 is made of a very soft and easily deformable material such as nonwoven fabric as described above, the suction force generated by the suction unit 11P (see the hollow arrows in FIG. 11A) pulls the portions corresponding to the openings 11pn, forming recessed regions 214 that correspond to the shape of the openings 11pn.

[0126] At this time, the supplied SAP particles 19S (not shown in FIG. 11A ) also tend to remain in the recessed regions 214 of the base sheet 14 due to the suction force generated by the suction section 11P. As a result, similar to the description in FIG. 6A above, a large number of SAP particles 19S are arranged in the recessed regions 214, forming high basis weight regions 211. On the other hand, in regions other than the recessed regions 214 (regions that are blocked by the vertical members 116 in FIG. 11A and do not become recessed regions 214), no SAP particles 19S are arranged, or even if SAP particles 19S are arranged, they are arranged in fewer numbers than in the recessed regions 214. As a result, low basis weight regions 212 (low basis weight laminated regions 212E or non-laminated regions 212N) are formed.

[0127] As described above, in the conveying section 11x of the absorbent body manufacturing apparatus 50, the support section (conveyor belt 11cn) has a plurality of openings 11pn, and by sucking the base sheet 14 from one side (bottom surface) of the base sheet 14 through the plurality of openings 11pn during the particle supply process, an absorbent body can be manufactured in which high basis weight regions 211 and low basis weight regions 212 are formed around each high basis weight region 211.

[0128] 11B , the diameter of the inscribed circle IC inscribed in the opening 11pn of the conveyor belt 11cn is equal to or greater than the average particle size of the SAP particles. For example, the diameter of the inscribed circle IC inscribed in the opening 11pn of the conveyor belt 11cn is preferably 2 mm to 4 mm. This allows the size of each of the multiple high basis weight regions 211 in a planar view to be reduced, thereby allowing a large number of high basis weight regions 211 and low basis weight regions 212 to be arranged on the base sheet 14. In this embodiment, an absorbent body containing SAP that has a good fit when worn while maintaining a thin profile can be easily manufactured.

[0129] In the support portion (transport belt 11cn), the opening ratio of the openings 11pn in the region where the openings 11pn are provided is preferably 40% or more and 60% or less. This allows the high basis weight region 211 to be appropriately formed in the absorbent body. In the following description, the opening ratio of the openings refers to the ratio of the area of ​​the openings per unit area.

[0130] Fig. 12 is a schematic plan view showing another example of the suction opening su of the suction unit 11P. For reference, in Fig. 12, the outline of the base sheet 14 is shown by a dashed line, along with the end 142 of the base sheet 14 in the cross direction. The position of the particle supply unit 19 in the plan view is also shown by a dashed line.

[0131] In the particle supply step, the suction unit 11P sucks the base sheet 14 from one side (the lower surface) of the base sheet 14 through the suction openings su (first opening region 111 and second opening region 112 described below) shown in Fig. 12 and the openings 11pn of the conveyor belt 11cn described above, thereby forming the absorbent body 20B having the channel region 215 shown in Fig. 8 described above. The features of the suction openings su of the suction unit 11P will be described below.

[0132] The suction opening su of the suction unit 11P has a first opening region 111 and a second opening region 112. As shown in Fig. 12, the second opening region 112 is adjacent to the first opening region 111 in the intersecting direction that intersects with the conveyance direction of the base sheet 14. A plurality of second opening regions 112 (two in this example) are provided in the intersecting direction. However, only one second opening region 112 may be provided.

[0133] Here, the aperture ratio of the first opening region 111 is equal to or greater than the aperture ratio of the openings 11pn in the region of the conveyor belt 11cn (support portion) where the openings 11pn are provided. For example, in the conveyor belt 11cn shown in FIG. 11B described above, the openings 11pn are defined by the vertical members 116 and the horizontal members 117. In this case, when considering the entire region of the conveyor belt 11cn where the openings 11pn are provided, the aperture ratio of the openings 11pn is reduced by the size (width) of the vertical members 116 and the horizontal members 117. In contrast, in the first opening region 111, the entire region is an opening (space). However, although not shown, the first opening region 111 may have bars provided at the edges of the openings. This can suppress suction forces that would distort the shape of the base sheet 14.

[0134] The aperture ratio of the second opening region 112 is lower than that of the first opening region 111 and is equal to or lower than the aperture ratio of the openings 11pn in the region where the openings 11pn of the conveyor belt 11cn (support portion) are provided. Specifically, the aperture ratio of the second opening region 112 is preferably equal to or higher than 25% and equal to or lower than 35%. However, the aperture ratio of the second opening region 112 may be in a range other than 25% or higher and 35% or lower, as long as it is lower than the aperture ratio of the first opening region 111 and is equal to or lower than the aperture ratio of the openings 11pn in the region where the openings 11pn of the conveyor belt 11cn (support portion) are provided.

[0135] As described above, in the particle supplying step, the particle supplying unit 19 supplies SAP particles 19S toward the other surface (upper surface) of the base sheet 14, and the suction unit 11P sucks the base sheet 14 from one surface (lower surface) of the base sheet 14 through the first and second opening regions 111 and 112 and the openings 11pn of the conveyor belt 11cn. As described above, the opening ratio of the second opening region 112 is lower than that of the first opening region 111. Therefore, in a plan view, the region of the base sheet 14 sucked through the second opening region 112 has a lower suction force than the region of the base sheet 14 sucked through the first opening region 111. At this time, the SAP particles 19S (not shown in FIG. 12 ) supplied to the base sheet 14 are more likely to remain in the region of the base sheet 14 sucked through the first opening region 111 than in the region of the base sheet 14 sucked through the second opening region 112.

[0136] Furthermore, as described above, the aperture ratio of the second opening regions 112 is equal to or less than the aperture ratio of the openings 11pn in the region of the conveyor belt 11cn where the openings 11pn are provided. Therefore, in the region of the base sheet 14 that is sucked through the second opening regions 112, the suction force is reduced by the second opening regions 112. As a result, in the region of the base sheet 14 that is sucked through the second opening regions 112, the suction force is reduced to such an extent that the portions of the base sheet 14 corresponding to the openings 11pn are pulled, forming recessed regions 214. Therefore, in the region of the base sheet 14 that is sucked through the second opening regions 112, the formation of high basis weight regions 211 is suppressed, and channel regions 215 having a basis weight of SAP lower than that of the high basis weight regions 211 are formed. Note that, as described above, two second opening regions 112 are provided in the intersecting direction, and therefore two channel regions 215 corresponding to each of the two second opening regions 112 are formed, as in the absorbent body 20B shown in FIG. 8 .

[0137] On the other hand, the opening ratio of the first opening region 111 is equal to or greater than the opening ratio of the openings 11pn in the region where the openings 11pn of the conveyor belt 11cn are provided. Therefore, in the region of the base sheet 14 that is sucked through the first opening region 111, the suction force is not reduced by the first opening region 111, and a recessed region 214 is formed, and the suction force generated by the suction section 11P makes it easier for the material to remain in the recessed region 214 of the base sheet 14. In other words, in the region that is sucked through the first opening region 111, a high basis weight region 211 and a low basis weight region 212 are formed.

[0138] The suction opening su of the suction unit 11P has a third opening region 113 and a non-opening region 114. As shown in FIG. 12 , the third opening region 113 is located downstream of the first opening region 111 in the transport direction and has a portion that overlaps with the first opening region 111 in the intersecting direction. The non-opening region 114 is located downstream of the second opening region 112 in the transport direction and has a portion that overlaps with the second opening region 112 in the intersecting direction. The aperture ratio of the third opening region 113 is lower than the aperture ratio of the first opening region 111. However, the third opening region 113 may be located further upstream in the transport direction than the first opening region 111, and the non-opening region 114 may be located further upstream in the transport direction than the second opening region 112. The suction opening su of the suction unit 11P does not have to have the third opening region 113 and the non-opening region 114.

[0139] In the particle supplying step, suction force continues to be generated in the third opening region 113 located downstream of the first opening region 111, while suction force is suppressed in the non-opening region 114 located downstream of the second opening region 112. This makes it possible to prevent SAP particles that have rebounded in the region of the base sheet 14 where the SAP particles are supplied, i.e., the region of the base sheet 14 that is sucked through the first opening region 111 and the second opening region 112, from being placed in the channel region 215 downstream.

[0140] Furthermore, the suction opening su of the suction unit 11P has a fourth opening region 115. In a plan view, the fourth opening region 115 is located outside the first opening region 111 and the third opening region 113 in the transverse direction and overlaps with the end of the base sheet 14 in the transverse direction. During the conveying process, the suction unit 11P sucks the end of the base sheet 14 from one surface (lower surface) of the base sheet 14 through the fourth opening region 115. This makes it possible to prevent the base sheet 14 from curling up during conveyance. However, the suction opening su of the suction unit 11P does not have to have the fourth opening region 115.

[0141] FIG. 13 is a diagram illustrating the manner in which SAP particles are supplied and adhesive is discharged in the absorbent body manufacturing apparatus 50. As shown in FIG.

[0142] In the absorbent body manufacturing apparatus 50 of this embodiment, immediately after the step of supplying SAP particles from the particle supply unit 19 (particle supply step), the adhesive discharge unit 15D (first adhesive discharge unit 15x1) discharges the adhesive 15H together with an air flow toward the base sheet 14 (downstream adhesive discharge step). The adhesive 15H is a hot melt adhesive, and is discharged from a plurality of discharge ports (nozzles, not shown) of the adhesive discharge unit 15D. After the first adhesive discharge unit 15x1 discharges the adhesive 15H, the second adhesive discharge unit 15x2, which is located downstream of the first adhesive discharge unit 15x1 in the conveyance direction, further discharges the adhesive 15H together with an air flow toward the base sheet 14.

[0143] The adhesive 15H is discharged together with the airflow, and in this embodiment, the pressure of this airflow is the same for both the first adhesive discharge portion 15x1 and the second adhesive discharge portion 15x2. However, this is not limiting, and the air pressures may be different for each portion.

[0144] The SAP particles 19S supplied from the particle supply unit 19 tend to bounce off the base sheet 14 on the conveying surface 11m (see FIG. 13 ), and in this embodiment, it is assumed that approximately 60% of the SAP particles 19S supplied at one time will bounce off. Furthermore, the supplied SAP particles 19S tend to bounce off in unintended directions, which may result in the particles scattering to locations where they should not be placed.

[0145] In this regard, in the absorbent body manufacturing apparatus 50 of this embodiment, as shown in FIG. 13 , the adhesive 15H discharged from the adhesive discharge unit 15D can push back at least some of the SAP particles 19S that have rebounded from the base sheet 14 toward the base sheet 14. Here, "pushing back" means moving the SAP particles 19S in the direction opposite to the conveyance direction and in the direction of gravity (vertically downward). In other words, the SAP particles 19S that have rebounded from the base sheet 14 are hit by the discharged adhesive 15H, causing the SAP particles 19S to fall back toward the base sheet 14. Furthermore, the airflow discharged together with the adhesive 15H can reduce the likelihood of the SAP particles 19S being disposed in an unintended position. Furthermore, the adhesive 15H entangles the rebounded SAP particles 19S, thereby more reliably fixing the SAP particles 19S to the base sheet 14.

[0146] Furthermore, in this embodiment, not only is the adhesive 15H discharged from the first adhesive discharge portion 15x1, but also the adhesive 15H is discharged from the second adhesive discharge portion 15x2, which is provided downstream in the conveyance direction from the first adhesive discharge portion 15x1. As a result, the SAP particles 19S that rebound cannot be fully pushed back by the adhesive 15H discharged from the first adhesive discharge portion 15x1 alone, but are pushed back toward the base sheet 14 by the adhesive 15H discharged from the second adhesive discharge portion 15x2, thereby further reducing the amount of rebound. This makes it possible to more reliably fix the SAP particles 19S to the base sheet 14.

[0147] Although the absorbent body manufacturing apparatus 50 of this embodiment has two adhesive discharging units 15D (first adhesive discharging unit 15x1 and second adhesive discharging unit 15x2), the present invention is not limited to this. For example, if the amount of SAP particles 19S to be supplied is small, only the first adhesive discharging unit 15x1 may be used. Furthermore, while the first adhesive discharging unit 15x1 and the second adhesive discharging unit 15x2 can push back rebounded SAP particles 19S, the first adhesive discharging unit 15x1 can be designed with an emphasis on fixing the SAP particles 19S to the base sheet 14, and the second adhesive discharging unit 15x2 can be designed primarily for the purpose of improving or adjusting the adhesive strength of materials (such as the base sheet 14).

[0148] In this embodiment, the first adhesive discharging unit 15x1 and the second adhesive discharging unit 15x2 are separated to increase the flexibility of each adhesive discharging unit 15D, but the first adhesive discharging unit 15x1 and the second adhesive discharging unit 15x2 may be an integrated adhesive discharging unit. If the first adhesive discharging unit 15x1 and the second adhesive discharging unit 15x2 are installed as an integrated unit, costs can be reduced compared to installing separate devices, and maintenance of the device is also easier.

[0149] As described above, the SAP particles 19S tend to bounce back when they are supplied from the particle supply unit 19, and therefore, in this embodiment, the conveying surface 11m of the conveyor belt 11cn is inclined with respect to the horizontal plane Hr so that the downstream side in the conveying direction is lowered, as shown in Fig. 13. This makes it easier for the SAP particles 19S that bounce back from the base sheet 14 to move downstream due to gravity, thereby reducing the likelihood of the SAP particles 19S being disposed in unintended positions.

[0150] 13 , the angle of inclination of the conveying surface 11m relative to the horizontal plane Hr is θ0. In this embodiment, the angle of inclination θ0 is approximately 30 degrees. This is because the angle of repose of SAP particles (the maximum angle of the slope at which particles remain stable without collapsing when piled up) is 32 to 38 degrees, and the angle of inclination is set to approximately this angle. Setting the angle of inclination θ0 to approximately 30 degrees prevents the SAP particles 19S discharged from the particle supply unit 19 from rolling after landing on the base sheet 14, and also makes them less likely to bounce back compared to when discharged onto a conveying surface parallel to the horizontal plane. When the conveying surface 11m of the conveyor belt 11cn is inclined downward toward the downstream side, the angle of inclination θ0 can be set up to approximately 75 degrees.

[0151] As described above, the conveying surface 11m is preferably inclined with respect to the horizontal plane Hr so that the downstream side in the conveying direction is lowered, but this is not limiting. For example, the conveying surface 11m may be horizontal, or may be inclined with respect to the horizontal plane Hr so that the upstream side in the conveying direction is lowered. It may also be inclined so that the upstream side in the conveying direction is lowered (i.e., so that the downstream side is raised). In the absorbent body manufacturing apparatus 50 of this embodiment, since the conveying belt 11cn is a suction belt conveyor, strengthening the suction force with which the suction unit 11P sucks the base sheet 14 can similarly suppress the rebound of the SAP particles 19S. When the conveying surface 11m is inclined with respect to the horizontal plane Hr so that the upstream side in the conveying direction is lowered, the inclination angle θ0 can be up to about 45 degrees, but is preferably up to about 30 degrees.

[0152] Fig. 14 is a diagram illustrating the suction opening 11su in the absorbent body manufacturing apparatus 50A of the first modified example. For reference, in Fig. 14, the outline of the base sheet 14 is shown by a dashed line.

[0153] In the absorbent body manufacturing apparatus 50A of the first modified example, similarly to the absorbent body manufacturing apparatus 50 described above, a suction section 11P is provided on the opposite side of the conveyor belt 11cn (support section) from the side on which the base sheet 14 is located. However, unlike the absorbent body manufacturing apparatus 50, in the absorbent body manufacturing apparatus 50A, the suction opening 11su is provided not in the suction section 11P but in the other conveyor belt 11cn1. As shown in Fig. 14, a plurality of suction openings 11su are provided along the circumference of the other conveyor belt 11cn1, and the position of the suction opening 11su also moves as the other conveyor belt 11cn1 moves.

[0154] In the absorbent body manufacturing apparatus 50A, the other conveyor belt 11cn1 is positioned between the conveyor belt 11cn and the suction unit 11P and moves in the same direction as the conveying direction of the conveyor belt 11cn. This reduces wear on the conveyor belt 11cn due to the conveyor belt 11cn rubbing against the edge of the suction opening 11su, thereby extending the life of the conveyor belt 11cn. Furthermore, in the absorbent body manufacturing apparatus 50A, the other conveyor belt 11cn1 is provided with a suction opening 11su, so when adhesive adheres to the suction opening 11su, only the other conveyor belt 11cn1 can be replaced. Therefore, compared to when the suction opening 11su is provided on the upper surface of the suction unit 11P, replacement work when adhesive adheres to the suction opening 11su can be easily performed.

[0155] In the absorbent body manufacturing apparatus 50A, the other conveyor belt 11cn1 and the conveyor belt 11cn move at the same speed, but the circumferential length of the other conveyor belt 11cn1 is different from that of the conveyor belt 11cn. Therefore, the location where the conveyor belt 11cn rubs against the edge of the suction opening 11su also changes with each revolution. This also contributes to extending the life of the conveyor belt 11cn. Furthermore, the position where the adhesive contacts the conveyor belt 11cn can be shifted with each revolution, reducing adhesive clogging at the openings 11pn of the conveyor belt 11cn. However, if the circumferential length of the conveyor belt 11cn is an integer multiple of the pitch PH of the multiple suction openings su, the position where the adhesive contacts the conveyor belt 11cn will not shift to the position of one of the multiple suction openings su, so it is necessary for the circumferential length of the conveyor belt 11cn to be other than an integer multiple of the pitch PH of the multiple suction openings su.

[0156] <<Configuration of Absorbent Body Manufacturing Apparatus 60 >> Next, an absorbent body manufacturing apparatus 60 according to another embodiment different from the above-described absorbent body manufacturing apparatus 50 will be described with reference to FIGS. 15 and 16 .

[0157] Fig. 15 is a schematic diagram showing an overview of the absorbent body manufacturing apparatus 60. Fig. 16 is a diagram illustrating the plate portion 11pt of the transport portion 11y.

[0158] The basic configuration of the absorbent body manufacturing apparatus 60 is the same as that of the above-mentioned absorbent body manufacturing apparatus 50, but differs in that the conveying section 11y that conveys the base sheet 14 in the conveying direction has a rotating body 11tn instead of a conveying belt 11cn in the absorbent body manufacturing apparatus 60. In the following description of the absorbent body manufacturing apparatus 60, the same components as those in the absorbent body manufacturing apparatus 50 are denoted by the same reference numerals, and descriptions of parts common to the absorbent body manufacturing apparatus 50 will be omitted.

[0159] 15 and 16 , in the absorbent body manufacturing apparatus 60, a plate portion 11pt is provided on the outer peripheral surface 11n of a rotor 11tn that rotates in the conveyance direction. The outer peripheral surface of the plate portion 11pt of the rotor 11tn serves as the conveyance surface for the base sheet 14. In other words, the plate portion 11pt of the rotor 11tn conveys the base sheet 14 while supporting the surface of the base sheet 14 on the center side of the rotor 11tn (hereinafter, sometimes referred to as "one surface"). Therefore, the plate portion 11pt of the rotor 11tn may be referred to as a support portion.

[0160] In addition, in the absorbent body manufacturing apparatus 60 shown in Figures 15 and 16, the conveying section 11y is a suction drum that conveys the base sheet 14 while sucking it with the suction section 11P through multiple openings 11pn provided on the conveying surface of the plate section 11pt of the rotating body 11tn.

[0161] In this embodiment, an absorbent body containing a superabsorbent polymer is manufactured using an absorbent body manufacturing apparatus 60 having the above-described configurations. The method for manufacturing an absorbent body containing a superabsorbent polymer includes at least a conveying step of conveying the base sheet 14 while supporting one surface of the base sheet 14 (the surface toward the center of the rotor 11tn) with a support portion (the plate portion 11pt of the rotor 11tn), and a particle supplying step of supplying SAP particles 19S toward the other surface of the base sheet 14 (the surface opposite the center of the rotor 11tn). This allows the manufacture of an absorbent body having a superabsorbent polymer laminated on the base sheet 14.

[0162] The plate portion 11pt is, for example, a punched metal plate, and has a plurality of openings 11pn formed on the conveying surface of the plate portion 11pt as shown in Fig. 16. In the particle supplying step described above, the suction portion 11P sucks the base sheet 14 through the plurality of openings 11pn formed on the conveying surface of the plate portion 11pt.

[0163] As described above, in the conveying unit 11y of the absorbent body manufacturing apparatus 60, the support unit (the plate portion 11pt of the rotor 11tn) has a plurality of openings 11pn, and in the particle supplying step, the base sheet 14 is sucked through the plurality of openings 11pn from one side of the base sheet 14 (the surface toward the center of the rotor 11tn) to manufacture an absorbent body having high basis weight regions 211 and low basis weight regions 212 around each high basis weight region 211. Although not shown, the diameter of the inscribed circle inscribed in the openings 11pn of the plate portion 11pt is equal to or greater than the average particle size of the SAP particles. This allows the SAP particles to be arranged in the recessed regions 214 of the base sheet 14 as described above. In this embodiment, an absorbent body having SAP that provides a good fit when worn while maintaining a thin profile can be easily manufactured.

[0164] FIG. 17 is a schematic plan view showing another example of the plate portion 11pt.

[0165] The plate portion 11pt shown in Fig. 17 is also a punched metal plate having a plurality of openings. The plate portion 11pt has a first opening region 111 and a second opening region 112. As shown in Fig. 17, the second opening region 112 is adjacent to the first opening region 111 in the intersecting direction that intersects with the conveyance direction of the base sheet 14. Furthermore, a plurality of second opening regions 112 (two in this example) are provided in the intersecting direction. However, only one second opening region 112 may be provided.

[0166] 17 , the aperture ratio of the openings in the second opening regions 112 is lower than the aperture ratio of the openings in the first opening regions 111. Therefore, in the region suctioned through the second opening regions 112, the formation of a high basis weight region 211 is suppressed, and a channel region 215 having a lower basis weight of SAP than the high basis weight region 211 is formed. Furthermore, in the region suctioned through the first opening regions 111, the high basis weight region 211 and the low basis weight region 212 are formed.

[0167] In the particle supply process, the suction section 11P sucks the base sheet 14 from one side (the side toward the center of the rotating body 11tn) of the base sheet 14 through the openings (first opening region 111 and second opening region 112) shown in Figure 17, thereby forming the absorbent body 20B having the channel region 215 shown in Figure 8 described above.

[0168] FIG. 18 is a diagram illustrating the manner in which SAP particles are supplied and adhesive is discharged in the absorbent body manufacturing apparatus 60. As shown in FIG.

[0169] In the absorbent manufacturing apparatus 60 of this embodiment, immediately after the process in which SAP particles are supplied from the particle supply section 19 (particle supply process), the first adhesive discharge section 15x1 (adhesive discharge section 15D) discharges the adhesive 15H together with the air flow, and further downstream, the second adhesive discharge section 15x2 (adhesive discharge section 15D) discharges the adhesive 15H together with the air flow toward the base sheet 14 (adhesive discharge process).

[0170] 18 , in the absorbent body manufacturing apparatus 60 of this embodiment, the adhesive 15H is also discharged in a predetermined direction from the discharge openings of each adhesive discharge unit 15D (the first adhesive discharge unit 15x1 and the second adhesive discharge unit 15x2). Specifically, in the first adhesive discharge unit 15x1, the adhesive 15H is discharged in a predetermined direction from the discharge openings of the first adhesive discharge unit 15x1, and the upstream side of the discharge direction is inclined toward the downstream side of the conveyance direction so that the angle θ1 formed between an imaginary line extending the discharge direction and a tangent to the rotating body 11tn at the intersection of the imaginary line and the outer peripheral surface 11n of the rotating body 11tn is greater than 90 degrees. Because the supplied SAP particles 19S partially bounce back toward the downstream side of the conveyance direction, discharging the adhesive 15H from the downstream side so as to cover the SAP particles 19S makes it easier to push back the SAP particles 19S that have bounced back downstream, rather than discharging the adhesive 15H perpendicular to the outer peripheral surface 11n.

[0171] In the absorbent body manufacturing apparatus 60 of this embodiment, a second adhesive discharge unit 15x2 is also provided downstream of the first adhesive discharge unit 15x1 in the conveyance direction, and like the first adhesive discharge unit 15x1, the second adhesive discharge unit 15x2 discharges adhesive 15H from a discharge port in a predetermined discharge direction. The discharge direction is such that the upstream side of the discharge direction 15d2 of the second adhesive discharge unit 15x2 is inclined downstream in the conveyance direction so that the angle θ2 formed by an imaginary line extending the discharge direction of the second adhesive discharge unit 15x2 and a tangent to the rotating body 11tn at the intersection of the imaginary line and the outer peripheral surface 11n of the rotating body 11tn is greater than 90 degrees. In the absorbent body manufacturing apparatus 60, adhesive 15H is ejected at such an angle not only from the first adhesive ejection section 15x1 but also from the second adhesive ejection section 15x2, making it easier to capture the rebounding SAP particles 19S that could not be pushed back by the adhesive 15H ejected from the first adhesive ejection section 15x1 alone.

[0172] Note that the angle θ2 formed by the virtual line extended from the second adhesive discharge portion 15x2 and the tangent to the rotating body 11tn at the intersection of the virtual line and the outer peripheral surface 11n of the rotating body 11tn is preferably larger than the angle θ1 formed by the virtual line extended from the first adhesive discharge portion 15x1 and the tangent to the rotating body 11tn at the intersection of the virtual line and the outer peripheral surface 11n of the rotating body 11tn (θ1<θ2). Because the supplied SAP particles 19S tend to bounce downstream in the conveyance direction, the second adhesive discharge portion 15x2, which is disposed downstream of the first adhesive discharge portion 15x1, discharges the adhesive 15H at a more inclined angle, thereby more easily capturing the SAP particles 19S that have fallen downstream.

[0173] FIG. 19 is a perspective view of an absorbent body manufacturing apparatus 60A according to a second modified example.

[0174] In the absorbent body manufacturing apparatus 60A of the second modified example, the plate portion 11pt is composed of a base plate 118 and a mesh plate 119. As shown in Fig. 19, a suction opening 11su is provided in the base plate 118. In addition, an opening 11pn is provided on the conveying surface of the mesh plate 119 for sucking the base sheet 14. In the absorbent body manufacturing apparatus 60A, even if clogging of the opening 11pn occurs with adhesive, it is only necessary to replace the mesh plate 119, which is easy to replace, and therefore replacement costs can be reduced.

[0175] FIG. 20 is a schematic plan view showing another example of the substrate 118 of the plate portion 11pt.

[0176] The basic configuration of the substrate 118 shown in Fig. 20 is the same as that of the plate portion 11pt shown in Fig. 17 described above, and includes a first opening region 111 and a second opening region 112. As shown in Fig. 20, the second opening region 112 is adjacent to the first opening region 111 in the intersecting direction that intersects with the conveyance direction of the base sheet 14. Furthermore, a plurality of second opening regions 112 (two in this example) are provided in the intersecting direction. However, only one second opening region 112 may be provided.

[0177] 20 , the aperture ratio of the openings in the second opening regions 112 is lower than the aperture ratio of the openings in the first opening regions 111. Therefore, in the region suctioned through the second opening regions 112, the formation of a high basis weight region 211 is suppressed, and a channel region 215 having a lower basis weight of SAP than the high basis weight region 211 is formed. Furthermore, in the region suctioned through the first opening regions 111, the high basis weight region 211 and the low basis weight region 212 are formed.

[0178] In the particle supply process, the suction section 11P sucks the base sheet 14 from one side (the side toward the center of the rotating body 11tn) of the base sheet 14 through the openings (first opening region 111 and second opening region 112) shown in Figure 20, thereby forming an absorbent body 20B having the channel region 215 shown in Figure 8 described above.

[0179] FIG. 21 is a perspective view of an absorbent body manufacturing apparatus 60B according to a third modified example.

[0180] The absorbent body manufacturing apparatus 60B of the third modification has a configuration in which a conveyor belt 11cn having a plurality of openings 11pn is wound around a rotor having a suction opening 11su on its outer circumferential surface. A method for manufacturing an absorbent body containing a superabsorbent polymer using the absorbent body manufacturing apparatus 60B includes at least a conveying step of conveying the base sheet 14 while supporting one side of the base sheet 14 (the side toward the center of the rotor 11tn) with a support section (conveyor belt 11cn), and a particle supplying step of supplying SAP particles 19S toward the other side of the base sheet 14 (the side opposite the center of the rotor 11tn). This allows for the manufacture of an absorbent body having a superabsorbent polymer laminated on the base sheet 14.

[0181] The conveyor belt 11cn is, for example, a mesh belt, and a plurality of openings 11pn are provided on a conveying surface 11m of the conveyor belt 11cn as shown in Fig. 21. In the particle supplying step described above, the suction unit 11P sucks the base sheet 14 through the plurality of openings 11pn provided on the conveying surface 11m of the conveyor belt 11cn.

[0182] As described above, in the conveying unit 11y of the absorbent body manufacturing apparatus 60B, the support unit (conveyor belt 11cn) has a plurality of openings 11pn, and in the particle supplying step, the base sheet 14 is sucked through the plurality of openings 11pn from one side of the base sheet 14 (the side closest to the center of the rotating body 11tn) to manufacture an absorbent body having high basis weight regions 211 and low basis weight regions 212 around each high basis weight region 211. Although not shown, the diameter of the inscribed circle inscribed in the openings 11pn of the conveying belt 11cn is equal to or greater than the average particle size of the SAP particles. This allows the SAP particles to be arranged in the recessed regions 214 of the base sheet 14 as described above. In this embodiment, an absorbent body having SAP that provides a good fit when worn while maintaining a thin profile can be easily manufactured.

[0183] ===Other=== The above embodiments are intended to facilitate understanding of the present invention and are not intended to limit the present invention. The present invention may be modified or improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

[0184] 1 Pants-type disposable diaper (absorbent article), 2 Side joint portion, 10 Absorbent body, 11x, 11y Conveying portion, 11cn, 11cn1 Conveying belt, 11em Joint forming portion, 11m Conveying surface, 11n Outer circumferential surface, 11P Suction portion, 11pn Opening, 11pt Plate portion, 11rn Conveying roller, 11su Suction opening, 11tn Rotating body, 12 Top sheet, 13a Back sheet (liquid-impermeable sheet), 13b Back sheet (exterior sheet), 14 Base sheet, 14S Another sheet, 15 Leakage preventing wall portion, 15D Adhesive discharge portion, 15H Adhesive, 15x1 First adhesive discharge portion, 15x2 Second adhesive discharge portion, 16 Leakage preventing wall elastic member, 17 Leg circumference elastic member, 18 Upstream adhesive application section, 19 particle supply section, 19S superabsorbent polymer (SAP) particles, 20, 20A, 20B absorbent body, 21 skin side layer (absorbent core), 22 intermediate layer (absorbent core), 23 non-skin side layer (absorbent core), 24, 25 core wrap sheet, 26 sheet, 27 SAP layer, 28 bonded region, 29 non-bonded region, 30 front waistline section, 31 skin side sheet, 32 non-skin side sheet, 33 waistline elastic member, 34 cover sheet, 40 rear waistline section, 40E region, 41 skin side sheet, 42 non-skin side sheet, 43 waistline elastic member, 44 cover sheet, 50, 50A, 60, 60A absorbent body manufacturing apparatus, 111 first opening region, 112 second opening region, 113 Third opening region, 114 Non-opening region, 115 Fourth opening region, 116 Vertical member, 117 Horizontal member, 118 Substrate, 119 Mesh plate, 142 Edge, 211 High basis weight region, 212 Low basis weight region, 212E Low basis weight laminated region, 212N Non-laminated region, 213 Compressed portion, 214, 214F, 214B Recessed region, 215 Channel region

Claims

1. A method for manufacturing an absorber containing a superabsorbent polymer, the method comprising: a conveying step of conveying a base sheet while supporting one surface of the base sheet by a support portion; and a particle supply step of supplying superabsorbent polymer particles toward the other surface of the base sheet, wherein the support portion has a plurality of openings, and in a plan view, a diameter of an inscribed circle inscribed in the opening is equal to or greater than an average particle diameter of the superabsorbent polymer particles, and in the particle supply step, the base sheet is sucked through the opening from the side of the one surface of the base sheet. A method for manufacturing an absorber, characterized by that.

2. The method for manufacturing an absorber according to claim 1, wherein in the conveying step, the support portion is a conveying belt that conveys the base sheet. A method for manufacturing an absorber, characterized by that.

3. The method for manufacturing an absorber according to claim 2, wherein a suction portion is provided on a side opposite to the side where the base sheet is located as viewed from the support portion, another conveying belt provided with a suction opening is provided, and the other conveying belt is located between the conveying belt and the suction portion and moves in the same direction as the conveying direction of the conveying belt. A method for manufacturing an absorber, characterized by that.

4. The method for manufacturing an absorber according to claim 2 or 3, wherein a suction portion is provided on a side opposite to the side where the base sheet is located as viewed from the support portion, a suction port of the suction portion includes a first opening region and a second opening region adjacent to the first opening region and having a lower opening ratio than the first opening region in an intersecting direction intersecting the conveying direction of the base sheet, and in the particle supply step, the suction portion sucks the base sheet through the opening, the first opening region, and the second opening region from the side of the one surface of the base sheet. A method for manufacturing an absorber, characterized by that.

5. The method for manufacturing an absorber according to claim 4, wherein an opening ratio of the first opening region is equal to or greater than an opening ratio of the opening in a region where the opening of the support portion is provided. A method for manufacturing an absorber, characterized by that.

6. The method for manufacturing an absorber according to claim 4, wherein an opening ratio of the second opening region is equal to or less than an opening ratio of the opening in a region where the opening of the support portion is provided. A method for manufacturing an absorber, characterized by that.

7. A method for manufacturing the absorber according to claim 4, wherein a plurality of the second opening regions are provided in the intersecting direction. A method for manufacturing an absorber.

8. A method for manufacturing the absorber according to claim 4, wherein the suction portion includes a third opening region and a non-opening region, the third opening region is located downstream of the first opening region in the conveying direction and has a portion overlapping the first opening region in the intersecting direction, the third opening region has a lower opening ratio than the first opening region, the non-opening region is located downstream of the second opening region in the conveying direction and has a portion overlapping the second opening region in the intersecting direction, and the suction portion sucks the base material sheet from the side of the one surface of the base material sheet through the third opening region downstream of the position where the superabsorbent polymer particles are supplied to the base material sheet in the conveying direction of the base material sheet. A method for manufacturing an absorber.

9. A method for manufacturing the absorber according to claim 8, wherein the suction portion includes a fourth opening region provided at a position overlapping the end portion of the base material sheet in the intersecting direction outside the intersecting direction of the first opening region and the third opening region in a plan view, and in the conveying step, the suction portion sucks the end portion from the side of the one surface of the base material sheet through the fourth opening region. A method for manufacturing an absorber.

10. A method for manufacturing the absorber according to claim 1, wherein in the conveying step, the support portion is a rotating body that conveys the base material sheet. A method for manufacturing an absorber.

11. A method for manufacturing the absorber according to claim 10, wherein a suction portion is provided on the side opposite to the side where the base material sheet is located as viewed from the support portion, the support portion includes a first opening and a second opening having a lower opening ratio than the first opening among the plurality of openings, the region where the first opening is provided and the region where the second opening is provided are arranged adjacent to each other in the intersecting direction intersecting the conveying direction of the base material sheet, and in the particle supply step, the suction portion sucks the base material sheet from the side of the one surface of the base material sheet through the first opening and the second opening. A method for manufacturing an absorber.

12. A method for manufacturing the absorber according to claim 11, characterized in that a plurality of regions where the second opening is provided are provided in the crossing direction. A method for manufacturing an absorber.

13. A method for manufacturing the absorber according to claim 1, having an upstream adhesive application step of applying an adhesive toward the other surface of the base sheet on the upstream side in the conveyance direction of the base sheet from the position where the superabsorbent polymer particles are supplied to the base sheet. A method for manufacturing an absorber.

14. A method for manufacturing the absorber according to claim 13, comprising: a separate sheet supply step of supplying a separate sheet so as to cover the superabsorbent polymer particles from the other surface side of the base sheet on the downstream side in the conveyance direction of the base sheet from the position where the superabsorbent polymer particles are supplied to the base sheet; and a joining portion forming step of joining the separate sheet and the base sheet in the thickness direction along a crossing direction crossing the conveyance direction of the base sheet in a region where the adhesive is not applied on the other surface of the base sheet. A method for manufacturing an absorber.

15. A method for manufacturing the absorber according to claim 1, characterized in that the diameter of the inscribed circle inscribed in the opening is 2 mm or more and 4 mm or less. A method for manufacturing an absorber.

16. A method for manufacturing the absorber according to claim 15, characterized in that the aperture ratio of the opening in the region where the opening is provided in the support portion is 40% or more and 60% or less. A method for manufacturing an absorber.

17. A method for manufacturing the absorber according to claim 1, having a downstream adhesive discharge step of discharging an adhesive together with an air flow toward the other surface of the base sheet on the downstream side in the conveyance direction of the base sheet from the position where the superabsorbent polymer particles are supplied to the base sheet, and at least a part of the superabsorbent polymer particles rebounded from the base sheet is pushed back to the base sheet side by the discharged adhesive. A method for manufacturing an absorber.

18. A method for manufacturing the absorber according to claim 17, wherein in the conveying step, the base sheet is conveyed by a conveying conveyor, and the conveying surface of the conveying conveyor is inclined such that the downstream side faces downward with respect to the horizontal plane. A method for manufacturing an absorber, characterized by this.

19. A method for manufacturing the absorber according to claim 17, wherein in the conveying step, the base sheet is conveyed by a rotating body, and the adhesive is discharged in a predetermined discharge direction, and the angle formed by an imaginary line extending the discharge direction and the tangent of the rotating body at the intersection of the imaginary line and the outer peripheral surface of the rotating body is greater than 90 degrees. A method for manufacturing an absorber, characterized in that the upstream side of the discharge direction is inclined toward the downstream side of the conveying direction.

20. A method for manufacturing the absorber according to claim 1, having a fibrous material supply step of supplying a fibrous material containing pulp from above the superabsorbent polymer laminated on the base sheet on the downstream side in the conveying direction of the base sheet from the position where the superabsorbent polymer particles are supplied to the base sheet. A method for manufacturing an absorber, characterized by this.

Images