Method of manufacturing an absorbent body

Abstract

A method for manufacturing absorbent bodies (SAP sheets) containing highly absorbent polymers that maintain a thin profile while providing a good fit when worn is readily available. The method includes the steps of: a conveying step in which a substrate sheet is conveyed by supporting one side of a substrate sheet using a support portion; and a particle supply step in which highly absorbent polymer particles are supplied toward the other side of the substrate sheet. The support portion has a plurality of openings, the diameter of the inscribed circle tangent to the openings being greater than or equal to the average particle size of the highly absorbent polymer particles when viewed from above. In the particle supply step, the substrate sheet is drawn from the one side of the substrate sheet through the openings.

Description

Technical Field

[0001] This invention relates to a method for manufacturing an absorbent. Background Technology

[0002] Previously, there were absorbent articles such as disposable diapers with absorbent bodies that possessed liquid absorbency. Among such absorbent bodies, SAP sheets containing a highly absorbent polymer (so-called SAP) and not containing fibrous materials such as pulp are known. Such SAP sheets are easier to reduce in thickness compared to absorbent bodies containing fibrous materials, and are therefore suitable for forming thin absorbent bodies. For example, Patent Document 1 discloses an absorbent body in which a highly absorbent polymer is disposed on a sheet material. Existing technical documents Patent documents

[0003] Patent Document 1: Japanese Patent Application Publication No. 2023-122342 Summary of the Invention The problem the invention aims to solve

[0004] In the SAP sheet (absorbent) described in Patent Document 1, a plurality of SAP particles are stacked on a material sheet (substrate sheet) in a uniform thickness manner. However, in such a SAP sheet, for example when it is sandwiched between the wearer's legs (i.e., groin area) during wear, it is difficult to deform along the contours of the wearer's body, and the fit may become poor.

[0005] The present invention was made in view of the aforementioned problems, and its object is to easily manufacture absorbent bodies (SAP sheets) with highly absorbent polymers that provide good fit when worn while maintaining a thinness. Solution for solving the problem

[0006] The main invention for achieving the above-mentioned objective is a method for manufacturing an absorbent containing a highly absorbent polymer. This method is characterized by comprising the following steps: a conveying step in which a substrate sheet is conveyed by means of a support supporting one side of the substrate sheet; and a particle supply step in which highly absorbent polymer particles are supplied toward another side of the substrate sheet. The support has a plurality of openings, and in plan view, the diameter of the inscribed circle inscribed in the openings is greater than or equal to the average particle size of the highly absorbent polymer particles. In the particle supply step, the substrate sheet is drawn from one side of the substrate sheet via the openings.

[0007] Other features of the invention will become clear from the description in this specification and the accompanying drawings. The effects of the invention

[0008] According to the present invention, it is possible to easily manufacture absorbent bodies with highly absorbent polymers that provide a good fit when worn while maintaining a relatively thin profile. Attached Figure Description

[0009] Figure 1 This is a rough 3D diagram of Diaper 1. Figure 2 This is a top view of the diaper 1 in its unfolded and elongated state, observed from the skin side. Figure 3 yes Figure 2 A schematic cross-sectional view at the center line CL. Figure 4A This is a cross-sectional schematic diagram of absorber 20. Figure 4B This is a cross-sectional schematic diagram of absorber 20A showing details of SAP layer 27. Figure 5 This is a top view of absorber 20A. Figure 6A This is a cross-sectional schematic diagram showing the case where a highly absorbent polymer is stacked in 14 layers on a substrate sheet. Figure 6B This is a top view schematic diagram showing the recessed region 214F on one side of the substrate sheet 14. Figure 7A This is a cross-sectional schematic diagram showing the state of absorber 20A before it absorbs moisture. Figure 7B This is a cross-sectional schematic diagram showing the state of absorber 20A after absorbing moisture. Figure 8 This is a top view schematic diagram of the absorber 20B of the modified example. Figure 9 This is a schematic diagram showing the outline of the absorber manufacturing apparatus 50. Figure 10 This is a diagram illustrating the suction opening 11su of the suction section 11P. Figure 11A This is a partial cross-sectional schematic diagram showing the 11cm section of the conveyor belt. Figure 11B This is a top view schematic diagram showing a portion of the conveyor belt 11 cm. Figure 12 This is a top view schematic diagram showing another example of the suction opening su of the suction section 11P. Figure 13 This diagram illustrates the supply of SAP particles and the ejection pattern of the adhesive in the absorber manufacturing apparatus 50. Figure 14 This is a diagram illustrating the suction opening 11su in the absorber manufacturing apparatus 50A of the first modified example. Figure 15 This is a schematic diagram showing the outline of the absorber manufacturing apparatus 60. Figure 16A diagram illustrating the plate section 11pt of the transmission section 11y. Figure 17 This is a top view schematic diagram showing another example of a 11pt plate. Figure 18 This diagram illustrates the supply of SAP particles and the ejection pattern of the adhesive in the absorber manufacturing apparatus 60. Figure 19 This is a perspective view of the absorber manufacturing apparatus 60A of the second modification. Figure 20 This is a top view schematic diagram showing another example of a substrate 118 with a plate portion of 11pt. Figure 21 This is a perspective view of the absorber manufacturing apparatus 60B of the third modification. Detailed Implementation

[0010] From the description in this specification and the accompanying drawings, at least the following will become clear.

[0011] (Method 1) A method for manufacturing an absorbent containing a highly absorbent polymer, characterized in that the method comprises the following steps: a conveying step in which a substrate sheet is conveyed by means of a support supporting one side of the substrate sheet; and a particle supply step in which highly absorbent polymer particles are supplied toward another side of the substrate sheet, the support having a plurality of openings, wherein, in plan view, the diameter of the inscribed circle inscribed in the openings is greater than or equal to the average particle size of the highly absorbent polymer particles, and in the particle supply step, the substrate sheet is drawn from the one side of the substrate sheet through the openings.

[0012] According to Method 1, an absorbent having a superabsorbent polymer laminated on a substrate sheet can be manufactured by a conveying process that conveys the substrate sheet to one side using a support portion and a particle supply process that supplies superabsorbent polymer particles toward the other side of the substrate sheet. Furthermore, the support portion has multiple openings, and by drawing the substrate sheet from one side of the substrate sheet through these openings during the particle supply process, an absorbent having high weight-per-unit area regions and low weight-per-unit area regions formed around each high weight-per-unit area region can be manufactured. Since the low weight-per-unit area regions serve as folding starting points, the absorbent easily conforms to the contours of the wearer's body, improving fit. By having the diameter of the inscribed circles tangent to the multiple openings in top view that is greater than or equal to the average particle size of the superabsorbent polymer particles, multiple high weight-per-unit area regions and low weight-per-unit area regions can be arranged while maintaining a thin absorbent. Therefore, according to Method 1, an absorbent having a superabsorbent polymer that provides good fit when worn while maintaining a thin profile can be easily manufactured.

[0013] (Method 2) The method for manufacturing an absorbent according to Method 1 is characterized in that, in the conveying process, the support is a conveyor belt for conveying the substrate sheet.

[0014] According to Method 2, even with an absorbent manufacturing device using a conveyor belt, it is possible to easily manufacture absorbents with highly absorbent polymers that maintain a thin profile while providing a good fit when worn.

[0015] (Method 3) The method for manufacturing an absorbent according to embodiment 2 is characterized in that a suction section is provided on the opposite side of the side where the substrate sheet is located when viewed from the support portion, and an additional conveyor belt having a suction opening is provided, the additional conveyor belt being located between the conveyor belt and the suction section and moving in the same direction as the conveying direction of the conveyor belt.

[0016] According to method 3, by having another conveyor belt positioned between the conveyor belt and the suction unit and moving in the same direction as the conveying direction of the conveyor belt, wear of the conveyor belt caused by friction between the conveyor belt and the edge of the suction opening can be suppressed, thereby extending the service life of the conveyor belt.

[0017] (Method 4) The method for manufacturing an absorbent according to method 2 or 3 is characterized in that a suction section is provided on the opposite side of the side where the substrate sheet is located when viewed from the support portion, and the suction port of the suction section has a first opening region and a second opening region in an intersecting direction that intersects the conveying direction of the substrate sheet, the second opening region being adjacent to the first opening region and having a lower opening ratio than the first opening region, and in the particle supply process, the suction section suctions the substrate sheet from one side of the substrate sheet via the opening, the first opening region and the second opening region.

[0018] According to method 4, an absorbent body with grooved areas can be formed. In an absorbent body with grooved areas, it is easy to deform in the width direction at the crotch of the wearer, increasing the crotch's capacity and further improving the fit.

[0019] (Method 5) The method for manufacturing an absorbent according to method 4 is characterized in that the opening ratio of the first opening region is greater than or equal to the opening ratio of the opening in the region of the support where the opening is provided.

[0020] According to method 5, an absorber with a grooved region can be properly formed.

[0021] (Method 6) The method for manufacturing an absorbent according to method 4 or 5 is characterized in that the opening ratio of the second opening region is less than or equal to the opening ratio of the opening in the region of the support where the opening is provided.

[0022] According to method 6, an absorber with a grooved region can be appropriately formed.

[0023] (Method 7) The method for manufacturing an absorbent according to any one of methods 4 to 6 is characterized in that the second opening region is provided with a plurality of openings in the intersecting direction.

[0024] According to method 7, an absorbent body with multiple grooved areas can be formed. In an absorbent body with multiple grooved areas, the storage capacity of the crotch is further increased, and the fit is further improved.

[0025] (Method 8) The method for manufacturing an absorbent according to any one of methods 4 to 7 is characterized in that the suction section has a third opening region and a non-opening region, the third opening region being located downstream of the first opening region in the conveying direction and having a portion overlapping the first opening region in the intersecting direction, the opening ratio of the third opening region being lower than that of the first opening region, the non-opening region being located downstream of the second opening region in the conveying direction and having a portion overlapping the second opening region in the intersecting direction, and being located downstream of the location where the highly absorbent polymer particles are supplied to the substrate sheet in the conveying direction, the suction section suctions the substrate sheet from one side of the substrate sheet via the third opening region.

[0026] According to method 8, highly absorbent polymer particles that can suppress rebound at the location where highly absorbent polymer particles are supplied are disposed in the tank area on the downstream side.

[0027] (Method 9) The method for manufacturing an absorbent according to embodiment 8 is characterized in that the suction portion includes a fourth opening region, which is located, in a top view, on the outer side of the intersecting direction than the first and third opening regions and overlaps with the end of the substrate sheet in the intersecting direction. In the conveying process, the suction unit draws the end from one side of the substrate sheet via the fourth opening region.

[0028] According to method 9, it is possible to suppress the rolling up of the substrate sheet being transported.

[0029] (Method 10) The method for manufacturing an absorbent according to any one of methods 1 to 9 is characterized in that, in the conveying step, the support is a rotating body that conveys the substrate sheet.

[0030] According to method 10, even using an absorbent manufacturing device with a rotating body, it is possible to easily manufacture an absorbent with a highly absorbent polymer that provides a good fit when worn while maintaining a thin profile.

[0031] (Method 11) The method for manufacturing an absorbent according to method 10 is characterized in that a suction portion is provided on the opposite side of the side where the substrate sheet is located when viewed from the support portion, the support portion having a first opening and a second opening with a lower opening ratio than the first opening, and the region having the first opening and the region having the second opening are arranged adjacent to each other in an intersecting direction that intersects the conveying direction of the substrate sheet, and in the particle supply process, the suction portion draws the substrate sheet from one side of the substrate sheet via the first opening and the second opening.

[0032] According to method 11, an absorbent body with a grooved area can be formed. In an absorbent body with a grooved area, it is easy to deform in the width direction at the crotch of the wearer, increasing the crotch's capacity and further improving the fit.

[0033] (Method 12) The method for manufacturing an absorbent according to method 11 is characterized in that the region having the second opening has a plurality of openings in the intersecting direction.

[0034] According to method 12, an absorbent body with multiple grooved areas can be formed. In an absorbent body with multiple grooved areas, the storage capacity of the crotch is further increased, and the fit is further improved.

[0035] (Method 13) The method for manufacturing an absorbent according to any one of methods 1 to 12 is characterized in that the method includes an upstream adhesive coating step, in which adhesive is applied to the other side of the substrate sheet at a position upstream of the position where the highly absorbent polymer particles are supplied to the substrate sheet, in the transport direction of the substrate sheet.

[0036] According to method 13, highly absorbent polymer particles can be easily adhered to the substrate sheet.

[0037] (Method 14) The method for manufacturing an absorbent according to embodiment 13 is characterized by comprising the following steps: an additional sheet supply step, in which additional sheets are supplied from the other side of the substrate sheet at a position downstream of the position to which the highly absorbent polymer particles are supplied to the substrate sheet in the transport direction of the substrate sheet, in a manner that covers the highly absorbent polymer particles; and a joint forming step, in which the additional sheets and the substrate sheet are joined in the thickness direction in an area of ​​the other side of the substrate sheet where the adhesive is not applied, along a cross direction that intersects the transport direction of the substrate sheet.

[0038] According to method 14, it is possible to suppress openings between the substrate sheet and other sheets.

[0039] (Method 15) The method for manufacturing an absorbent according to any one of methods 1 to 14 is characterized in that the diameter of the inscribed circle inscribed in the opening is 2 mm or more and 4 mm or less.

[0040] According to method 15, by reducing the top-view size of each of the multiple high weight-per-unit area regions, it is possible to configure a number of high weight-per-unit area regions and low weight-per-unit area regions on the substrate sheet, making it easy for the absorbent to deform along the contours of the wearer's body, thereby improving fit.

[0041] (Method 16) The method for manufacturing an absorbent according to method 15 is characterized in that, in the support portion, the opening ratio of the opening in the region where the opening is provided is 40% or more and 60% or less.

[0042] According to method 16, a region with a high weight per unit area can be appropriately formed in the absorber.

[0043] (Method 17) The method for manufacturing an absorbent according to any one of methods 1 to 16 is characterized in that the method includes a downstream adhesive spraying step, in which adhesive is sprayed toward the other side of the substrate sheet along with an airflow at a position downstream of the position where the highly absorbent polymer particles are supplied to the substrate sheet, and at least a portion of the highly absorbent polymer particles that bounce off the substrate sheet is pushed back toward the substrate sheet side by the sprayed adhesive.

[0044] According to method 17, it is possible to reduce the occurrence of highly absorbent polymer particles being disposed in unexpected locations on the substrate sheet.

[0045] (Method 18) The method for manufacturing an absorbent according to method 17 is characterized in that, in the conveying step, the substrate sheet is conveyed by a conveyor, the conveying surface of the conveyor being inclined downwards relative to the horizontal plane on the downstream side.

[0046] According to method 18, it is possible to further reduce the occurrence of highly absorbent polymer particles being disposed in unexpected locations on the substrate sheet.

[0047] (Method 19) The method for manufacturing an absorbent according to method 17 is characterized in that, in the conveying step, the substrate sheet is conveyed by a rotating body, the adhesive is sprayed in a predetermined spraying direction, and the upstream side of the spraying direction is inclined to the downstream side of the conveying direction in such a way that the angle between the imaginary line obtained by extending the spraying 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.

[0048] According to method 19, it is possible to reduce the occurrence of highly absorbent polymer particles being disposed in unexpected locations on the substrate sheet.

[0049] (Method 20) The method for manufacturing an absorbent according to any one of methods 1 to 19 is characterized in that the method includes a fibrous material supply step, in which a fibrous material containing pulp is supplied from the superabsorbent polymer laminated on the substrate sheet at a position downstream of the position where the superabsorbent polymer particles are supplied to the substrate sheet in the transport direction of the substrate sheet.

[0050] According to method 20, an absorbent that can quickly and temporarily absorb excrement can be easily manufactured to suppress the overflow and leakage of excrement during excretion.

[0051] ===Absorbent Items and Absorbent Bodies=== As an absorbent article of the present invention, a disposable diaper 1 (hereinafter also referred to as "diaper 1") of the underwear type for infants and young children will be used as an example for description. However, the absorbent articles of the present invention also include strip-type disposable diapers, panty-type sanitary napkins, absorbent pads, menstrual sanitary napkins, and other absorbent articles. In addition, the wearer of the absorbent article is not limited to infants and young children, but may also be an adult or an animal.

[0052] <<Structure of Absorbent Material (Diaper 1)>> Figure 1 This is a rough 3D diagram of Diaper 1. Figure 2 This is a top view of the diaper 1 in its unfolded and elongated state, observed from the skin side. Figure 3 yes Figure 2 A schematic cross-sectional view at the center line CL.

[0053] The "unfolded state" of diaper 1 refers to the state in which it will be unfolded. Figure 1 The diaper 1 shown has a pair of side joints 2 on both sides that separate and are as follows: Figure 2 The diaper 1 is shown in its unfolded, flat state. The "stretched state" of the diaper 1 refers to the state in which the diaper 1 is stretched out without wrinkles. Specifically, it means that the diaper 1 is stretched out to the point where the size of each component constituting the diaper 1 (such as the absorbent body 10, waist section 30, 40, etc., described later) is the same as or close to the size of the individual component.

[0054] like Figure 1 As shown, the diaper 1 has mutually orthogonal vertical, width, and front-back directions, and has a waist opening BH and a pair of leg openings LH. The upper side of the vertical direction corresponds to the waist opening BH side, and the lower side of the vertical direction corresponds to the crotch side. The front side of the front-back direction corresponds to the wearer's abdomen, and the back side of the front-back direction corresponds to the wearer's back. Figure 2 As shown, the width direction is along the direction of extension and retraction of the elastic members 33 and 43, such as the elastic bands provided on the front waist section 30 and the rear waist section 40. The vertical direction is along a direction orthogonal to the direction of extension and retraction.

[0055] Diaper 1 is a so-called three-piece pant-type diaper with a liquid-absorbing absorbent body 10 and a pair of waist sections 30, 40. The waist section that covers the wearer's flank is also called the front waist section 30, and the waist section that covers the wearer's back is also called the back waist section 40.

[0056] exist Figure 2 In the unfolded state shown, the diaper 1 has mutually orthogonal length, width, and thickness directions. The length direction is along the length of the absorbent body 10 and along the vertical direction of the panty-type diaper 1. Figure 3 As shown, the thickness direction is the direction in which the materials constituting diaper 1 are stacked. The side in the thickness direction that comes into contact with the wearer's skin is designated as the skin side, and the opposite side is designated as the non-skin side.

[0057] In addition, Figure 2In its unfolded state, with the front waist section 30 and the rear waist section 40 arranged parallel to each other at intervals along their length, an absorbent body 10 is positioned between the front waist section 30 and the rear waist section 40. Each end of the absorbent body 10 along its length is respectively joined and fixed to the skin side of the nearest waist section of the waist section 30 or 40, and its appearance, viewed from above, is roughly the shape of the letter H. Furthermore, from this state, the absorbent body 10 is folded in half at its center line CL along its length. In this folded state, the opposing front waist section 30 and rear waist section 40 are joined together on both sides in the width direction, forming a pair of side joints 2. Moreover, the side joints 2 are formed by known joining methods such as welding or bonding.

[0058] like Figure 3 As shown, the absorbent body 10 has an absorbent body 20 (details below), a liquid-permeable top sheet 12 disposed on the skin side of the absorbent body 20, and a bottom sheet 13 disposed on the non-skin side of the absorbent body 20. The bottom sheet 13 has a double-layer structure consisting of a liquid-impermeable sheet 13a and a hydrophobic outer sheet 13b disposed on its non-skin side. However, the absorbent body 10 may also have other sheet components. 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 leak-proof wall portions 15 are provided on both sides of the absorbent body 10 in the width direction and along the length direction of the absorbent body 10. Figure 3 In this structure, a pair of leak-proof wall portions 15 are formed by extending a portion of the outer sheet 13b in the width direction to a position further outward than both ends of the absorbent body 20 and bending towards the skin at multiple locations. At the ends of the leak-proof wall portions 15, elastic members such as elastic bands are installed, extending along the length direction of the absorbent body 10. The leak-proof wall portions 15 are configured to stand upright towards the skin. Furthermore, elastic leg members such as elastic bands are installed on both sides of the absorbent body 10 in the width direction, extending along the length direction of the absorbent body 10.

[0060] like Figure 2As shown, the front waist section 30 and the rear waist section 40 each have skin-friendly side panels 31 and 41, non-skin-friendly side panels 32 and 42, and multiple elastic waist members 33 and 43, such as elastic bands. These elastic waist members 33 and 43 are arranged vertically and are installed between the skin-friendly side panels 31 and 41 and the non-skin-friendly side panels 32 and 42, extending in the width direction. The elasticity of the waist members 33 and 43 allows the front waist section 30 and the rear waist section 40 to conform to the wearer's waist. Additionally, cover plates 34 and 44 can be provided to cover the upper part of the absorbent body 10 from the skin side. The cover plates 34 and 44 can suppress openings in the absorbent body 10.

[0061] In addition, such as Figure 2 As shown, the front waist section 30 and the rear waist section 40 have different planar shapes when unfolded and extended. The front waist section 30 has a length in the vertical direction that is approximately the same as the side joint 2, and it is a rectangular shape that is longer in the width direction. The rear waist section 40 has a rectangular portion that overlaps with the front waist section 30 and a roughly trapezoidal portion 40E that extends to a position lower than the rectangular portion. This extended portion 40E can cover the wearer's buttocks.

[0062] The basic structure of diaper 1 has been described above, but the structure described above is an example and is not limited to this. For example, the front waist section 30 and the back waist section 40 may be formed by a continuous single member, or an external member may be provided at the crotch area to connect the front waist section 30 and the back waist section 40. In addition, the elastic members such as waist elastic members 33 and 43 may not be elastic cords, but sheet-like elastic members.

[0063] <<Structure of Absorbers>> Next, based on Figure 4A , Figure 4B and Figure 5 Details of the absorbent element 20 in the above-mentioned absorbent article (diaper 1) will be explained.

[0064] Figure 4A This is a cross-sectional schematic diagram of absorber 20. Figure 4B This is a cross-sectional schematic diagram of absorber 20A showing details of SAP layer 27. Figure 5 This is a top view of absorber 20A.

[0065] like Figure 4AAs shown, the absorbent body 20 of the above-mentioned absorbent article (diaper 1) has absorbent cores 21 to 23 between the skin-side core sheet 24 and the non-skin-side core sheet 25. The absorbent cores 21 to 23 are components that absorb and retain excretory fluids such as urine, and contain at least one of fibrous material and super absorbent polymer (hereinafter also referred to as SAP).

[0066] There are no particular restrictions on the use of fibrous materials and superabsorbent polymers as absorbent cores in absorbent articles, as long as they can be used. Fibrous materials are fibrous materials with liquid absorbency, such as wood pulp fibers, bagasse, kenaf, bamboo, hemp, cotton, and other non-wood pulp fibers, regenerated cellulose fibers such as rayon, semi-synthetic fibers such as acetate fibers, or mixtures of these materials. Superabsorbent polymers (SAPs) can be, for example, starch-based, cellulose-based, synthetic polymer-based absorbents, or mixtures of these substances. Furthermore, the core sheets 24 and 25 are liquid-permeable sheets, such as nonwoven fabrics and cotton paper.

[0067] The absorbent cores 21-23 are sometimes referred to sequentially from the skin side in the thickness direction as skin-side layer 21, intermediate layer 22, and non-skin-side layer 23. Figure 4A In the absorbent 20 shown, the skin-side layer 21 is not integrally formed with the intermediate layer 22, which is located on the non-skin side of the skin-side layer 21. Instead, it is stacked adjacent to the intermediate layer 22 in the thickness direction, separated by a sheet 26 made of non-woven fabric, cotton paper, etc. Furthermore, in Figure 4A In the absorber 20 shown, the intermediate layer 22 and the non-skin side layer 23 are integrally formed. That is, the non-skin side layer 23 is directly laminated to the non-skin side of the intermediate layer 22 without being separated by non-woven fabric or other sheets, adhesives such as HMA.

[0068] The volume fraction of the fibrous material or SAP in the absorbent cores 21-23 can be varied for each of the absorbent cores 21-23 according to its purpose. For example, the volume fraction of SAP in the skin-side layer 21 may be higher, the volume fraction of the fibrous material in the intermediate layer 22 may be higher, and the volume fraction of SAP in the non-skin-side layer 23 may be higher. Furthermore, the skin-side layer 21 may contain only SAP and no fibrous material, the intermediate layer 22 may contain only fibrous material and no SAP, and the non-skin-side layer 23 may contain only SAP and no fibrous material. Since the absorption rate of the liquid in SAP is slower than that of the liquid in the fibrous material, the excretory fluid is easily transferred to the intermediate layer 22 before being absorbed by the SAP in the skin-side layer 21. Additionally, the excretory fluid between the fibers of the fibrous material absorbed into the intermediate layer 22 gradually transfers to the non-skin-side layer 23 under the influence of gravity and is fully absorbed and retained by the SAP in the non-skin-side layer 23.

[0069] Therefore, it is easy to introduce excrement into the non-skin side layer 23, and the absorbent cores 21-23 can be effectively utilized in the thickness direction. As a result, the water retention capacity of the absorbent cores 21-23 is increased, and leakage of excrement can be suppressed even with repeated urination. Furthermore, the dryness of the skin-side surfaces of the absorbent cores 21-23 is ensured, improving the wearing comfort of the diaper 1. In addition, when excrement in the middle layer 22 and the non-skin side layer 23 tends to flow back towards the skin side, the SAP (absorbent polymer) absorption of the skin-side layer 21 retains the excrement. Therefore, the back-wetting of excrement can be suppressed. From this perspective, the dryness of the skin-side surfaces of the absorbent cores 21-23 is also ensured.

[0070] In addition, such as Figure 4A As shown, in the thickness direction, sheet 26 is located closer to the skin side (the side where skin-side layer 21 is located) than intermediate layer 22, and adhesive HMA is provided between intermediate layer 22 and sheet 26. Furthermore, adhesive HMA here is a hot-melt adhesive. In other words, adhesive HMA is provided between the fibrous material (intermediate layer 22) and SAP (skin-side layer 21). Moreover, core sheet 25 is located closer to the non-skin side than non-skin side layer 23, and adhesive HMA is provided between non-skin side layer 23 and core sheet 25. Sheet 26 and core sheet 25 can be joined using adhesive HMA provided between intermediate layer 22 and sheet 26 and adhesive HMA provided between non-skin side layer 23 and core sheet 25, and intermediate layer 22 and non-skin side layer 23 can be fixed to sheet 26 and core sheet 25.

[0071] Here, the absorber 20 is not limited to Figure 4A As shown. In Figure 4AIn the absorbent 20 shown, starting from the skin side in the thickness direction, a sheet (core-encapsulated sheet 24), a skin-side layer 21, a sheet 26, an integrally formed intermediate layer 22, and a non-skin-side layer 23 are stacked sequentially, followed by a sheet (core-encapsulated sheet 25). However, the sheet 26 may not be located between the skin-side layer 21 and the intermediate layer 22, but rather between the intermediate layer 22 and the non-skin-side layer 23. In this case, the skin-side layer 21 (the layer with a higher volume fraction of SAP) and the intermediate layer 22 (the layer with a higher volume fraction of fibrous material) may be integrally formed. That is, the intermediate layer 22 (the layer with a higher volume fraction of fibrous material) may be directly stacked on the non-skin side of the skin-side layer 21 (the layer with a higher volume fraction of SAP) without being separated by a sheet such as a nonwoven fabric or an adhesive such as HMA. In this case, the absorbent 20 has a fibrous material containing pulp at a position adjacent to the SAP in the thickness direction. As a result, it can quickly and temporarily absorb the excretory fluid and suppress the overflow and leakage of the excretory fluid during excretion. In addition, the non-skin side layer 23 (the layer with a higher volume fraction of SAP) can also be stacked adjacent to each other in the thickness direction through the sheet 26.

[0072] Furthermore, not limited to the above, the skin-side layer 21, which is not integrally formed with the intermediate layer 22, may also be laminated to the intermediate layer 22 without being separated by a sheet of nonwoven fabric or adhesive HMA. Similarly, the non-skin-side layer 23, which is not integrally formed with the intermediate layer 22, may also be laminated to the intermediate layer 22 without being separated by a sheet of nonwoven fabric or adhesive HMA. Moreover, the intermediate layer 22 is not limited to being integrally formed with only one of the skin-side layer 21 and the non-skin-side layer 23, but may be integrally formed with both the skin-side layer 21 and the non-skin-side layer 23. Between the skin-side layer 21 and the intermediate layer 22, and between the intermediate layer 22 and the non-skin-side layer 23, a sheet of nonwoven fabric or adhesive HMA may be provided, or no sheet of nonwoven fabric or adhesive HMA may be provided.

[0073] The absorbent core 20 is not limited to the three-layer absorbent core consisting of a skin-side layer 21, a middle layer 22, and a non-skin-side layer 23. It can also be a two-layer absorbent core, or a single-layer absorbent core. Hereinafter, we will continue to explain using an absorbent core (hereinafter referred to as a SAP sheet) laminated on a sheet such as non-woven fabric, as a single-layer absorbent core.

[0074] like Figure 4BAs shown, the absorber 20A comprises a substrate sheet 14, a SAP layer 27, and other sheets 14S. The combination of the substrate sheet 14 and SAP layer 27 with the other sheets 14S in the absorber 20A is, for example, equivalent to the combination of the core sheet 24, skin-side layer 21, and sheet 26 of the absorber 20 described above, or the combination of the core sheet 25, non-skin-side layer 23, and sheet 26 where the sheet 26 is located between the intermediate layer 22 and the non-skin-side layer 23. Here, the SAP layer 27 (the high weight-per-unit area region 211 and the low weight-per-unit area region 212, described later) contains only SAP and does not contain any fibrous materials other than SAP. Therefore, compared to absorbers containing fibrous materials, a thinner absorber 20A can be formed. The SAP in the SAP layer 27 is fixed to the substrate sheet 14 and the other sheets 14S using an adhesive HMA. This allows for reliable fixation of the SAP to the substrate sheet 14 and the other sheets 14S.

[0075] In the following description, the term "particle" used with "superabsorbent polymer (SAP)" encompasses any shape or form, including granules, aggregates, flakes, fibers, spheres, and combinations thereof. Furthermore, particles can have any desired shape, such as spherical, polygonal, rod-shaped, polyhedral, or other regular or irregular shapes, whether circular or square.

[0076] like Figure 4B As shown, SAP layer 27 has a high weight-per-unit-area region 211 where the SAP's weight-per-unit-area is higher than its surroundings. Additionally, as... Figure 5 As shown, the point S in the region 211 with the highest unit area weight, which represents the maximum thickness in the thickness direction, is located at a discontinuous position in both the length and width directions. Therefore, Figure 5 The high unit area weight region 211 shown is intermittently arranged in the length and width directions. Moreover, between adjacent points S that are the points of maximum thickness (i.e., around the high unit area weight region 211), low unit area weight regions 212 are formed where the unit area weight of SAP is lower than that of the high unit area weight region 211.

[0077] However, as long as the point S that becomes the point of maximum thickness is located at a discontinuous position in both the length and width directions, the local areas between adjacent points S that become the point of maximum thickness can also be formed by regions with high weight per unit area 211. That is, the local areas between adjacent points S that become the point of maximum thickness can also be connected by regions with high weight per unit area 211. Figure 5 In the diagram, a solid line represents the area of ​​high weight per unit area 211 when viewed from above, and a dashed line represents the area of ​​low weight per unit area 212. For convenience, in... Figure 5The ranges of the high unit area weight region 211 and the low unit area weight region 212 are schematically shown in the figure.

[0078] like Figure 4B and Figure 5 As shown, the low weight-per-unit-area region 212 has a low weight-per-unit-area stacked region 212E with stacked SAP and a non-stacked region 212N without SAP. Here, "without SAP" includes not only the absence of SAP particles, but also the case where the number of stacked SAP particles is extremely small, thus essentially eliminating the presence of SAP particles. Furthermore, in Figure 5 In the diagram, the center of the low-weight-per-unit-area-layered region 212E is marked with a △ symbol, and the center of the non-layered region 212N is marked with an × symbol.

[0079] In the absorbent 20A of this embodiment, the low weight-per-unit area region 212 (low weight-per-unit area layered region 212E and non-layered region 212N) serves as the folding starting point, making it easy to deform along the contours of the wearer's body and improving fit. Furthermore, the low weight-per-unit area region 212, which serves as the folding starting point, includes the low weight-per-unit area layered region 212E, which is capable of absorbing and retaining excrement, and the non-layered region 212N, which is easier to bend due to the absence of SAP. Thus, even in the low weight-per-unit area region 212, where the SAP weight-per-unit area is lower than that of the high weight-per-unit area region 211, both ease of deformation along the contours of the wearer's body and the ability to absorb and retain excrement are balanced.

[0080] As described above, the low weight-per-unit-area region 212 is formed between points S, which are discontinuously arranged in the length and width directions and have the maximum thickness. Therefore, as Figure 5 As shown, the low weight-per-unit area region 212 is also intermittently arranged in the length and width directions. That is, the low weight-per-unit area layered region 212E is intermittently arranged in the length and width directions, and similarly, the non-layered region 212N is also intermittently arranged in the length and width directions. By sparsely arranging the low weight-per-unit area layered region 212E and the non-layered region 212N in the plane, the absorber 20A can have a degree of flexibility in deforming along the contours of the wearer's body and a high degree of retention of excrement with a degree of expansion in the plane.

[0081] In the absorber 20A of this embodiment, for example in Figure 5As shown in the top view, the number of low weight-per-unit-area laminated regions 212E varies in each of the regions that divide the absorber 20A into three equal parts along its length. Similarly, the number of non-laminated regions 212N also varies in each of the regions that divide the absorber 20A into three equal parts along its length. Details will be described later. When the absorber is manufactured by supplying SAP particles toward the substrate sheet, the regions where SAP particles are not adhered to become non-laminated regions 212N, and the regions where some SAP particles are adhered to become low weight-per-unit-area laminated regions 212E. Since the non-laminated regions 212N and low weight-per-unit-area laminated regions 212E are randomly generated in the plane, as described above, in the top view, the number of low weight-per-unit-area laminated regions 212E and the number of non-laminated regions 212N vary in each of the regions that divide the absorber 20A into three equal parts along its length. In this way, by randomly arranging the low-weight-per-unit-area-area-layered regions 212E and the non-layered regions 212N in a plane, the absorber 20A can easily deform along the contours of the wearer's body, thereby improving fit.

[0082] Furthermore, in the absorbent 20A of this embodiment, by having a low unit area weight region 212 surrounding the high unit area weight region 211, the excrement can easily diffuse in the planar direction. Assuming that the unit area weight of the SAP is constant in the plane, adjacent SAPs tend to clump together due to adhesion when absorbing moisture, which can sometimes hinder further diffusion of the excrement. In other words, when the unit area weight of the SAP is constant in the plane, so-called gel retardation may occur.

[0083] Therefore, in the absorber 20A of this embodiment, the absorber 20A has a low unit area weight region 212 around the high unit area weight region 211, so that even after absorbing a certain amount of excrement, the excrement can easily diffuse along the low unit area weight region 212, and the occurrence of the above-mentioned gel retardation can be suppressed.

[0084] The non-stacked regions 212N are arranged in such a way that, when viewed from a high unit area weight region 211, there are more points on the width side than on the length side. In other words, among the points S that become the maximum thickness, the number of points S located adjacent to the non-stacked regions 212N on one or the other side in the width direction is greater than the number of points S located adjacent to the non-stacked regions 212N on one or the other side in the length direction. As a result, the low unit area weight stacked regions 212E are arranged in such a way that, when viewed from the high unit area weight region 211, there are more points on the length side than on the width side. In this case, when the absorbent 20A has absorbed the excretion liquid, that is, in the swollen state, more SAP adheres to each other in the length direction where more low unit area weight stacked regions 212E are arranged. Therefore, it is possible to suppress the loss of flexibility in the width direction of the absorbent 20A in the swollen state.

[0085] exist Figure 5 The absorber 20A shown may also include the element described later. Figure 8 The groove region 215 is shown. A detailed description of the groove region 215 will be given later, but by having the groove region 215 in the absorbent body 20A, for example, when it is sandwiched between the wearer's legs (i.e., the groin area) during wear, it is easy to deform in the width direction at the wearer's crotch, increasing the crotch's capacity and further improving the fit. In this case, since the groove region 215 itself becomes the folding starting point, it helps to improve the fit. However, it is also possible not to provide the groove region 215 in the absorbent body 20A.

[0086] Furthermore, in the absorber 20A of this embodiment, it is suitable to have, for example... Figure 4B As shown, the maximum thickness T is within 3 mm, and the spacing between adjacent points S that constitute the maximum thickness is less than 5 times the maximum thickness T. Therefore, it is possible to arrange numerous high-weight-per-unit-area regions and low-weight-per-unit-area regions while maintaining a relatively thin absorbent body 20A. Consequently, in the absorbent body 20A with the highly absorbent polymer, it is possible to improve the fit when worn while maintaining a relatively thin profile. Furthermore, it is even more suitable that the maximum thickness T is within 2 mm, and the spacing between adjacent points S that constitute the maximum thickness is less than 4 times the maximum thickness T. Therefore, in the absorbent body 20A with the highly absorbent polymer, it is possible to improve the fit when worn while maintaining an even thinner profile.

[0087] exist Figure 5In the top view shown, it is suitable that the diameter of the circumscribed circle CC of each of the multiple high weight-per-unit area regions 211 is 2 mm or more and 4 mm or less. This allows for a reduction in the size of each of the multiple high weight-per-unit area regions 211, enabling the arrangement of numerous high weight-per-unit area regions 211 and low weight-per-unit area regions 212 on the substrate sheet 14. Consequently, the absorber 20A can easily deform along the contours of the wearer's body, improving fit.

[0088] Additionally, it is suitable to be in Figure 5 As shown in the top view, the largest diameter among the diameters of the inscribed circles IC that are inscribed within the plurality of non-stacked regions 212N is less than or equal to the maximum thickness T. In this way, by reducing the size of the non-stacked regions 212N without SAP in the top view, leakage of the drain fluid through the non-stacked regions 212N can be suppressed.

[0089] Moreover, in Figure 5 In the top view shown, a joint 213 is provided on the outer side of the region where the SAP (i.e., the high weight-per-unit area region 211 and the low weight-per-unit area region 212) in the length direction. The joint 213 is the part where the substrate sheet 14 is joined to the other sheets 14S in the thickness direction. The joint 213 is formed by known joining methods such as embossing, welding, and bonding. As a result, openings between the substrate sheet 14 and the other sheets 14S can be suppressed.

[0090] Furthermore, the area in the substrate sheet 14 where the joint 213 is formed is an area where no SAP is provided, and an area where no adhesive for fixing the SAP is provided. Here, an area where no SAP is provided means an area where SAP is substantially not provided (for example, the weight of SAP provided in this area is less than 10% of the total weight of SAP provided in the substrate sheet 14). Alternatively, the joint 213 may not be provided.

[0091] Figure 6A This is a cross-sectional schematic diagram showing the case where a highly absorbent polymer is stacked in 14 layers on a substrate sheet. Figure 6B This is a top view schematic diagram showing the recessed region 214F on one side of the substrate sheet 14.

[0092] In this embodiment, such as Figure 6AAs shown, recessed regions 214 are formed on one side and the other side in the thickness direction of the substrate sheet 14. Specifically, a recessed region 214F is formed on one side of the substrate sheet 14, and a recessed region 214B is formed on the other side. On one side of the substrate sheet 14 in the thickness direction, a larger amount of SAP is disposed in the recessed region 214F, thereby forming a high weight-per-unit area region 211. On the other hand, in regions other than the recessed region 214F, by not disposing of SAP, or even if SAP is disposed, it is disposed in fewer amounts than in the recessed region 214F, thereby forming a low weight-per-unit area region 212 (low weight-per-unit area laminated region 212E or non-laminated region 212N).

[0093] In addition, such as Figure 6B As shown, on one side of the substrate sheet 14, the recessed region 214F is discontinuously arranged in both the length and width directions. Consequently, the high weight-per-unit area region 211 is arranged such that the point S, which represents the maximum thickness in the thickness direction, is discontinuously located in both the length and width directions. Similarly, the low weight-per-unit area regions 212 (low weight-per-unit area laminated region 212E and non-laminated region 212N) are also discontinuously arranged in both the length and width directions.

[0094] Furthermore, the difference SB1 between the highest point H1 and the lowest point L1 in the thickness direction on one side of the substrate sheet 14 and the difference SB2 between the highest point H2 and the lowest point L2 in the thickness direction on the other side of the substrate sheet 14 are different. That is, the depth of the recessed region 214 where the SAP is disposed can be different in the recessed region 214F on one side of the substrate sheet 14 and the recessed region 214B on the other side. In other words, in Figure 6B In the substrate sheet 14 shown, the recessed area 214F on one side is formed to be shallower, while the recessed area 214B on the other side is formed to be deeper.

[0095] Here, in Figure 6A In the substrate sheet 14 shown, the absorber 20A is formed by distributing SAP in the recessed region 214F on the shallower side of the recess. However, the absorber 20A can also be formed by distributing SAP in the recessed region 214B on the deeper side of the recess. For example, compared to the recessed region 214F on the shallower side, more SAP can be distributed in the recessed region 214B on the deeper side, which can improve the absorption and retention capacity of the drained liquid. Conversely, by distributing SAP in the recessed region 214F on the shallower side of the recess, the liquid diffusivity can be improved compared to the recessed region 214B. Therefore, by making the depths different in the recessed regions 214F and 214B as described above, it is possible to select which recessed region 214 to distribute SAP, thereby forming an absorber with properties corresponding to the purpose.

[0096] However, the difference SB1 between the highest point H1 and the lowest point L1 in the thickness direction on the surface side of the substrate 14 and the difference SB2 between the highest point H2 and the lowest point L2 in the thickness direction on the back side of the substrate 14 can also be the same. That is, the depth of the recessed region 214 where the SAP is disposed can also be the same on one side and the other side of the substrate 14.

[0097] like Figure 6A As shown, on the surface side of the substrate sheet 14, the weight of the SAP stacked at a position lower than the highest point H1 is more than 50% of the weight of the SAP stacked on the entire substrate sheet 14. Therefore, by stacking the desired weight of the SAP in the recessed area of ​​the substrate sheet 14, a high weight-per-unit-area region 211 can be formed in the appropriate location.

[0098] In addition, Figure 6B As shown in the top view, the largest diameter among the diameters of the inscribed circles IC that are inscribed within the plurality of non-stacked regions 212N is less than or equal to the difference SB1 on the surface side. Thus, by reducing the size of the non-stacked regions 212N without SAP in the top view, leakage of the drain fluid through the non-stacked regions 212N can be suppressed.

[0099] Here, in Figure 6B When viewed from above, it will be more than Figure 6A The area below the midpoint M1 between the highest point H1 and the lowest point L1 is represented as the range of the recessed region 214F. In this case, it is suitable that the sum of the lengths LG1 of the multiple recessed regions 214F along the imaginary line V1 passing through the center C of the multiple recessed regions 214F in the longitudinal direction is more than 50% of the overall length of the substrate sheet 14. Thus, by laminating SAP onto the desired area of ​​the substrate sheet 14, it is possible to form a high weight-per-unit area region 211 and a low weight-per-unit area region 212 in appropriate locations.

[0100] Similarly, it is suitable that the sum of the lengths LG2 of the plurality of recessed regions 214F along an imaginary line V2 passing through the center of the plurality of recessed regions 214F in the width direction is more than 50% of the overall length of the substrate sheet 14. Thus, by laminating SAP onto the desired areas of the substrate sheet 14, it is possible to form high weight-per-unit area regions 211 and low weight-per-unit area regions 212 in appropriate locations.

[0101] Figure 7A This is a cross-sectional schematic diagram showing the state of absorber 20A before it absorbs moisture. Figure 7B This is a cross-sectional schematic diagram showing the state of absorber 20A after absorbing moisture.

[0102] The absorbent 20A of this embodiment includes: a joining region 28 in which the substrate sheet 14 and other sheets 14S are joined to each other at adjacent points S that are the points of maximum thickness; and a non-jointing region 29 in which the substrate sheet 14 and other sheets 14S are not joined to each other at adjacent points S that are the points of maximum thickness. Thus, by having the joining region 28 that serves as the starting point for folding and the non-jointing region 29 that allows for the arrangement of SAPs between the substrate sheet 14 and other sheets 14S, it is possible to balance ease of deformation along the contours of the wearer's body with the absorption and retention of excrement.

[0103] In the bonding region 28, and in the non-laminated region 212N, the substrate sheet 14 and other sheets 14S are bonded using an adhesive HMA. Additionally, when the absorbent 20A absorbs moisture, as... Figure 7B As shown, the SAP swells, and the bonding portion of the substrate sheet 14 to the bonding area 28 of the other sheets 14S detaches. In this way, the bonding portion of the bonding area 28 detaches as the absorbent 20A absorbs moisture, thereby suppressing the swelling of the SAP from being hindered by the bonding area 28.

[0104] Figure 8 This is a top view schematic diagram of the absorber 20B of the modified example.

[0105] The modified absorber 20B has a groove region 215 where the weight per unit area of ​​SAP is lower than that of the high weight per unit area region 211. For example... Figure 8 As shown, the groove region 215 extends along the length direction, and in the width direction, the width of the groove region 215 is greater than the distance between adjacent points S that are the points of maximum thickness. That is, the width of the groove region 215 is greater than the width of the low unit area weight region 212 formed between adjacent high unit area weight regions 211 (i.e., around the high unit area weight region 211). In the modified example, when the absorbent 20B is sandwiched between the wearer's legs (i.e., in the groin area) during wear, the groove region 215 becomes a folding starting point, easily deforming in the width direction at the wearer's crotch, increasing the crotch's containment capacity and further improving the fit. Additionally, excretory fluid easily diffuses in the length direction.

[0106] The groove region 215 has multiple grooves in the width direction. Specifically, as shown in the example... Figure 8 As shown, two groove areas 215 are provided. This further increases the storage capacity of the crotch and improves the fit. However, there may also be only one groove area 215 in the width direction.

[0107] ===Absorbent Manufacturing Apparatus and Method for Manufacturing Absorbents=== The following describes the absorber manufacturing apparatus and the method for manufacturing the absorber, as described above, regarding the absorber 20A.

[0108] <<Structure of Absorber Manufacturing Apparatus 50>> Figure 9 This is a schematic diagram showing the outline of the absorber manufacturing apparatus 50.

[0109] The absorbent manufacturing apparatus 50 is an apparatus for manufacturing absorbents containing highly absorbent polymer (SAP). The absorbent manufacturing apparatus 50 includes a conveying section 11x, an upstream adhesive coating section 18, a particle supply section 19, a suction section 11P, an adhesive ejection section 15D, and a joint forming section 11em.

[0110] The conveying unit 11x is a component that conveys the substrate sheet 14 in the conveying direction. Figure 9 In the absorber manufacturing apparatus 50 shown, the conveying section 11x has a conveyor belt 11cn and a plurality of conveying rollers 11rn. The conveyor belt 11cn uses the upper surface of the driven, surrounding annular belt as the conveying surface of the substrate sheet 14. That is, the conveyor belt 11cn supports the lower surface (hereinafter sometimes referred to as "one surface") of the substrate sheet 14 while conveying it. Therefore, the conveyor belt 11cn is sometimes referred to as the support section.

[0111] In addition, Figure 9 In the absorbent manufacturing apparatus 50 shown, the conveying unit 11x is a suction belt conveyor that conveys the substrate sheet 14 by suctioning the substrate sheet 14 through multiple openings 11pn (described later) provided on the conveying surface of the conveyor belt 11cn. The conveying roller 11rn can be a drive roller that is driven to rotate by a drive source such as a motor, or a driven roller that rotates passively without a drive source.

[0112] The upstream adhesive coating section 18 is a component that pre-coats the substrate sheet 14 with adhesive before supplying SAP particles 19S to the substrate sheet 14. For example... Figure 9 As shown, the upstream adhesive coating section 18 is located upstream of the particle supply section 19 that supplies SAP particles 19S in the conveying direction. Here, the adhesive applied to the upstream adhesive coating section 18 is a hot-melt adhesive. By applying the adhesive to the substrate sheet 14 before supplying the SAP particles 19S to the substrate sheet 14 using the particle supply section 19, the SAP particles 19S adhere more easily to the substrate sheet 14, reducing the amount of SAP particles 19S rebounding. This prevents the SAP particles 19S from being positioned unexpectedly. However, the absorbent manufacturing apparatus 50 may also lack the upstream adhesive coating section 18.

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

[0114] The suction unit 11P draws components from one side (lower surface) of the substrate sheet 14 through multiple openings 11pn of the conveyor belt 11cn. Details of the suction unit 11P will be described later.

[0115] The adhesive ejection section 15D is a component that ejects adhesive along with an airflow toward the substrate sheet 14. The adhesive ejection section 15D is positioned downstream of the particle supply section 19 in the conveying direction. Furthermore, in Figure 9 In the absorbent manufacturing apparatus 50 shown, the adhesive dispensing section 15D has two adhesive dispensing sections 15D: a first adhesive dispensing section 15x1 and a second adhesive dispensing section 15x2 disposed downstream of the first adhesive dispensing section 15x1 in the conveying direction. Details of the adhesive dispensing section 15D will be described later.

[0116] The joint forming portion 11em is a component formed by joining the substrate sheet 14 and other sheets 14S in the thickness direction after they are joined together. The joint forming portion 11em can be subjected to processes such as embossing on the substrate sheet 14 and other sheets 14S, or other known joining methods such as welding and bonding. The joint forming portion 11em can be used to form the aforementioned... Figure 5 The junction 213 of the absorber 20A shown.

[0117] In this embodiment, the absorber containing the highly absorbent polymer described above is manufactured using the absorber manufacturing apparatus 50 having the structures described above. The method for manufacturing the absorber containing the highly absorbent polymer includes at least a conveying step and a particle supply step. First, in the conveying step, the substrate sheet 14 is conveyed with one side (lower surface) supported by a support (conveyor belt 11cn). In the particle supply step, SAP particles 19S are supplied toward the other side (upper surface) of the substrate sheet 14. Thus, an absorber having a highly absorbent polymer laminated on the substrate sheet 14 can be manufactured.

[0118] In this embodiment, as a method for manufacturing an absorbent containing a highly absorbent polymer, adhesive can be applied to the other side (upper surface) of the substrate 14 using the upstream adhesive application section 18 at a position upstream of the position where the SAP particles 19S are supplied to the substrate 14 in the conveying direction (upstream adhesive application step). This allows the SAP particles 19S to be easily adhered to the substrate 14. However, as a method for manufacturing an absorbent containing a highly absorbent polymer, the upstream adhesive application step may not be included.

[0119] Furthermore, as a method for manufacturing an absorbent containing a highly absorbent polymer, in this embodiment, other sheets 14S may be supplied from the other side (upper surface) of the substrate sheet 14 at a position downstream of the position where the SAP particles 19S are supplied to the substrate sheet 14 in the transport direction of the substrate sheet 14, in a manner covering the SAP particles 19S (other sheet supply step). Furthermore, in this embodiment, in the area of ​​the other side (upper surface) of the substrate sheet 14 where no adhesive is applied, the other sheets 14S and the substrate sheet 14 may be joined in the thickness direction along a cross direction intersecting the transport direction of the substrate sheet 14 (joint formation step). This allows for the suppression of openings between the substrate sheet 14 and the other sheets 14S. However, as a method for manufacturing an absorbent containing a highly absorbent polymer, the other sheet supply step and the joint formation step may be omitted.

[0120] In this embodiment, the absorbent is formed by cutting it to the desired size further downstream of the joint forming process. Furthermore, although in this embodiment other sheets 14S are laminated after SAP particles are supplied to the substrate sheet 14, this is not a limitation. For example, the absorbent can also be formed simply by cutting the substrate sheet 14 to the desired size after laminating the SAP particles onto it. Alternatively, the absorbent can be formed by laminating a fibrous material containing pulp after laminating the SAP particles onto the substrate sheet 14. Thus, it is easy to manufacture an absorbent capable of rapidly and temporarily absorbing excrement, thereby suppressing the overflow and leakage of excrement during excretion. Furthermore, if the absorbent is made from a fibrous material containing pulp mixed in addition to SAP particles, such fibrous material can be supplied to the substrate sheet 14 before or after supplying the SAP particles 19S to the particle supply section 19.

[0121] As described above, the conveying section 11x of the absorbent manufacturing apparatus 50 is a suction belt conveyor, which conveys the substrate sheet 14 by suctioning the substrate sheet 14 through a plurality of openings 11pn provided on the conveying surface of the conveyor belt 11cn using the suction section 11P. Details of the suction section 11P and the conveyor belt 11cn will be explained in this regard.

[0122] Figure 10This is a diagram illustrating the suction opening 11su of the suction section 11P. Figure 11A This is a partial cross-sectional schematic diagram showing the 11cm section of the conveyor belt. Figure 11B This is a top view schematic diagram showing a portion of the conveyor belt 11 cm. Furthermore, in Figure 10 and Figure 11A In the diagram, for reference, the outline of the substrate sheet 14 is represented by dashed lines.

[0123] like Figure 10 As shown, when viewed from the conveyor belt 11cn (support portion), the suction portion 11P is located on the opposite side of the side where the substrate sheet 14 is located. Furthermore, a suction opening 11su is provided on the side of the suction portion 11P where the substrate sheet 14 is located. The suction portion 11P performs suction through the suction opening 11su. Additionally, when viewed from the suction opening 11su of the suction portion 11P, the conveyor belt 11cn is located between the suction portion 11P and the substrate sheet 14, and the conveyor belt 11cn transports the substrate sheet 14 in the conveying direction.

[0124] The conveyor belt 11cn is, for example, a mesh belt, and multiple openings 11pn are provided on the conveying surface 11m of the conveyor belt 11cn. Specifically, such as... Figure 11A and Figure 11B As shown, the conveyor surface 11m of the conveyor belt 11cn is formed by weaving a linear member made of fibers from synthetic resins such as nylon. However, the linear member can also be made of metal such as metal wire. This linear member is, for example, composed of a longitudinal member 116 and a transverse member 117, and the opening defined by the longitudinal member 116 and the transverse member 117 becomes the opening 11pn when suctioning the substrate sheet 14.

[0125] In the aforementioned particle supply process, such as Figure 11A As shown, the suction unit 11P draws the substrate sheet 14 from one side (lower surface) of the substrate sheet 14 through a plurality of openings 11pn provided on the conveyor surface 11m of the conveyor belt 11cn. Since the substrate sheet 14 is formed from a very soft and easily deformable material such as nonwoven fabric, as described above, the suction force generated by the suction unit 11P (see reference) Figure 11A (The hollow arrow) is pulled to the part corresponding to the opening 11pn, so as to form a concave region 214 in a manner corresponding to the shape of the opening 11pn.

[0126] At this time, the supplied SAP particles 19S (in) Figure 11A (Not shown in the figure) It is also easy to remain in the recessed area 214 of the substrate sheet 14 due to the suction force generated by the suction part 11P. Therefore, compared with the above... Figure 6A Similarly, in the concave region 214, a greater number of SAP particles 19S are disposed, thereby forming a high weight-per-unit-area region 211. On the other hand, in the regions other than the concave region 214 (in... Figure 11AIn the region (which is blocked by the longitudinal member 116 and does not become a recessed region 214), SAP particles 19S are not arranged, or even if SAP particles 19S are arranged, they are arranged in fewer quantities than in the recessed region 214. This forms a low weight-per-unit area region 212 (low weight-per-unit area stacked region 212E or non-stacked region 212N).

[0127] As described above, in the conveying section 11x of the absorber manufacturing apparatus 50, the support section (conveyor belt 11cn) has a plurality of openings 11pn. By drawing the substrate sheet 14 from one side (lower surface) of the substrate sheet 14 through the plurality of openings 11pn during the particle supply process, an absorber having a high unit area weight region 211 and a low unit area weight region 212 formed around each high unit area weight region 211 can be manufactured.

[0128] In addition, such as Figure 11B As shown, the diameter of the inscribed circle IC of the opening 11pn, which is tangent to the conveyor belt 11cn, is greater than or equal to the average particle size of the SAP particles. For example, it is suitable that the diameter of the inscribed circle IC of the opening 11pn, which is tangent to the conveyor belt 11cn, is 2 mm or more and 4 mm or less. Therefore, by reducing the top-view dimensions of each of the multiple high weight-per-unit area regions 211, a large number of high weight-per-unit area regions 211 and low weight-per-unit area regions 212 can be disposed on the substrate sheet 14. In this embodiment, an absorbent material with SAP that maintains a thin profile while providing good fit when worn can be easily manufactured.

[0129] Furthermore, it is preferable that the opening ratio of the openings 11pn in the support section (conveyor belt 11cn) is 40% or more and 60% or less. This allows a high weight-per-unit-area region 211 to be appropriately formed in the absorber. In the following description, the opening ratio refers to the proportion of the area of ​​the opening per unit area.

[0130] Figure 12 This is a top view schematic diagram showing another example of the suction opening su of the suction section 11P. Additionally, in Figure 12 In the diagram, for reference, the outline of the substrate sheet 14 and the end 142 of the substrate sheet 14 in the intersecting direction are indicated by dashed lines. Additionally, the position of the particle supply section 19 in a top view is indicated by a single-dotted line.

[0131] In the particle supply process, the particles are fed from one side (lower surface) of the substrate sheet 14 via the suction unit 11P. Figure 12 The suction opening su (first opening region 111 and second opening region 112 described later) and the opening 11pn of the conveyor belt 11cn described above, together with the suction substrate sheet 14, enable the formation of the aforementioned... Figure 8The absorber 20B shown has a groove region 215. The features of the suction opening su of the suction section 11P will be described below.

[0132] The suction opening su of the suction section 11P has a first opening region 111 and a second opening region 112. For example... Figure 12 As shown, the second opening region 112 is adjacent to the first opening region 111 in the intersecting direction with the transport direction of the substrate sheet 14. Furthermore, the second opening region 112 may have multiple opening regions (two in this case) in the intersecting direction. However, there may also be only one second opening region 112.

[0133] Here, the opening ratio of the first opening region 111 is greater than or equal to the opening ratio of the opening 11pn in the region of the conveyor belt 11cn (support portion) where the opening 11pn is provided. For example, in the above-described... Figure 11B In the conveyor belt 11cn shown, the opening 11pn is defined by the longitudinal member 116 and the transverse member 117. In this case, in the entire region of the conveyor belt 11cn where the opening 11pn is provided, the opening ratio of the opening 11pn is reduced by an amount corresponding to the size (width) of the longitudinal member 116 and the transverse member 117. In contrast, in the first opening region 111, the entire region becomes an opening (space). However, although not shown, grid strips may be provided at the edge of the opening in the first opening region 111. This can suppress the suction force that causes the shape distortion of the substrate sheet 14.

[0134] Furthermore, the opening ratio of the second opening region 112 is lower than that of the first opening region 111, and is lower than the opening ratio of the opening 11pn in the region of the conveyor belt 11cn (support portion) where the opening 11pn is located. Specifically, it is suitable that the opening ratio of the second opening region 112 is 25% or more and 35% or less. However, as long as the opening ratio of the second opening region 112 is lower than that of the first opening region 111 and is lower than the opening ratio of the opening 11pn in the region of the conveyor belt 11cn (support portion) where the opening 11pn is located, it can also be in a range other than 25% or more and 35% or less.

[0135] As described above, in the particle supply process, the particle supply unit 19 supplies SAP particles 19S toward the other side (upper surface) of the substrate sheet 14, and the suction unit 11P suctions the substrate sheet 14 from one side (lower surface) via the first opening region 111 and the second opening region 112 and the opening 11pn of the conveyor belt 11cn. Here, as described above, the opening ratio of the second opening region 112 is lower than that of the first opening region 111. Therefore, when viewed from above, the suction force of the area of ​​the substrate sheet 14 that is suctioned via the second opening region 112 is lower than the suction force of the area of ​​the substrate sheet 14 that is suctioned via the first opening region 111. At this time, compared with the area of ​​the substrate sheet 14 that is suctioned via the second opening region 112, the SAP particles 19S supplied to the substrate sheet 14 (in...) Figure 12 (Not shown in the figure) It is easy to remain in the area of ​​the substrate sheet 14 that is sucked in through the first opening area 111.

[0136] Furthermore, as described above, the opening ratio of the second opening region 112 is less than the opening ratio of the opening 11pn in the region of the conveyor belt 11cn where the opening 11pn is provided. Therefore, in the region where the substrate sheet 14 is drawn through the second opening region 112, the suction force is reduced due to the second opening region 112. Thus, in the region where the substrate sheet 14 is drawn through the second opening region 112, the suction force to the extent that the portion corresponding to the opening 11pn of the substrate sheet 14 is pulled and forms a recessed region 214 can be suppressed. Therefore, in the region where the substrate sheet 14 is drawn through the second opening region 112, the formation of a high unit area weight region 211 can be suppressed, and a groove region 215 with a lower unit area weight of SAP than the high unit area weight region 211 can be formed. In addition, since there are two second opening regions 112 in the intersecting direction as described above, like Figure 8 The absorber 20B shown has two groove regions 215 that correspond to the two second opening regions 112 respectively.

[0137] On the other hand, the opening ratio of the first opening region 111 is greater than or equal to the opening ratio of the opening 11pn in the region of the conveyor belt 11cn where the opening 11pn is provided. Therefore, in the region of the substrate sheet 14 that is drawn through the first opening region 111, the suction force is not reduced by the first opening region 111, forming a recessed region 214, which is easily retained in the recessed region 214 of the substrate sheet 14 by the suction force generated by the suction part 11P. In other words, a high unit area weight region 211 and a low unit area weight region 212 are formed in the region that is drawn through the first opening region 111.

[0138] Furthermore, the suction opening su of the suction section 11P has a third opening region 113 and a non-opening region 114. For example... Figure 12As shown, the third opening region 113 is located downstream of the first opening region 111 in the conveying direction and has a portion overlapping the first opening region 111 in the crossing direction. Similarly, the non-opening region 114 is located downstream of the second opening region 112 in the conveying direction and also has a portion overlapping the second opening region 112 in the crossing direction. The opening ratio of the third opening region 113 is lower than that of the first opening region 111. However, the third opening region 113 may also be located upstream of the first opening region 111 in the conveying direction, and the non-opening region 114 may also be located upstream of the second opening region 112 in the conveying direction. Furthermore, the suction opening su of the suction section 11P may not have the third opening region 113 or the non-opening region 114.

[0139] In the particle supply process, a suction force is continuously generated in the third opening region 113, which is downstream of the first opening region 111, and the suction force is suppressed in the non-opening region 114, which is downstream of the second opening region 112. As a result, SAP particles that bounce off the substrate sheet 14 in the region where SAP particles are supplied, i.e., in the region of the substrate sheet 14 that is sucked through the first opening region 111 and the second opening region 112, can be disposed in the groove region 215 on the downstream side.

[0140] Furthermore, the suction opening su of the suction section 11P has a fourth opening region 115. The fourth opening region 115 is located, when viewed from above, further outward in the intersecting direction than the first opening region 111 and the third opening region 113, and overlaps with the end of the substrate sheet 14 in the intersecting direction. During the conveying process, the suction section 11P suctions the end of the substrate sheet 14 from one side (lower surface) of the substrate sheet 14 via the fourth opening region 115. This helps to prevent the substrate sheet 14 from rolling up during conveying. However, the suction opening su of the suction section 11P may also not have a fourth opening region 115.

[0141] Figure 13 This diagram illustrates the supply of SAP particles and the ejection pattern of the adhesive in the absorber manufacturing apparatus 50.

[0142] In the absorber manufacturing apparatus 50 of this embodiment, immediately following the process of supplying SAP particles from the particle supply unit 19 (particle supply process), the adhesive spraying unit 15D (first adhesive spraying unit 15x1) sprays adhesive 15H along with an airflow toward the substrate sheet 14 (downstream adhesive spraying process). Here, the adhesive 15H is a hot melt adhesive, sprayed from a plurality of spray outlets (nozzles) (not shown) provided by the adhesive spraying unit 15D. Then, after the adhesive 15H is sprayed by the first adhesive spraying unit 15x1, the second adhesive spraying unit 15x2, located downstream of the first adhesive spraying unit 15x1 in the conveying direction, further sprays adhesive 15H along with an airflow toward the substrate sheet 14.

[0143] Furthermore, the adhesive 15H is sprayed out together with the airflow. In this embodiment, the pressure of the airflow is the same in both the first adhesive spray section 15x1 and the second adhesive spray section 15x2. However, it is not limited to this, and the air pressures can be different for each section.

[0144] SAP particles 19S supplied from particle supply unit 19 are prone to colliding with substrate sheet 14 on conveyor surface 11m and bouncing (see reference). Figure 13 In this embodiment, it is envisioned that approximately 60% of the supplied SAP particles 19S will bounce off. Furthermore, the supplied SAP particles 19S are prone to bouncing off in unexpected directions, potentially scattering into locations where they should not be placed.

[0145] Regarding this point, in the absorber manufacturing apparatus 50 of this embodiment, as... Figure 13 As shown, the adhesive 15H sprayed from the adhesive spraying section 15D can push at least a portion of the SAP particles 19S that bounce off the substrate sheet 14 back towards the substrate sheet 14 side. Here, "pushing back" means causing the SAP particles 19S to move in the opposite direction to the conveying direction and in the direction of gravity (vertically downward). In other words, by colliding with the SAP particles 19S that bounce off the substrate sheet 14, the sprayed adhesive 15H can cause the SAP particles 19S to fall back towards the substrate sheet 14 side. Furthermore, the airflow sprayed along with the adhesive 15H can reduce the possibility of the SAP particles 19S being positioned unexpectedly. Additionally, by the adhesive 15H adhering to the bounced SAP particles 19S, the fixation of the SAP particles 19S to the substrate sheet 14 can be more reliable.

[0146] Furthermore, in this embodiment, adhesive 15H is sprayed not only from the first adhesive spraying section 15x1, but also from the second adhesive spraying section 15x2, which is located downstream of the first adhesive spraying section 15x1 in the conveying direction. Therefore, by utilizing the adhesive 15H sprayed from the second adhesive spraying section 15x2, the SAP particles 19S that were not completely pushed back by the adhesive 15H sprayed from the first adhesive spraying section 15x1 are pushed back towards the substrate sheet 14, thereby further reducing the amount of rebound. By doing so, the SAP particles 19S can be more reliably fixed to the substrate sheet 14.

[0147] Furthermore, the absorbent manufacturing apparatus 50 of this embodiment has two adhesive spraying sections 15D (first adhesive spraying section 15x1 and second adhesive spraying section 15x2), but is not limited to this. For example, when the amount of supplied SAP particles 19S is small, only the first adhesive spraying section 15x1 may be used. In addition, the first adhesive spraying section 15x1 and the second adhesive spraying section 15x2 can push back the rebounding SAP particles 19S, but they can also be designed such that the first adhesive spraying section 15x1 focuses on fixing the SAP particles 19S to the substrate sheet 14, and the second adhesive spraying section 15x2 is mainly used to improve the bonding strength of the material (substrate sheet 14, etc.) and to adjust the strength.

[0148] Furthermore, in this embodiment, the first adhesive spraying section 15x1 and the second adhesive spraying section 15x2 are separated to increase the degree of freedom of each adhesive spraying section 15D. However, the first adhesive spraying section 15x1 and the second adhesive spraying section 15x2 can also be an integral adhesive spraying section. When the first adhesive spraying section 15x1 and the second adhesive spraying section 15x2 are provided as an integral unit, costs can be reduced compared to providing a separate device, and the maintenance and management of the device are also easier.

[0149] As described above, when SAP particles 19S are supplied from the particle supply unit 19, the SAP particles 19S tend to bounce back. Therefore, in this embodiment, if... Figure 13 As shown, the conveyor surface 11m of the conveyor belt 11cn is inclined relative to the horizontal plane Hr in a manner that descends downstream in the conveying direction. By doing so, the SAP particles 19S rebounding from the substrate sheet 14 can easily travel downstream under the influence of gravity, reducing the possibility of the SAP particles 19S being configured in unexpected positions.

[0150] In addition, in the Figure 13When the angle of inclination of the conveyor surface 11m relative to the horizontal plane Hr is set to θ0, the inclination angle θ0 in this embodiment is approximately 30 degrees. This is because the rest angle of SAP particles (the maximum angle at which the inclined plane remains stable without collapsing when accumulating particles) is 32 to 38 degrees, so the inclination angle is set near this angle. By setting the inclination angle θ0 to approximately 30 degrees, SAP particles 19S ejected from the particle supply section 19 are prevented from rolling after landing on the substrate sheet 14, and compared to the case where they are ejected towards the conveyor surface parallel to the horizontal plane, the SAP particles 19S are less likely to bounce back. When the conveyor surface 11m of the conveyor belt 11cn is inclined in a manner that the downstream side descends, the inclination angle θ0 can be set to approximately 75 degrees.

[0151] Furthermore, while it is suitable for the conveyor surface 11m to be inclined relative to the horizontal plane Hr in a manner that descends downstream in the conveying direction, as described above, it is not limited to this. For example, the conveyor surface 11m may also be horizontal, or it may be inclined relative to the horizontal plane Hr in a manner that descends upstream in the conveying direction. It may also be inclined in a manner that descends upstream in the conveying direction (that is, in a manner that rises downstream). In the absorbent manufacturing apparatus 50 of this embodiment, since the conveyor belt 11cn is a suction belt conveyor, the rebound of SAP particles 19S can be suppressed in the same way as long as the suction force of the suction section 11P suctions the substrate sheet 14 is increased. When it is inclined relative to the horizontal plane Hr in a manner that descends upstream in the conveying direction, the inclination angle θ0 can reach about 45 degrees, but about 30 degrees is suitable.

[0152] Figure 14 This is a diagram illustrating the suction opening 11su in the absorber manufacturing apparatus 50A of the first modified example. Furthermore, in Figure 14 In the diagram, for reference, the outline of the substrate sheet 14 is represented by dashed lines.

[0153] In the first modified absorbent manufacturing apparatus 50A, similar to the absorbent manufacturing apparatus 50 described above, the suction section 11P is provided on the opposite side of the side where the substrate sheet 14 is located when viewed from the conveyor belt 11cn (support section). However, unlike the absorbent manufacturing apparatus 500, in the absorbent manufacturing apparatus 50A, the suction opening 11su is provided on another conveyor belt 11cn1, instead of on the suction section 11P. Figure 14 As shown, multiple suction openings 11su are provided around the other conveyor belts 11cn1, and the position of the suction openings 11su also moves as the other conveyor belts 11cn1 move.

[0154] In the absorbent manufacturing apparatus 50A, the other conveyor belt 11cn1 is located between the conveyor belt 11cn and the suction section 11P, and moves in the same direction as the conveying direction of the conveyor belt 11cn. This suppresses wear on the conveyor belt 11cn caused by edge friction between the conveyor belt 11cn and the suction opening 11su, thereby extending the lifespan of the conveyor belt 11cn. Furthermore, since the suction opening 11su is located on the other conveyor belt 11cn1 in the absorbent manufacturing apparatus 50A, when adhesive adheres to the suction opening 11su, only the other conveyor belt 11cn1 needs to be replaced. Therefore, compared to the case where the suction opening 11su is located on the upper surface of the suction section 11P, replacement operations when adhesive adheres to the suction opening 11su can be performed more easily.

[0155] In the absorber manufacturing apparatus 50A, the other conveyor belts 11cn1 and conveyor belt 11cn move at the same speed, but the wrapping lengths of the other conveyor belts 11cn1 and conveyor belt 11cn are different. Therefore, the area where the conveyor belt 11cn rubs against the edge of the suction opening 11su changes with each wrap. From this perspective, the lifespan of the conveyor belt 11cn can be extended. Furthermore, by ensuring that the contact points between the adhesive and the conveyor belt 11cn are staggered with each wrap, adhesive clogging at the opening 11pn of the conveyor belt 11cn can be reduced. However, when the wrapping length of the conveyor belt 11cn is an integer multiple of the spacing PH of the multiple suction openings su, the contact point between the adhesive and the conveyor belt 11cn will be any one of the multiple suction openings su without being staggered. Therefore, the wrapping length of the conveyor belt 11cn needs to be a length other than an integer multiple of the spacing PH of the multiple suction openings su.

[0156] <<Structure of Absorber Manufacturing Apparatus 60>> Next, based on Figure 15 and Figure 16 An absorber manufacturing apparatus 60, which is different from the absorber manufacturing apparatus 50 described above, will be described.

[0157] Figure 15 This is a schematic diagram showing the outline of the absorber manufacturing apparatus 60. Figure 16 This is a diagram illustrating the plate portion 11pt of the conveyor section 11y.

[0158] The basic structure of the absorber manufacturing apparatus 60 is the same as that of the absorber manufacturing apparatus 50 described above. The difference is that in the absorber manufacturing apparatus 60, the conveying section 11y that conveys the substrate sheet 14 in the conveying direction has a rotating body 11tn instead of a conveyor belt 11cn. Furthermore, in the following description of the absorber manufacturing apparatus 60, the same reference numerals are used to refer to structures that are the same as those in the absorber manufacturing apparatus 50, and the description of parts common to the absorber manufacturing apparatus 50 is omitted.

[0159] like Figure 15 and Figure 16 As shown, in the absorber manufacturing apparatus 60, a plate portion 11pt is provided on the outer peripheral surface 11n of a rotating body 11tn that rotates in the conveying direction. The outer peripheral surface of this plate portion 11pt of the rotating body 11tn serves as the conveying surface of the substrate sheet 14. In other words, the plate portion 11pt of the rotating body 11tn supports the substrate sheet 14 on the central side surface of the rotating body 11tn (hereinafter sometimes referred to as "one surface") while conveying the substrate sheet 14. Therefore, the plate portion 11pt of the rotating body 11tn is sometimes referred to as a support portion.

[0160] In addition, Figure 15 and Figure 16 In the absorber manufacturing apparatus 60 shown, the conveying section 11y is a suction roller, which conveys the substrate sheet 14 by suctioning the substrate sheet 14 through a plurality of openings 11pn provided on the conveying surface of the plate section 11pt of the rotating body 11tn.

[0161] In this embodiment, an absorber containing a highly absorbent polymer is manufactured using an absorber manufacturing apparatus 60 having the structures described above. The method for manufacturing an absorber containing a highly absorbent polymer includes at least a conveying step and a particle supply step. First, in the conveying step, the substrate sheet 14 is conveyed by supporting one side (the side facing the center of the rotating body 11tn) with a support portion (the plate portion 11pt of the rotating body 11tn). In the particle supply step, SAP particles 19S are supplied toward the other side of the substrate sheet 14 (the side opposite to the center of the rotating body 11tn). Thus, an absorber having a highly absorbent polymer laminated on the substrate sheet 14 can be manufactured.

[0162] For example, a 11pt sheet is a perforated metal sheet, such as... Figure 16 As shown, a plurality of openings 11pn are provided on the conveying surface of the plate portion 11pt. ​​In the above-described particle supply process, the suction unit 11P suctions the substrate sheet 14 through the plurality of openings 11pn provided on the conveying surface of the plate portion 11pt.

[0163] Based on the above, in the conveying section 11y of the absorber manufacturing apparatus 60, the support section (the plate portion 11pt of the rotating body 11tn) has multiple openings 11pn. During the particle supply process, by drawing the substrate sheet 14 from one side (the side facing the center of the rotating body 11tn) through the multiple openings 11pn, an absorber with a high weight-per-unit area region 211 and a low weight-per-unit area region 212 formed around each of the high weight-per-unit area regions 211 can be manufactured. Furthermore, although not shown, the diameter of the inscribed circle of the opening 11pn tangent to the plate portion 11pt is greater than or equal to the average particle size of the SAP particles. Therefore, SAP particles can be disposed in the recessed region 214 of the substrate sheet 14 as described above. In this embodiment, an absorber with SAP that maintains a thin profile while providing good fit when worn can be easily manufactured.

[0164] Figure 17 This is a top view schematic diagram showing another example of a 11pt plate.

[0165] Figure 17 The plate portion 11pt shown is also a perforated metal plate with multiple openings. This plate portion 11pt has a first opening region 111 and a second opening region 112. For example... Figure 17 As shown, the second opening region 112 is adjacent to the first opening region 111 in the intersecting direction with the transport direction of the substrate sheet 14. Furthermore, the second opening region 112 may have multiple opening regions (two in this case) in the intersecting direction. However, there may also be only one second opening region 112.

[0166] exist Figure 17 In the plate portion 11pt shown, the opening ratio of the second opening region 112 is lower than that of the first opening region 111. Therefore, in the region being drawn through the second opening region 112, the formation of a high weight-per-unit area region 211 can be suppressed, while a groove region 215 with a lower weight-per-unit area for SAP is formed. Furthermore, in the region being drawn through the first opening region 111, both a high weight-per-unit area region 211 and a low weight-per-unit area region 212 are formed.

[0167] In the particle supply process, the particles are fed from one side of the substrate sheet 14 (the side facing the center of the rotating body 11tn) via the suction unit 11P. Figure 17 The openings shown (first opening region 111 and second opening region 112) draw in the substrate sheet 14, thereby enabling the formation of the aforementioned... Figure 8 The absorber 20B shown has a groove region 215.

[0168] Figure 18 This diagram illustrates the supply of SAP particles and the ejection pattern of the adhesive in the absorber manufacturing apparatus 60.

[0169] In the absorber manufacturing apparatus 60 of this embodiment, immediately after the process of supplying SAP particles from the particle supply unit 19 (particle supply process), the first adhesive spraying unit 15x1 (adhesive spraying unit 15D) sprays adhesive 15H together with the air flow, and further downstream, the second adhesive spraying unit 15x2 (adhesive spraying unit 15D) sprays adhesive 15H together with the air flow toward the substrate sheet 14 (adhesive spraying process).

[0170] like Figure 18 As shown, in the absorber manufacturing apparatus 60 of this embodiment, the adhesive 15H is also ejected from the nozzles of each adhesive ejection section 15D (the first adhesive ejection section 15x1 and the second adhesive ejection section 15x2) in a predetermined ejection direction. Specifically, in the first adhesive ejection section 15x1, the adhesive 15H is ejected from the nozzle of the first adhesive ejection section 15x1 in a predetermined ejection direction, and the upstream side of the ejection direction is inclined to the downstream side of the conveying direction in such a way that the angle θ1 formed by the imaginary line obtained by extending the ejection direction and the tangent at the intersection of the imaginary line and the outer peripheral surface 11n of the rotating body 11tn is greater than 90 degrees. Since a portion of the supplied SAP particles 19S bounces downstream in the conveying direction, it is easier to push back the SAP particles 19S that bounced downstream by spraying them from the downstream side in a manner that covers the SAP particles 19S, compared to spraying the adhesive 15H perpendicular to the outer peripheral surface 11n.

[0171] In the absorber manufacturing apparatus 60 of this embodiment, a second adhesive spraying section 15x2 is provided downstream of the first adhesive spraying section 15x1 in the conveying direction. Similar to the first adhesive spraying section 15x1, the second adhesive spraying section 15x2 sprays adhesive 15H from the nozzle in a predetermined spraying direction. In addition, regarding this spraying direction, the upstream side of the spraying direction 15d2 of the second adhesive spraying section 15x2 is inclined to the downstream side of the conveying direction in such a way that the angle θ2 formed by the imaginary line obtained by extending the spraying direction of the second adhesive spraying section 15x2 and the tangent 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 absorber manufacturing apparatus 60, by spraying adhesive 15H not only from the first adhesive spray section 15x1 but also from the second adhesive spray section 15x2 at such an angle, it is easier to capture the rebounding SAP particles 19S that were not completely pushed back by the adhesive 15H sprayed only from the first adhesive spray section 15x1.

[0172] Furthermore, it is preferable that the angle θ2 formed by the imaginary line obtained by extending the second adhesive spray section 15x2 and the tangent at the intersection of the imaginary line and the outer peripheral surface 11n of the rotating body 11tn is greater than the angle θ1 (θ1 < θ2) formed by the imaginary line obtained by extending the first adhesive spray section 15x1 and the tangent at the intersection of the imaginary line and the outer peripheral surface 11n of the rotating body 11tn. Since the supplied SAP particles 19S tend to bounce downstream in the conveying direction, by spraying the adhesive 15H at a more inclined angle by the second adhesive spray section 15x2, which is positioned further downstream than the first adhesive spray section 15x1, it is easier to capture the SAP particles 19S that fall to the downstream side.

[0173] Figure 19 This is a perspective view of the absorber manufacturing apparatus 60A of the second modification.

[0174] In the absorber manufacturing apparatus 60A of the second modification, the plate portion 11pt is composed of a substrate 118 and a mesh plate 119. For example... Figure 19 As shown, a suction opening 11su is provided on the substrate 118. Additionally, an opening 11pn for suctioning the substrate sheet 14 is provided on the conveying surface of the stencil 119. In the absorbent manufacturing apparatus 60A, even if adhesive blockage occurs at the opening 11pn, only the easily replaceable stencil 119 needs to be replaced, thus reducing replacement costs.

[0175] Figure 20 This is a top view schematic diagram showing another example of a substrate 118 with a plate portion of 11pt.

[0176] Figure 20 The basic structure of the substrate 118 shown is the same as described above. Figure 17 The plate portion 11pt shown is identical, having a first opening region 111 and a second opening region 112. For example... Figure 20 As shown, the second opening region 112 is adjacent to the first opening region 111 in the intersecting direction with the transport direction of the substrate sheet 14. Furthermore, the second opening region 112 may have multiple opening regions (two in this case) in the intersecting direction. However, there may also be only one second opening region 112.

[0177] exist Figure 20 In the plate portion 11pt shown, the opening ratio of the second opening region 112 is lower than that of the first opening region 111. Therefore, in the region being drawn through the second opening region 112, the formation of a high weight-per-unit area region 211 can be suppressed, while a groove region 215 with a lower weight-per-unit area for SAP is formed. Furthermore, in the region being drawn through the first opening region 111, both a high weight-per-unit area region 211 and a low weight-per-unit area region 212 are formed.

[0178] In the particle supply process, the particles are fed from one side of the substrate sheet 14 (the side facing the center of the rotating body 11tn) via the suction unit 11P. Figure 20 The openings shown (first opening region 111 and second opening region 112) draw in the substrate sheet 14, thereby enabling the formation of the aforementioned... Figure 8 The absorber 20B shown has a groove region 215.

[0179] Figure 21 This is a perspective view of the absorber manufacturing apparatus 60B of the third modification.

[0180] The absorber manufacturing apparatus 60B of the third modification has a structure in which a conveyor belt 11cn is wound around a rotating body having suction openings 11su on its outer peripheral surface. The conveyor belt 11cn has multiple openings 11pn. As a method for manufacturing an absorber containing a highly absorbent polymer using the absorber manufacturing apparatus 60B, at least a conveying step and a particle supply step are included. First, in the conveying step, the substrate sheet 14 is conveyed by supporting one side (the side facing the center of the rotating body 11tn) with a support (conveyor belt 11cn). In the particle supply step, SAP particles 19S are supplied toward the other side of the substrate sheet 14 (the side opposite to the center of the rotating body 11tn). Thus, an absorber having a highly absorbent polymer laminated on the substrate sheet 14 can be manufactured.

[0181] 11cn conveyor belt, for example, is a mesh belt. Figure 21 As shown, a plurality of openings 11pn are provided on the conveying surface 11m of the conveyor belt 11cn. In the above-described particle supply process, the suction unit 11P suctions the substrate sheet 14 through the plurality of openings 11pn provided on the conveying surface 11m of the conveyor belt 11cn.

[0182] Based on the above, in the conveying section 11y of the absorber manufacturing apparatus 60B, the support section (conveyor belt 11cn) has multiple openings 11pn. By drawing the substrate sheet 14 from one side (the side facing the center of the rotating body 11tn) through the multiple openings 11pn during the particle supply process, an absorber with a high weight-per-unit area region 211 and a low weight-per-unit area region 212 formed around each high weight-per-unit area region 211 can be manufactured. Furthermore, although not shown, the diameter of the inscribed circle of the opening 11pn tangent to the conveyor belt 11cn is greater than or equal to the average particle size of the SAP particles. Therefore, SAP particles can be disposed in the recessed region 214 of the substrate sheet 14 as described above. In this embodiment, an absorber with SAP that maintains a thin profile while providing good fit when worn can be easily manufactured.

[0183] ===Others==== Furthermore, the above-described embodiments are intended to facilitate understanding of the present invention and are not intended to limit the scope of the invention. It is self-evident that the present invention can be modified and improved without departing from its spirit, and that equivalents are included in the present invention. Explanation of reference numerals in the attached figures

[0184] 1. Underwear-type disposable diapers (absorbent items); 2. Side joint; 10. Absorbent body; 11x, 11y, conveying section; 11cn, 11cn1, conveyor belt; 11em, joint forming section; 11m, conveying surface; 11n, outer peripheral surface; 11P, suction section; 11pn, opening; 11pt, plate section; 11rn, conveying roller; 11su, suction opening; 11tn, rotating body; 12. Top sheet; 13a, bottom sheet (liquid-proof sheet); 13b, bottom sheet (outer covering sheet); 1 4. Substrate sheet; 14S, other sheets; 15. Leak-proof wall section; 15D, adhesive spray section; 15H, adhesive; 15x1, first adhesive spray section; 15x2, second adhesive spray section; 16. Leak-proof wall elastic member; 17. Leg circumference elastic member; 18. Upstream side adhesive coating section; 19. Particle supply section; 19S, superabsorbent polymer (SAP) particles; 20, 20A, 20B, absorbent; 21. Skin side layer (absorbent core); 22. Intermediate layer (absorbent core); 23. Non-skin side layer (absorbent core); 24, 25, core-pack sheet; 26, sheet; 27, SAP layer; 28, bonding area; 29, non-bonding area; 30, front waist section; 31, skin side sheet; 32, non-skin side sheet; 33, waist elastic member; 34, cover sheet; 40, rear waist section; 40E, part; 41, skin side sheet; 42, non-skin side sheet; 43, waist elastic member; 44, cover sheet; 50, 50A, 60, 60A, absorbent manufacturing device; 111, first opening Regions; 112, Second opening region; 113, Third opening region; 114, Non-opening region; 115, Fourth opening region; 116, Longitudinal member; 117, Transverse member; 118, Substrate; 119, Mesh plate; 142, End; 211, High weight per unit area region; 212, Low weight per unit area region; 212E, Low weight per unit area laminated region; 212N, Non-laminated region; 213, Compression section; 214, 214F, 214B, Recessed region; 215, Groove region.

Claims

1. A method for manufacturing an absorbent containing a highly absorbent polymer, characterized in that... This method has the following steps: A conveying process in which the substrate sheet is conveyed by supporting one side of the substrate sheet using a support portion; and In the particle supply process, highly absorbent polymer particles are supplied toward the other side of the substrate sheet. The support portion has multiple openings. Viewed from above, the diameter of the inscribed circle tangent to the opening is greater than or equal to the average particle size of the highly absorbent polymer particles. In the particle supply process, the substrate sheet is drawn from one side of the substrate sheet through the opening.

2. The method for manufacturing an absorbent according to claim 1, characterized in that, In the conveying process, the support is a conveyor belt that conveys the substrate sheet.

3. The method for manufacturing an absorbent according to claim 2, characterized in that, A suction section is provided on the opposite side of the side where the substrate sheet is located when viewed from the support portion. Install other conveyor belts with suction openings. Other conveyor belts are located between the conveyor belt and the suction unit, and move in the same direction as the conveying direction of the conveyor belt.

4. The method for manufacturing an absorbent according to claim 2 or 3, characterized in that, A suction section is provided on the opposite side of the side where the substrate sheet is located when viewed from the support portion. The suction port of the suction section has a first opening region and a second opening region in an intersecting direction with the conveying direction of the substrate sheet. The second opening region is adjacent to the first opening region and has a lower opening ratio than the first opening region. In the particle supply process, the suction unit draws the substrate sheet from one side of the substrate sheet via the opening, the first opening region, and the second opening region.

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

6. The method for manufacturing an absorbent according to claim 4, characterized in that, The opening ratio of the second opening region is less than or equal to the opening ratio of the opening in the region of the support where the opening is located.

7. The method for manufacturing an absorbent according to claim 4, characterized in that, The second opening region has multiple openings in the intersecting direction.

8. The method for manufacturing an absorbent according to claim 4, characterized in that, The suction section has 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 intersecting direction. The aperture ratio of the third opening region is lower than that of 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 intersecting direction. At a position downstream of the location where the highly absorbent polymer particles are supplied to the substrate sheet in the transport direction of the substrate sheet, the suction unit draws the substrate sheet from one side of the substrate sheet via the third opening region.

9. The method for manufacturing an absorbent according to claim 8, characterized in that, The suction portion includes a fourth opening region, which is located, when viewed from above, on the outer side of the intersection direction compared to the first and third opening regions, and overlaps with the end of the substrate sheet in the intersection direction. In the conveying process, the suction unit draws the end from one side of the substrate sheet via the fourth opening region.

10. The method for manufacturing an absorbent according to claim 1, characterized in that, In the conveying process, the support is a rotating body that conveys the substrate sheet.

11. The method for manufacturing an absorbent according to claim 10, characterized in that, A suction section is provided on the opposite side of the side where the substrate sheet is located when viewed from the support portion. The support portion includes a first opening among the plurality of openings and a second opening with a lower opening ratio than the first opening. In a direction intersecting the transport direction of the substrate sheet, the region having the first opening and the region having the second opening are arranged adjacent to each other. In the particle supply process, the suction unit draws the substrate sheet from one side of the substrate sheet via the first opening and the second opening.

12. The method for manufacturing an absorbent according to claim 11, characterized in that, The area with the second opening has multiple openings in the intersecting direction.

13. The method for manufacturing an absorbent according to claim 1, characterized in that, The method includes an upstream adhesive coating step in which adhesive is applied to the other side of the substrate sheet at a position upstream of the location where the highly absorbent polymer particles are supplied to the substrate sheet, in the transport direction of the substrate sheet.

14. The method for manufacturing an absorbent according to claim 13, characterized in that, This method has the following steps: In another sheet supply process, in which other sheets are supplied from the other side of the substrate sheet at a position downstream of the location where the highly absorbent polymer particles are supplied to the substrate sheet, in a manner that covers the highly absorbent polymer particles; and In the joint forming process, in the area on the other side of the substrate sheet where the adhesive is not applied, the other sheet and the substrate sheet are joined in the thickness direction along an intersecting direction that intersects the transport direction of the substrate sheet.

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

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

17. The method for manufacturing an absorbent according to claim 1, characterized in that, The method includes a downstream adhesive spraying step, in which adhesive is sprayed along with an airflow toward the other side of the substrate sheet at a position downstream of the location where the highly absorbent polymer particles are supplied to the substrate sheet. The sprayed adhesive pushes at least a portion of the highly absorbent polymer particles that bounce off the substrate back toward the substrate side.

18. The method for manufacturing an absorbent according to claim 17, characterized in that, In the conveying process, the substrate sheet is conveyed by a conveyor, the conveying surface of which is inclined downwards relative to the horizontal plane on the downstream side.

19. The method for manufacturing an absorbent according to claim 17, characterized in that, In the conveying process, the substrate sheet is conveyed using a rotating body. The adhesive is sprayed in a predetermined spraying direction, the upstream side of which is inclined to the downstream side of the conveying direction in such a way that the angle between the imaginary line obtained by extending the spraying 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.

20. The method for manufacturing an absorbent according to claim 1, characterized in that, The method includes a fibrous material supply step in which a fibrous material containing pulp is supplied from the superabsorbent polymer laminated on the substrate sheet at a position downstream of the position where the superabsorbent polymer particles are supplied to the substrate sheet in the transport direction of the substrate sheet.

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