Manufacturing method and manufacturing device for absorbent sheet used in absorbent article

Abstract

Provided are a manufacturing method and a manufacturing device for an absorbent sheet used in an absorbent article, with which it is possible to reduce the manufacturing cost of an absorbent sheet in which two layers of absorbent materials are arranged. A first continuous sheet (2) is wound on a first conveyance roller (12a) and conveyed, a first absorbent material (3) is supplied to the first continuous sheet (2) being conveyed, and a second continuous sheet (4) is overlaid on the first continuous sheet (2) to cover the first absorbent material (3), thereby forming a first composite sheet (7). A first composite sheet (7) is wound around a second conveyance roller (14a) and conveyed, a second absorbent material (5) is supplied to the first composite sheet (7) being conveyed, and a third continuous sheet (6) is superimposed on the first composite sheet (7) so as to cover the second absorbent material (5), thereby forming a second composite sheet (8). The second composite sheet (8) is compressed in the thickness direction to form an absorbent sheet (9).

Description

Technical Field

[0001] This invention relates to a method and apparatus for manufacturing absorbent sheets used in absorbent articles, and more specifically, to a technique for manufacturing absorbent sheets having two layers of absorbent material. Background Technology

[0002] In absorbent products such as diapers, absorbent materials are incorporated to absorb and retain liquids. These absorbent materials, such as powdered or granular SAP (Super Absorbent Polymer), are incorporated between sheets of nonwoven fabric.

[0003] Such absorbents are formed by cutting absorbent sheets. For example, using... Figure 7 The absorbent sheet manufacturing apparatus 101 shown uses a conveyor 150 to transport a first continuous sheet 201, and supplies SAP from an SAP supply device 140 onto the first continuous sheet 201. Then, a second continuous sheet 202 is overlapped and joined on the first continuous sheet 201 to which SAP has been supplied. Next, the joined first and second continuous sheets 201 and 202 are compressed using a compression device 170 to form an absorbent sheet. The SAP supply device 140 is configured such that the opening for supplying SAP opens and closes at appropriate times (for example, see Patent Document 1). Existing technical documents Patent documents

[0004] Patent Document 1: International Publication No. 2017 / 131025 Summary of the Invention

[0005] By appropriately combining the types, amounts, and patterns of absorbent materials disposed in the absorbent, the variability of the absorbent can be increased. Further variations can be achieved by configuring two layers of absorbent material and changing the combination of the types, amounts, and patterns of the absorbent materials in each layer.

[0006] So, I thought of preparing two units. Figure 7 Such an apparatus, in each device, forms a composite sheet with absorbent material disposed between two continuous sheets, then overlaps the two composite sheets to form an absorbent sheet, and cuts it, thereby forming an absorbent body with two layers of absorbent material disposed thereon.

[0007] However, if manufactured in this way, four continuous sheets would be needed to form an absorbent sheet with two layers of absorbent material, thus increasing manufacturing costs.

[0008] In view of the above-mentioned actual situation, the problem to be solved by the present invention is to provide a method and apparatus for manufacturing absorbent sheets used in absorbent articles, which can reduce the manufacturing cost of absorbent sheets configured with two layers of absorbent material.

[0009] In order to solve the above-mentioned problems, the present invention provides a method for manufacturing an absorbent sheet used in an absorbent article configured as follows.

[0010] A method for manufacturing an absorbent sheet used in absorbent articles includes: (i) a first step of winding and transporting a first continuous sheet on a rotating first transport roller; (ii) a second step of supplying a first absorbent material to the first continuous sheet wound on the first transport roller and transported; (iii) a third step of overlapping a second continuous sheet on the first continuous sheet to cover the first absorbent material supplied to the first continuous sheet, thereby forming a first composite sheet with the first absorbent material sandwiched between the first continuous sheet and the second continuous sheet; (iv) a fourth step of winding and transporting the first composite sheet on a rotating second transport roller; (v) (vi) Fifth step, supplying a second absorbent material to the first composite sheet wound on and transported by the first transport roller; (vii) Sixth step, overlapping a third continuous sheet on the first composite sheet to cover the second absorbent material supplied to the first composite sheet, thereby forming a second composite sheet in which the first absorbent material is sandwiched between the first continuous sheet and the second continuous sheet, and in which the second absorbent material is sandwiched between the first continuous sheet and the third continuous sheet or between the second continuous sheet and the third continuous sheet; and (vii) Seventh step, compressing the second composite sheet in the thickness direction.

[0011] According to the above method, an absorbent sheet with two layers of absorbent material can be manufactured using three continuous sheets, which reduces the number of continuous sheets by one compared to manufacturing an absorbent sheet with two layers of absorbent material using four continuous sheets. Therefore, the manufacturing cost of the absorbent sheet with two layers of absorbent material can be reduced.

[0012] Furthermore, compared to the case where a conveyor is used to transport the first and second continuous sheets along a straight path while forming the first and second composite sheets, instead of replacing the first and second transport rollers, it is easier to miniaturize the equipment for manufacturing absorbent sheets.

[0013] Preferably, between the third and fourth steps, the first composite sheet is supported by a first support surface and attracted to the first support surface while the first support surface is moved, thereby transporting the first composite sheet.

[0014] In this case, even with high-speed transport of the first composite sheet between the third and fourth processes, the first absorbent material within the first composite sheet will be prevented from becoming misaligned in the surface direction. Therefore, increased production efficiency can be achieved by increasing the transport speed. Furthermore, the apparatus for manufacturing the first composite sheet and the apparatus for manufacturing the second composite sheet can be arranged with intervals between them, making it easy to simplify and standardize the apparatus structure.

[0015] Preferably, between the third and fourth steps, the first composite sheet is transported while being wound and supported on the first folding roller, wherein the first folding roller is disposed adjacent to the first transport roller and rotates in the opposite direction to the first transport roller.

[0016] In this case, by winding the first composite sheet onto the first flipping roller, the pressing between the first continuous sheet and the second continuous sheet of the first composite sheet can be strengthened, and the movement of the first absorbent material in the surface direction within the first composite sheet can be suppressed.

[0017] More preferably, the first composite sheet is fed to the second conveyor by horizontally supporting it while transporting it in a horizontal direction using a first conveyor.

[0018] In this case, the movement of the first absorbent material in the planar direction within the first composite sheet can be suppressed in the interval from the first flipping roller to the second conveying roller.

[0019] Preferably, between the sixth and seventh steps, the second composite sheet is moved while being supported by the second support surface and attracted to the second support surface, thereby transporting the second composite sheet.

[0020] In this case, even if the second composite sheet is transported at high speed between the sixth and seventh processes, the first and second absorbent materials within the second composite sheet will be prevented from becoming misaligned in the surface direction. Therefore, production efficiency can be improved by increasing the transport speed. Furthermore, the apparatus for manufacturing the second composite sheet and the pressing device can be arranged with a gap between them.

[0021] Preferably, between the sixth and seventh steps, the second composite sheet is wound and supported on the second flip roller while being transported, wherein the second flip roller is arranged adjacent to the second transport roller and rotates in the opposite direction to the second transport roller.

[0022] In this case, by winding the second composite sheet onto the second flipping roller, the pressing between the first to third continuous sheets of the second composite sheet can be strengthened, and the movement of the first and second absorbent materials in the surface direction within the second composite sheet can be suppressed.

[0023] More preferably, the second composite sheet is fed to the pressing device by using a second conveyor to horizontally support the second composite sheet discharged from the second flip roller and transport it in a horizontal direction.

[0024] In this case, the movement of the first and second absorbent materials in the planar direction within the second composite sheet can be suppressed in the interval from the second flipping roller to the second conveying roller.

[0025] Preferably, between the third and fourth steps, the first composite sheet, which is wound on the first flip roller and transported, is pressed toward the first flip roller by a first belt and / or a first pressing roller.

[0026] In this case, the movement of the first absorbent material in the first composite sheet in the planar direction can be suppressed.

[0027] Preferably, between the sixth and seventh steps, the second composite sheet, which is wound on the second flip roller and transported, is pressed toward the second flip roller by a second belt and / or a second pressing roller.

[0028] In this case, the movement of the second absorbent material in the surface direction within the second composite sheet can be suppressed.

[0029] Preferably, the pressing device uses the second belt and / or the second pressing roller and the second flipping roller to compress the second composite sheet in the thickness direction.

[0030] In this case, the structure of the apparatus used to manufacture absorbent sheets can be simplified.

[0031] In addition, in order to solve the above-mentioned problems, the present invention provides an apparatus for manufacturing an absorbent sheet used in an absorbent article configured as follows.

[0032] An apparatus for manufacturing absorbent sheets used in absorbent articles comprises: (a) a first composite sheet forming apparatus to which a first continuous sheet and a second continuous sheet are supplied, the first composite sheet forming apparatus forming a first composite sheet with a first absorbent material disposed between the first continuous sheet and the second continuous sheet; (b) a second composite sheet forming apparatus to which the first composite sheet and a third continuous sheet are supplied, the second composite sheet forming apparatus forming a second composite sheet with a second absorbent material disposed between the first composite sheet and the third continuous sheet; and (c) a pressing device that compresses the second composite sheet in the thickness direction.

[0033] Based on the above structure, an absorbent sheet with two layers of absorbent material can be manufactured using three continuous sheets, which reduces the number of continuous sheets by one compared to manufacturing an absorbent sheet with two layers of absorbent material using four continuous sheets. Therefore, the manufacturing cost of the absorbent sheet with two layers of absorbent material can be reduced.

[0034] Preferably, the apparatus for manufacturing absorbent sheet further includes (d) a first conveyor disposed between the first composite sheet forming apparatus and the second composite sheet forming apparatus, having a first transport surface that supports and attracts the first composite sheet while moving, and transporting the first composite sheet toward the second composite sheet forming apparatus.

[0035] In this case, even when the first composite sheet is transported at high speed, the first absorbent material within the first composite sheet during transport on the first conveyor will be prevented from becoming misaligned in the surface direction. Therefore, production efficiency can be improved by increasing the transport speed. Furthermore, by arranging the first composite sheet forming apparatus and the second composite sheet forming apparatus at intervals, the structures of the two apparatuses can be easily simplified and standardized.

[0036] Preferably, the first composite sheet forming apparatus is configured to include: (i) a first transport roller that winds and transports the first continuous sheet; (ii) a first absorbent material supply device that supplies the first absorbent material to the first continuous sheet wound and transported by the first transport roller; (iii) a first guide roller that guides the second continuous sheet such that the second continuous sheet overlaps on the first continuous sheet to cover the first absorbent material supplied to the first continuous sheet, thereby forming the first composite sheet; and (iv) a first turning roller that is disposed adjacent to the first transport roller, winds the first composite sheet such that the second continuous sheet supports the first composite sheet, rotates in the opposite direction to the first transport roller to transport the first composite sheet, and the first composite sheet is attracted to a first support surface supporting the first composite sheet.

[0037] In this case, the movement of the first absorbent material within the first composite sheet in the planar direction can be suppressed, and production efficiency can be improved based on the increased transport speed. Furthermore, compared to transporting the first continuous sheet along a straight path, the apparatus for forming the first composite sheet can be miniaturized.

[0038] Preferably, the apparatus for manufacturing absorbent sheet further includes (e) a second conveyor disposed between the second composite sheet forming apparatus and the pressing device, having a second transport surface that supports and attracts the second composite sheet while moving to transport the second composite sheet.

[0039] In this case, even with high-speed transport of the second composite sheet, the first and second absorbent materials within the second composite sheet will be prevented from becoming misaligned in the surface direction during transport on the second conveyor. Therefore, production efficiency can be improved by increasing the transport speed. Furthermore, the second composite sheet forming apparatus and the pressing device can be arranged at intervals, facilitating the simplification and standardization of the apparatus structure.

[0040] Preferably, the second composite sheet forming apparatus is configured to include: (i) a second transport roller that winds up the first composite sheet and transports the second composite sheet; (ii) a second absorbent material supply device that supplies the second absorbent material to the first composite sheet wound on and transported by the second transport roller; (iii) a second guide roller that guides the third continuous sheet such that the third continuous sheet is overlapped on the first composite sheet to cover the second absorbent material supplied to the second composite sheet, thereby forming the second composite sheet; and (iv) a second turning roller that is disposed adjacent to the second transport roller, winds up the second composite sheet in such a manner that it supports the third continuous sheet of the second composite sheet, rotates in the opposite direction to the first transport roller to transport the second composite sheet, and the second composite sheet is attracted to a second support surface supporting the second composite sheet.

[0041] In this case, the movement of the first and second absorbent materials within the second composite sheet in the planar direction can be suppressed, and production efficiency can be improved based on the high speed of handling. Furthermore, compared to handling the second composite sheet along a straight path, the second composite sheet forming apparatus can be miniaturized.

[0042] Preferably, the apparatus for manufacturing absorbent sheet further includes a first belt and / or a first pressing roller, which is configured to face the first turning roller and press the first composite sheet, which is wound on the first turning roller and transported, toward the first turning roller.

[0043] In this case, the movement of the first absorbent material in the first composite sheet in the planar direction can be suppressed.

[0044] Preferably, the apparatus for manufacturing absorbent sheet further includes a second belt and / or a second pressing roller, which is configured to face the second turning roller to press the second composite sheet, which is wound on and transported by the second turning roller, toward the second turning roller.

[0045] In this case, the movement of the second absorbent material in the surface direction within the second composite sheet can be suppressed.

[0046] Preferably, the second belt and / or the second pressing roller and the second flipping roller constitute the pressing device for compressing the second composite sheet in the thickness direction.

[0047] In this case, the structure of the apparatus for manufacturing absorbent sheets can be simplified. Invention Effects

[0048] According to the present invention, the manufacturing cost of absorbent sheets having two layers of absorbent material can be reduced. Attached Figure Description

[0049] Figure 1 This is a schematic diagram showing the overall structure of an apparatus for manufacturing absorbent sheets. (Example 1) Figure 2 This is an enlarged schematic diagram showing the main structural components of an apparatus for manufacturing absorbent sheets. (Example 1) Figure 3 This is an enlarged schematic diagram showing the main structural components of an apparatus for manufacturing absorbent sheets. (Example 1) Figure 4 middle, Figure 4 (a) is a schematic diagram of the dissection of the absorber. Figure 4 (b) is along Figure 4 The plan view observed by line BB in (a). Figure 4 (c) is along Figure 4 The plan view observed by line CC in (a). Figure 5 middle, Figure 5 (a) is a partial cross-sectional side view of the first pressing roller on the upstream side. Figure 5 (b) is a side schematic view of the first pressing roller on the downstream side. (Example 1) Figure 6 This is a simplified cross-sectional view of the second composite sheet in the width direction. (Example 1) Figure 7 This is a schematic diagram of an apparatus for manufacturing absorbent sheets. (Previous Example 1) Detailed Implementation

[0050] The following is a reference to the appendix. Figure 1 The embodiments of the present invention will be described below.

[0051] <Example 1> While referring to Figures 1-4 The apparatus for manufacturing the absorbent sheet of Example 1 will be described. Figure 1 This is a schematic diagram showing the overall structure of the apparatus 10 for manufacturing absorbent sheets. Figure 2 and Figure 3 This is an enlarged schematic diagram showing the main structure of the manufacturing apparatus 10 for absorbent sheets.

[0052] like Figures 1 to 3 As shown, the absorbent sheet manufacturing apparatus 10 includes a first composite sheet forming apparatus 12, a first conveyor 13, a second composite sheet forming apparatus 14, a second conveyor 15, and a pressing device 16.

[0053] The first composite sheet forming apparatus 12 supplies a first continuous sheet 2 and a second continuous sheet 4, such as a nonwoven fabric, in the directions indicated by arrows 2f and 4f, and forms a first absorbent material 3, such as granular or powdered SAP, between the first continuous sheet 2 and the second continuous sheet 4 (see...). Figure 4 The first composite sheet 7 of (a)).

[0054] In detail, the first composite sheet forming apparatus 12 is provided with a first SAP supply device 12d, a first guide roller 12c and a first turnover roller 12b around the first transport roller 12a.

[0055] The first conveying roller 12a has a cylindrical outer peripheral surface 12s for winding the first continuous sheet 2, and rotates in the direction indicated by arrow 12f to convey the first continuous sheet 2.

[0056] The first SAP supply device 12d is configured to have an opening 12e opposite to the first continuous sheet 2 wound on the first transport roller 12a, through which the first absorbent material 3 falls. The opening 12e is opened and closed at appropriate times, thereby supplying the first absorbent material 3 such that the first absorbent material 3 is disposed in a predetermined area on the first continuous sheet 2 wound on the first transport roller 12a and transported.

[0057] The first guide roller 12c guides the second continuous sheet 4 so that the second continuous sheet 4 overlaps with the first continuous sheet 2 to which the first absorbent material 3 has been supplied, and covers the first absorbent material 3. Thus, the first composite sheet 7 is formed.

[0058] The first flip roller 12b is arranged adjacent to the first transport roller 12a, and winds the first composite sheet 7 in such a way as to support the second continuous sheet 4 of the first composite sheet 7. The first flip roller 12b rotates in the opposite direction to the first transport roller 12a as shown by arrow 12g, and transports the first composite sheet 7.

[0059] like Figure 2 As shown, the outer peripheral surface 12s of the first conveying roller 12a and the outer peripheral surface 12t of the first turning roller 12b are the first support surfaces 12s and 12t that support the first composite sheet 7, and are configured to attract the first composite sheet 7.

[0060] For example, inside the first transport roller 12a and inside the first flip roller 12b, there are first suction boxes 12u and 12v connected to a vacuum source or a pressure reduction source. Through holes (not shown) communicating with the first suction boxes 12u and 12v are formed on the first support surfaces 12s and 12t. The first composite sheet 7 is attracted to the first support surfaces 12s and 12t by air flow in the direction indicated by arrows 15u and 15v.

[0061] By attracting the first composite sheet 7 to the first support surfaces 12s and 12t, even with high-speed transport of the first composite sheet 7, misalignment of the first absorbent material 3 within the first composite sheet 7 in the planar direction can be suppressed. Therefore, the transport speed can be increased, improving the production efficiency of the absorbent sheet 9.

[0062] The first belt 12m can be configured such that it can move along the first tilting roller 12b around the first tilting roller 12b, while the first composite sheet 7 is being transported between the first tilting roller 12b and the first belt 12m. In this case, the pressing between the first continuous sheet 2 and the second continuous sheet 4 of the first composite sheet 7 can be strengthened, and the movement of the first absorbent material 3 in the planar direction within the first composite sheet 7 can be further suppressed. The first belt 12m may be non-ventilated or may be ventilated to the extent that it is attracted to the first tilting roller 12b.

[0063] Alternatively, the first pressing rollers 12p and 12q can replace the first belt 12m or be arranged together with the first belt 12m in a manner opposite to the first turning roller 12b. The first pressing rollers 12p and 12q press the first composite sheet 7, which is wound on the first turning roller 12b and being transported, toward the first turning roller 12b. There can be one first pressing roller or three or more first pressing rollers 12p and 12q.

[0064] When the first pressing rollers 12p and 12q are configured together with the first belt 12m, the first pressing rollers 12p and 12q press the first composite sheet 7 toward the first turning roller 12b via the first belt 12m.

[0065] If the first pressing rollers 12p and 12q are provided, the offset between the first continuous sheet 2 and the second continuous sheet 4 of the first composite sheet 7 can be suppressed, and the movement of the first absorbent material 3 in the surface direction within the first composite sheet 7 can be further suppressed.

[0066] The first conveyor 13 is positioned between the first composite sheet forming apparatus 12 and the second composite sheet forming apparatus 14, and transports the first composite sheet 7 discharged from the first flip roller 12b of the first composite sheet forming apparatus 12 toward the second composite sheet forming apparatus 14.

[0067] The first conveyor 13 is configured to circulate a first annular belt 13b with ventilation. A third suction box 13k, connected to a vacuum source or a pressure reduction source, is disposed inside the first annular belt 13b. The conveyor is configured to attract the first composite sheet 7 to the upper surface 13a of the first annular belt 13b via airflow in the direction indicated by arrow 15W. The upper surface 13a of the first annular belt 13b is a first conveying surface 13a that horizontally supports and attracts the first composite sheet 7 while moving it in the horizontal direction.

[0068] Regarding the second composite sheet forming apparatus 14, a first composite sheet 7 discharged from the first conveyor 13 in the direction indicated by arrow 7x and a third continuous sheet 6 such as nonwoven fabric are supplied to the apparatus. A second absorbent material 5, such as granular or powdered SAP, is disposed between the first composite sheet 7 and the third continuous sheet 6 (see reference). Figure 4 The second composite sheet 8 of (a)).

[0069] The second composite sheet forming apparatus 14 has the same structure as the first composite sheet forming apparatus 12, and a second SAP supply device 14d, a second guide roller 14c, and a second flip roller 14b are arranged around the second transport roller 14a.

[0070] Second suction boxes 14u and 14v are arranged inside the second transport roller 14a and the second flip roller 14b, respectively, and are configured to attract the second composite sheet 8 to the second support surfaces 14s and 14t of the second transport roller 14a and the second flip roller 14b by airflow in the directions indicated by arrows 17u and 17v.

[0071] Around the second tumbling roller 14b, a second belt 14m can be arranged in a manner similar to the first tumbling roller 12b, allowing it to move along the second tumbling roller 14b, thus transporting the second composite sheet 8 while clamping it between the second tumbling roller 14b and the second belt 14m. In this case, the pressing between the first composite sheet 7 and the third continuous sheet 6 of the second composite sheet 8 can be strengthened, further suppressing the movement of the second absorbent material 5 within the second composite sheet 8 in the planar direction. The second belt 14m may be non-ventilated or ventilated to the extent that it is attracted to the second tumbling roller 14b.

[0072] Alternatively, the second pressing rollers 14p and 14q can be configured opposite to the second turning roller 14b, either on or in place of the second belt 14m, pressing the second composite sheet 8 toward the second turning roller 14b. In this case, the movement of the second absorbent material 5 within the second composite sheet 8 in the planar direction can be further suppressed. The second pressing rollers 14p and 14q can be one or more.

[0073] The second composite sheet 8 discharged from the second flipping roller 14b of the second composite sheet forming apparatus 14 is transported toward the pressing device 16 via the second conveyor 15.

[0074] The second conveyor 15 has the same structure as the first conveyor 13, which causes the second annular belt 15b with ventilation to move in a cycle. On the inner side of the second annular belt 15b, a fourth suction box 15k connected to a vacuum source or a pressure reduction source is arranged, which is configured to attract the second composite sheet 8 to the upper surface 15a of the second annular belt 15b, that is, the second conveying surface 15a.

[0075] The second composite sheet 8, discharged from the second conveyor 15 in the direction indicated by arrow 8x, is compressed along its thickness direction as it passes between a pair of rollers 16a and 16b of the pressing device 16. This forms an absorbent sheet 9.

[0076] The absorbent sheet 9 is cut to specified dimensions in a subsequent process to form, for example... Figure 4 The image shows a single piece of absorbent 8k. Absorbent 8k is used in absorbent products such as diapers and sanitary napkins.

[0077] Figure 4 (a) is a schematic diagram of the 8k absorber. Figure 4 (b) is along Figure 4 The plan view observed by line BB in (a). Figure 4 (c) is along Figure 4 The plan view observed by line CC in (a).

[0078] like Figure 4 As shown in (a), a first absorbent material 3 is disposed on one main surface 2a of a first sheet 2k formed from a first continuous sheet 2, and a second absorbent material 5 is disposed on the other main surface 2b of the first sheet 2k. The first absorbent material 3 is sandwiched between the first sheet 2k and a second sheet 4k formed from a second continuous sheet 4. The second absorbent material 5 is sandwiched between the first sheet 2k and a third sheet 6k formed from a third continuous sheet 6. That is, the first absorbent material 3 is disposed in a first layer between the first sheet 2k and the second sheet 4k, and the second absorbent material 5 is disposed in a second layer between the first sheet 2k and the third sheet 6k. The first absorbent material 3 and the second absorbent material 5 can be arranged in various patterns.

[0079] For example, Figure 4 As shown in (b), the first absorbent material 3 is disposed in two regions 3a and 3b on both sides of the length direction, as... Figure 4 As shown in (c), the second absorbent material 5 is disposed in three regions 5a, 5b, and 5c that extend along the length direction, with the second absorbent material 5 spaced apart from each other at the center of the length direction.

[0080] If the absorbent sheet manufacturing apparatus 10 described above is used, an absorbent sheet 9 having two layers of absorbent material 3 and 5 can be manufactured using three continuous sheets 2, 4, and 6. Compared to the case where an absorbent sheet with two layers of absorbent material is manufactured using four continuous sheets by forming two composite sheets with absorbent material sandwiched between two continuous sheets and overlapping the two composite sheets, one continuous sheet can be reduced. Therefore, by using the absorbent sheet manufacturing apparatus 10, the manufacturing cost of the absorbent sheet 9 can be reduced.

[0081] By using the first conveyor 13 to simultaneously attract and transport the first composite sheet 7, even at high speeds, the first absorbent material 3 within the first composite sheet 7 will be prevented from becoming misaligned in the surface direction during transport. Therefore, increased production efficiency can be achieved by increasing the transport speed. Furthermore, by arranging the first composite sheet forming apparatus 12 and the second composite sheet forming apparatus 14 at intervals, the structures of the first composite sheet forming apparatus 12 and the second composite sheet forming apparatus 14 can be easily simplified and standardized.

[0082] Similarly, by using the second conveyor 15 to both attract and transport the second composite sheet 8, even at high speeds, the misalignment of the first absorbent material 3 and the second absorbent material 5 within the second composite sheet 8 during transport is prevented. Therefore, increased production efficiency can be achieved by increasing the transport speed. Furthermore, the second composite sheet forming apparatus 14 and the pressing device 16 can be arranged at intervals between each other.

[0083] If the first composite sheet forming apparatus 12 is composed of the first transport roller 12a, the first turning roller 12b, etc., and the first composite sheet 7 is attracted to the first support surfaces 12s and 12t while being transported, the movement of the first absorbent material 3 in the surface direction within the first composite sheet 7 can be suppressed, and production efficiency can be improved based on the high speed of transport. In addition, compared with the case of transporting the first composite sheet 7 along a straight path, the first composite sheet forming apparatus 12 can be miniaturized.

[0084] Similarly, if the second composite sheet forming apparatus 14 is composed of the second transport roller 14a, the second flip roller 14b, etc., and the second composite sheet 8 is attracted to the second support surfaces 14s and 14t while being transported, the movement of the first absorbent material 3 and the second absorbent material 5 within the second composite sheet 8 in the planar direction can be suppressed, and production efficiency can be improved based on the high speed of transport. In addition, compared with the case of transporting the second composite sheet 8 along a straight path, the second composite sheet forming apparatus 14 can be miniaturized.

[0085] Next, the first pressing rollers 12p and 12q and the second pressing rollers 14p and 14q will be described in further detail.

[0086] Figure 5 (a) is a partial cross-sectional side view of the second pressing roller 14p on the upstream side. Figure 5 As shown in (a), the second pressing roller 14p on the upstream side has four circumferentially extending protrusions 14x formed on the cylindrical outer peripheral surface 14u. The second pressing roller 14p on the upstream side has, for example, an elongated component 14r for forming the protrusions 14x fixed to the outer peripheral component 14n by welding or the like.

[0087] Figure 5 (b) is a side view of the second pressing roller 14q on the downstream side. Figure 5 As shown in (b), the second pressing roller 14q on the downstream side has a cylindrical outer peripheral surface 14v, on which no protrusions or strips are formed.

[0088] Figure 6 This is a schematic cross-sectional view of the second composite sheet 8 in the width direction when compressed by the second pressing rollers 14p and 14q.

[0089] like Figure 6 As shown in (a), the second composite sheet 8 is sandwiched between the second support surface 14t of the second turning roller 14b and the second belt 14m.

[0090] Next, as Figure 6 As shown in (b), the protrusions 14x of the second pressing roller 14p on the upstream side press against the region 5k adjacent to the regions 5s and 5t where the second absorbent material 5 is disposed (refer to...). Figure 6 (a) As a result, the second absorbent materials 5p and 5q, located near the boundary lines of regions 5s and 5t, are compressed.

[0091] Next, as Figure 6 As shown in (c), the second composite sheet 8 is pressed in the width direction by the second pressing roller 14q on the downstream side.

[0092] At this time, the second absorbent materials 5p and 5q located near the boundary lines of regions 5s and 5t will not move outward toward regions 5s and 5t, thus forming a well-shaped slit (elongated gap) between regions 5s and 5t where the second absorbent material 5 is located.

[0093] That is, assuming the use of a roller with a cylindrical outer surface to immediately press down the entire width direction. Figure 6 In the state shown in (a), the second composite sheet 8, where the second absorbent materials 5p and 5q are located near the boundary lines of regions 5s and 5t, tend to move outwards from regions 5s and 5t as indicated by arrow 5x, which can easily narrow the slit width and cause the slit shape to become disordered. Conversely, if the second absorbent materials 5p and 5q located near the boundary lines of regions 5s and 5t are first compressed using the upstream second pressing roller 14p, then when the entire width direction is pressed using the downstream second pressing roller 14q, the second absorbent materials 5p and 5q near the boundary lines of regions 5s and 5t will not move outwards from regions 5s and 5t. Therefore, a slit with a good shape can be formed.

[0094] In other words, the upstream second pressing roller 14p is used to form the slit, and the downstream second pressing roller 14q is used to press the second composite sheet 8 as a whole after the slit is formed.

[0095] also, Figure 5 Figure (b) shows the case where the outer peripheral surface 14u of the second pressing roller 14p on the upstream side does not press the second belt 14m, but it is also possible that the outer peripheral surface 14u of the second pressing roller 14p on the upstream side presses the areas 14s and 14t of the second composite sheet 8 via the second belt 14m.

[0096] In such Figure 4 In the case shown in (b), where absorbent sheets 9 of the first absorbent material 3 are arranged in two regions 3a and 3b with a gap between them, the first pressing roller 12p on the upstream side has protrusions extending in the width direction formed by a circumferential gap on its cylindrical outer peripheral surface, such that these protrusions are located near the boundary lines of the pressing regions 3a and 3b; and / or, the first pressing roller 12p on the upstream side has protrusions extending in the circumferential direction formed by a axial gap on its outer peripheral surface, such that these protrusions are located near the boundary lines on both sides of the width direction of the pressing regions 3a and 3b. Similarly, the first pressing roller 12q on the downstream side and the second pressing roller 14q on the downstream side do not have protrusions or strips formed on their cylindrical outer peripheral surfaces.

[0097] Although not shown in the figure, it is also possible to construct the first pressing rollers 12p and 12q and the second pressing rollers 14p and 14q in the same way, using the upstream first pressing roller 12p to form the slit, and using the downstream first pressing roller 12q to press the first composite sheet 7 as a whole after the slit is formed.

[0098] Next, a method for manufacturing absorbent sheet 9 using absorbent sheet manufacturing apparatus 10 will be described. The method for manufacturing absorbent sheet 9 includes the first to seventh steps.

[0099] In the first process, the first continuous sheet 2 is wound and transported on the rotating first transport roller 12a of the first composite sheet forming apparatus 12.

[0100] In the second process, the first SAP supply device 12d of the first composite sheet forming apparatus 12 supplies the first absorbent material 3 to the first continuous sheet 2 wound on the first transport roller 12a and transported.

[0101] In the third process, the first guide roller 12c of the first composite sheet forming apparatus 12 overlaps the second continuous sheet 4 on the first continuous sheet 2 in such a way that the first absorbent material 3 supplied to the first continuous sheet 2 is covered, thereby forming a first composite sheet 7 with the first absorbent material 3 sandwiched between the first continuous sheet 2 and the second continuous sheet 4.

[0102] In the fourth process, the first composite sheet 7 is hung on the rotating second transport roller 14a of the second composite sheet forming device 14 and transported.

[0103] In the fifth process, the second SAP supply device 14d of the second composite sheet forming apparatus 14 supplies the second absorbent material 5 to the first composite sheet 7 that is wound on the second transport roller 14a and transported.

[0104] In the sixth step, the second guide roller 14c of the second composite sheet forming apparatus 14 overlaps the third continuous sheet 6 on the first composite sheet 7 in such a way that the second absorbent material 5 supplied to the first composite sheet 7 is covered, thereby forming a second composite sheet 8 in which the first absorbent material 3 is sandwiched between the first continuous sheet 2 and the second continuous sheet 4, and the second SAP4 is sandwiched between the second continuous sheet 4 and the third continuous sheet 6.

[0105] In the seventh process, the second composite sheet 8 is compressed along the thickness direction using the pressing device 16 to form an absorbent sheet 9.

[0106] Preferably, between the third and fourth processes, the first composite sheet 7 is supported by the first support surfaces 12s and 12t and attracted to the first support surfaces 12s and 12t, while the first support surfaces 12s and 12t are moved, thereby transporting the first composite sheet 7.

[0107] Specifically, between the third and fourth processes, the first composite sheet 7 is transported while being wound and supported on a first flip roller 12b, which is adjacent to the first transport roller 12a and rotates in the opposite direction to the first transport roller 12a. In this case, by winding the first composite sheet 7 onto the first flip roller 12b, the pressing between the first continuous sheet 2 and the second continuous sheet 4 of the first composite sheet 7 can be strengthened, and the movement of the first absorbent material 3 within the first composite sheet 7 in the planar direction can be suppressed.

[0108] Furthermore, the first composite sheet 7, which is discharged from the first tilting roller 12b, is horizontally supported by the first conveyor 13 and transported in the horizontal direction to the second transport roller 14a. In this case, the movement of the first absorbent material 3 in the planar direction within the first composite sheet 7 can be suppressed in the interval from the first tilting roller 12b to the second transport roller 14a.

[0109] Preferably, a first belt 12m configured to move along the first tilting roller 12b is used to transport the first composite sheet 7 while clamping it between the first tilting roller 12b and the first belt 12m. In this case, the pressing between the first continuous sheet 2 and the second continuous sheet 4 of the first composite sheet 7 can be further strengthened, and the movement of the first absorbent material 3 in the planar direction within the first composite sheet 7 can be further suppressed.

[0110] Preferably, the first composite sheet 7, which is wound on and transported by the first flip roller 12b, is pressed towards the first flip roller 12b using first pressing rollers 12p and 12q arranged opposite to the first flip roller 12b. In this case, the offset between the first continuous sheet 2 and the second continuous sheet 4 of the first composite sheet 7 can be suppressed, and the movement of the first absorbent material 3 in the planar direction within the first composite sheet 7 can be further suppressed.

[0111] Preferably, between the sixth and seventh processes, the second composite sheet 8 is supported by the second support surfaces 14s and 14t and attracted to the second support surfaces 14s and 14t, while the second support surfaces 14s and 14t are moved, thereby transporting the second composite sheet 8.

[0112] In detail, between the sixth and seventh processes, the second composite sheet 8 is transported while being wound and supported on a second turning roller 14b, which is adjacent to the second transport roller 14a and rotates in the opposite direction to the second transport roller 14a. In this case, by winding the second composite sheet 8 onto the second turning roller 14b, the pressing between the first to third consecutive sheets 2, 4, and 6 of the second composite sheet 8 can be strengthened, and the movement of the first absorbent material 3 and the second absorbent material 5 within the second composite sheet 8 in the planar direction can be suppressed.

[0113] Furthermore, the second composite sheet 8, which is discharged from the second flip roller 14b, is horizontally supported by the second conveyor 15 and transported in the horizontal direction, and supplied to the pressing device 16. In this case, the movement of the first absorbent material 3 and the second absorbent material 5 in the planar direction within the section from the second flip roller 14b to the pressing device 16 can be suppressed.

[0114] Preferably, a second belt 14m, configured to move along the second tilting roller 14b, is used to transport the second composite sheet 8 while clamping it between the second tilting roller 14b and the second belt 14m. In this case, the pressing between the first to third continuous sheets 2, 4, and 6 of the second composite sheet 8 can be further strengthened, and the movement of the first absorbent material 3 and the second absorbent material 5 within the second composite sheet 8 in the planar direction can be further suppressed.

[0115] Preferably, the second composite sheet 8, which is wound on and transported by the second flip roller 14b, is pressed towards the second flip roller 14b using second pressing rollers 14p and 14q configured opposite to the second flip roller 14b. In this case, the displacement between the first to third consecutive sheets 2, 4, and 6 of the second composite sheet 8 can be suppressed, and the movement of the first absorbent material 3 and the second absorbent material 5 within the second composite sheet 8 in the planar direction can be further suppressed.

[0116] Next, a variation of the first embodiment will be described.

[0117] <Modification 1> Absorbent sheet 9 can also be formed without using the first conveyor 13 and / or the second conveyor 15.

[0118] <Modification 2> Absorbent sheets can also be formed without using the first tumbling roller 12b and / or the second tumbling roller 14b.

[0119] Without using the first flipping roller 12b, the second continuous sheet 4, which can be configured as the first composite sheet 7, is supported on the transport roller 14a of the second composite sheet forming apparatus 14, forming a second composite sheet 8 where the second absorbent material 5 is not sandwiched between the second continuous sheet 4 and the third continuous sheet 6, but between the first continuous sheet 2 and the third continuous sheet 6.

[0120] <Modification Example 3> Regarding the attraction during the handling of the first composite sheet 7 and / or the attraction during the handling of the second composite sheet 8, all or part of them can be removed.

[0121] <Modification 4> The first transport roller 12a and / or the second transport roller 14a can also be replaced to form the first composite sheet 7 and / or the second composite sheet 8 while transporting the first continuous sheet 2 and / or the first composite sheet 7 along a straight path using a conveyor or the like.

[0122] <Modification 5> A first composite sheet 7 can also be formed by bonding the first continuous sheet 2 and the second continuous sheet 4 together. For example, the second continuous sheet 4 coated with adhesive is overlapped on the first continuous sheet 2 to which the first absorbent material 3 has been supplied and then bonded. Alternatively, adhesive can be applied to the first continuous sheet 2 to which the first absorbent material 3 has been supplied and the first continuous sheet 2 and the second continuous sheet 4 can be bonded together. It is also possible to apply adhesive to the first continuous sheet 2, then supply the first absorbent material 3, and then bond the first continuous sheet 2 and the second continuous sheet 4 together.

[0123] In this case, it is preferable that the first turning roller 12b and / or the first pressing rollers 12p, 12q have a heating function to heat the first composite sheet 7. For example, a heater is provided inside or around the first turning roller 12b and / or the first pressing rollers 12p, 12q to heat the first composite sheet 7, so that the temperature of the adhesive in the first composite sheet 7 is the same as or higher than the temperature at which the adhesive was applied. By heating, the adhesive in the first composite sheet 7 becomes easier to penetrate around the first absorbent material 3 sandwiched between the first continuous sheet 2 and the second continuous sheet 4, thus suppressing the positional displacement of the first absorbent material 3. As a result, the first absorbent material 3 can be positioned with high precision at the desired location between the first continuous sheet 2 and the second continuous sheet 4.

[0124] <Modification 6> A second continuous sheet 8 can also be formed by bonding the first composite sheet 7 and the third continuous sheet 6 together. For example, the third continuous sheet 6 coated with adhesive is laminated onto the first composite sheet 7 to which the second absorbent material 5 has been supplied and then bonded. Alternatively, adhesive can be applied to the first composite sheet 7 to which the second absorbent material 5 has been supplied, and the first composite sheet 7 and the third continuous sheet 6 can be bonded together. It is also possible to apply adhesive to the first composite sheet 7, then supply the second absorbent material 5, and then bond the first composite sheet 7 and the third continuous sheet 6 together.

[0125] In this case, it is preferable that the second flip roller 14b and / or the second pressing rollers 14p, 14q have a heating function to heat the second composite sheet 8. For example, a heater is provided inside or around the second flip roller 14b and / or the second pressing rollers 14p, 14q to heat the second composite sheet 8, so that the temperature of the adhesive in the second composite sheet 8 is the same as or higher than the temperature at which the adhesive was applied. By heating, the adhesive in the second composite sheet 8 becomes easier to penetrate around the second absorbent material 5 sandwiched between the first composite sheet 7 and the third continuous sheet 6, thus suppressing the positional displacement of the second absorbent material 5. As a result, the second absorbent material 5 can be positioned with high precision at the desired location between the first composite sheet 7 and the third continuous sheet 6.

[0126] <Modification 7> The pressing device 16 of Embodiment 1 can also be omitted. In this case, the second belt 14m and / or the second pressing rollers 14p, 14q and the second flip roller 14 are configured as a pressing device to compress the second composite sheet 8 in the thickness direction. That is, as a pressing device, the second belt 14m and / or the second pressing rollers 14p, 14q and the second flip roller 14b are used to compress the second composite sheet 8 in the thickness direction, thereby forming an absorbent sheet 9.

[0127] Alternatively, the structure can be obtained by appropriately combining the structures of Embodiment 1 and Modifications 1 to 7. For example, if the structures of Modification 5 and Modification 6 are combined to enable the first flipping roller 12b and / or the first pressing rollers 12p and 12q, and the second flipping roller 14b and / or the second pressing rollers 14p and 14q to have heating functions, then the first absorbent material 3 and the second absorbent material 5 can be positioned with high precision at the desired location.

[0128] <Summary> As explained above, three continuous sheets 2, 4, and 6 can be used to manufacture an absorbent sheet 9 with two SAP layers. Compared to using four continuous sheets to manufacture an absorbent sheet with two layers of absorbent material, one continuous sheet can be reduced. Therefore, the manufacturing cost of the absorbent sheet with two layers of absorbent material can be reduced.

[0129] Furthermore, the present invention is not limited to the above-described embodiments and can be implemented with various modifications.

[0130] For example, appropriate portions of the first to third continuous sheets 2, 4, and 6 can be joined together by heat fusion, ultrasonic bonding, or other methods. The first absorbent material 3 and the second absorbent material 5 can be the same or different. Explanation of reference numerals in the attached figures

[0131] 2 First continuous sheet 3 First absorbent material 4 Second continuous sheet 5 Secondary absorbent material 6 Third continuous sheet 7 First composite sheet 8 Second composite sheet 9 Absorbent Sheets 10. Manufacturing apparatus for absorbent sheets 12 First Composite Sheet Forming Apparatus 12a First conveying roller 12b First Tilting Roller 12c First guide roller 12d First SAP supply unit (first absorbent material supply unit) 12m First Belt 12p, 12q First pressing roller 12s, 12t First support surface 13 First Conveyor 13a Upper surface (first transport surface) 14 Second Composite Sheet Forming Apparatus 14a Second conveying roller 14b Second Tilting Roller (Pressing Device) 14c Second guide roller 14d Second SAP supply unit (second absorbent material supply unit) 14m Second Belt (Pressing Device) 14p, 14q Second pressing roller (pressing device) 14s, 14t Second support surface 15 Second Conveyor 15a Upper surface (second transport surface) 16. Pressing device.

Claims

1. A method for manufacturing an absorbent sheet, which is a method for manufacturing an absorbent sheet used in absorbent articles, comprising: The first process involves winding and transporting a first continuous sheet of material on a rotating first conveying roller. The second step involves supplying a first absorbent material to the first continuous sheet that is wound on and transported by the first transport roller. In the third step, a second continuous sheet is overlapped on the first continuous sheet to cover the first absorbent material supplied to the first continuous sheet, thereby forming a first composite sheet with the first absorbent material sandwiched between the first continuous sheet and the second continuous sheet. The fourth step involves winding the first composite sheet onto a rotating second conveying roller and transporting it. The fifth step involves supplying a second absorbent material to the first composite sheet that is wound on and transported by the first transport roller. In the sixth step, a third continuous sheet is overlapped on the first composite sheet to cover the second absorbent material supplied to the first composite sheet, thereby forming a second composite sheet. The second composite sheet has the first absorbent material sandwiched between the first continuous sheet and the second continuous sheet, and the second absorbent material sandwiched between the first continuous sheet and the third continuous sheet or between the second continuous sheet and the third continuous sheet. and In the seventh step, a pressing device is used to compress the second composite sheet along its thickness direction.

2. The method for manufacturing the absorbent sheet according to claim 1, wherein, Between the third and fourth steps, the first composite sheet is supported by a first support surface and attracted to the first support surface, while the first support surface is moved to transport the first composite sheet.

3. The method for manufacturing the absorbent sheet according to claim 1 or 2, wherein, Between the third and fourth processes, the first composite sheet is wound and supported on a first tumbling roller while being transported, wherein the first tumbling roller is arranged adjacent to the first transport roller and rotates in the opposite direction to the first transport roller.

4. The method for manufacturing the absorbent sheet according to claim 3, wherein, The first composite sheet is fed to the second conveyor roller by horizontally supporting it while transporting it horizontally from the first turning roller.

5. The method for manufacturing the absorbent sheet according to claim 1, wherein, Between the sixth and seventh steps, the second composite sheet is transported by moving the second support surface while supporting the second composite sheet with the second support surface and attracting it to the second support surface.

6. The method for manufacturing the absorbent sheet according to claim 1 or 5, wherein, Between the sixth and seventh steps, the second composite sheet is wound and supported on the second flip roller while being transported, wherein the second flip roller is arranged adjacent to the second transport roller and rotates in the opposite direction to the second transport roller.

7. The method for manufacturing the absorbent sheet according to claim 6, wherein, The second composite sheet is fed to the pressing device by horizontally supporting it while being transported horizontally by a second conveyor that supports it from the second turning roller.

8. The method for manufacturing the absorbent sheet according to claim 3, wherein, Between the third and fourth steps, the first composite sheet, which is wound on the first flip roller and being transported, is pressed toward the first flip roller by the first belt and / or the first pressing roller.

9. The method for manufacturing the absorbent sheet according to claim 6, wherein, Between the sixth and seventh steps, the second composite sheet, which is wound on the second flip roller and being transported, is pressed toward the second flip roller by the second belt and / or the second pressing roller.

10. The method for manufacturing the absorbent sheet according to claim 9, wherein, As the pressing device, the second belt and / or the second pressing roller and the second flipping roller are used to compress the second composite sheet in the thickness direction.

11. An apparatus for manufacturing an absorbent sheet, which is an apparatus for manufacturing absorbent sheets used in absorbent articles, comprising: A first composite sheet forming apparatus supplies a first continuous sheet and a second continuous sheet to the first composite sheet forming apparatus, wherein a first absorbent material is disposed between the first continuous sheet and the second continuous sheet; A second composite sheet forming apparatus supplies a first composite sheet and a third continuous sheet to the second composite sheet forming apparatus, wherein a second absorbent material is disposed between the first composite sheet and the third continuous sheet; and The pressing device compresses the second composite sheet along its thickness direction.

12. The apparatus for manufacturing absorbent sheets according to claim 11, wherein, It also includes a first conveyor, which is disposed between the first composite sheet forming apparatus and the second composite sheet forming apparatus, and has a first conveying surface that supports and attracts the first composite sheet while moving, so as to convey the first composite sheet toward the second composite sheet forming apparatus.

13. The apparatus for manufacturing absorbent sheets according to claim 11 or 12, wherein, The first continuous body forming apparatus is configured to include: A first conveying roller, which winds up the first continuous sheet and conveys the first continuous sheet; A first absorbent material supply device supplies the first absorbent material to the first continuous sheet wound on and transported by the first transport roller. A first guide roller guides the second continuous sheet such that the second continuous sheet is overlapped on the first continuous sheet to cover the first absorbent material supplied to the first continuous sheet, thereby forming the first composite sheet; and A first turning roller, disposed adjacent to the first transport roller, winds the first composite sheet in a manner that supports the second continuous sheet of the first composite sheet, and transports the first composite sheet by rotating in the opposite direction to the first transport roller. The first composite sheet is attracted to the first support surface that supports the first composite sheet.

14. The apparatus for manufacturing absorbent sheets according to claim 11, wherein, It also includes a second conveyor, which is disposed between the second composite sheet forming apparatus and the pressing device, and has a second transport surface that supports and attracts the second composite sheet while moving, transporting the second composite sheet toward the pressing device.

15. The apparatus for manufacturing absorbent sheets according to claim 11 or 14, wherein, The second continuous body forming apparatus is configured to include: The second conveying roller is used to wind up the first composite sheet and convey the second composite sheet. A second absorbent material supply device supplies the second absorbent material to the first composite sheet that is wound on and transported by the second transport roller. A second guide roller guides the third continuous sheet such that the third continuous sheet is overlapped on the first composite sheet to cover the second absorbent material supplied to the second composite sheet, thereby forming the second composite sheet. and The second flipping roller, which is arranged adjacent to the second transport roller, winds the second composite sheet in a manner that supports the third continuous sheet of the second composite sheet, and transports the second composite sheet by rotating in the opposite direction to the first transport roller. The second composite sheet is attracted to the second support surface that supports the second composite sheet.

16. The apparatus for manufacturing absorbent sheets according to claim 13, wherein, It also includes a first pressing roller, which is configured to face the first turning roller and press the first composite sheet, which is wound on the first turning roller and transported, toward the first turning roller.

17. The apparatus for manufacturing absorbent sheets according to claim 15, wherein, It also includes a second pressing roller, which is configured to face the second flip roller and press the second composite sheet, which is wound on and transported by the second flip roller, toward the second flip roller.

18. The apparatus for manufacturing absorbent sheet according to claim 17, wherein, The second belt and / or the second pressing roller and the second flipping roller constitute the pressing device for compressing the second composite sheet in the thickness direction.

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