Fiber deposition device, absorbent manufacturing method, and manufacturing device

Abstract

The present invention provides a fiber accumulation device and a manufacturing method and device for an absorbent body. The fiber accumulation device (1) divides a suction area (S) into two areas (S1) and (S2) in a flow direction (MD). In the area (S1), a control body opening (26) of a first suction area corresponding portion (23) of a fixed cylinder (2) and an opening closing member (30) of a rotating cylinder (3) are used to reduce the flow rate of a vacuum airflow in a portion (41A) and (41B) of a plurality of fiber accumulation areas (41) arranged in the flow direction (MD) of a collecting recess (40). Furthermore, in the area (S1), the distance between the first suction area corresponding portion (23) and the opening closing member (30) that overlap with each other is adjusted, or the relationship between the width of the opening closing member (30) and the width of the control body opening (26) that overlaps with it in the area (S1) is adjusted.

Description

Technical Field

[0001] The present invention relates to a manufacturing technology of an absorbent body with locally different grammages. Background Art

[0002] As absorbent bodies used in absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads, there are known biased (uneven) absorbent bodies in which the gram weight of fiber materials such as wood pulp is locally different, and there are high-gram weight parts with relatively more of the gram weight and low-gram weight parts with relatively less of the gram weight. As a typical example of a biased absorbent, there is known an absorbent body in which the gram weight of the fiber material is larger in the central part (the so-called middle-high part) compared with the peripheral part in the direction (longitudinal direction) corresponding to the front-back direction of the wearer of the absorbent article. In such a biased absorbent, the fiber material with body fluid absorption (hydrophilicity) is biased towards the part requiring high liquid absorbency, and the other parts suppress the gram weight of the fiber material and are thinner, so both liquid absorbency and wearing comfort are good.

[0003] In addition, as a manufacturing device for an absorbent body, there is a known fiber accumulation device, which includes a fixed cylinder and a rotating cylinder having a collection recess on the outer periphery, and is constructed to carry a fiber material transported by an air flow (vacuum airflow) generated by suction from the side of the fixed cylinder, and accumulate the fibers in the collection recess (patent documents 1 to 4).

[0004] Patent Document 1 describes a fiber accumulation device that divides a suction chamber located inside a rotating drum into multiple suction chambers along a cross-section extending along the flow direction, and independently provides suction mechanisms within each of the multiple suction chambers. The fiber accumulation device described in Patent Document 1 can even out the thickness of an absorbent body across its width, locally vary the weight of the absorbent body, and form a fluffy portion within the absorbent body. However, the fiber accumulation device described in Patent Document 1 cannot control the weight of the absorbent body in the flow direction during absorbent manufacturing.

[0005] Patent Document 2 describes a fiber accumulation device comprising a core bag and an air distribution manifold operatively associated with the core bag. The fiber accumulation device described in Patent Document 2 has a relatively complex structure, leading to concerns about increased manufacturing costs and equipment failures.

[0006] Patent Document 3 describes a fiber accumulation device in which a regulating element for adjusting the volume and flow of the vacuumed airflow is arranged on the inner surface of a porous member of a rotating drum, along the rotational direction of the rotating drum, and a non-registered area. Furthermore, a selective suction area for localized suction and a full-surface suction area for full-surface suction are sequentially arranged on the outer periphery of a fixed drum in the rotational direction. The fiber accumulation device described in Patent Document 3 enables stable production of biased absorbents with a relatively simple structure.

[0007] Patent Document 4 describes a fiber accumulation device comprising a duct that supplies fiber material in a scattered state to the outer circumference of a rotating drum. Excess fiber material overflowing from a collecting recess in the rotating drum is scraped off by a scraping roller disposed within the duct, and the scraped fiber material is then deposited back into the collecting recess. The fiber accumulation device described in Patent Document 4 enables the stable production of biased absorbent bodies.

[0008] Prior art literature

[0009] Patent Literature

[0010] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-272782

[0011] Patent Document 2: U.S. Patent Application Publication No. 2008 / 111270

[0012] Patent Document 3: Japanese Patent Application Laid-Open No. 2015-59287

[0013] Patent Document 4: Japanese Patent Application Publication No. 2018-11630 Summary of the Invention

[0014] The present invention (first invention) relates to a fiber accumulation device, which has a fixed cylinder and a rotating cylinder, the rotating cylinder is arranged to be able to rotate around the outer periphery of the fixed cylinder, and has a gathering recess for accumulating fiber materials on the outer periphery of the rotating cylinder. While the rotating cylinder is rotated to transport the gathering recess in the conveying direction along the circumferential direction of the cylinder, the fiber material transported by the air flow generated by suction from the side of the fixed cylinder is accumulated on the bottom surface of the gathering recess in a prescribed suction area in the circumferential direction of the cylinder, thereby manufacturing a fiber accumulation body having multiple parts with different gram weights in the conveying direction.

[0015] In one embodiment of the fiber accumulation device of the present invention (first invention), the gathering recess preferably has a plurality of fiber accumulation areas corresponding to the plurality of parts of the fiber accumulation body having different gram weights in the circumferential direction of the tube, and the plurality of fiber accumulation areas include a first fiber accumulation area and a second fiber accumulation area forming a part with a higher gram weight than the first fiber accumulation area.

[0016] In one embodiment of the fiber depositing device of the present invention (first invention), the suction area preferably includes a first suction area where suction from the fixed tube side can be performed locally and a second suction area where suction can be performed over the entire surface in the tube circumferential direction.

[0017] In one embodiment of the fiber depositing device of the present invention (first invention), preferably, a first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are provided on the outer periphery of the fixed cylinder.

[0018] In one embodiment of the fiber accumulation device of the present invention (first invention), the first suction region corresponding portion is preferably formed of a non-air-permeable member partially provided with openings, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the openings.

[0019] In one embodiment of the fiber accumulation device of the present invention (first invention), the second suction region corresponding portion preferably does not include a non-air-permeable member, and the airflow can pass through the entire second suction region corresponding portion in the thickness direction.

[0020] In one embodiment of the fiber accumulation device of the present invention (first invention), it is preferred that a non-air-permeable first opening sealing component corresponding to the first fiber accumulation area and a non-air-permeable second opening sealing component corresponding to the second fiber accumulation area are arranged in the opposite part of the rotating cylinder and the outer periphery of the fixed cylinder.

[0021] In one embodiment of the fiber accumulation device of the present invention (first invention), it is preferred that during the transportation of the accumulation recess in the first suction area, the flow rate of the air flow in the first fiber accumulation area and the second fiber accumulation area can be reduced by overlapping the first opening closing component and the second opening closing component with the opening corresponding to the first suction area.

[0022] The present invention (second invention) described later can also have the configuration of the present invention (first invention) described above.

[0023] In one embodiment of the fiber accumulation device of the present invention (first invention), preferably, in the first suction area, when the first opening closing component overlaps with the opening of the first suction area corresponding part, the first suction area corresponding part is separated from the first opening closing component by a predetermined spacing distance G1.

[0024] In one embodiment of the fiber accumulation device of the present invention (first invention), preferably, in the first suction area, when the second opening portion closing component overlaps with the opening portion of the first suction area corresponding portion, the first suction area corresponding portion is separated from the second opening portion closing component by a predetermined spacing distance G2.

[0025] In one embodiment of the fiber depositing device of the present invention (first invention), it is preferable that the relationship of the gap distance G1 < the gap distance G2 holds.

[0026] In one embodiment of the fiber accumulation device of the present invention (second invention), the length of the first opening closing component in the conveying direction orthogonal to the conveying direction is preferably longer than that of the opening corresponding to the first suction area, and in the first suction area, the first opening closing component is overlapped with the opening, and the first opening closing component extends over the entire length of the opening in the conveying direction.

[0027] In one embodiment of the fiber accumulation device of the present invention (second invention), the length of the second opening closing component in the conveying direction is preferably shorter than that of the opening corresponding to the first suction area, and in the first suction area, when the second opening closing component overlaps with the opening, there is a portion of the opening in the conveying direction that is not covered by the second opening closing component.

[0028] The present invention (third invention) relates to a method for producing an absorbent body, which uses a fiber accumulation device to produce an absorbent body having a plurality of portions having different basis weights in one direction.

[0029] In one embodiment of the method for manufacturing an absorbent body of the present invention (the third invention), the fiber accumulation device preferably has a fixed cylinder and a rotating cylinder, the rotating cylinder is configured to be able to rotate around the outer periphery of the fixed cylinder, and the outer periphery of the rotating cylinder has a gathering recess for accumulating the fiber material, and the rotating cylinder is rotated to convey the gathering recess in a conveying direction along the circumferential direction of the cylinder, while the fiber material conveyed by the air flow generated by suction from the side of the fixed cylinder is accumulated on the bottom surface of the gathering recess in a prescribed suction area in the circumferential direction of the cylinder.

[0030] In one embodiment of the method for manufacturing an absorbent body according to the present invention (third invention), the collecting recess preferably has a plurality of fiber accumulation regions corresponding to the plurality of portions of the absorbent body having different basis weights in the circumferential direction of the tube.

[0031] In one embodiment of the method for manufacturing an absorbent body of the present invention (third invention), the suction area preferably includes a first suction area in which suction from the fixed tube side can be performed locally and a second suction area in which suction can be performed over the entire surface in the tube circumferential direction.

[0032] In one embodiment of the method for manufacturing an absorbent body according to the present invention (third invention), preferably, a first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are provided on the outer periphery of the fixed tube.

[0033] In one embodiment of the manufacturing method of the absorbent body of the present invention (the third invention), the first suction area corresponding part is preferably formed by a non-air-permeable component with an opening part locally provided, and the air flow can pass through the first suction area corresponding part in the thickness direction only through the opening part.

[0034] In one embodiment of the method for manufacturing an absorbent body according to the present invention (third invention), the second suction region corresponding portion preferably does not include a non-air-permeable member, and the airflow can pass through the entire second suction region corresponding portion in the thickness direction.

[0035] In one embodiment of the method for manufacturing an absorbent body of the present invention (the third invention), it is preferred that a plurality of non-air-permeable opening sealing components are arranged in the circumferential direction of the cylinder in the relative portion of the outer periphery of the rotating cylinder and the fixed cylinder, corresponding to at least a portion of the plurality of fiber accumulation areas of the gathering recess.

[0036] In one embodiment of the method for manufacturing an absorbent body of the present invention (the third invention), it is preferred that during the transportation of the gathering recess in the first suction area, the flow rate of the air flow in the fiber accumulation area corresponding to the opening closing component in the gathering recess is reduced by overlapping the opening corresponding to the first suction area with the opening closing component.

[0037] The configuration of the present invention (third invention) described above can also include the present invention (fourth invention) described later.

[0038] In one embodiment of the manufacturing method of the absorbent body of the present invention (the third invention), the multiple opening sealing parts arranged in the circumferential direction of the cylinder are preferably spaced apart from the corresponding part of the first suction area at a predetermined spacing distance in a state where they overlap with the opening parts of the corresponding part of the first suction area in the first suction area.

[0039] In one embodiment of the method for manufacturing an absorbent body of the present invention (the third invention), it is preferred that the spacing distances among the multiple opening sealing components arranged in the circumferential direction of the tube are different from each other, and the multiple opening sealing components are arranged in a manner that the spacing distance gradually changes from one side to the other side in the circumferential direction of the tube.

[0040] In one embodiment of the method for manufacturing an absorbent body of the present invention (the third invention), it is preferred that there is a fiber accumulation step in which the fiber material is supplied to the outer periphery of the rotating cylinder in a scattered state while the rotating cylinder is rotated around the outer periphery of the fixed cylinder, so that the fiber material is accumulated in the gathering recess in the suction area.

[0041] In one embodiment of the method for manufacturing an absorbent body of the present invention (the third invention), it is preferred that in the fiber accumulation process, in the first suction area, among the multiple fiber accumulation areas corresponding to the multiple opening closing parts, the flow rate of the air flow in the fiber accumulation area with a longer spacing distance is greater.

[0042] In one embodiment of the method for manufacturing an absorbent body of the present invention (the fourth invention), it is preferred that the lengths of the plurality of opening sealing components arranged in the circumferential direction of the cylinder are different from each other in the conveying direction orthogonal to the conveying direction of the opening sealing components, and the plurality of opening sealing components are arranged in such a manner that the length of the opening sealing components in the conveying direction orthogonal to the conveying direction gradually changes from one side to the other side of the circumferential direction of the cylinder.

[0043] In one embodiment of the method for manufacturing an absorbent body of the present invention (the fourth invention), it is preferred that there is a fiber accumulation step in which the fiber material is supplied to the outer periphery of the rotating cylinder in a scattered state while the rotating cylinder is rotated around the outer periphery of the fixed cylinder, so that the fiber material is accumulated in the gathering recess in the suction area.

[0044] In one embodiment of the method for manufacturing an absorbent body of the present invention (the fourth invention), preferably, in the fiber accumulation process, in the first suction area, among the multiple fiber accumulation areas corresponding to the multiple opening closing components, the shorter the length of the opening closing component in the conveying orthogonal direction, the greater the flow rate of the air flow in the fiber accumulation area.

[0045] The present invention (fifth invention) relates to a method for manufacturing an absorbent body, which uses a fiber accumulation device to manufacture an absorbent body having a high-weight portion with a relatively large weight of fiber material and a relatively small low-weight portion in one direction.

[0046] In one embodiment of the method for manufacturing an absorbent body of the present invention (the fifth invention), the fiber accumulation device preferably has a fixed cylinder and a rotating cylinder, the rotating cylinder is configured to be able to rotate around the outer periphery of the fixed cylinder, and the outer periphery of the rotating cylinder has a gathering recess for gathering the fiber material, so that the fiber material transported by the air flow generated by suction from the side of the fixed cylinder is accumulated on the bottom surface of the gathering recess.

[0047] In one embodiment of the method for manufacturing an absorbent body of the present invention (fifth invention), the gathering recess preferably has a high grammage portion corresponding portion forming the high grammage portion and a low grammage portion corresponding portion forming the low grammage portion in the circumferential direction of the tube.

[0048] In one embodiment of the method for manufacturing an absorbent body of the present invention (the fifth invention), it is preferred that there is a fiber accumulation step in which the fiber material is supplied to the outer periphery of the rotating cylinder in a scattered state while the rotating cylinder is rotated around the outer periphery of the fixed cylinder, so that the fiber material is accumulated in the gathering recess in a prescribed suction area in the circumferential direction of the cylinder.

[0049] In one embodiment of the method for manufacturing an absorbent body of the present invention (the fifth invention), it is preferred that, after the fiber accumulation process, a scraping roller arranged opposite to the outer periphery of the rotating drum is used to scrape the fiber material accumulated in the portion corresponding to the high grammage portion, and the scraped fiber material is re-accumulated in the portion corresponding to the low grammage portion.

[0050] In one embodiment of the method for manufacturing an absorbent body of the present invention (the fifth invention), the fiber accumulation process preferably includes: a high-weight portion priority fiber accumulation process for causing the fiber material to be preferentially accumulated in the portion corresponding to the high-weight portion; and a fiber accumulation process for causing the fiber material to be accumulated in both the portion corresponding to the high-weight portion and the portion corresponding to the low-weight portion, which is implemented in an area of ​​the suction area different from the implementation area of ​​the high-weight portion priority fiber accumulation process.

[0051] In one embodiment of the method for manufacturing an absorbent body of the present invention (fifth invention), it is preferred that in the high-weight portion priority fiber accumulation process, the flow rate difference of the air flow between the portion corresponding to the high-weight portion and the portion corresponding to the low-weight portion is made larger than that in the entire fiber accumulation process.

[0052] The present invention (sixth invention) relates to an apparatus for manufacturing an absorbent body that can be used to manufacture an absorbent body having a high-weight portion having a relatively large weight of fiber material and a relatively small low-weight portion in one direction.

[0053] In one embodiment of the manufacturing device of the absorbent body of the present invention (the sixth invention), it is preferably provided with a fixed cylinder and a rotating cylinder, wherein the rotating cylinder is arranged to be able to rotate around the outer periphery of the fixed cylinder, and the outer periphery of the rotating cylinder has a gathering recess for depositing the fiber material. While the rotating cylinder is rotated, the fiber material transported by the air flow generated by suction from the side of the fixed cylinder is deposited on the bottom surface of the gathering recess in a prescribed suction area in the circumferential direction of the cylinder.

[0054] In one embodiment of the manufacturing device of the absorbent body of the present invention (sixth invention), the gathering recess preferably has a high grammage portion corresponding portion forming the high grammage portion and a low grammage portion corresponding portion forming the low grammage portion in the circumferential direction of the tube.

[0055] In one embodiment of the manufacturing device of the absorbent body of the present invention (the sixth invention), the suction area preferably has in the circumferential direction of the tube: a first suction area that preferentially accumulates the fiber material in the corresponding part of the high grammage part; and a second suction area that accumulates the fiber material in both the corresponding part of the high grammage part and the corresponding part of the low grammage part.

[0056] In one embodiment of the manufacturing device of the absorbent body of the present invention (sixth invention), it is preferred that the first suction area makes the flow rate difference of the air flow between the portion corresponding to the high grammage portion and the portion corresponding to the low grammage portion larger than that of the second suction area.

[0057] In one embodiment of the manufacturing device of the absorbent body of the present invention (the sixth invention), it is preferred that there is also a scraping roller arranged opposite to the outer periphery of the rotating drum, and the scraping roller is configured to scrape the fiber material accumulated in the corresponding part of the high grammage part, and then accumulate the scraped fiber material in the corresponding part of the low grammage part.

[0058] Other features, effects, and embodiments of the present invention are described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 This is a schematic perspective view of one embodiment of the absorbent body provided by the present invention (first to fourth inventions).

[0060] Figure 2 This is a perspective view schematically showing one embodiment of the fiber deposition device of the present invention (first to fourth inventions) in a partially transparent manner.

[0061] Figure 3 Viewed from the cylinder axis Figure 2 The fiber deposition device shown is a schematic side view.

[0062] Figure 4 yes Figure 2 The figure shows a schematic exploded perspective view of the collecting portion of the fiber accumulation device.

[0063] Figure 5 yes Figure 2 FIG. 1 is a schematic top view of a portion of a collecting recess of the fiber accumulation device shown.

[0064] Figure 6 yes Figure 2 A schematic top view of the suction area of ​​the fiber deposition device is shown.

[0065] Figure 7 It is schematically represented in Figure 5 A cross-sectional view of the cross section at line II (a cross section of the first fiber accumulation area along the barrel axis direction), Figure 7 (a) represents the attraction state of the first attraction area, Figure 7(b) shows the attraction state of the second attraction area.

[0066] Figure 8 It is schematically represented in Figure 5 The cross-sectional view of the cross section at the III-III line (the cross section of the third fiber accumulation area along the barrel axis direction) is shown in FIG. Figure 8 (a) represents the attraction state of the first attraction area, Figure 8 (b) shows the attraction state of the second attraction area.

[0067] Figure 9 It is schematically represented in Figure 5 A cross-sectional view of the cross section at line IV-IV (a cross section of the gathering recess along the circumferential direction of the cylinder).

[0068] Figure 10 It is schematically represented Figure 2 In one embodiment of the fiber deposition device shown in FIG. Figure 5 The cross-sectional view of the cross section taken along the II line (a cross section of the first fiber accumulation area along the barrel axis direction) is a diagram showing the suction state of the first suction area.

[0069] Figure 11 It is schematically represented Figure 10 In the fiber deposition device shown Figure 5 The cross-sectional view of the cross section taken along the II-II line (a cross section of the second fiber accumulation area along the barrel axis direction) is a diagram showing the suction state of the first suction area.

[0070] Figure 12 It is schematically represented Figure 10 In the fiber deposition device shown Figure 5 The cross-sectional view of the cross section taken along the IV-IV line (a cross section of the collecting recess along the cylinder circumferential direction) is a diagram showing the suction state of the first suction area.

[0071] Figure 13 It is schematically represented Figure 2 In another embodiment of the fiber deposition device shown in FIG. Figure 5 The cross-sectional view of the cross section taken along the II-II line (a cross section of the second fiber accumulation area along the barrel axis direction) is a diagram showing the suction state of the first suction area.

[0072] Figure 14 It is schematically represented Figure 13 In the fiber deposition device shown Figure 5 The cross-sectional view of the cross section taken along the IV-IV line (a cross section of the collecting recess along the cylinder circumferential direction) is a diagram showing the suction state of the first suction area.

[0073] Figure 15 It is schematically represented Figure 2In another embodiment of the fiber deposition device shown in FIG. Figure 5 The cross-sectional view taken along the II line or the II-II line (a cross-sectional view of the first fiber accumulation region or the second fiber accumulation region along the barrel axis) shows the suction state of the first suction region.

[0074] Figure 16 (a) and Figure 16 (b) are schematic perspective views of one embodiment of the absorbent body provided by the present invention (fifth to sixth inventions).

[0075] Figure 17 This is a perspective view schematically showing one embodiment of an absorbent body manufacturing apparatus according to the present invention (fifth to sixth inventions) in a partially transparent manner.

[0076] Figure 18 Viewed from the cylinder axis Figure 17 A schematic side view of the manufacturing device is shown.

[0077] Figure 19 yes Figure 17 A schematic top view of a portion of a collecting recess of the manufacturing apparatus shown.

[0078] Figure 20 yes Figure 17 A schematic top view of the suction area of ​​the production device is shown.

[0079] Figure 21 It is schematically represented in Figure 19 The cross-sectional view of the cross section at line II (the cross section along the cylinder axis direction of the portion corresponding to the low grammage portion) is shown. Figure 21 (a) shows the suction state of the first suction area (high-weight portion priority fiber accumulation process), Figure 21 (b) shows the suction state in the second suction zone (entire fiber forming step).

[0080] Figure 22 It is schematically represented in Figure 19 The cross-sectional view of the cross section at the II-II line (the cross section along the cylinder axis direction of the high-weight portion corresponding portion) is shown. Figure 22 (a) shows the suction state in the first suction area (high-weight portion priority fiber accumulation process), Figure 22 (b) shows the suction state in the second suction zone (entire fiber forming step).

[0081] Figure 23 It is schematically represented in Figure 19 A cross-sectional view of the cross section at line III-III (a cross section of the gathering recess along the circumferential direction of the cylinder).

[0082] Figure 24 (a) and Figure 24 (b) indicates the use of Figure 17 FIG. 1 is a diagram showing a refibering step in one embodiment of a manufacturing method of a manufacturing apparatus shown. DETAILED DESCRIPTION

[0083] Biased absorbers are desired to have a shape that is elongated in one direction (typically the front-to-back direction of the wearer of the absorbent article), with a large degree of fiber material bias in the longitudinal direction, and a relatively large weight difference between the high-weight portion and the low-weight portion. However, existing absorbent manufacturing technologies are unable to fully meet such requirements. The longitudinal direction of such an elongated absorbent typically aligns with the flow direction during manufacturing, but there is no technology that can appropriately control the amount of fiber accumulation in the flow direction using a relatively simple device structure.

[0084] The present invention (first to fourth inventions) relates to a technique capable of providing an absorbent body in which the degree of deviation of the fiber material in the direction corresponding to the flow direction during production is large.

[0085] Furthermore, as a biased absorber, it is desirable to have a high degree of fiber material bias, with a relatively large weight difference between the high-weight portion and the low-weight portion. However, the reality is that existing absorber manufacturing technologies are not yet able to fully meet such requirements. Furthermore, even if there are technologies that can produce absorbers with a high degree of fiber material bias, the devices used to implement such technologies are complex in structure, making their implementation difficult. Furthermore, as will be described later, as the degree of bias in the absorber increases, the low-weight portion continues to be further reduced in weight, reducing the uniformity of the weight in the low-weight portion, which may lead to reduced performance of the absorber. No technology has yet been developed to address this issue.

[0086] The present invention (fifth to sixth invention) relates to a technology capable of providing an absorbent body having a large degree of unevenness of fiber material and a uniform basis weight in a low basis weight portion.

[0087] The present invention (the first to sixth inventions) will be described below based on preferred embodiments thereof with reference to the accompanying drawings. In the following drawings, identical or similar parts are denoted by identical or similar reference numerals. The drawings are primarily schematic illustrations, and the proportions of various dimensions and the like may differ from actual figures.

[0088] The absorbent bodies provided by the present invention (the first to sixth inventions) are capable of absorbing aqueous liquids, typically body fluids. The use of the absorbent bodies is not particularly limited, but they are particularly suitable as absorbent articles. "Absorbent articles" as used herein broadly encompass articles used to absorb body fluids (such as urine, loose stools, menstrual blood, and sweat) discharged from the human body, including, for example, disposable diapers, sanitary napkins, menstrual panties, and incontinence pads.

[0089] Absorbent articles typically include an absorber, a liquid-permeable topsheet disposed on the wearer's skin side relative to the absorber, and a liquid-impermeable or impermeable backsheet disposed on the wearer's skin side relative to the absorber.

[0090] Hereinafter, the first to fourth inventions will be described.

[0091] Figure 1 1 shows an absorber 10 as one embodiment of the absorber provided by the present invention (the first to fourth inventions). The absorber 10 is an absorber for an absorbent article and has a longitudinal direction X corresponding to the front-back direction of the wearer of the absorbent article and a transverse direction Y orthogonal thereto.

[0092] The longitudinal direction X coincides with the flow direction MD (machine direction) during the manufacture of the absorbent body 10 described later, and the transverse direction Y coincides with the cross-machine direction CD (cross-machine direction) which is a direction perpendicular to the flow direction MD. In addition, the flow direction MD coincides with the rotation direction R1 of the rotating drum 3 along the drum circumferential direction X1 described later (the conveying direction of the collecting recess 40), and the cross-machine direction CD coincides with the drum axial direction Y1 described later (see FIG. Figure 2 ).

[0093] The absorbent body 10 is primarily composed of a fiber material. The fiber material content in the absorbent body 10 is at least 50% by mass, and may be 100% by mass, meaning that it is composed solely of the fiber material. The type of fiber material is not particularly limited; hydrophobic fibers formed from synthetic resins such as thermoplastic resins can be used, and hydrophilic fibers are typically used. Examples of hydrophilic fibers include natural fibers such as wood pulps such as coniferous or hardwood pulp, non-wood pulps such as cotton or hemp pulp, modified pulps such as cationized pulp and mercerized pulp (each, a cellulosic fiber), and hydrophilic synthetic fibers. These can be used alone or in combination of two or more.

[0094] The absorbent body 10 may further contain a water-absorbing polymer in addition to the fiber material. While granular water-absorbing polymers are typically used, fibrous water-absorbing polymers may also be used. The shape of the granular water-absorbing polymer is not particularly limited and may be, for example, spherical, blocky, bag-like, or irregularly shaped. The water-absorbing polymer typically comprises a polymer or copolymer of acrylic acid or an alkali metal acrylate.

[0095] The absorbent body 10 is as follows Figure 1 As shown, in one direction, there is a high gram weight portion 11 with a relatively large gram weight of fiber material and a relatively small low gram weight portion 12. In this embodiment, the absorbent body 10 has a shape that is long in the longitudinal direction X (approximately a rectangular shape) when viewed from above, and the high gram weight portion 11 is arranged in the central part of the longitudinal direction X, that is, the longitudinal direction X, and the low gram weight portions 12 are arranged at both ends of the longitudinal direction X. The absorbent body 10 is arranged in the longitudinal direction X in the order of the low gram weight portion 12, the high gram weight portion 11, and the low gram weight portion 12.

[0096] The high gram-weight portion 11 is a region in a direction (longitudinal direction X) in which the high gram-weight portion 11 and the low gram-weight portion 12 are connected, and includes a portion having a larger gram-weight of fiber material than the low gram-weight portion 12. When other portions other than this portion are included, this portion and other portions that are at the same position as this portion in the longitudinal direction X are included. For example, in the present embodiment, a middle-high portion 11A, which is the portion having the largest gram-weight of fiber material in the absorbent body 10, is formed in the central portion in the transverse direction Y (short side direction) of the high gram-weight portion 11. The two outer sides in the transverse direction Y sandwiching the middle-high portion 11A become standard gram-weight portions 11B having a smaller gram-weight of fiber material than the middle-high portion 11A. The region constituted by the middle-high portion 11A and the standard gram-weight portion 11B (other portions that are at the same position as the middle-high portion 11A in the longitudinal direction X) is the high gram-weight portion 11 as a whole.

[0097] The middle high portion 11A is thicker than the peripheral portion, protrudes toward one side of the absorbent body 10, and has a substantially rectangular shape that is long in the longitudinal direction X when viewed from above. The absorbent body 10 has the protruding surface ( Figure 1 The absorbent article may be used with the upper surface (in the middle) facing the skin side of the wearer of the absorbent article using the absorbent body 10, or may be used with the surface opposite to the protruding surface side of the middle high portion 11A facing the skin side of the wearer.

[0098] The standard basic weight portion 11B may have a smaller basic weight of the fiber material than the low basic weight portion 12 .

[0099] The low gram weight portion 12 may have a uniform gram weight throughout its entire area, or may have a partially different gram weight. As an example of the latter, the inner side (high gram weight portion 11 side) of the low gram weight portion 12 in the longitudinal direction X may have a higher or lower gram weight of the fiber material than the outer side. In addition, as another example of the latter, the central portion 12A ( Figure 1 The portion marked with oblique lines in the middle) is a form in which the gram weight of the fiber material is greater or less than the two end portions 12B, 12B in the transverse direction Y of the low gram weight portion 12.

[0100] In this embodiment, the high-weight portion 11 and the low-weight portion 12 are divided into a plurality of regions by a plurality of groove-shaped recesses 13X and 13Y that are mutually intersecting and straight in plan view. The groove-shaped recesses 13X extend in the longitudinal direction X, and the groove-shaped recesses 13Y extend in the transverse direction Y. In the illustrated embodiment, the groove-shaped recesses 13X and 13Y are formed on the protruding surface ( Figure 1 The upper surface) side may also be formed on the surface opposite to the protruding surface side.

[0101] The groove-shaped recesses 13X and 13Y function as flow paths for liquids such as excrement, thereby improving the liquid absorption capacity of the absorbent body 10 and enhancing the softness and flexibility of the absorbent body 10, thereby improving the conformability of the absorbent article to the wearer's body. The groove-shaped recesses 13X and 13Y may also be omitted.

[0102] The high-weight portion 11 mainly contributes to improving the liquid absorbency of the absorbent body 10, and the low-weight portion 12 mainly contributes to improving the wearing feel of the absorbent article having the absorbent body 10. With respect to the absorbent body 10, when the absorbent body 10 is used as an absorbent body for an absorbent article such as a disposable diaper or a sanitary napkin, the absorbent body 10 is the portion disposed in the crotch portion (excretion areas such as the penis and vaginal opening) of the wearer of the absorbent article. The central portion in the longitudinal direction X is the high-weight portion 11, and the other portions are the low-weight portions 12. Since the central portion in the longitudinal direction X of the absorbent body 10 is where the wearer's excretions are concentrated, sufficient liquid absorbency can be ensured by making the central portion the high-weight portion 11. Furthermore, since the portions other than the central portion of the absorbent body 10 are less likely to be used for liquid absorption than the central portion, the wearing feel can be improved by reducing the gram weight of the fiber material as much as possible and making the thickness thinner.

[0103] Hereinafter, the fiber accumulation device and the manufacturing method of the absorbent body of the present invention (the first to fourth inventions) will be described with reference to the accompanying drawings, taking the manufacturing method of the absorbent body 10 as an example. Figure 2 and Figure 3 1 shows the overall structure of a fiber accumulation device 1 as one embodiment of the fiber accumulation device for an absorbent body according to the present invention.

[0104] The fiber accumulation device 1 has a fixed cylinder 2 and a rotating cylinder 3. The rotating cylinder 3 is configured to be able to rotate around the outer periphery 2S of the fixed cylinder 2. The outer periphery 3S has a gathering recess 40 for accumulating fiber materials. The rotating cylinder 3 is rotated to transport the gathering recess 40 in the conveying direction along the cylinder circumferential direction X1, and the fiber material carried by the air flow (hereinafter also referred to as "vacuum airflow") generated by suction from the side of the fixed cylinder 2 is deposited on the bottom surface of the gathering recess 40 in a specified suction area S in the cylinder circumferential direction X1, thereby manufacturing an absorbent body 10 (fiber accumulation body) having multiple parts with different gram weights in the conveying direction.

[0105] As described above, the absorbent body 10 has at least a high grammage portion 11 and a low grammage portion 12 in the longitudinal direction X corresponding to the conveying direction of the collecting recess 40, and each of the two grammage portions 11 and 12 may have a plurality of portions having different grammages in the longitudinal direction X, or may have three or more portions having different grammages in the longitudinal direction X. For example, the low grammage portion 12 may have a higher grammage on the inner side (the high grammage portion 11 side) in the longitudinal direction X than on the outer side.

[0106] In this embodiment, the fiber accumulation device 1 has: a gathering section 4 including a fixed drum 2 and a rotating drum 3; a raw material supply mechanism 5 for supplying raw materials such as fiber materials to the gathering section 4 (rotating drum 3); and a conveying mechanism 6 for conveying the absorbent body 10 (a fiber accumulation material of raw materials such as fiber materials) discharged from the gathering recess 40 of the rotating drum 3.

[0107] The raw material supply mechanism 5 includes a pipe 51 having a raw material supply passage 50 therein, and a raw material introduction section 52 for introducing the raw material into the pipe 51. Both ends of the pipe 51 are open in the direction of the raw material supply. The opening at one end covers a portion of the outer periphery of the collecting section 4 (rotating drum 3), and the opening at the other end houses a pulverizer 53 included in the raw material introduction section 52. The raw material introduction section 52 is configured to pulverize sheet-like wood pulp SP using the pulverizer 53 to form pulp fibers serving as the fiber material, and then feed the pulp fibers into the pipe 51. Furthermore, a water-absorbent polymer introduction section 54 is disposed in the pipe 51 to introduce water-absorbent polymer particles into the supply passage 50.

[0108] The conveying mechanism 6 is arranged below the gathering section 4 and includes a vacuum conveyor (not shown) that conveys the absorbent bodies 10 discharged from the gathering section 4 while sucking them onto the conveying surface. An air blowing mechanism (not shown) is arranged inside the fixed cylinder 2 of the gathering section 4. This air blowing mechanism blows air from the inside of the gathering section 4 toward the outer peripheral portion 3S of the rotating cylinder 3, causing the absorbent bodies 10 to be discharged from the gathering recesses 40 in the outer peripheral portion 3S and transferred to the conveying surface of the vacuum conveyor.

[0109] In this embodiment, a sheet 14, also called a core wrap, is pre-placed on the conveying surface of the vacuum conveyor to cover the outer surface of the absorbent body 10. The absorbent body 10 discharged from the collecting unit 4 is transferred to the sheet 14 and conveyed together with the sheet 14. The sheet 14 is bent so as to cover the entire absorbent body 10 during conveyance by the vacuum conveyor.

[0110] The collecting section 4, which is a main part of the fiber depositing device 1, will be described. Figures 2 to 4 As shown, the cylindrical shape is mainly composed of a fixed cylinder 2 formed of a metal rigid body and a rotating cylinder 3 arranged to overlap the outer peripheral portion 2S of the fixed cylinder 2. The collecting portion 4 has a cylinder circumferential direction X1 corresponding to the circumferential direction of the two cylinders 2 and 3, and a cylinder axial direction Y1 corresponding to the direction in which the rotation axis of the rotating cylinder 3 extends.

[0111] The fixed cylinder 2 has a cylindrical shape, with the openings at both axial ends of the cylindrical cylinder 2 being airtightly sealed by sidewalls 21 and seals such as felt (not shown). The interior of the fixed cylinder 2 is circumferentially divided into a plurality of sections (three in this embodiment) by partition walls 22, forming a plurality of spaces A to C corresponding to each section.

[0112] A pressure-reducing mechanism (not shown) is connected to the fixed cylinder 2 to reduce the pressure within the cylinder. This pressure-reducing mechanism includes an exhaust pipe (not shown) connected to the side wall 21 and an exhaust fan (not shown) connected to the exhaust pipe. By operating this pressure-reducing mechanism, any of the multiple spaces A through C within the fixed cylinder 2 can be maintained at a negative pressure. The fixed cylinder 2 is configured so that the negative pressure (suction force) in each of the multiple spaces A through C, separated by the partition wall 22, can be independently adjusted.

[0113] The rotating drum 3 receives power from a motor such as an electric motor and rotates in a direction R1 along the drum circumferential direction X1 around a horizontal rotation axis as a rotation center. However, the fixed drum 2 does not rotate.

[0114] In this embodiment, the rotating drum 3 is as follows Figure 4 As shown, the rotating cylinder 3 comprises a cylindrical metal cylinder body 3A and an outer layer portion 3B composed of a plurality of components 33 to 38 stacked on an outer periphery 3AS of the cylinder body 3A. The cylinder body 3A is the component of the rotating cylinder 3 closest to the stationary cylinder 2 and is positioned opposite the outer periphery 2S of the stationary cylinder 2.

[0115] Unlike the barrel body 3A, which is a continuous annular member extending along the entire length of the barrel circumferential direction X1, the multiple components 33 to 38 constituting the outer layer portion 3B are each divided into multiple sections along the barrel circumferential direction X1. These multiple components 33 to 38 are detachably joined to each other using fasteners such as bolts or adhesives, and are also detachably joined to the outer circumferential portion 3AS of the barrel body 3A.

[0116] The multiple components constituting the outer layer portion 3B are specifically as follows Figure 4 As shown, in order from near to far from the cylinder body 3A, it includes a first suction adjustment plate 33, a first recessed bottom surface forming plate 34, a second suction adjustment plate 35, a second recessed bottom surface forming plate 36, a recessed portion dividing plate 37, and a ring plate 38. Among these multiple components, the first suction adjustment plate 33, the second suction adjustment plate 35, the second recessed bottom surface forming plate 36, and the recessed portion dividing plate 37 have the same length (width) in the cylinder axis direction Y1, and the width of the outer layer portion 3B is the same as the width of each of these four plates 33, 35 to 37.

[0117] The ring plate 38 is arranged at the outermost side of the rotating drum 3. The ring plate 38 is narrower than the four plates 33, 35 to 37. Figure 4 and Figure 5 As shown, a pair of the collecting recessed portion 40 is arranged on both sides in the cylindrical axial direction Y1.

[0118] The recessed portion partitioning plate 37 is a member for forming the groove-shaped recessed portions 13X and 13Y in the absorbent body 10. In the portion of the recessed portion partitioning plate 37 corresponding to the collecting recessed portion 40, a plurality of partitioning members 370 (see FIG. Figure 4 ) are arranged in the same pattern as the groove-shaped recesses 13X and 13Y.

[0119] The first recess bottom forming plate 34 and the second recess bottom forming plate 36 respectively form the bottom of the collecting recess 40 for accumulating the fiber material, and are air-permeable members having a large number of suction holes through which vacuum air can pass.

[0120] The first recessed portion bottom-forming plate 34 is a structure for forming the middle-high portion 11A, which is part of the high-weight portion 11 of the absorbent body 10, and therefore corresponds to the third fiber accumulation region 41C, described later, of the collecting recess 40. The first recessed portion bottom-forming plate 34 has a generally rectangular shape in a plan view and is narrower than the second recessed portion bottom-forming plate 36.

[0121] The second recess bottom-forming plate 36 is used to form the portion other than the mid-high portion 11A of the absorbent body 10. Therefore, it corresponds to the portion of the first fiber accumulation region 41A, the second fiber accumulation region 41B, and the third fiber accumulation region 41C, described later, of the collecting recess 40, other than the portion corresponding to the mid-high portion 11A. In the portion of the second recess bottom-forming plate 36 that overlaps with the first recess bottom-forming plate 34 in a plan view, an opening 360 having the same shape as the plan view shape of the plate 34 is formed corresponding to the plate 34.

[0122] The first suction adjustment plate 33 is constructed from a non-air-permeable member having multiple openings 330, 331, and 332 through which vacuum air can pass. Suction is performed only at the openings 330, 331, and 332, and suction is not performed elsewhere. The opening 332 is located at the center of the portion of the first suction adjustment plate 33 corresponding to the third fiber accumulation area 41C in the barrel axial direction Y1, corresponding to the first recessed portion bottom surface forming plate 34. Openings 330 are located on both sides of the opening 332 in the barrel axial direction Y1. The second suction adjustment plate 35 is constructed from a non-air-permeable member having multiple openings 350 and 351 through which vacuum air can pass. Suction is performed only at the openings 350 and 351, and suction is not performed elsewhere.

[0123] In addition, in the present invention, the structure of the outer layer 3B of the rotating cylinder 3 is not limited to the form shown in the figure, and can be appropriately changed within the scope of the main purpose of the present invention. For example, the outer layer 3B may not include the first suction adjustment plate 33 and the second suction adjustment plate 35. The two suction adjustment plates 33 and 35 are structures that function as suction adjustment bodies for adjusting the flow rate of the vacuum airflow of the gathering recess 40 (hereinafter also referred to as "suction air volume"). By appropriately adjusting the setting of the above-mentioned suction adjustment body, the opening area of ​​all or part of the multiple openings (for example, the openings 330, 331, 332 of the first suction adjustment plate 33 and the openings 350, 351 of the second suction adjustment plate 35) arranged corresponding to the gathering recess 40 can be independently adjusted, thereby independently adjusting the flow rate (suction air volume) of the vacuum airflow passing through the multiple openings. As the above-mentioned suction adjustment body, the suction adjustment body in the fifth to sixth inventions described later can be used.

[0124] The rotating drum 3 has a gathering concave portion 40 on the outer periphery 3S, as shown in FIG. Figure 5As shown, there are multiple fiber accumulation areas 41 corresponding to multiple parts (for example, high gram weight part 11, low gram weight part 12) of the absorbent body 10 (fiber accumulation body) which is the manufacturing target object in the circumferential direction X1. The multiple fiber accumulation areas 41 include a first fiber accumulation area 41A and a second fiber accumulation area 41B which forms a part of the fiber accumulation body with a higher gram weight than the first fiber accumulation area 41A.

[0125] In the present invention, the number of fiber accumulation areas 41 provided in the collecting recess 40 is determined by the number of portions having different grammages in the direction corresponding to the flow direction MD of the fiber accumulation body as the manufacturing target object during manufacturing, and is not particularly limited. For example, the absorbent body 10 described above has at least two portions having different grammages in the longitudinal direction X corresponding to the flow direction MD during manufacturing (the rotation direction R1 of the rotating drum 3), namely, a high grammages portion 11 and a low grammages portion 12. Moreover, since the high grammages portion 11 and the low grammages portion 12 each have a plurality of portions having different grammages in the longitudinal direction X, the number of fiber accumulation areas 41 provided in the collecting recess 40 used to manufacture one absorbent body 10 is at least 2, and may also be 3, 4, or 5 or more.

[0126] In this embodiment, Figure 5 As shown, the collecting recess 40 has, as the fiber accumulation region 41 , a first fiber accumulation region 41A and a second fiber accumulation region 41B, and further has a third fiber accumulation region 41C in the drum circumferential direction X1 .

[0127] The first fiber accumulation area 41A and the second fiber accumulation area 41B are respectively portions of the low-weight portion 12 forming the absorbent body 10 , and have an opening sealing component 30 described later (overlapping with the opening sealing component 30 when viewed from above), and are fiber accumulation areas whose suction is restricted by the opening sealing component 30 .

[0128] In contrast, the third fiber accumulation area 41C is the portion forming the high-weight portion 11 of the absorbent body 10, does not have the opening sealing component 30 described later (does not overlap with the opening sealing component 30 when viewed from above), and is a fiber accumulation area that is not restricted by the opening sealing component 30.

[0129] Hereinafter, areas of the collecting recess 40 that have the opening-closing member 30 (where suction is restricted by the opening-closing member 30), such as the first fiber accumulation area 41A and the second fiber accumulation area 41B, are also referred to as "suction-restricted areas." Furthermore, areas of the collecting recess 40 that do not have the opening-closing member 30 (where suction is not restricted by the opening-closing member 30), such as the third fiber accumulation area 41C, are also referred to as "suction-unrestricted areas."

[0130] In the present invention, there may be three or more suction restriction areas in the collecting recess 40 used to manufacture one fiber-packed body. Typically, there is one suction non-restricted area in the collecting recess 40 used to manufacture one absorbent body 10 (fiber-packed body).

[0131] In this embodiment, the collecting recesses 40 are continuously arranged along the entire length of the rotating drum 3 in the drum circumferential direction X1. First and second fiber accumulation regions 41A, 41B (suction-restricted regions) and third fiber accumulation regions 41C (suction-unrestricted regions), which are adjacent in the drum circumferential direction X1, are alternately arranged along the entire length of the drum 3 in the drum circumferential direction X1. The combination of one third fiber accumulation region 41C and the two fiber accumulation regions 41A and 41B sandwiched therebetween in the drum circumferential direction X1 corresponds to one absorbent body 10, so the absorbent bodies 10 discharged from the collecting recesses 40 to the vacuum conveyor of the conveying mechanism 6 form a continuous absorbent body consisting of a plurality of absorbent bodies 10 arranged continuously in the longitudinal direction X.

[0132] The rotating drum 3 moves around the outer periphery 2S of the fixed drum 2 from the upstream side to the downstream side in the rotation direction R1, in the order of the area corresponding to space A, the area corresponding to space B, and the area corresponding to space C. The "area corresponding to space A" refers to the area overlapping the portion of space A of the fixed drum 2 that would be hypothetically extended outward in the radial direction (orthogonal to the drum axis) of the fixed drum 2. The "area corresponding to space B" and the "area corresponding to space C" can be described by replacing "space A" with "space B" or "space C" in the above description of the "area corresponding to space A."

[0133] In this embodiment, the areas corresponding to spaces A and B constitute the suction area S, where the fiber-accumulating material is accumulated within the collecting recess 40. The opening at one end of the duct 51 of the material supply mechanism 5 covers the suction area S. Within the suction area S, the area corresponding to space A serves as a first suction area S1, where suction from the fixed drum 2 side is partially performed, and the area corresponding to space B serves as a second suction area S2, where suction from the fixed drum 2 side is fully performed. The suction area S comprises the first suction area S1 and the second suction area S2 in the drum circumferential direction X1.

[0134] When the rotating drum 3 is rotated in the rotational direction R1 while the above-mentioned pressure reducing mechanism is activated to maintain negative pressure in spaces A and B of the fixed drum 2, the negative pressure within spaces A and B acts on the air-permeable member (the plates 34 and 36 forming the bottom surface of the air-permeable member) while the collecting recess 40 of the rotating drum 3 passes through the suction area S corresponding to the spaces A and B. This causes air to be drawn through the numerous suction holes in the air-permeable member. This suction through the suction holes generates a vacuum airflow in the supply passage 50 within the duct 51 covering the suction area S, and raw materials such as fiber materials carried by this vacuum airflow are supplied to the suction area S.

[0135] like Figure 4 As shown, the outer periphery 2S of the fixed cylinder 2 is provided with a first suction region corresponding portion 23 corresponding to the first suction region S1, and a second suction region corresponding portion 24 corresponding to the second suction region S2. In this embodiment, they are arranged in this order in the rotational direction R1 of the rotating cylinder 3 (the conveying direction of the collecting recess 40). The first suction region corresponding portion 23 is a portion where suction from the interior of the fixed cylinder 2 is partially performed, and can also be called a selective suction region 23. The second suction region corresponding portion 24 is a portion where suction from the interior of the fixed cylinder 2 is performed over the entire surface, and can also be called a full-surface suction region 24.

[0136] The first suction region corresponding portion 23 is formed of a non-air-permeable member partially provided with openings, and the vacuum airflow can pass through the first suction region corresponding portion 23 in the thickness direction only through the openings.

[0137] In the present embodiment, a suction control body 25 corresponding to the above-mentioned "non-air-permeable component partially provided with an opening portion" is arranged in the portion of the outer peripheral portion 2S of the fixed cylinder 2 corresponding to the portion 23 corresponding to the first suction area. The suction control body 25 has one or more control body openings 26 that pass through the suction control body 25 in the thickness direction. In the illustrated form, the control body openings 26 have a strip shape (straight line shape) extending in the cylinder circumferential direction X1 when viewed from above, and a plurality of them are arranged at predetermined intervals in the cylinder axial direction Y1. The suction control body 25 is non-air-permeable, and therefore, the portion other than the control body openings 26 in the suction control body 25 cannot be sucked. Metal, resin, etc. can be used as the non-air-permeable component constituting the suction control body 25.

[0138] On the other hand, the second suction region corresponding portion 24 does not include any non-air-permeable member, and the entire area corresponding to the collecting recess is open. Therefore, the vacuum airflow can pass through the entire area of ​​the second suction region corresponding portion 24 in the thickness direction.

[0139] In addition, in this specification, "top view" or "top view" of a curved portion, such as the outer periphery of the gathering portion 4 (fixed cylinder 2, rotating cylinder 3), refers to the situation of looking from the outside in the normal direction (direction perpendicular to the cylinder axis direction) of the curved portion (such as the suction control body 25, the gathering recess 40, etc.).

[0140] Corresponding to the first suction region corresponding portion 23 of the outer periphery 2S of the fixed cylinder 2, the portion of the rotating cylinder 3 that faces the outer periphery 2S of the fixed cylinder 2, that is, the outer periphery 3AS of the cylinder body 3A, is as shown. Figure 4 As shown, a non-air-permeable opening sealing member 30 is provided to seal the control body opening 26 of the first suction region corresponding portion 23. The opening sealing member 30 is as shown in FIG. Figure 6 As shown, the collecting recess 40 closes the control body opening 26 during the process of being transported in the first suction area S1.

[0141] The opening sealing member 30 is as follows Figure 6 As shown, the drum includes a first opening-closing member 30A corresponding to (and overlapping with) the first fiber-accumulating region 41A of the collecting recess 40, and a second opening-closing member 30B corresponding to (and overlapping with) the second fiber-accumulating region 41B of the collecting recess 40. The two opening-closing members 30A and 30B correspond to the two fiber-accumulating regions 41A and 41B and are arranged side by side in the drum circumferential direction X1.

[0142] In addition, as described above, in the present invention, the number of fiber accumulation areas 41 possessed by the gathering recess 40 for manufacturing a fiber accumulation body (absorbent body) is not particularly limited, provided that it is multiple, and can be more than three. In this case, more than three opening closing components 30 can be arranged in the circumferential direction X1 of the cylinder.

[0143] The description of the opening blocking member 30 in this specification is applicable to a plurality of opening blocking members included in the fiber accumulation device of the present invention, represented by the first opening blocking member 30A and the second opening blocking member 30B, unless otherwise specified.

[0144] In this embodiment, as described above, the collecting recess 40 has, in addition to the first fiber accumulation area 41A and the second fiber accumulation area 41B (suction restriction area), a third fiber accumulation area 41C (suction non-restriction area) forming the high-weight portion 11 of the absorbent body 10. Figure 4 and Figure 6 As shown, the opening blocking member 30 is not provided in the portion 32 corresponding to the third fiber accumulation region 41C in the outer peripheral portion 3AS of the barrel body 3A. The opening blocking member 30 can be formed of an airtight material such as metal or resin.

[0145] In this embodiment, Figure 4 As shown, on the outer peripheral portion 3AS of the cylinder body 3A, a suction obstruction portion 31 having an opening sealing component 30 is arranged, and a suction non-obstruction portion 32 composed of a through hole that passes through the outer peripheral portion 3AS in the thickness direction and on which no opening sealing component 30 is arranged is alternately arranged in the cylinder circumferential direction X1.

[0146] In each of the plurality of suction obstruction sections 31, the number of opening-sealing components 30 disposed in the cylinder axial direction Y1 is set to be the same as the number of control body openings 26 disposed in the cylinder axial direction Y1 in the first suction region corresponding portion 23 of the outer peripheral portion 2S of the fixed cylinder 2. In the illustrated embodiment, the number of control body openings 26 disposed in the cylinder axial direction Y1 is three, and therefore the number of opening-sealing components 30 disposed in the cylinder axial direction Y1 in the suction obstruction section 31 is also three. In each of the plurality of suction obstruction sections 31, the plurality (three) of opening-sealing components 30 have a strip-like (straight) shape extending in the cylinder circumferential direction X1 when viewed from above and are disposed at intervals in the cylinder axial direction Y1. Furthermore, the opening-sealing components 30 and the control body openings 26 are disposed in the same position in the cylinder axial direction Y1. When the first suction region corresponding portion 23 and the suction obstruction section 31 overlap, the control body opening 26 in the first suction region corresponding portion 23 is sealed by the opening-sealing components 30 of the suction obstruction section 31. The term "sealed" as used herein includes: 1) an arrangement in which the opening sealing member 30 overlaps the control body opening 26, preventing vacuum flow from passing through the control body opening 26, i.e., completely preventing suction at the control body opening 26; and 2) an arrangement in which the opening sealing member 30 overlaps the control body opening 26, allowing suction to proceed to some extent. Both of these arrangements 1) and 2) are identical in that the opening sealing member 30 obstructs suction at the control body opening 26.

[0147] On the other hand, the suction non-obstructing portion 32 does not include an airtight member such as the opening sealing member 30, and the entire area corresponding to the collecting recess is open. Therefore, the vacuum airflow can pass through the entire area of ​​the suction non-obstructing portion 32 in the thickness direction.

[0148] In the fiber accumulation device 1 constructed as described above, the fixed cylinder 2 and the rotating cylinder 3 are arranged. During the transportation of the collecting recess 40 in the first suction area S1, the opening closing component 30 (the first opening closing component 30A, the second opening closing component 30B) overlaps with the control body opening 26 (the opening required for suction from the fixed cylinder 2 side) of the first suction area corresponding portion 23 of the outer peripheral portion 2S of the fixed cylinder 2, thereby reducing the flow rate (suction air volume) of the vacuum airflow in the first fiber accumulation area 41A and the second fiber accumulation area 41B (suction restriction area) of the collecting recess 40.

[0149] Hereinafter, a method of controlling the vacuum airflow in the suction area S (the first suction area S1 and the second suction area S2) will be described.

[0150] In the fiber deposition device 1 as described above, Figure 3 and Figure 6 As shown, the area corresponding to space A is used as the first suction area S1 (the portion of the outer periphery 3S of the rotating cylinder 3 that overlaps with the first suction area corresponding portion 23 of the outer periphery 2S of the fixed cylinder 2 when viewed from above), and the area corresponding to space B is used as the second suction area S2 (the portion of the outer periphery 3S of the rotating cylinder 3 that overlaps with the second suction area corresponding portion 24 of the outer periphery 2S of the fixed cylinder 2 when viewed from above). From the upstream side to the downstream side of the rotation direction R1 of the rotating cylinder 3, that is, the conveying direction (flow direction MD) of the aggregation recess 40, the two suction areas S1 and S2 are arranged in this order.

[0151] Furthermore, in the fiber deposition device of the present invention, the positions of the two suction zones S1 and S2 are not particularly limited, and they may be arranged in the order of the second suction zone S2 and the first suction zone S1 from upstream to downstream in the flow direction MD, contrary to the illustrated embodiment.

[0152] In addition, on the outer peripheral portion 2S of the fixed cylinder 2 serving as the source of the vacuum airflow (suction source), there are arranged a first suction area corresponding portion 23 corresponding to the first suction area S1, which includes a suction control body 25 partially having a control body opening portion 26, and a second suction area corresponding portion 24 corresponding to the second suction area S2, which is open in the entire area corresponding to the gathering recess 40.

[0153] In addition, in the outer peripheral portion 3AS of the cylinder main body 3A, which is the portion of the rotating cylinder 3 opposite to the outer peripheral portion 2S of the fixed cylinder 2, there are arranged a suction obstruction portion 31 including a non-air-permeable opening sealing component 30 (a first opening sealing component 30A and a second opening sealing component 30B) corresponding to the first fiber accumulation area 41A and the second fiber accumulation area 41B (suction restriction area) which are part of the gathering recess 40; and a suction non-obstruction portion 32 consisting of a through hole that passes through the outer peripheral portion 3AS in the thickness direction and does not have an opening sealing component 30, corresponding to the third fiber accumulation area 41C which is another part of the gathering recess 40.

[0154] In the fiber depositing device 1 having such a structure, when the rotary drum 3 rotates in the rotation direction R1, the collecting recess 40 is formed as shown in FIG. Figure 6 As shown, the attraction area S moves in the order of the first attraction area S1 and the second attraction area S2.

[0155] exist Figure 7 FIG. 4 shows the suction state of the first fiber accumulation area 41A (suction restriction area) in the two suction areas S1 and S2. Figure 8 3 shows the suction state of the third fiber accumulation area 41C (suction non-restricted area) in the two suction areas S1 and S2. Figure 7 and Figure 8 The arrows in the figure indicate the vacuum flow. Figure 7 (a) and Figure 8 (a) shows the attraction state in the first attraction area S1, Figure 7 (b) and Figure 8 (b) shows the attraction state in the second attraction area S2.

[0156] In addition, as will be described later, in the first fiber accumulation area 41A and the second fiber accumulation area 41B, the distances between the control body opening 26 of the fixed cylinder 2 and the opening sealing member 30 (30A, 30B) of the rotating cylinder 3 are different. Due to this influence, the flow rate of the vacuum airflow (suction air volume) will be different. However, the control method of the suction air volume implemented by the control body opening 26 and the opening sealing member 30 in the first suction area S1 is substantially the same. Figure 7 The form shown, and based on Figure 7 The following description of the method for controlling the suction air volume of the first fiber accumulation area 41A (first opening closing member 30A) is also applicable to the second fiber accumulation area 41B (second opening closing member 30B).

[0157] When the collecting recess 40 passes through the first suction area S1, in the first fiber accumulation area 41A (suction restriction area), the opening closing member 30 (first opening closing member 30A) of the rotating drum 3 overlaps the control body opening 26 of the first suction area corresponding portion 23 of the fixed drum 2, thereby closing the control body opening 26 (see FIG. Figure 7 (a)), but in the third fiber accumulation area 41C (suction non-restricted area), the control body opening 26 is not closed (refer to Figure 8 (a)). As a result, during the passage of the collecting recess 40 through the first suction area S1, in the first fiber accumulation area 41A, suction from the fixed cylinder 2 side (passage of the vacuum airflow control body opening 26) is not possible or is significantly restricted, so the suction air volume is zero or significantly reduced, hindering the suction of the fiber material. In the third fiber accumulation area 41C, since suction from the fixed cylinder 2 side is substantially unrestricted, the suction air volume is substantially not reduced, and the fiber material is preferentially accumulated compared to the first fiber accumulation area 41A.

[0158] On the other hand, when the collecting recess 40 passes through the second suction area S2, since the second suction area corresponding portion 24 of the fixed cylinder 2 corresponding to the second suction area S2 does not include a non-air-permeable component such as the suction control body 25, the entire area of ​​the portion corresponding to the collecting recess 40 in the second suction area corresponding portion 24 is open. Therefore, in each of the multiple fiber accumulation areas 41 (the first fiber accumulation area 41A, the second fiber accumulation area 41B, and the third fiber accumulation area 41C in this embodiment) divided in the cylinder circumferential direction X1 of the collecting recess 40, the suction from the fixed cylinder 2 side is not substantially restricted, and the suction air volume is not substantially reduced. Therefore, the fiber accumulation material can be accumulated in the entire collecting recess 40 (refer to Figure 7 (b) and Figure 8 (b)).

[0159] In the fiber accumulation device 1, the periodic overlap of the control body opening 26 of the fixed drum 2 and the opening sealing members 30 (30A, 30B) of the rotating drum 3 as the rotating drum 3 rotates is utilized to selectively block the flow of the vacuum airflow only in the first fiber accumulation area 41A and the second fiber accumulation area 41B (suction-restricted area) in the first suction area S1, which is part of the suction area S. This allows fiber material to be accumulated in the third fiber accumulation area 41C (suction-unrestricted area). Consequently, in the first suction area S1, fiber material can be preferentially accumulated in the third fiber accumulation area 41C. For example, in the first suction area S1, fiber material is substantially accumulated only in the third fiber accumulation area 41C, while no fiber material is accumulated in the first and second fiber accumulation areas 41A, 41B. Even if fiber accumulation occurs, the amount of fiber accumulated in the third fiber accumulation area 41C can be minimized compared to that in the third fiber accumulation area 41C. As described above, such selective suction obstruction is not performed in the second suction area S2, and fiber accumulation is performed in the entire gathering recess 40. Therefore, in the gathering recess 40 after passing through the suction area S, a fiber accumulation body of the fiber material is formed that strongly reflects the influence of the fiber accumulation method in the first suction area S1, that is, an absorbent body 10 is formed in which the degree of deviation of the fiber material is large in the conveying direction of the gathering recess 40 along the circumferential direction X1 of the cylinder.

[0160] From the perspective of making the above-mentioned effect of flow control of the vacuum airflow using the control body opening portion 26 and the opening sealing part 30 in the first suction area S1 more reliable, the ratio of the area of ​​the control body opening portion 26 to the area of ​​the corresponding portion 23 of the first suction area is preferably greater than 5%, more preferably greater than 15%, and preferably less than 80%, more preferably less than 60%.

[0161] In this embodiment, at least a portion of the third fiber accumulation region 41C (suction non-restricted region) has a deeper recess than the first fiber accumulation region 41A and the second fiber accumulation region 41B (suction restricted region). Figure 8 and Figure 9As shown, the central portion of the third fiber accumulation region 41C in the barrel axial direction Y1 (the portion forming the mid-height portion 11A of the absorbent core 10) has a deeper recess depth than both the portions of the two fiber accumulation regions 41A and 41B and the third fiber accumulation region 41C outside of the central portion (the ends of the third fiber accumulation region 41C in the barrel axial direction Y1). Specifically, the first recess bottom-forming plate 34, which forms the bottom of the central portion of the third fiber accumulation region 41C in the barrel axial direction Y1, is located closer to the fixed tube 2 than the second recess bottom-forming plate 36, which forms the bottom of the two fiber accumulation regions 41A and 41B and the portions of the third fiber accumulation region 41C outside of the central portion. The "recess depth" mentioned above refers to the distance between the outer surface of the member located on either side of the collecting recess 40 in the barrel axial direction Y1 and the bottom of the collecting recess 40. In this embodiment, the member is the ring plate 38. In this manner, the third fiber accumulation region 41C (suction non-restricted region) has a structure in which at least a portion of the third fiber accumulation region 41C has a deeper recess than the two fiber accumulation regions 41A and 41B (suction restricted regions). Figure 1 This is useful in increasing the degree of bias in the fiber material in the absorbent body, as in the absorbent body 10 shown. However, the first recess bottom forming plate 34 and the second recess bottom forming plate 36 may have the same depth.

[0162] If the above-mentioned closing of the control body opening 26 (the opening required for suction from the fixed cylinder 2 side) based on the opening closing component 30 (30A, 30B) is designed in a manner that the opening closing component 30 is in contact with the corresponding part 23 of the first suction area (the suction control body 25), these components will wear out each time they come into contact, and there is a concern that adverse conditions such as failure will occur in a relatively short period of time.

[0163] In view of this, in the fiber deposition device 1, Figure 7 As shown in (a), in the first suction area S1, in a state where the first opening portion closing component 30A of the rotating cylinder 3 overlaps the control body opening portion 26 of the first suction area corresponding portion 23 of the fixed cylinder 2, the first suction area corresponding portion 23 (specifically, the suction control body 25 forming the first suction area corresponding portion 23) is spaced apart from the first opening portion closing component 30A. Figure 7 In the embodiment shown in (a), there is a gap G0 ( Figure 7 The part surrounded by 0 in (a) is separated by a gap.

[0164] Similarly, in a state where the second opening closing member 30B of the rotating drum 3 overlaps the control body opening 26 , the first suction region corresponding portion 23 (suction control body 25 ) is also spaced apart from the second opening closing member 30B.

[0165] By configuring the fiber accumulation device 1 in this manner, the above-mentioned concerns can be eliminated, and an absorbent body (fiber accumulation body) in which the degree of unevenness of the fiber material in the direction corresponding to the flow direction MD during production can be stably produced.

[0166] In the fiber accumulation device of the present invention, in order to solve the problem of obtaining an absorbent body in which the fiber material has a large degree of bias in the direction corresponding to the flow direction MD during manufacturing, the suction area S is divided into a first suction area S1 and a second suction area S2 in the conveying direction of the accumulation recess 40 as described above. In the first suction area S1, which is one of the first suction areas, the control body opening 26 and the opening sealing component 30 are used to reduce the flow rate of the vacuum airflow in the first fiber accumulation area 41A and the second fiber accumulation area 41B (suction restriction area) (structure A).

[0167] In order to solve the above-mentioned problems, the fiber deposition device of the present invention is characterized by further comprising the following structure B1 or B2 in addition to the above-mentioned structure A.

[0168] Structure B1: In the first suction area S1, the spacing distance between the first suction area corresponding part 23 and the opening sealing part 30 when the opening sealing part 30 overlaps with the opening part 26 of the control body is different from each other among the multiple opening sealing parts 30 (specifically, for example, the first opening sealing part 30A and the second opening sealing part 30B) arranged in the cylinder circumferential direction X1.

[0169] More specifically, in the above-mentioned structure B1, the above-mentioned spacing distances of the multiple opening sealing components 30 arranged in the cylinder circumferential direction X1 are different from each other, and the multiple opening sealing components 30 are arranged in a manner such that the spacing distance gradually changes from one side to the other side of the cylinder circumferential direction X1.

[0170] Structure B2: Multiple opening sealing components 30 (specifically, for example, the first opening sealing component 30A and the second opening sealing component 30B) are arranged in the cylinder circumferential direction X1, and the lengths of the opening sealing components 30 in the conveying orthogonal direction CD (width, length in the cylinder axis direction Y1) are different.

[0171] More specifically, in the above-mentioned structure B2, a plurality of opening closing components 30 are arranged in the circumferential direction X1 of the cylinder, and the widths of the opening closing components 30 are different from each other. The plurality of opening closing components 30 are arranged in such a manner that the width of the opening closing components 30 gradually changes from one side to the other side of the circumferential direction X1 of the cylinder.

[0172] The above structure B1 is described as follows: Figure 10As shown, in the first suction area S1, when the first opening portion closing component 30A corresponding to the first fiber accumulation area 41A of the gathering recess 40 overlaps with the control body opening portion 26 of the first suction area corresponding portion 23, the first suction area corresponding portion 23 (suction control body 25) is separated from the first opening portion closing component 30A by a specified spacing distance G1.

[0173] In addition, if Figure 11 As shown, in the first suction area S1, when the second opening portion closing component 30B corresponding to the second fiber accumulation area 41B of the gathering recess 40 overlaps with the control body opening portion 26 of the first suction area corresponding portion 23, the first suction area corresponding portion 23 (suction control body 25) is separated from the second opening portion closing component 30B by a specified spacing distance G2.

[0174] The relationship "gap distance G1 < gap distance G2" holds true. That is, the second opening-closing member 30B corresponding to the second fiber accumulation area 41B is spaced farther from the first suction area-corresponding portion 23 when overlapping the control body opening 26 than the first opening-closing member 30A corresponding to the first fiber accumulation area 41A.

[0175] exist Figure 12 : shows a cross section along the drum circumferential direction X1 in a state where a portion of the collecting recess 40 corresponding to one product unit (one absorbent body 10) is located in the first suction area S1 in the fiber accumulation device having the above-mentioned structure B1. Figure 12 The cross section of the first fiber accumulation area 41A along the barrel axis direction Y1 is Figure 10 , Figure 12 The cross section of the second fiber accumulation area 41B along the barrel axis direction Y1 is Figure 11 As described above, the third fiber accumulation area 41C is a suction non-restriction area that does not include the opening closing member 30 .

[0176] In the fiber accumulation device having the aforementioned structure B1, the longer the distance between the first suction region corresponding portion 23 and the opening-closing member 30 when the opening-closing member 30 overlaps the control body opening 26 in the first suction region S1, the weaker the degree of closure of the control body opening 26 by the opening-closing member 30, allowing the vacuumed airflow to pass more easily through the control body opening 26, thereby increasing the suction volume and enhancing the attraction of the fiber material. Thus, in the fiber accumulation device having the aforementioned structure B1, the relationship of gap distance G1 < gap distance G2 holds, and the relationship of first fiber accumulation region 41A < second fiber accumulation region 41B holds with respect to the basis weight of the fiber material attracted and accumulated in the collecting recess 40. This, in conjunction with the aforementioned effects of the aforementioned structure A, can increase the degree of bias of the fiber material in the flow direction MD during production.

[0177] From the viewpoint of more reliably exhibiting the above-mentioned effects, the difference between the gap distance G1 and the gap distance G2, obtained by subtracting the gap distance G1 from the gap distance G2, is preferably 0.1 mm to 2.9 mm, and more preferably 0.1 mm to 1.9 mm.

[0178] When the gap distances G1 and G2 are too short, in addition to the concern about wear caused by contact between the opening-sealing members 30 (30A, 30B) and the first suction region-corresponding portion 23 (suction control body 25), it is also difficult to control the degree of fiber material bias in the flow direction MD by adjusting the gap distances G1 and G2, as it is virtually impossible for the vacuum airflow to pass through the control body opening 26. Furthermore, when the gap distances G1 and G2 are too long, the intentional reduction in the suction air volume in the suction-restricted region (fiber accumulation regions 41A, 41B) in the first suction region S1 (due to the effect of the aforementioned structure A) becomes insufficient, and there is a concern that controlling the degree of fiber material bias in the flow direction MD itself becomes difficult.

[0179] In consideration of the above, the spacing distances G1 and G2 are each preferably larger than 0 mm and smaller than 3 mm, and more preferably larger than 0 mm and smaller than 2 mm.

[0180] In the present invention, as described above, the number of fiber accumulation areas 41 provided in the collecting recess 40 is not particularly limited, provided that the number is multiple. The number of parts having different gram weights in the direction corresponding to the flow direction MD during manufacturing (the longitudinal direction X in the absorbent body 10) of the fiber accumulation body as the manufacturing target may be three or more. In this case, three or more opening-closing members 30 may be arranged in the drum circumferential direction X1. That is, in the present invention, the embodiment includes a first opening-closing member, a second opening-closing member, a third opening-closing member, and the nth opening-closing member from the upstream side to the downstream side in the flow direction MD during manufacturing (the rotation direction R1 of the rotating drum 3, the conveying direction of the collecting recess 40). (hereinafter also referred to as "specific embodiment A").

[0181] In the fiber deposition device having the above-described structure B1 in the above-described specific embodiment A, n (n is a natural number greater than or equal to 3) opening-closing members 30 arranged in the drum circumferential direction X1 are spaced apart from the first suction region-corresponding portion 23 by a predetermined spacing distance G, while overlapping the control body opening 26 in the first suction region-corresponding portion 23 in the first suction region S1. The spacing distances G of the n opening-closing members 30 arranged in the drum circumferential direction X1 are mutually different, and the plurality of opening-closing members 30 are arranged so that the spacing distance G gradually changes from one side of the drum circumferential direction X1 to the other. For example, when the first opening-closing member, the second opening-closing member, the third opening-closing member, and so on, to the nth opening-closing member are arranged from upstream to downstream in the flow direction MD along the drum circumferential direction X1, the relationship of spacing distance G1 of the first opening-closing member < spacing distance G2 of the second opening-closing member < spacing distance G3 of the third opening-closing member < ... < spacing distance Gn of the nth opening-closing member holds.

[0182] In a fiber accumulation device where this size relationship is established, in the first suction area S1, within the plurality of (a natural number greater than or equal to n) fiber accumulation areas 41 (suction restriction areas) corresponding to n opening-closing members 30, the longer the spacing distance G, the greater the suction air volume. Therefore, with respect to the basis weight of the fiber material attracted and accumulated in the collecting recess 40, the size relationship of "fiber accumulation areas 41 corresponding to opening-closing members 30 with a relatively short spacing distance G < fiber accumulation areas 41 corresponding to opening-closing members 30 with a relatively long spacing distance G" is established. This, in conjunction with the effects of the aforementioned structure A, can increase the degree of bias in the flow direction MD during production. The spacing distance Gn herein can be set within the same range as the spacing distances G1 and G2 described above.

[0183] From the perspective of making the effects of the above-mentioned structure B1 more reliable, refer to Figure 10 Relative to the width W1 of the first opening portion closing part 30A, the width W26 of the control body opening portion 26 of the first suction area corresponding portion 23 overlapping with the first opening portion closing part 30A is preferably greater than 10%, more preferably greater than 20%, and preferably less than 90%, more preferably less than 80%.

[0184] In addition, refer to Figure 11 Relative to the width W2 of the second opening portion closing part 30B, the width W26 of the control body opening portion 26 of the first suction area corresponding part 23 overlapping with the second opening portion closing part 30B in the first suction area corresponding part 23 is preferably greater than 10%, more preferably greater than 20%, and preferably less than 90%, more preferably less than 80%.

[0185] That is, the width (length in the conveying orthogonal direction CD) of the opening-closing member 30 is preferably slightly longer than the width W26 of the control body opening 26 overlapping with the opening-closing member 30 in the first suction region corresponding portion 23. In the above-mentioned specific embodiment A, when three or more opening-closing members 30 are arranged in the cylinder circumferential direction X1, in the case of the above-mentioned structure B1, the ratio of the width of each of the plurality of opening-closing members 30 to the width W26 of the corresponding control body opening 26 is preferably also within the above-mentioned range.

[0186] Furthermore, in the fiber deposition device having the above-described structure B1, the width W1 of the first opening closing member 30A and the width W2 of the second opening closing member 30B may be the same or different. Typically, the widths W1 and W2 are the same.

[0187] The above structure B2 is described as follows. Figure 10 As shown, the width W1 of the first opening portion closing component 30A is longer than the width W26 of the control body opening portion 26 of the first suction area corresponding portion 23. When the first opening portion closing component 30A overlaps with the control body opening portion 26 in the first suction area S1, the first opening portion closing component 30A extends to the entire length of the control body opening portion 26 in the conveying orthogonal direction CD (cylinder axis direction Y1).

[0188] In addition, if Figure 13As shown, the width W2 of the second opening-sealing member 30B1 is shorter than the width W26 of the control body opening 26 in the first suction region corresponding portion 23. When the second opening-sealing member 30B1 overlaps the control body opening 26 in the first suction region S1, portions of the control body opening 26 in the conveying direction CD (cylinder axis direction Y1) are not covered by the second opening-sealing member 30B1, typically at both ends of the control body opening 26 in the conveying direction CD. The second opening-sealing member 30B1 is identical to the second opening-sealing member 30B described above, except for the width W2.

[0189] exist Figure 14 : shows a cross section along the drum circumferential direction X1 in a state where a portion of the collecting recess 40 corresponding to one product unit (one absorbent body 10) is located in the first suction area S1 in the fiber accumulation device having the above-mentioned structure B2. Figure 14 The cross section of the first fiber accumulation area 41A along the barrel axis direction Y1 is Figure 10 , Figure 14 The cross section of the second fiber accumulation area 41B along the barrel axis direction Y1 is Figure 13 As described above, the third fiber accumulation area 41C is a suction non-restriction area that does not include the opening closing member 30 .

[0190] Furthermore, in the fiber accumulation device having the above-described structure B2, the width W26 of the control body opening 26 is typically constant regardless of the width of the opening closing member 30 overlapping the control body opening 26.

[0191] In the fiber accumulation device having the aforementioned structure B2, in the first suction zone S1, the first opening-closing member 30A entirely covers the rotating drum 3 side of the control body opening 26. In contrast, the second opening-closing member 30B does not partially cover the rotating drum 3 side of the control body opening 26. Therefore, in the first fiber accumulation region 41A corresponding to the first opening-closing member 30A and the second fiber accumulation region 41B corresponding to the second opening-closing member 30B, the relationship of suction air volume is such that the first fiber accumulation region 41A is less than the second fiber accumulation region 41B. Thus, according to the fiber accumulation device having the aforementioned structure B2, the relationship of the first fiber accumulation region 41A is less than the second fiber accumulation region 41B in terms of the basis weight of the fiber material attracted and accumulated in the collecting recess 40. This, in conjunction with the aforementioned effects of the aforementioned structure A, can increase the degree of bias in the flow direction MD of the fiber material during production.

[0192] The technical concept of the above-mentioned structure B2 is the same as that of the above-mentioned structure B1 and can also be applied to the above-mentioned specific embodiment A. Specifically, in the fiber accumulation device having the above-mentioned structure B2 in the above-mentioned specific embodiment A, n (n is a natural number greater than or equal to 3) opening-closing members 30 are arranged in the drum circumferential direction X1. The widths W (lengths in the conveying direction CD) of the opening-closing members 30 differ from one another, and the plurality of opening-closing members 30 are arranged so that the widths W gradually change from one side of the drum circumferential direction to the other. For example, when the first opening-closing member, the second opening-closing member, the third opening-closing member, and so on to the nth opening-closing member are arranged from upstream to downstream in the flow direction MD along the drum circumferential direction X1, the following magnitude relationship holds: width W1 of the first opening-closing member < width W2 of the second opening-closing member < width W3 of the third opening-closing member < ... < width Wn of the nth opening-closing member.

[0193] In the fiber accumulation device in which such a size relationship is established, in the first suction area S1, in the plurality of (a natural number greater than or equal to n) fiber accumulation areas 41 (suction restriction areas) corresponding to the n opening closing members 30, the width W26 of the control body opening 26 (see FIG. 1 ) which overlaps with the opening closing members 30 in the first suction area S1 is set. Figure 13 etc.) is a premise that a certain value is used in the fiber accumulation device. The shorter the width W, the more air is attracted. Therefore, regarding the gram weight of the fiber material attracted to the gathering recess 40 and accumulated, the size relationship of "the fiber accumulation area 41 corresponding to the opening closing component 30 with a relatively long width W < the fiber accumulation area 41 corresponding to the opening closing component 30 with a relatively short width W" is established. This is complementary to the effect produced by the above-mentioned structure A, and can increase the degree of bias of the fiber material in the flow direction MD during manufacturing.

[0194] Regarding the large opening closing component 30 such as the first opening closing component 30A, which has a longer width (length in the conveying orthogonal direction CD) than the control body opening 26 that overlaps with each other in the first suction area S1, on the premise that the width of the large opening closing component 30 is longer than the width of the control body opening 26, the width of the large opening closing component 30 relative to the width of the control body opening 26 is preferably 110% or more, more preferably 125% or more, and preferably less than 1000%, more preferably less than 500%.

[0195] In addition, regarding the small-width opening closing component 30 such as the second opening closing component 30B1, which has a shorter width (length in the conveying orthogonal direction CD) than the control body opening 26 that overlaps in the first suction area S1, the width of the small-width opening closing component 30 is preferably greater than 50% and less than 100% relative to the width of the control body opening 26, and more preferably greater than 60% and less than 100%.

[0196] In the fiber deposition device having the above-mentioned structure B2, from the perspective of solving the above-mentioned wear problem caused by the contact between the opening portion closing component 30 (30A, 30B) and the first suction area corresponding part 23 (suction control body 25), in the first suction area S1, when the first opening portion closing component 30A overlaps with the control body opening 26 of the first suction area corresponding part 23, the first suction area corresponding part 23 is preferably separated from the first opening portion closing component 30A by a prescribed spacing distance, and the spacing distance is preferably greater than 0 mm and less than 3 mm, and more preferably greater than 0 mm and less than 2 mm.

[0197] From the same point of view, when the second opening portion closing part 30B overlaps with the control body opening part 26 of the first suction area corresponding part 23 in the first suction area S1, it is preferred that the first suction area corresponding part 23 and the second opening portion closing part 30B are separated by a specified spacing distance, and the spacing distance is preferably greater than 0 mm and less than 3 mm, and more preferably greater than 0 mm and less than 2 mm.

[0198] In the above-mentioned specific form A, when more than three opening closing components 30 are arranged in the cylinder circumferential direction X1, in the case of having the above-mentioned structure B2, the spacing distance between each of the multiple opening closing components 30 and the corresponding part 23 of the first suction area is preferably also within the above-mentioned range.

[0199] In the fiber deposition device 1, as described above, Figure 4 As shown, when the rotating cylinder 3 includes a cylinder body 3A disposed opposite to the outer peripheral portion 2S of the fixed cylinder 2 and an outer layer portion 3B disposed farther from the fixed cylinder 2 than the cylinder body 3A, as shown in FIG. Figure 15 As shown, the opening sealing members 30 (first opening sealing member 30A, second opening sealing member 30B) are arranged in the cylinder body 3A at positions spaced a predetermined distance from the outer layer portion 3B toward the cylinder body 3A.

[0200] The outer layer portion 3B includes a component that forms the bottom surface of the gathering recess 40 (in the fiber accumulation device 1, the first recess bottom surface forming plate 34 and the second recess bottom surface forming plate 36). Therefore, as described above, the structure in which the opening closing component 30 is separated from the outer layer portion 3B becomes a structure in which the opening closing component 30 is also separated from the bottom surface of the gathering recess 40.

[0201] exist Figure 15 In the illustrated embodiment, the opening closing member 30 is disposed at a distance L from the outer layer portion 3B toward the fixed cylinder 2 , and is disposed near the outer peripheral portion 2S of the fixed cylinder 2 having the first suction region corresponding portion 23 and the second suction region corresponding portion 24 .

[0202] When the position of the opening sealing component 30 in the radial direction of the rotating cylinder 3 becomes such a position, the flow of air sucked through the outer layer 3B can be rectified in the cylinder axis direction Y1, thereby making the turbulence of the vacuum airflow and the deviation of the air volume in the cylinder axis direction Y1 uniform, and the improvement of the formability of the fiber accumulation body (absorbent body) can be expected.

[0203] In the above-mentioned specific embodiment A, when three or more opening closing members 30 are arranged in the drum circumferential direction X1, the radial position of each of the opening closing members 30 on the rotating drum 3 can be set in the same manner as described above.

[0204] Next, the manufacturing method of the absorbent body of the present invention will be described using the manufacturing method of the absorbent body 10 (an absorbent body having multiple portions with different basis weights in one direction) using the aforementioned fiber accumulation device 1 as an example. The description of the aforementioned fiber accumulation device 1 applies appropriately to any points not specifically described in this manufacturing method.

[0205] The method for manufacturing an absorbent body using the fiber accumulation device 1 includes a fiber accumulation step. Figure 2 and Figure 3 As shown, the above-mentioned fiber accumulation process is a process of supplying fiber material in a scattered state to the outer periphery 3S of the rotating cylinder 3 while rotating the rotating cylinder 3 around the outer periphery 2S of the fixed cylinder 2, so that the fibers are accumulated in the accumulation recess 40 in the specified suction area S in the cylinder circumferential direction X1.

[0206] In the above-mentioned specific embodiment A, the fiber accumulation device 1 further includes the above-mentioned structure B1 in addition to the above-mentioned structure A (a structure in which the suction area S is divided into a first suction area S1 and a second suction area S2 in the conveying direction of the collecting recess 40, and in one of the first suction areas S1, the control body opening 26 and the opening sealing member 30 are used to reduce the flow rate of the vacuum airflow in the plurality of fiber accumulation areas 41 (suction restriction areas)).

[0207] The plurality of opening sealing members 30 arranged in the cylinder circumferential direction X1 are spaced apart from the first suction area corresponding portion 23 by a predetermined spacing distance G while overlapping the control body opening 26 of the first suction area corresponding portion 23 in the first suction area S1, and

[0208] The plurality of opening sealing members 30 arranged in the cylinder circumferential direction X1 have different spacing distances G from each other, and the plurality of opening sealing members 30 are arranged in such a manner that the spacing distance G gradually changes from one side to the other side in the cylinder circumferential direction X1.

[0209] In the fiber accumulation step, in the first suction area S1 , in the plurality of fiber accumulation areas 41 (the suction restriction areas) corresponding to the plurality of opening closing members 30 , the flow rate of the vacuum airflow increases as the spacing distance G increases.

[0210] That is, regarding the gram weight of the fiber material attracted to the gathering recess 40 and accumulated, the size relationship of "the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively short spacing distance G < the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively long spacing distance G" holds.

[0211] For example, in the above-mentioned fiber accumulation device 1, the above-mentioned suction restriction area includes a first fiber accumulation area 41A and a second fiber accumulation area 41B, and regarding the spacing distance G related to the two fiber accumulation areas 41A and 41B, as described above, the size relationship of spacing distance G1 < spacing distance G2 holds true, so regarding the flow rate of the vacuum airflow, the size relationship of the first fiber accumulation area 41A < the second fiber accumulation area 41B holds true, and thus the same size relationship also holds true regarding the gram weight of the fiber material (fiber accumulation amount).

[0212] Furthermore, in the fiber accumulation device 1 described above, when the third fiber accumulation area 41C is included as the suction non-restricted area, the third fiber accumulation area 41C does not have the opening-closing member 30 and is not subject to suction restriction thereby. Therefore, with respect to the flow rate of the vacuumed airflow, the relationship of magnitude holds: first fiber accumulation area 41A (suction restricted area) < second fiber accumulation area 41B (suction restricted area) < third fiber accumulation area 41C (suction non-restricted area). Consequently, in the fiber accumulation process using the fiber accumulation device 1 described above, in the first suction area S1, the fiber material having the most fiber accumulation in the third fiber accumulation area 41C is hereinafter referred to as the second fiber accumulation area 41B, followed by the first fiber accumulation area 41A, in descending order of fiber accumulation.

[0213] As described above, according to the absorbent manufacturing method of the present invention using the fiber accumulation device having the above-described structures A and B1, an absorbent can be obtained in which the fiber material has a large degree of bias in the direction corresponding to the flow direction during manufacturing. Furthermore, since the opening closing member 30 of the fiber accumulation device is configured so that it overlaps with the control body opening 26 of the first suction area corresponding portion 23 in the first suction area S1, it is separated from the first suction area corresponding portion 23 by a predetermined spacing distance G. Therefore, the problem of wear caused by contact between the opening closing member 30 and the first suction area corresponding portion 23 is less likely to occur, and the absorbent 10 can be stably manufactured as a high-quality fiber accumulation body.

[0214] However, the above-mentioned structure B1 is a structure that controls the degree of bias of the fiber material in the flow direction MD during manufacturing along the cylinder circumferential direction X1 by adjusting the spacing distance G between the first suction area S1 and the corresponding part 23 of the first suction area through multiple opening sealing parts 30 arranged in the cylinder circumferential direction X1. By applying it in the cylinder axial direction Y1, the degree of bias of the fiber material in the conveying orthogonal direction CD can also be controlled.

[0215] Specifically, in the above-mentioned fiber accumulation device 1, a plurality of (3) control body openings 26 are arranged in the cylinder axial direction Y1 in the first suction area corresponding portion 23, and a plurality of (3) opening closing members 30 are arranged in the cylinder axial direction Y1 in the portion of the rotating cylinder 3 opposite to the outer peripheral portion 2S of the fixed cylinder 2 (the outer peripheral portion 3AS of the cylinder main body 3A), and the accumulation recess 40 is constructed so that the plurality of opening closing members 30 arranged in the cylinder axial direction Y1 overlap with the plurality of control body openings 26 arranged in the cylinder axial direction Y1 during the conveying process in the first suction area S1, and the plurality of opening closing members 30 arranged in the cylinder axial direction Y1 are separated from the first suction area corresponding portion 23 by a predetermined spacing distance G in a state where they overlap with the control body openings 26 of the first suction area corresponding portion 23 in the first suction area S1 (refer to Figure 4 、 Figure 6 、 Figure 10 and Figure 11 The fiber deposition device 1 having such a structure adopts the following structure B1a.

[0216] Structure B1a: The spacing distances G among the plurality of opening closing members 30 arranged in the cylindrical axial direction Y1 are different from each other, and the plurality of opening closing members 30 are arranged so that the spacing distance G gradually changes from one side to the other side in the cylindrical axial direction Y1.

[0217] As a specific example of the above-described structure B1a, a configuration can be exemplified in which a plurality of opening-closing members 30 are arranged such that the spacing G therebetween gradually increases from the outside to the inside in the barrel axial direction Y1. According to this specific example, with respect to the flow rate of the vacuumed airflow, the relationship of the fiber accumulation region 41 located outside the barrel axial direction Y1 < the fiber accumulation region 41 located inside the barrel axial direction Y1 holds true. Consequently, the same relationship holds true with respect to the basis weight (accumulated fiber amount) of the fiber material.

[0218] As described above, according to the manufacturing method of the absorbent body of the present invention using the fiber accumulation device having the above-mentioned structure A, the above-mentioned structure B1 and the above-mentioned structure B1a, in the above-mentioned fiber accumulation process, in the first suction area S1, in both the cylinder circumferential direction X1 and the cylinder axial direction Y1, with respect to the gram weight of the fiber material attracted to the accumulation recess 40 and accumulated, the size relationship of "the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively short spacing distance G < the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively long spacing distance G" holds, and therefore the degree of bias of the fiber material can be controlled to a higher degree.

[0219] Furthermore, in the above-mentioned specific embodiment A, the fiber accumulation device 1 further includes the above-mentioned structure B2 in addition to the above-mentioned structure A (a structure in which the suction area S is divided into a first suction area S1 and a second suction area S2 in the conveying direction of the collecting recess 40, and in one of the first suction areas S1, the flow rate of the vacuum airflow in the plurality of fiber accumulation areas 41 (suction restriction areas) is reduced using the control body opening 26 and the opening sealing member 30).

[0220] The plurality of opening sealing members 30 arranged in the cylinder circumferential direction X1 have different widths W (lengths in the conveying orthogonal direction CD) from one another. The plurality of opening sealing members 30 are arranged so that the widths W of the opening sealing members 30 gradually change from one side to the other side in the cylinder circumferential direction X1.

[0221] In the fiber accumulation step, in the first suction area S1, in the plurality of fiber accumulation areas 41 (the suction restriction areas) corresponding to the plurality of opening closing members 30, the shorter the width W of the opening closing member 30, the greater the flow rate of the vacuum airflow.

[0222] That is, regarding the gram weight of the fiber material attracted to the collecting recess 40 and accumulated, the size relationship of "the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively long width W < the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively short width W" holds.

[0223] For example, in the above-mentioned fiber accumulation device 1, the above-mentioned suction restriction area includes a first fiber accumulation area 41A and a second fiber accumulation area 41B, and the above-mentioned suction non-restriction area includes a third fiber accumulation area 41C. In addition, the width W of the opening sealing component 30 related to the two fiber accumulation areas 41A and 41B is as described above. Therefore, with respect to the flow rate of the vacuum airflow, the size relationship of the first fiber accumulation area 41A < the second fiber accumulation area 41B < the third fiber accumulation area 41C holds, and the same size relationship also holds with respect to the gram weight of the fiber material (fiber accumulation amount).

[0224] As described above, according to the absorbent manufacturing method of the present invention using the fiber accumulation device having the above-mentioned configurations A and B2, an absorbent can be obtained in which the fiber material has a large degree of bias in the direction corresponding to the flow direction during manufacturing.

[0225] The above-mentioned structure B2 is a structure that controls the degree of bias of the fiber material in the flow direction MD during manufacturing along the cylinder circumferential direction X1 by adjusting the width W of the opening closing components 30 among the multiple opening closing components 30 arranged in the cylinder circumferential direction X1. By applying it in the cylinder axial direction Y1, the degree of bias of the fiber material in the conveying orthogonal direction CD can also be controlled.

[0226] Specifically, in the above-mentioned fiber accumulation device 1, a plurality of (3) control body openings 26 are arranged in the cylinder axial direction Y1 in the first suction area corresponding portion 23, and a plurality of (3) opening closing members 30 are arranged in the cylinder axial direction Y1 in the portion of the rotating cylinder 3 that is opposite to the outer peripheral portion 2S of the fixed cylinder 2 (the outer peripheral portion 3AS of the cylinder main body 3A). During the conveyance process of the collecting recess 40 in the first suction area S1, the plurality of opening closing members 30 arranged in the cylinder axial direction Y1 are overlapped with the plurality of control body openings 26 arranged in the cylinder axial direction Y1 (see Figure 4 、 Figure 6 、 Figure 10 and Figure 11 In the fiber deposition device 1 having such a structure, the following structure B2a is adopted.

[0227] Structure B2a: Among the above-mentioned multiple opening closing components 30 arranged in the cylinder axis direction Y1, the widths W (lengths in the conveying orthogonal direction CD) of the opening closing components 30 are different from each other, and the multiple opening closing components 30 are arranged in a manner such that the width W of the opening closing components 30 gradually changes from one side to the other side in the cylinder axis direction Y1.

[0228] As a specific example of the above-described structure B2a, a configuration can be exemplified in which a plurality of opening-closing members 30 are arranged such that the width W of the opening-closing members 30 gradually decreases from the outside toward the inside in the cylinder axial direction Y1. According to this specific example, with respect to the flow rate of the vacuumed airflow, the relationship of fiber accumulation region 41 located outside in the cylinder axial direction Y1 < fiber accumulation region 41 located inside in the cylinder axial direction Y1 holds true. Consequently, the same relationship holds true with respect to the basis weight (accumulated fiber amount) of the fiber material.

[0229] As described above, according to the manufacturing method of the absorbent body of the present invention using the fiber accumulation device having the above-mentioned structure A, the above-mentioned structure B2 and the above-mentioned structure B2a, in the above-mentioned fiber accumulation process, in the first suction area S1, in both the cylinder circumferential direction X1 and the cylinder axial direction Y1, with respect to the gram weight of the fiber material attracted to the accumulation recess 40 and accumulated, the size relationship of "the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively long width W < the fiber accumulation area 41 corresponding to the opening sealing component 30 with a relatively short width W" holds, and therefore the degree of bias of the fiber material can be controlled to a higher degree.

[0230] As mentioned above, the present invention (the first to fourth inventions) has been described based on preferred embodiments thereof. However, the present invention is not limited to the above embodiments at all and can be modified appropriately without departing from the gist of the present invention.

[0231] Regarding the embodiments of the present invention (first to fourth inventions) described above, the following is further disclosed.

[0232] <1A>

[0233] A fiber accumulation device comprises a fixed drum and a rotating drum, wherein the rotating drum is arranged to be able to rotate around the outer periphery of the fixed drum, and the outer periphery of the rotating drum is provided with a gathering recess for accumulating fiber materials, and the rotating drum is rotated to transport the gathering recess in a conveying direction along the circumferential direction of the drum, while the fiber material conveyed by the air flow generated by suction from the side of the fixed drum is deposited on the bottom surface of the gathering recess in a prescribed suction area in the circumferential direction of the drum, thereby manufacturing a fiber accumulation body having a plurality of parts with different gram weights in the conveying direction. In the fiber accumulation device,

[0234] The gathering recess has a plurality of fiber accumulation areas corresponding to a plurality of parts of the fiber accumulation body having different gram weights in the circumferential direction of the tube, the plurality of fiber accumulation areas including a first fiber accumulation area and a second fiber accumulation area forming a part with a higher gram weight than the first fiber accumulation area.

[0235] The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface.

[0236] A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder.

[0237] The first suction region corresponding portion is formed by a non-air-permeable member having an opening (control body opening 26) provided locally therein, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening.

[0238] The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction.

[0239] A first non-air-permeable opening sealing member corresponding to the first fiber accumulation area and a second non-air-permeable opening sealing member corresponding to the second fiber accumulation area are arranged on the outer circumference of the rotating cylinder facing the fixed cylinder.

[0240] During the conveying process of the collecting recess in the first suction area, the first opening closing member and the second opening closing member overlap the opening corresponding to the first suction area, thereby reducing the flow rate of the air flow in the first fiber accumulation area and the second fiber accumulation area.

[0241] In the first suction region, the first opening closing member overlaps the opening of the first suction region corresponding portion, and the first suction region corresponding portion is spaced apart from the first opening closing member by a predetermined spacing distance G1.

[0242] In the first suction region, when the second opening closing member overlaps the opening of the first suction region corresponding portion, the first suction region corresponding portion is separated from the second opening closing member by a predetermined spacing distance G2, and

[0243] The relationship of the spacing distance G1 < the spacing distance G2 holds true.

[0244] <2A>

[0245] The fiber deposition device as described in <1A> above, wherein

[0246] The spacing distance G1 and the spacing distance G2 are respectively greater than 0 mm and less than 3 mm.

[0247] <3A>

[0248] The fiber deposition device as described in <1A> or <2A>, wherein

[0249] With respect to the length of the first opening closing member in the conveying direction orthogonal to the conveying direction, the length of the opening portion in the conveying direction orthogonal to the conveying direction of the portion corresponding to the first suction area that overlaps with the first opening closing member in the first suction area is not less than 10% and not more than 90%.

[0250] Relative to the length of the second opening sealing member in the conveying orthogonal direction, the length of the opening portion in the conveying orthogonal direction of the first suction area corresponding portion overlapping with the second opening sealing member in the first suction area is greater than 10% and less than 90%.

[0251] <4A>

[0252] A fiber accumulation device comprises a fixed drum and a rotating drum, wherein the rotating drum is arranged to be able to rotate around the outer periphery of the fixed drum, and the outer periphery of the rotating drum is provided with a gathering recess for accumulating fiber materials, and the rotating drum is rotated to transport the gathering recess in a conveying direction along the circumferential direction of the drum, while the fiber material conveyed by the air flow generated by suction from the side of the fixed drum is deposited on the bottom surface of the gathering recess in a prescribed suction area in the circumferential direction of the drum, thereby manufacturing a fiber accumulation body having a plurality of parts with different gram weights in the conveying direction. In the fiber accumulation device,

[0253] The gathering recess has a plurality of fiber accumulation areas corresponding to a plurality of parts of the fiber accumulation body having different gram weights in the circumferential direction of the tube, the plurality of fiber accumulation areas including a first fiber accumulation area and a second fiber accumulation area forming a part with a higher gram weight than the first fiber accumulation area.

[0254] The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface.

[0255] A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder.

[0256] The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening (control body opening 26), and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening.

[0257] The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction.

[0258] A first non-air-permeable opening sealing member corresponding to the first fiber accumulation area and a second non-air-permeable opening sealing member corresponding to the second fiber accumulation area are arranged on the outer circumference of the rotating cylinder facing the fixed cylinder.

[0259] During the conveying process of the collecting recess in the first suction area, the first opening closing member and the second opening closing member overlap the opening corresponding to the first suction area, thereby reducing the flow rate of the air flow in the first fiber accumulation area and the second fiber accumulation area.

[0260] The first opening sealing member is longer in the conveying direction orthogonal to the conveying direction than the opening corresponding to the first suction area, and in the first suction area, the first opening sealing member is overlapped with the opening and extends over the entire length of the opening in the conveying direction.

[0261] The second opening closing component is shorter in length in the conveying orthogonal direction than the opening corresponding to the first suction area. When the second opening closing component overlaps with the opening in the first suction area, there is a portion of the opening in the conveying orthogonal direction that is not covered by the second opening closing component.

[0262] <5A>

[0263] The fiber deposition device as described in <4A> above, wherein

[0264] The length of the first opening closing component (an opening closing component having a longer length in the conveying direction and a wider width than the opening corresponding to the first suction area in an overlapping relationship in the first suction area) in the conveying direction is preferably 110% or more, more preferably 125% or more, relative to the length of the opening corresponding to the first suction area in the conveying direction, and is preferably less than 1000%, more preferably less than 500%.

[0265] <6A>

[0266] The fiber deposition device as described in <4A> or <5A>, wherein

[0267] The length of the second opening closing component in the conveying direction (an opening closing component that is shorter and narrower in width than the opening corresponding to the first suction area that is in an overlapping relationship in the first suction area) is preferably greater than 50% and less than 100% of the length of the opening corresponding to the first suction area in the conveying direction, and more preferably greater than 60% and less than 100%.

[0268] <7A>

[0269] The fiber deposition device according to any one of <4A> to <6A>, wherein

[0270] In the first suction area, when the first opening sealing member overlaps the opening of the first suction area corresponding portion, the first suction area corresponding portion and the first opening sealing member are separated by a distance greater than 0 mm and less than 3 mm.

[0271] In the first suction area, when the second opening sealing member overlaps the opening of the first suction area corresponding portion, the first suction area corresponding portion and the second opening sealing member are separated by a distance greater than 0 mm and less than 3 mm.

[0272] <8A>

[0273] The fiber deposition device according to any one of <1A> to <7A>, wherein

[0274] A ratio of an area of ​​the opening of the first suction region corresponding portion to an area of ​​the first suction region corresponding portion is 5% or more and 80% or less.

[0275] <9A>

[0276] The fiber deposition device according to any one of <1A> to <8A>, wherein

[0277] The rotating drum includes: a drum body disposed opposite to the outer peripheral portion of the fixed drum; and an outer layer portion disposed farther from the fixed drum than the drum body.

[0278] The first opening sealing member and the second opening sealing member are respectively arranged in the cylinder body at positions spaced a predetermined distance from the outer layer portion toward the cylinder body.

[0279] <10A>

[0280] The fiber deposition device as described in <9A> above, wherein

[0281] The outer layer portion includes: a recess bottom forming plate which forms the bottom of the collecting recess and is formed by an air-permeable component having a plurality of suction holes through which the air flow can pass; and a recess dividing plate which is a component for forming a groove-shaped recess in the fiber-accumulating body.

[0282] <11A>

[0283] The fiber deposition device as described in <9A> or <10A>, wherein

[0284] The outer layer portion includes a suction adjustment plate that is a member for adjusting a flow rate of the air flow in the collecting recess.

[0285] <12A>

[0286] The fiber deposition device according to any one of <1A> to <11A>, wherein

[0287] The collecting recess has, in addition to the first fiber accumulation area and the second fiber accumulation area, a suction non-restriction area where suction is not restricted.

[0288] <13A>

[0289] The fiber deposition device as described in <12A> above, wherein

[0290] The suction non-restriction area does not include the opening blocking members (the first opening blocking member and the second opening blocking member) (does not overlap with the opening blocking members in a plan view).

[0291] <14A>

[0292] A method for manufacturing an absorbent body, wherein the method uses a fiber deposition device to manufacture an absorbent body having a plurality of portions having different grammages in one direction.

[0293] The fiber accumulation device includes a fixed drum and a rotating drum, the rotating drum being arranged to be rotatable around the outer periphery of the fixed drum, and having a collecting recess on the outer periphery of the rotating drum for accumulating fiber materials, and while the rotating drum is rotated to convey the collecting recess in a conveying direction along the circumferential direction of the drum, the fiber materials conveyed by the air flow generated by suction from the side of the fixed drum are deposited on the bottom surface of the collecting recess in a prescribed suction area in the circumferential direction of the drum.

[0294] The collecting recess has a plurality of fiber accumulation areas corresponding to the plurality of parts of the absorbent body having different gram weights in the circumferential direction of the tube.

[0295] The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface.

[0296] A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder.

[0297] The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening.

[0298] The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction.

[0299] A plurality of non-air-permeable opening sealing members are arranged in the circumferential direction of the drum in a portion of the rotating drum facing the outer periphery of the fixed drum, corresponding to at least a portion of the plurality of fiber accumulation areas of the collecting recess.

[0300] During the conveying process of the collecting recess in the first suction area, the opening of the collecting recess corresponding to the opening of the first suction area is overlapped by the opening closing member, thereby reducing the flow rate of the air flow in the fiber accumulation area corresponding to the opening closing member in the collecting recess.

[0301] The plurality of opening sealing members arranged in the circumferential direction of the cylinder are respectively spaced apart from the first suction area corresponding portion by a predetermined spacing distance in a state where they overlap with the openings of the first suction area corresponding portion in the first suction area, and

[0302] In the plurality of opening sealing members arranged in the circumferential direction of the cylinder, the spacing distances are different from each other, and the plurality of opening sealing members are arranged in a manner such that the spacing distances gradually change from one side to the other side in the circumferential direction of the cylinder.

[0303] The method comprises the step of supplying the fiber material in a scattered state to the outer periphery of the rotating cylinder while rotating the rotating cylinder around the outer periphery of the fixed cylinder, and depositing the fiber material in the collecting recess in the suction area.

[0304] In the fiber accumulation step, in the first suction region, among the plurality of fiber accumulation regions corresponding to the plurality of opening-closing members, the flow rate of the air flow is greater in the fiber accumulation region having a longer spacing therebetween.

[0305] <15A>

[0306] The method for producing an absorbent body as described in <14A> above, wherein

[0307] A plurality of the openings are arranged in the cylinder axis direction in the portion corresponding to the first suction area, and a plurality of the opening closing members are arranged in the cylinder axis direction in the portion of the rotating cylinder facing the outer periphery of the fixed cylinder. During the conveying process of the collecting recess in the first suction area, the plurality of opening closing members arranged in the cylinder axis direction overlap with the plurality of the openings arranged in the cylinder axis direction.

[0308] The plurality of opening-sealing members arranged in the cylinder axis direction are spaced apart from the first suction region corresponding portion by a predetermined spacing distance in a state where the openings of the first suction region corresponding portion overlap in the first suction region, and

[0309] The plurality of opening-sealing components arranged in the cylinder axis direction have different spacing distances from each other, and the plurality of opening-sealing components are arranged in such a manner that the spacing distance gradually changes from one side to the other side in the cylinder axis direction.

[0310] <16A>

[0311] A method for manufacturing an absorbent body, wherein the method uses a fiber deposition device to manufacture an absorbent body having a plurality of portions having different grammages in one direction.

[0312] The fiber accumulation device includes a fixed drum and a rotating drum, the rotating drum being arranged to be rotatable around the outer periphery of the fixed drum, and having a collecting recess on the outer periphery of the rotating drum for accumulating fiber materials, and while the rotating drum is rotated to convey the collecting recess in a conveying direction along the circumferential direction of the drum, the fiber materials conveyed by the air flow generated by suction from the side of the fixed drum are deposited on the bottom surface of the collecting recess in a prescribed suction area in the circumferential direction of the drum.

[0313] The collecting recess has a plurality of fiber accumulation areas corresponding to the plurality of parts of the absorbent body having different gram weights in the circumferential direction of the tube.

[0314] The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface.

[0315] A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder.

[0316] The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening.

[0317] The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction.

[0318] A plurality of non-air-permeable opening sealing members are arranged in the circumferential direction of the drum in a portion of the rotating drum facing the outer periphery of the fixed drum, corresponding to at least a portion of the plurality of fiber accumulation areas of the collecting recess.

[0319] During the conveying process of the collecting recess in the first suction area, the opening of the collecting recess is overlapped with the opening of the corresponding portion of the first suction area, thereby reducing the flow rate of the air flow in the fiber accumulation area corresponding to the opening of the collecting recess.

[0320] The plurality of opening-sealing components arranged in the circumferential direction of the cylinder have different lengths in the conveying direction perpendicular to the conveying direction of the opening-sealing components, and the plurality of opening-sealing components are arranged in such a manner that the lengths in the conveying direction perpendicular to the conveying direction of the opening-sealing components gradually change from one side to the other side of the circumferential direction of the cylinder.

[0321] The method comprises the step of supplying the fiber material in a scattered state to the outer periphery of the rotating cylinder while rotating the rotating cylinder around the outer periphery of the fixed cylinder, and depositing the fiber material in the collecting recess in the suction area.

[0322] In the fiber accumulation step, in the first suction area, among the fiber accumulation areas corresponding to the plurality of opening closing members, the shorter the length of the opening closing member in the direction perpendicular to conveyance, the greater the flow rate of the air flow in the fiber accumulation area.

[0323] <17A>

[0324] The method for producing an absorbent body as described in <16A> above, wherein

[0325] A plurality of the openings are arranged in the cylinder axis direction at a portion corresponding to the first suction area, and a plurality of the opening closing members are arranged in the cylinder axis direction at a portion of the rotating cylinder opposite to the outer periphery of the fixed cylinder. During the conveying process of the collecting recess in the first suction area, the plurality of opening closing members arranged in the cylinder axis direction overlap with the plurality of the openings arranged in the cylinder axis direction.

[0326] Among the multiple opening closing components arranged in the cylinder axis direction, the lengths in the conveying direction orthogonal to the conveying direction of the opening closing components are different from each other, and the multiple opening closing components are arranged in a manner such that the lengths in the conveying direction orthogonal to the opening closing components gradually change from one side to the other side of the cylinder axis direction.

[0327] The fifth and sixth inventions are described below. Regarding the fifth and sixth inventions, the structures that differ from the first to fourth inventions described above are mainly described. Structures identical to those of the first to fourth inventions are denoted by the same reference numerals, and their description is omitted. For structures not specifically described in the fifth and sixth inventions, the description of the first to fourth inventions described above can be appropriately applied.

[0328] exist Figure 16 10A and 10B are shown as one embodiment of the absorbent body provided by the present invention (fifth and sixth inventions). Hereinafter, the two absorbent bodies 10A and 10B are collectively referred to as the "absorbent body 10." Unless otherwise specified, the description of the absorbent body 10 applies to both absorbent bodies 10A and 10B. The absorbent body 10 is an absorbent body for an absorbent article and has a longitudinal direction X corresponding to the front-to-back direction of the wearer of the absorbent article and a transverse direction Y perpendicular thereto.

[0329] The absorbent core 10A and the absorbent core 10B have the same mass content of fiber material, but the degree of fiber material bias is different. That is, the absorbent core 10A has more fiber material in the high-weight portion 11 than the absorbent core 10B, and the difference in grammage between the high-weight portion 11 and the low-weight portion 12 is greater.

[0330] Here, absorbent bodies commonly used in absorbent articles such as disposable diapers and sanitary napkins are preferably absorbent bodies with excellent liquid absorbency. In normal use, the liquid absorbency is fully and effectively utilized in the portion of the absorbent article disposed in and around the crotch of the wearer, while other portions of the absorbent article may have little or no effective liquid absorbency. Furthermore, from the perspective of improving the liquid absorbency of the absorbent body, a higher gram weight of the fiber material (hydrophilic fiber) is generally preferred. However, a higher gram weight of the fiber material may reduce softness, resulting in a reduced wearing feel of the absorbent article. From the perspective of improving the wearing feel, a lower gram weight of the fiber material is preferred.

[0331] Therefore, the inventors believe that absorbent bodies suitable for absorbent articles have a high fiber material (hydrophilic fiber) concentration in areas requiring high liquid absorbency, while areas requiring less liquid absorbency have less fiber material and are thinner, resulting in a body with a high degree of fiber material bias. In other words, if the current biased absorbent body is absorbent body 10B, then absorbent body 10A, which has a higher degree of bias, can be considered a form of absorbent body targeted by the present invention. Such absorbent bodies achieve a high balance between liquid absorbency and wearability.

[0332] However, conventional biased absorbent manufacturing technology has shown that it is difficult to stably manufacture absorbents such as the absorbent 10A, whose fiber material has a high degree of bias. In particular, as the degree of bias increases, the low-weight portion becomes even lighter, reducing the uniformity of the weight within the low-weight portion. In other words, the grammatical variations within the low-weight portion become significant. As a result, problems such as reduced conformability of the absorbent article to the wearer's body, resulting in a reduced fit and leak-proof performance, and reduced liquid absorbency in the low-weight portion, leading to leakage, and a reduction in appearance and design, can occur.

[0333] The present invention (fifth and sixth inventions) was completed in view of the problems of the prior art. One of its important issues is to provide a technology that can provide an absorbent body with a large degree of fiber material bias and a uniform grammage in the low grammage portion. Although the characteristic structure of the present invention described below is a relatively simple device structure, it can increase the degree of fiber material bias, concentrate the fiber material in the high grammage portion, and ensure the uniformity of the grammage in the low grammage portion.

[0334] First, regarding the manufacturing method and manufacturing apparatus of the absorbent body of the present invention (fifth to sixth inventions), the manufacturing method of the absorbent body 10 described above will be described with reference to the drawings as an example. Figure 17 and Figure 18 1A shows the overall structure of a manufacturing apparatus 1A as one embodiment of the manufacturing apparatus of the absorbent body of the present invention.

[0335] The manufacturing device 1A includes a fixed cylinder 2 and a rotating cylinder 3. The rotating cylinder 3 is configured to be able to rotate around the outer periphery 2S of the fixed cylinder 2. The outer periphery 3S has a gathering recess 40 for stacking the fiber material. While the rotating cylinder 3 is rotated, the fiber material carried by the air flow (hereinafter also referred to as "vacuum airflow") generated by suction from the side of the fixed cylinder 2 is stacked on the bottom surface of the gathering recess 40 in a specified suction area S in the cylinder circumferential direction X1.

[0336] In this embodiment, the manufacturing device 1A has: a gathering section 4 including a fixed drum 2 and a rotating drum 3; a raw material supply mechanism 5 for supplying raw materials such as fiber materials to the gathering section 4 (rotating drum 3); and a conveying mechanism 6 for conveying the absorbent body 10 (a fiber accumulation of raw materials such as fiber materials) discharged from the gathering recess 40 of the rotating drum 3. The basic structure of these parts of the manufacturing device 1A is the same as the basic structure of the parts of the fiber accumulation device (absorbent manufacturing device) 1 as an embodiment of the first to fourth inventions described above. Figure 4 The present invention can be applied to the manufacturing apparatus 1A.

[0337] The rotating drum 3 has a collecting recess 40 for collecting the fiber material on its outer circumference 3S. Figure 19 As shown, in the circumferential direction X1 of the cylinder, there are a high-weight portion corresponding portion 410 forming the high-weight portion 11 of the absorbent body 10 as the manufacturing target, and a low-weight portion corresponding portion 420 forming the low-weight portion 12 of the absorbent body 10. The bottom surface of the accumulation recess 40 for fibrous material accumulation is formed by an air-permeable member (recess bottom forming plates 34, 36) having a plurality of suction holes through which vacuum air can pass, and has air permeability.

[0338] In addition, the "high-weight portion corresponding portion 410" in the fifth and sixth inventions corresponds to the third fiber accumulation region 41C in the first to fourth inventions, and the "low-weight portion corresponding portion 420" in the fifth and sixth inventions corresponds to the first fiber accumulation region 41A and the second fiber accumulation region 41B in the first to fourth inventions (see Figure 5 ).

[0339] In this embodiment, the collecting recesses 40 are continuously arranged along the entire length of the rotating drum 3 in the circumferential direction X1, and the high-weight portion corresponding portions 410 and the low-weight portion corresponding portions 420 are alternately arranged along the entire length of the rotating drum 3 in the circumferential direction X1. One high-weight portion corresponding portion 410 and two low-weight portion corresponding portions 420, 420 sandwiched therebetween in the circumferential direction X1 correspond to one absorbent body 10. Therefore, the absorbent bodies 10 discharged from the collecting recesses 40 to the vacuum conveyor of the conveying mechanism 6 are a continuous absorbent body composed of a plurality of absorbent bodies 10 continuous in the longitudinal direction X.

[0340] In the fifth and sixth inventions, the outer peripheral portion 3AS of the tube body 3A is provided with a portion 420 (see FIG. 1 ) corresponding to the low basic weight portion of the concave portion 40 for collecting. Figure 19 ) is provided with a non-air-permeable opening sealing member 30. On the other hand, in the outer peripheral portion 3AS of the tube body 3A, a portion 410 (refer to Figure 19 ) The corresponding part 32 is not equipped with an opening sealing component 30.

[0341] In the fifth and sixth inventions, the second recess bottom surface forming plate 36 corresponds to the portion other than the portion corresponding to the middle-high portion 11A of the low basic weight portion corresponding portion 420 and the high basic weight portion corresponding portion 410 of the gathering recess 40 .

[0342] In this embodiment, a suction regulating body is provided on the rotating drum 3 for regulating the flow rate (suction air volume) of the vacuumed airflow in the collecting recess 40. By appropriately adjusting the setting of the suction regulating body, the opening areas of all or part of the plurality of openings (e.g., the openings 330, 331, 332 of the first suction regulating plate 33 and the openings 350, 351 of the second suction regulating plate 35) arranged corresponding to the collecting recess 40 can be independently adjusted, thereby independently regulating the flow rate (suction air volume) of the vacuumed airflow passing through the plurality of openings.

[0343] The above-mentioned suction regulating body will be described. In this embodiment, the two suction regulating plates 33 and 35 (see Figure 4 ) functions as the attraction regulator.

[0344] The first suction adjustment plate 33 is composed of a non-air-permeable component having a plurality of openings 330, 331 through which the vacuum airflow can pass. Suction can be performed only at the openings 330, 331, and suction cannot be performed at parts other than the openings 330, 331. Figure 19 As shown, the opening portion 330 is arranged in the portion corresponding to the portion 410 corresponding to the high-weight portion, and the opening portion 331 is arranged in the portion corresponding to the portion 420 corresponding to the low-weight portion. The opening portion 331 includes opening portions 331A arranged at both ends in the cylindrical axis direction Y1, and an opening portion 331B arranged in the central portion in the cylindrical axis direction Y1 and having an opening area smaller than that of the opening portion 331A. Hereinafter, the two opening portions 331A and 331B will also be collectively referred to as the "opening portion 331." Unless otherwise specified, the description of the opening portion 331 also applies to the two opening portions 331A and 331B. In the central portion in the cylindrical axis direction Y1 of the portion corresponding to the high-weight portion 410 in the first suction adjustment plate 33, an opening portion 332 corresponding to the first recessed bottom surface forming plate 34 is arranged, and the opening portion 330 is arranged on both sides of the opening portion 332 in the cylindrical axis direction Y1.

[0345] The second suction adjustment plate 35 is composed of a non-air-permeable component with a plurality of openings 350, 351 through which the vacuum airflow can pass. Suction can be performed only at the openings 350, 351, and suction cannot be performed at parts other than the openings 350, 351. Figure 19As shown, the opening 350 is arranged in a portion corresponding to the high-basic-weight portion corresponding portion 410 , and the opening 351 is arranged in a portion corresponding to the low-basic-weight portion corresponding portion 420 .

[0346] The openings 330 and 331 of the first suction adjustment plate 33 correspond to the openings 350 and 351 of the second suction adjustment plate 35 in a one-to-one manner. Figure 19 As shown in the top view of the gathering recess 40, in the portion 410 corresponding to the high gram weight portion, the opening portion 330 of the first suction adjustment plate 33 overlaps one-to-one with the opening portion 350 of the second suction adjustment plate 35, and in the portion 420 corresponding to the low gram weight portion, the opening portion 331 (331A, 331B) of the first suction adjustment plate 33 overlaps one-to-one with the opening portion 351 of the second suction adjustment plate 35.

[0347] Furthermore, the openings of the two plates 33 and 35, which overlap one another, are similar in shape when viewed from above. Specifically, the openings 330 and 331 of the first suction adjustment plate 33, which is relatively close to the fixed cylinder 2, have smaller opening areas than the openings 350 and 351 of the second suction adjustment plate 35, which is relatively far from the fixed cylinder 2.

[0348] The flow rate (suction volume) of the vacuum airflow in the portion where multiple openings that are in a similar relationship to each other in the direction of passage of the vacuum airflow (radial direction of the rotating drum 3) are present is affected by the openings with relatively smaller opening areas among the multiple openings (hereinafter also referred to as "small openings"), and is reduced compared to a case where there are no small openings and only openings with relatively larger opening areas (hereinafter also referred to as "large openings").

[0349] For example, in the vacuum flow path combining opening 330 (small opening) and opening 350 (large opening), the suction air volume is reduced due to the influence of opening 330 compared to a case where opening 350 exists alone and there is no opening 330 in the flow path. Furthermore, in the vacuum flow path combining opening 331 (331A, 331B) (small opening) and opening 351 (large opening), the suction air volume is reduced due to the influence of opening 331 compared to a case where opening 351 exists alone and there is no opening 331 in the flow path.

[0350] As described above, the suction regulating body includes a plurality of openings that overlap and are in a similar relationship with each other in the direction of passage of the vacuumed airflow (radial direction of the rotating cylinder 3), and can reduce the flow rate of the vacuumed airflow passing through the plurality of openings compared to before the suction regulating body (the plurality of openings) is installed. According to the suction regulating body, since the opening areas of the plurality of openings corresponding to the plurality of flow paths of the vacuumed airflow passing between the fixed cylinder 2 and the gathering recess 40 can be independently adjusted, the suction air volume of the gathering recess 40 can be locally different in both the flow direction MD (rotation direction R1 of the rotating cylinder 3) and the direction orthogonal thereto (cylinder axis direction Y1).

[0351] In this embodiment, if Figure 19 As shown, the low-weight portion corresponding portion 420 has two openings 331A and 331B, which are small openings with different opening areas. The openings 331A with relatively large opening areas are arranged at both ends of the low-weight portion corresponding portion 420 in the cylinder axis direction Y1 (the portions adjacent to the pair of ring plates 38, 38), and the openings 331B with relatively small opening areas are arranged in the center of the low-weight portion corresponding portion 420 in the cylinder axis direction Y1. As a result, in the low-weight portion corresponding portion 420, the relationship of "ends in the cylinder axis direction Y1 > center in the cylinder axis direction Y1" regarding the suction air volume is established.

[0352] On the other hand, in the portion corresponding to the high-weight portion 410, the central portion in the cylinder axis direction Y1 (where the first recessed bottom surface forming plate 34 is located and which forms the middle height portion 11A) is not provided with the aforementioned suction regulating body. In contrast, at both ends in the cylinder axis direction Y1, the flow path for the vacuum airflow, which combines the aforementioned openings 330 (small opening) and 350 (large opening), is provided. Due to the influence of the openings 330, the suction air volume is reduced compared to a case where only the openings 350 exist in the flow path without the openings 330. Therefore, in the portion corresponding to the high-weight portion 410, the magnitude relationship of suction air volume is established: "central portion in the cylinder axis direction Y1 > end portions in the cylinder axis direction Y1."

[0353] Therefore, in this embodiment, with respect to the suction air volume (flow rate of the vacuum airflow), the size relationship of "the portion corresponding to the high gram weight part 410 > the end portion of the portion corresponding to the low gram weight part 420 in the cylindrical axis direction Y1 > the central portion of the portion corresponding to the low gram weight part 420 in the cylindrical axis direction Y1" is established, and it becomes easy to accumulate fiber materials in this order. More specifically, in this embodiment, with respect to the amount of suction air, the size relationship of "the central part of the cylinder axis direction Y1 of the portion corresponding to the high gram weight portion 410 > the end part of the cylinder axis direction Y1 of the portion corresponding to the high gram weight portion 410 > the end part of the cylinder axis direction Y1 of the portion corresponding to the low gram weight portion 420 > the central part of the cylinder axis direction Y1 of the portion corresponding to the low gram weight portion 420" or the size relationship of "the central part of the cylinder axis direction Y1 of the portion corresponding to the high gram weight portion 410 > the end part of the cylinder axis direction Y1 of the portion corresponding to the high gram weight portion 410 = the end part of the cylinder axis direction Y1 of the portion corresponding to the low gram weight portion 420 > the central part of the cylinder axis direction Y1 of the portion corresponding to the low gram weight portion 420" can be established.

[0354] The rotating drum 3 of the above structure rotates, and the collecting recess 40 of the outer peripheral portion 3S of the rotating drum 3 passes through the suction area S (refer to Figure 18 ), the raw material containing the fiber material supplied through the pipe 51 is accumulated in the collecting recess 40, thereby forming the absorbent body 10 in the collecting recess 40. In the manufacturing device 1A, as one of the methods for obtaining an absorbent body with a large degree of bias in the fiber material, the conveying path of the collecting recess 40 in the suction area S is divided into a plurality of areas S1 and S2 in its conveying direction (the cylinder circumferential direction X1), so that the fiber accumulation methods of each area S1 and S2 are different from each other. Specifically, the suction area S of the manufacturing device 1A has a first suction area S1 in the cylinder circumferential direction X1, which causes the fiber material to be preferentially accumulated in the portion 410 corresponding to the high grammage portion, and a second suction area S2, which causes the fiber material to be accumulated in both the portion 410 corresponding to the high grammage portion and the portion 420 corresponding to the low grammage portion.

[0355] The first suction zone S1 is also referred to as the "high-weight portion priority fiber accumulation zone S1" because the high-weight portion priority fiber accumulation process described later is implemented. Furthermore, the second suction zone S2 is also referred to as the "full-surface fiber accumulation zone S2" because the entire surface fiber accumulation process described later is preferably implemented.

[0356] In this embodiment, if Figure 18 and Figure 20 As shown, the area corresponding to the space A is the first suction area S1, and the area corresponding to the space B is the second suction area S2, which are sequentially arranged in the rotation direction R1 of the rotating drum 3, that is, the flow direction MD.

[0357] In the absorbent manufacturing apparatus of the present invention, the positions of the two regions S1 and S2 are not particularly limited, and they may be arranged in the order of the second suction region S2 and the first suction region S1 from upstream to downstream in the flow direction MD, contrary to the illustrated form.

[0358] In this embodiment, the methods of controlling the vacuum airflow in the first suction zone S1 and the second suction zone S2 are different from each other, so that the fiber deposition methods in the two zones S1 and S2 are different from each other.

[0359] The control method of the vacuum airflow in the two areas S1 and S2 is described as follows. Figure 4 and Figure 20 As shown, on the peripheral portion 2S of the fixed cylinder 2 serving as the source of the vacuum airflow (suction source), there are provided a first suction area corresponding portion (selective suction area) 23 corresponding to the area S1, which includes a suction control body 25 partially having a control body opening 26, and a second suction area corresponding portion (whole-surface suction area) 24 corresponding to the area S2, which is open in the entire area of ​​the portion corresponding to the gathering recess 40. In addition, in the rotating cylinder 3, the peripheral portion 3AS of the cylinder main body 3A which is the opposite portion to the peripheral portion 2S of the fixed cylinder 2 is provided with: a suction obstruction portion 31 including a non-air-permeable opening sealing component 30 corresponding to the low-weight portion corresponding portion 420 which is a part of the gathering recess 40; and a suction non-obstruction portion 32 which is composed of a through hole penetrating the peripheral portion 3AS in the thickness direction and does not have an opening sealing component 30, but corresponds to the high-weight portion corresponding portion 410 which is another part of the gathering recess 40. When the rotating cylinder 3 is rotated in the direction R1 (refer to Figure 17 ) is rotated, the collecting recess 40 moves in the suction area S in the order of area S1 and area S2. Figure 21 The figure shows the attraction state of the low-weight portion corresponding portion 420 in the regions S1 and S2. Figure 22 The suction state of the high-weight portion corresponding portion 410 in the areas S1 and S2 is shown in FIG. Figure 21 and Figure 22 The arrows in the figure indicate the vacuum flow. Figure 21 (a) and Figure 22 (a) shows the suction state in the area S1 (the first suction area corresponding portion 23 of the outer peripheral portion 2S of the fixed cylinder 2). Figure 21 (b) and Figure 22 (b) shows the suction state in the area S2 (the second suction area corresponding portion 24 of the outer peripheral portion 2S of the fixed cylinder 2).

[0360] When the gathering recess 40 passes through the area S1, at the low-weight portion corresponding portion 420, the opening portion closing component 30 of the rotating cylinder 3 overlaps the control body opening 26 of the first suction area corresponding portion 23 of the fixed cylinder 2 to close the control body opening 26 (refer to Figure 21 (a)), in the high-weight portion corresponding portion 410, the control body opening portion 26 is not closed (refer to Figure 22 (a)). Thus, in the process of the gathering recess 40 passing through the area S1, in the portion 420 corresponding to the low grammage portion, since the vacuum airflow can hardly pass through the opening portion 26 of the control body, the fiber material is not substantially accumulated. In the portion 410 corresponding to the high grammage portion, since the vacuum airflow can pass through the opening portion 26 of the control body, the fiber material can be attracted and accumulated. In this way, the attraction of the portion 420 corresponding to the low grammage portion is selectively hindered in the area S1. The above-mentioned "in the portion 420 corresponding to the low grammage portion, the vacuum airflow can hardly pass through the opening portion 26 of the control body" specifically means that in the process of the gathering recess 40 passing through the area S1, the ratio of the suction air volume of the portion 420 corresponding to the low grammage portion to the suction air volume of the portion 410 corresponding to the high grammage portion is preferably less than 5%, more preferably less than 3%, and even more preferably less than 1%.

[0361] On the other hand, when the gathering recess 40 passes through the area S2, the second suction area corresponding portion 24 of the fixed cylinder 2 corresponding to the area S2 does not include a non-air-permeable component such as the suction control body 25. Since the entire area of ​​the portion corresponding to the gathering recess 40 in the area 24 is open, the fiber material can be attracted by the vacuum airflow in both the low-weight portion corresponding portion 420 and the high-weight portion corresponding portion 410, thereby performing fiber accumulation (refer to FIG. Figure 21 (b) and Figure 22 (b)).

[0362] As shown in this embodiment, by utilizing the periodic overlap of the control body opening 26 of the fixed drum 2 and the opening sealing member 30 of the rotating drum 3 as the rotating drum 3 rotates, in the first suction area S1, which is a part of the suction area S, only the flow of the vacuum airflow with respect to the low-weight portion corresponding portion 420 is selectively blocked, thereby enabling concentrated accumulation of fiber material in the high-weight portion corresponding portion 410. As a result, in the area S1, the fiber material is preferentially accumulated in the high-weight portion corresponding portion 410. Typically, in the area S1, the fiber material is substantially accumulated only in the high-weight portion corresponding portion 410, and no fiber material is accumulated in the low-weight portion corresponding portion 420, or even if fiber material is accumulated, the amount is extremely small compared to the high-weight portion corresponding portion 410. As described above, since such selective suction obstruction is not performed in the second suction area S2, fiber accumulation is performed in the entire collecting recess 40. Therefore, even if it is assumed that there is no re-fiber accumulation process based on the scraper roller 45 described later, a fiber accumulation object of the fiber material that strongly reflects the influence of the fiber accumulation method in the area S1, that is, an absorbent body with a large degree of fiber material bias, can be formed in the collecting recess 40 after passing through the suction area S.

[0363] As described above, in the present embodiment, in order to preferentially deposit the fiber material in the high-weight portion corresponding portion 410 in the first suction area S1, the control body opening 26 of the peripheral portion 2S (first suction area corresponding portion 23) of the fixed cylinder 2 that functions as a flow path for the vacuum airflow with respect to the low-weight portion corresponding portion 420 is periodically overlapped by the rotation of the rotating cylinder 3, thereby periodically closing the control body opening 26 (refer to FIG. Figure 21 (a)), at this time, if the opening sealing component 30 is designed in such a way that it contacts the outer peripheral portion 2S of the fixed tube 2 when the opening portion 26 of the control body is closed based on the opening sealing component 30, these components will wear each time they contact, and there is a concern that a malfunction or other adverse condition may occur in a relatively short period of time.

[0364] Therefore, in this embodiment, Figure 21 The structure shown in (a) is that, in the first suction area S1, when the opening closing member 30 overlaps with the control body opening 26 of the first suction area corresponding portion 23 (when the two members 26 and 30 overlap each other in a plan view), there is a gap G ( Figure 21 The part surrounded by 0 in (a) can eliminate the above concerns.

[0365] The gap G is preferably larger than 0 mm and smaller than 3 mm, and more preferably larger than 0 mm and smaller than 2 mm, from the viewpoint of obtaining the effect of providing the gap G and preventing problems caused by an excessively large gap G.

[0366] In the manufacturing apparatus 1A, in order to obtain an absorbent with a greater degree of fiber material bias, not only are the aforementioned multiple regions S1 and S2 having different fiber accumulation methods arranged in the suction region S, but the difference in the flow rate of the vacuumed airflow (suction air volume difference) in each portion of the accumulation recess 40 is also made different between the multiple regions S1 and S2. Specifically, in the manufacturing apparatus 1A, the difference in suction air volume between the portion corresponding to the high-weight portion 410 and the portion corresponding to the low-weight portion 420 is made greater in region S1 than in region S2. Thus, when the suction air volume of the portion corresponding to the high-weight portion 410 is 41V and the suction air volume of the portion corresponding to the low-weight portion 420 is 42V, in the suction region S, the ratio of the suction air volumes (41V / 42V) of the two holds the relationship of "region S1 > region S2," and in region S1, the fiber material preferentially accumulates in the portion corresponding to the high-weight portion 410.

[0367] In the manufacturing device 1A, by adopting the above-mentioned two characteristic structures, namely, "the suction area S is divided into multiple areas S1 and S2 in the flow direction MD" (Structure 1) and "the ratio of the suction air volume of area S1 (41V / 42V) is larger than the ratio of area S2" (Structure 2), the fiber material is concentrated in the corresponding part 410 of the high-weight part, and the manufacture of an absorbent body with a large degree of fiber material bias can be achieved.

[0368] In this embodiment, by adopting the above-mentioned suction regulating body, at least in area S1, the suction air volume of the high-weight portion corresponding part 410 and the low-weight portion corresponding part 420 has a size relationship of the former > the latter, and the ratio of the suction air volume (41V / 42V) > 1. Moreover, as a means to realize the above-mentioned structure 2, in area S1, the fiber material is preferentially deposited in the high-weight portion corresponding part 410. As described above, the control method utilizing the vacuum airflow is adopted, that is, "with respect to the opening through which the vacuum airflow in the fixed cylinder 2 passes (the control body opening 26), in area S1, the part corresponding to the high-weight portion corresponding part 410 does not hinder suction, and only the part corresponding to the low-weight portion corresponding part 420 hinders suction, and in area S2, the parts corresponding to the two corresponding parts 410 and 420 do not hinder suction." Therefore, of course, the ratio of the suction air volume (41V / 42V) in area S1 is larger than that in area S2, and the above-mentioned structures 1) and 2) are adopted as a whole.

[0369] In addition, in region S2, the difference in suction air volume between the portion corresponding to the high grammage portion 410 and the portion corresponding to the low grammage portion 420 may also be zero. Based on this, a preferred embodiment of the manufacturing apparatus of the absorbent body of the present invention can be exemplified as follows: in region S1, the suction air volume of at least a portion of the portion corresponding to the high grammage portion 410 is greater than the suction air volume of the portion corresponding to the low grammage portion 420, that is, the magnitude relationship of "(41V / 42V)>1" holds true; in region S2, the suction air volume of at least a portion of the portion corresponding to the high grammage portion 410 is equal to or greater than (larger than) the suction air volume of the portion corresponding to the low grammage portion 420, that is, the magnitude relationship of "(41V / 42V)≥1" holds true.

[0370] Regarding the above-mentioned structure 2, as a method for adjusting the difference between the ratio (41V / 42V) of the suction air volume of the area S1 and the ratio of the area S2, for example, in the manufacturing device 1A of the above-mentioned structure, a method for adjusting the degree of closure of the control body opening 26 corresponding to the low-weight portion corresponding portion 420 by the opening closure member 30 can be cited. The "degree of closure of the control body opening 26" can be adjusted, for example, by appropriately adjusting the size of the control body opening 26 and / or the opening closure member 30 when viewed from above, or the gap G between the two members 26 and 30 (see Figure 21 (a)) can be adjusted.

[0371] The ratio of the suction air volume ratio of area S1 (41V / 42V) to the suction air volume ratio of area S2 (41V / 42V) is preferably greater than 2, more preferably greater than 4, and preferably less than 1000, more preferably less than 500, on the premise that the former is greater than the latter.

[0372] The ratio of the suction air volume in the region S1 (41V / 42V) is preferably 20 or more, more preferably 30 or more, and is preferably 1000 or less, more preferably 500 or less.

[0373] The ratio of the suction air volume in the region S2 (41V / 42V) is preferably 1 or more, more preferably 2 or more, and is preferably 10 or less, more preferably 5 or less.

[0374] The suction air volume (vacuum air flow rate) of each portion of the collecting recess 40 can be measured using a high-temperature ANEMOMASTER (registered trademark) anemometer (Kanomax Japan Inc. Model 6162). After measuring the wind speed using this measuring device, the suction flow rate is calculated based on the suction cross-sectional area.

[0375] The suction air volume 41V of the high-weight portion corresponding part 410 is the measured value of the suction air volume on the first recessed bottom surface forming plate 34 corresponding to the high-weight portion corresponding part 410 of the manufacturing device 1A, and the suction air volume 42V of the low-weight portion corresponding part 420 is the measured value of the suction air volume on the second recessed bottom surface forming plate 36 corresponding to the low-weight portion corresponding part 420 of the manufacturing device 1A.

[0376] In this embodiment, at least a portion of the high-weight portion corresponding portion 410 has a deeper recess depth than the low-weight portion corresponding portion 420. Specifically, in this embodiment, Figure 22 and Figure 23 As shown, the central portion of the high-weight portion corresponding portion 410 in the cylinder axis direction Y1 (the portion forming the middle-high portion 11A of the absorbent body 10) has a deeper recess depth than both the low-weight portion corresponding portion 420 and the portions of the high-weight portion corresponding portion 410 other than the central portion (the ends of the high-weight portion corresponding portion 410 in the cylinder axis direction Y1). Specifically, the first recess bottom-forming plate 34 forming the bottom surface of the central portion of the high-weight portion corresponding portion 410 in the cylinder axis direction Y1 is located closer to the fixed cylinder 2 than the second recess bottom-forming plate 36 forming the bottom surface of the portions of the low-weight portion corresponding portion 420 and the high-weight portion corresponding portion 410 other than the central portion. The "recess depth" described above refers to the distance between the outer surface of the components located on both sides of the collecting recess 40 in the cylinder axis direction Y1 and the bottom surface of the collecting recess 40. In this embodiment, the components are the ring plates 38.

[0377] Like this, the structure in which at least a part of the high-weight portion corresponding portion 410 has a deeper recess than the low-weight portion corresponding portion 420 not only increases the Figure 16 This is useful for improving the degree of bias in the fiber material in the biased absorbent such as the absorbent 10A shown in (a), and is also useful for improving the uniformity of the grammage of the low grammage portion in the biased absorbent by combining it with the refibering process using the scraper roller 45 described later. This will be described later.

[0378] From the perspective of solving the problem of "increasing the degree of bias of the fiber material in the absorbent body", it is effective to make the fiber accumulation time in the first suction area S1 longer. When the fiber accumulation time in the area S1 becomes longer, the fiber accumulation time in the second suction area S2 usually becomes shorter accordingly, and the fiber is absorbed toward the low-weight part 12 (refer to Figure 16) becomes insufficient, and there is a concern that this may be disadvantageous in terms of "uniformity of the grammage of the low-grammage portion of the absorbent body", which is another subject of the present invention. Taking this into account, the length of the region S1 in the cylinder circumferential direction X1 relative to the length of the suction region S (the portion covered by the duct 51 in the outer periphery 3S of the rotating cylinder 3) in the cylinder circumferential direction X1 is preferably 2 / 3 or less, and more preferably 1 / 2 or less. That is, the ratio of the total length of the region S1 to the total length of the suction region S is preferably approximately 70% or less. On the other hand, from the viewpoint of reliably obtaining an absorbent body with a greater degree of bias in the fiber material, the lower limit of this ratio is preferably 1 / 8 or more, and more preferably 1 / 4 or more.

[0379] In addition, since the area S1 corresponds to the first suction area corresponding portion 23 of the outer peripheral portion 2S of the fixed cylinder 2, and the area S corresponds to the first suction area corresponding portion 23 and the second suction area S2 of the outer peripheral portion 2S of the fixed cylinder 2, the ratio of the total length of the first suction area corresponding portion 23 in the cylinder circumferential direction X1 to the total value of the total length of the two areas 23 and 24 in the cylinder circumferential direction X1 is preferably also within the above range.

[0380] In this embodiment, the first suction area S1 and the second suction area S2 can independently adjust the flow rate of the vacuum airflow (suction air volume). Specifically, in this embodiment, as described above, the interior of the fixed cylinder 2 is divided into a plurality of spaces A to C in the cylinder circumferential direction X1. The negative pressure (suction force) of the plurality of spaces A to C can be independently adjusted by a decompression mechanism (not shown) connected to the fixed cylinder 2, and space A corresponds to area S1, and space B corresponds to area S2 (see FIG. Figure 18 ), therefore, by operating the decompression mechanism, the suction air volume of areas S1 and S2 can be adjusted independently.

[0381] When the suction air volume of areas S1 and S2 can be adjusted independently like this, for example, the size relationship of "area S1>area S2" can be established regarding the suction air volume. Through the complementary effect of this size relationship and the above-mentioned structures 1 and 2, the degree of bias of the fiber material in the absorbent body can be further increased.

[0382] As a method for increasing the degree of bias of the fiber material in the absorbent body, in addition to the method based on the above-mentioned method of controlling the suction air volume, for example, a method of physically blocking the supply of the fiber material to a part of the collecting recess 40 (the low-weight portion corresponding portion 420) can be cited. In this embodiment, as a method for physically blocking the supply of the fiber material, Figure 17 、 Figure 18 、 Figure 21 and Figure 22 A divider plate 43 is shown.

[0383] In the manufacturing apparatus 1A, the partition plate 43 is provided inside the duct 51 of the suction area S, as shown in FIG. Figure 21 and Figure 22 As shown, a pair of partition plates 43 are arranged on both sides in the cylinder axial direction Y1 with the collecting recess 40 interposed therebetween. The pair of partition plates 43, 43 are fixed to the ring plate 38 forming the outer surface of the rotating cylinder 3, respectively.

[0384] The partition plate 43 must be in contact with the fiber material supplied from the duct 51 to the suction area S before the fiber material is accumulated in the collecting recess 40. Figure 17 and Figure 18 As shown, the partition plate 43 is arranged so that at least a portion of it overlaps the intersection of the fiber material supply passage 50 within the duct 51 and the suction area S (the duct 51 covering the suction area S) (the opening of the duct 51 on the suction area S side). In this embodiment, the partition plate 43 extends substantially the entire length, in the cylinder circumferential direction X1, of the first suction area S1 located upstream in the flow direction MD of the suction area S. The material of the partition plate 43 is not particularly limited; for example, metal, synthetic resin, or a combination thereof can be used.

[0385] A pair of partition plates 43, 43 as shown Figure 21 and Figure 22 As shown, the collecting recess 40 is arranged at predetermined intervals in the cylindrical axial direction Y1, and the fiber material is concentratedly supplied to the region corresponding to the interval in the collecting recess 40, specifically, the central portion of the collecting recess 40 in the cylindrical axial direction Y1. The two ends of the collecting recess 40 in the cylindrical axial direction Y1 are covered by a pair of partition plates 43, 43, thereby physically blocking the supply of fiber material to these two end portions.

[0386] The opposing surface of each of the pair of partition plates 43, 43 is a supply obstruction surface 43a that contacts the scattered fiber material supplied from the duct 51 and obstructs the supply of the fiber material into the collecting recess 40. The supply obstruction surface 43a is inclined with respect to the radial direction of the rotating drum 3 and extends from the outer side to the inner side of the radial direction ( Figure 21 or Figure 22 As a result, the distance between the supply obstruction surface 43a on one side of the pair of partition plates 43 and the supply obstruction surface 43a on the other side gradually decreases as it moves from the outer side to the inner side in the radial direction of the rotating drum 3. By tilting the supply obstruction surface 43a in this manner, the fiber material is less likely to accumulate on the supply obstruction surface 43a.

[0387] In the first suction area S1, which is the area where the partition plates 43 are arranged, the supply of fiber material is blocked in the portion of the collecting recess 40 covered by the partition plates 43 (the ends of the collecting recess 40 in the cylindrical axial direction Y1). However, the portion of the collecting recess 40 not covered by the partition plates 43 (the central portion of the collecting recess 40 in the cylindrical axial direction Y1) is supplied with almost all of the fiber material. In addition to the fiber material that would be supplied to the portion of the collecting recess 40 not covered by the partition plates 43, the fiber material that would be supplied to the portion of the collecting recess 40 covered by the partition plates 43 in the absence of the partition plates 43 is also supplied to the portion of the collecting recess 40 not covered by the partition plates 43. This allows for the accumulation of an excess amount of fiber material exceeding the height of the ring plate 38.

[0388] Therefore, on the basis of the above-mentioned control of the suction air volume (the above-mentioned structures 1 and 2), a method of physically blocking the supply of fiber material to the gathering recess 40 such as the partition plate 43 is also adopted, thereby further increasing the degree of bias of the fiber material in the absorbent body.

[0389] From the perspective of stably manufacturing an absorbent body with a relatively large degree of fiber material bias, the ratio of the fiber material supply weight per unit time to the portion of the configuration area of ​​the partition plate 43 that is not covered by the partition plate 43 (in the illustrated form, the central portion of the gathering recess 40 in the cylindrical axial direction Y1) relative to the fiber material supply weight per unit time to the configuration area of ​​the partition plate 43 (the area at the same position as the partition plate 43 in the cylindrical circumferential direction X1) is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more.

[0390] Manufacturing device 1A Figure 17 and Figure 18 As shown, a scraping roller 45 is provided opposite to the outer peripheral portion 3S of the rotating drum 3. The scraping roller 45 is configured to scrape the fiber material accumulated in the portion 410 corresponding to the high grammage portion and deposit the scraped fiber material in the portion 420 corresponding to the low grammage portion. In this embodiment, the scraping roller 45 is arranged inside the duct 51 on the downstream side of the suction area S in the flow direction MD, specifically on the downstream side of the second suction area S2 in the flow direction MD.

[0391] The main purpose of the characteristic structure of the manufacturing apparatus 1A is to make Figure 16 The degree of bias of the fiber material in the biased absorbent such as the absorbent 10A shown in (a) increases, but the main purpose of the fiber material re-fibering process using the scraper roller 45 is to improve the uniformity of the weight of the low-weight part in the biased absorbent.

[0392] Figure 24 (a) and Figure 24(b) is a diagram showing a state of a re-fiber deposition process using a scraper roller 45, both of which are one embodiment of the present invention. Figure 24 The form shown in (a) is a combination of a rotating drum 3 and a scraping roller 45 in which the depth D of the recess of at least a part of the high-weight portion corresponding portion 410 (for example, the central part in the drum axis direction Y1) is formed deeper than that of other parts. Figure 24 The embodiment shown in (b) is a combination of a rotating drum 3 and a scraper roller 45 in which the depth D of the concave portion 40 for collecting is formed uniformly. The following description is applicable to Figure 24 Both of the two forms shown.

[0393] In this embodiment, if Figure 24 As shown, the scraping roller 45 includes a cylindrical roller body 451 and a plurality of scraping protrusions 452 provided upright on the outer periphery of the roller body 451. The roller axis direction of the roller body 451 is aligned with the cylinder axis direction Y1, and the roller body 451 is arranged over substantially the entire length of the collecting recess 40 in the cylinder axis direction Y1. The protrusions 452 are preferably arranged on the outer periphery of the roller body 451 at least in an area corresponding to the center of the collecting recess 40 in the cylinder axis direction Y1, and more preferably over the entire length in the cylinder axis direction Y1.

[0394] The scraper roller 45 receives power from a motor (not shown) and rotates about a horizontal axis. In the illustrated embodiment, the direction of rotation of the scraper roller 45 is the same as the rotation direction R1 of the rotating drum 3. From the perspective of balancing the amount of scraped fiber material and the re-deposition of the scraped fiber material nearby, the peripheral speed of the scraper roller 45 is preferably 2 times or more and 10 times or less, and more preferably 3 times or more and 5 times or less, compared to the peripheral speed of the rotating drum 3.

[0395] The scraping roller 45 is a component provided for scraping the fiber material accumulated in the high-weight portion corresponding portion 410 and re-accumulating the fiber in the low-weight portion corresponding portion 420. In order to reliably achieve this purpose, the manufacturing device 1A is typically as follows: Figure 24 As shown, first, in the suction area S, the excess fiber material having a height exceeding the ring plate 38 is accumulated in the portion 410 corresponding to the high grammage portion, and then the excess fiber material in the portion 410 corresponding to the high grammage portion is scraped off by the scraping roller 45 and accumulated in the portion 420 corresponding to the low grammage portion. Figure 24 In the figure, reference symbol RP represents the fiber material scraped by the scraper roller 45 and deposited in another place.

[0396] The process of depositing the excess fiber material on the high-weight portion corresponding portion 410 can be performed, for example, by controlling the suction air volume using the above-mentioned suction regulating body (suction regulating plates 33, 35) or controlling the supply destination of the fiber material using the partition plate 43. In addition, the amount of fiber material scraped from the high-weight portion corresponding portion 410 by the scraping roller 45 can be adjusted by adjusting the gap between the scraping roller 45 and the fiber material of the high-weight portion corresponding portion 410 to be scraped.

[0397] As a method for re-accumulating the fiber material scraped from the high-weight portion corresponding portion 410 in the low-weight portion corresponding portion 420, in this embodiment, Figure 24 As shown, a guide component 44 is provided inside the pipe 51 at a position upstream of the scraper roller 45 in the flow direction MD (rotation direction R1 of the rotating drum 3) for guiding the scattered fiber material RP scraped by the scraper roller 45 to the desired position of the gathering recess 40.

[0398] The guide member 44 extends from the inner surface of the duct 51 facing the collecting recess 40 toward the collecting recess 40, that is, from the outer side to the inner side of the rotating drum 3 in the radial direction ( Figure 24 The front end of the guide member 44 does not enter the collecting recess 40, but is located at a position on the outside of the radial direction of the rotating cylinder 3 relative to the ring plate 38 forming the outer surface of the rotating cylinder 3. In addition, the guide member 44 extends over the entire length of the collecting recess 40 in the cylinder axis direction Y1. In addition, the guide member 44 is as shown in FIG. Figure 24 In the cross-sectional view along the cylinder circumferential direction X1 shown, there is a portion that is convexly curved toward the upstream side of the flow direction MD.

[0399] The guide component 44 is set at an appropriate position in accordance with the relationship with the scraping roller 45, so as to prevent the fiber material RP in a scattered state scraped by the scraping roller 45 from passing over the corresponding portion 420 of the low-weight portion where the fiber is predetermined to be deposited and being deposited on the upstream side of the flow direction MD, thereby facilitating the deposition of the fiber material RP in the desired corresponding portion 420 of the low-weight portion.

[0400] The shape and position of the guide member 44 are not particularly limited and can be adjusted as appropriate to achieve the intended purpose. Furthermore, the method for installing the guide member 44 is also not particularly limited. For example, the guide member 44, which is a component separate from the duct 51, can be fixed to the inner surface of the duct 51 (e.g., the surface facing the collecting recess 40), or the wall portion constituting the duct 51 itself can be processed into a shape that allows it to function as the guide member 44.

[0401] In this embodiment, the manufacturing apparatus 1A is configured to adjust the rotation of the scraper roller 45, specifically, the rotation direction and rotation speed. The rotation of the scraper roller 45 is closely related to the flight distance and landing position of the fiber material RP scraped and scattered by the scraper roller 45. By appropriately adjusting the rotation of the scraper roller 45 and the position and shape of the guide member 44, the fiber material RP can be accurately deposited in the low-weight portion corresponding portion 420.

[0402] The characteristic structures of the manufacturing apparatus 1A, represented by the above-mentioned structures 1 and 2, function primarily during the accumulation of the fiber material, causing the fiber material to be concentrated in the high-weight portion corresponding portion 410, thereby contributing to increasing the degree of fiber material bias in the biased absorbent. However, using only these structures makes it difficult to ensure uniformity in the grammage of the low-weight portion. To address this issue, the manufacturing apparatus 1A includes a fiber material re-accumulation mechanism using the scraper roller 45. This allows the fiber material to be distributed from the high-weight portion corresponding portion 410, where excessive fiber accumulation is likely, to the low-weight portion corresponding portion 420. This allows for appropriate weight adjustment of both the high-weight portion corresponding portion 410 and the low-weight portion corresponding portion 420, enabling the manufacture of a biased absorbent having a large degree of fiber material bias and a balanced grammage as a whole.

[0403] Regarding the fiber re-deposition technology using a scraper roller in the present invention, the technology described in Japanese Patent Application Laid-Open No. 2018-11630 can be appropriately applied, for example.

[0404] The fiber material re-accumulation mechanism using the scraper roller 45 basically does not select the form of the collecting recess 40, for example, it can be applied to Figure 24 Any of the two forms shown, but particularly applicable to Figure 24 When at least a portion of the high-weight portion corresponding portion 410 is deeper than the recess depth D of the low-weight portion corresponding portion 420 as shown in (a), the method is the same as that applied to Figure 24 Compared to the embodiment in which the depth D of the concave portion 40 for gathering is uniform as shown in (b), further improvement in the uniformity of the basic weight of the low basic weight portion corresponding portion 420 can be expected.

[0405] That is, when the depth D of the recess is uniform, in order to obtain an absorbent with a large degree of bias in the fiber material, the fiber material is preferentially accumulated in the portion 410 corresponding to the high-weight portion. The outer surface of the fiber accumulation material (the surface on the opposite side of the contact surface side of the bottom surface of the gathering recess 40) after the fiber material in the portion 420 corresponding to the low-weight portion is located inside the gathering recess 40, and the protrusion 452 of the scraper roller 45 is difficult to contact the outer surface of the fiber accumulation material (refer to Figure 24(b)). In contrast, when the recess depth D of the portion 410 corresponding to the high gram weight portion is deeper than the recess depth D of the portion 420 corresponding to the low gram weight portion, when the fiber material is preferentially deposited in the portion 410 corresponding to the high gram weight portion, the difference in recess depth D between the two corresponding portions 410 and 420 corresponds to the difference in the amount of fiber deposited in the two corresponding portions 410 and 420. This increases the degree of bias of the fiber material between the two corresponding portions 410 and 420, and enables the outer surface of the fiber deposited in the portion 420 corresponding to the low gram weight portion just after fiber depositing to be located outside the gathering recess 40 (outside the radial direction of the rotating drum 3 closer to the ring plate 38). In this way, in the re-deposition process using the scraper roller 45 performed after the fiber material is deposited, the outer surface of the fiber deposited in the portion 420 corresponding to the low gram weight portion can be made uniform by using the protrusion 452 of the scraper roller 45 (refer to Figure 24 (a)), thereby achieving an improvement in the uniformity of the grammage of the portion 420 corresponding to the low grammage portion.

[0406] Next, the manufacturing method of the absorbent body of the present invention (fifth to sixth invention) is described, using the absorbent body 10 (see Figure 16 ) is described as an example. Regarding this manufacturing method, the description of the manufacturing apparatus 1A described above can be appropriately applied to any matters not specifically described.

[0407] The method for manufacturing an absorbent body using the manufacturing apparatus 1A includes a fiber accumulation step and a fiber re-accumulation step.

[0408] The above fiber deposition process is as follows Figure 17 and Figure 18 As shown in FIG. 1 , the fiber material is supplied to the outer periphery 3S of the rotating drum 3 in a scattered state while rotating the rotating drum 3 around the outer periphery 2S of the fixed drum 2, so that the fiber material is accumulated in the collecting recess 40 in the predetermined suction area S in the drum circumferential direction X1. Figure 24 As shown, after the above-mentioned fiber accumulation process, the fiber material accumulated in the portion 410 corresponding to the high gram weight portion is scraped by a scraping roller 45 arranged opposite to the outer periphery 3S of the rotating drum 3, and the scraped fiber material is again accumulated in the portion 420 corresponding to the low gram weight portion.

[0409] The above-mentioned fiber accumulation process includes: a high-weight portion priority fiber accumulation process (first suction process) for allowing the fiber material to be preferentially accumulated in the high-weight portion corresponding portion 410; and a fiber accumulation process (second suction process) for allowing the fiber material to be accumulated in the entire portion 410 corresponding to the high-weight portion and the portion 420 corresponding to the low-weight portion, which is implemented in an area of ​​the suction area S that is different from the implementation area of ​​the high-weight portion priority fiber accumulation process.

[0410] In the manufacturing method using the manufacturing apparatus 1A, the high-weight portion priority fiber accumulation step is implemented in the first suction area (high-weight portion priority fiber accumulation area) S1, and the entire surface fiber accumulation step is implemented in the second suction area (entire surface fiber accumulation area) S2 (refer to Figure 18 、 Figures 20 to 22 ).

[0411] In the high-weight portion priority fiber accumulation step, the difference in the flow rate (suction air volume) of the vacuum airflow between the high-weight portion corresponding portion 410 and the low-weight portion corresponding portion 420 is increased compared to the entire fiber accumulation step. This has been described in the description of the manufacturing apparatus 1A.

[0412] According to the manufacturing method of the present invention having the above steps, the following can be obtained: Figure 16 The absorbent body 10A shown in (a) has a large degree of unevenness of the fiber material and a uniform basis weight in the low basis weight portion.

[0413] In the manufacturing method of the present invention, the order of implementing the above two processes is not particularly limited, and they can also be implemented in the order of the whole fiber accumulation process and the high-weight portion priority fiber accumulation process. From the perspective of reliably exerting the prescribed effect of the present invention, it is preferred to implement them in the order of the high-weight portion priority fiber accumulation process and the whole fiber accumulation process. In the manufacturing method using the manufacturing device 1A, the preferred order is implemented (refer to Figure 20 ).

[0414] In the fiber accumulation step, the suction air volume of the low-weight portion corresponding part 420 may be uniform or non-uniform in the cylinder axis direction Y1. Both can be adopted for the purpose of making the basis weight of the low-weight portion of the absorbent body uniform.

[0415] For example, when the partition plate 43 is used, the fiber material is concentratedly accumulated in the central portion of the collecting recess 40 in the cylinder axis direction Y1, and substantially no fiber is accumulated at the two ends in the cylinder axis direction Y1. If this state is maintained, the low-weight portion corresponding portion 420 will be contrary to the purpose of the present invention, and the grammage of the fiber material will become uneven. Therefore, when the partition plate 43 is used, by making the suction air volume of the portion of the collecting recess 40 where the fiber material supply is blocked by the partition plate 43, that is, the two ends in the cylinder axis direction Y1, greater than the portion where the fiber material supply is not blocked by the partition plate 43, that is, the central portion in the cylinder axis direction Y1, the degree of fiber material bias can be further increased, and the grammage uniformity of the low-weight portion can be ensured.

[0416] In the manufacturing apparatus 1A, as described above Figure 4 、 Figure 21 and Figure 22As shown, in the rotating drum 3, two suction adjustment plates 33 and 35 overlapping with the radial direction of the rotating drum 3 are arranged as a suction adjustment body for adjusting the suction air volume. By using this suction adjustment body, with respect to the suction air volume of the low-weight portion corresponding part 420, the size relationship of "the end part of the low-weight portion corresponding part 420 in the cylinder axis direction Y1 > the central part of the low-weight portion corresponding part 420 in the cylinder axis direction Y1" is established. Therefore, in the manufacturing method using the manufacturing device 1A, in the above-mentioned fiber accumulation process, the suction air volume of the central part of the low-weight portion corresponding part 420 in the cylinder axis direction Y1 is smaller than the suction air volume of the two end parts of the low-weight portion corresponding part 420 in the cylinder axis direction Y1.

[0417] Furthermore, in the fiber accumulation step, the suction air volume of the high-weight portion corresponding portion 410 may be uniform or non-uniform in the cylinder axis direction Y1. When manufacturing an absorbent in which the fibrous material in the high-weight portion has a non-uniform basis weight, the suction air volume of the high-weight portion corresponding portion 410 is typically set to be non-uniform in the cylinder axis direction Y1.

[0418] For example, Figure 16 The high-weight part 11 of the absorbent body 10 shown has a standard-weight part 11B at both ends in a direction (transverse Y) perpendicular to one direction (longitudinal X), and the weight of the fiber material is smaller than that of the middle-high part 11A in the center sandwiched by the standard-weight part 11B. When manufacturing the absorbent body 10, in the above-mentioned fiber accumulation process, corresponding to the high-weight part 11 with uneven weight of the fiber material, the suction air volume at both ends of the high-weight part corresponding part 410 in the cylindrical axis direction Y1 (the parts corresponding to the standard-weight part 11B) is smaller than the suction air volume of the central part in the cylindrical axis direction Y1 of the high-weight part corresponding part 410.

[0419] In the manufacturing apparatus 1A, as described above Figure 4 、 Figure 21 and Figure 22 As shown, in the rotating drum 3, two suction adjustment plates 33 and 35 overlapping with the radial direction of the rotating drum 3 are arranged as a suction adjustment body for adjusting the suction air volume. By using this suction adjustment body, with respect to the suction air volume of the high gram weight portion corresponding part 410, the size relationship of "the central part of the high gram weight portion corresponding part 410 in the cylinder axis direction Y1 (the part forming the middle and high part 11A) > the two end parts of the high gram weight portion corresponding part 410 in the cylinder axis direction Y1" is established. Therefore, in the manufacturing method using the manufacturing device 1A, in the above-mentioned fiber accumulation process, the suction air volume of the two end parts of the high gram weight portion corresponding part 410 in the cylinder axis direction Y1 is smaller than the suction air volume of the central part of the high gram weight portion corresponding part 410 in the cylinder axis direction Y1.

[0420] In the above-mentioned fiber accumulation process, from the perspective of stably manufacturing an absorbent body with a large degree of bias in fiber material, typically, the suction air volume of at least a portion of the high-weight portion corresponding portion 410 is set to be larger than the suction air volume of the low-weight portion corresponding portion 420.

[0421] For example, when the suction air volume of the part with the largest suction air volume in the high-weight portion corresponding part 410 (for example, the central part of the high-weight portion corresponding part 410 in the cylindrical axis direction Y1) is 100%, the suction air volume of each part of the gathering recess 40 can be set as follows.

[0422] The suction air volume of the portion other than the portion with the largest suction air volume in the high basic weight portion corresponding portion 410 (for example, the end portion in the cylindrical axis direction Y1 of the high basic weight portion corresponding portion 410) is preferably 5 to 50%, and more preferably 10 to 40%.

[0423] The suction air volume of the end portion of the low basic weight portion corresponding portion 420 in the cylindrical axis direction Y1 is preferably 10 to 50%, and more preferably 15 to 40%.

[0424] The suction air volume of the central portion of the low basic weight portion corresponding portion 420 in the cylindrical axis direction Y1 is preferably 5 to 50%, more preferably 10 to 30%.

[0425] In the fiber accumulation step, from the perspective of stably producing an absorbent having a high degree of fiber material bias, in the high-weight portion priority fiber accumulation step, the suction air volume of at least a portion of the high-weight portion corresponding portion 410 is preferably greater than the suction air volume of the low-weight portion corresponding portion 420. Furthermore, in the entire fiber accumulation step, the suction air volume of at least a portion of the high-weight portion corresponding portion 410 is preferably equal to or greater than the suction air volume of the low-weight portion corresponding portion 420. Specifically, assuming that the suction air volume of the high-weight portion corresponding portion 410 is 41V and the suction air volume of the low-weight portion corresponding portion 420 is 42V, it is preferable that, in the first suction zone S1 where the high-weight portion priority fiber accumulation step is performed, the magnitude relationship of "(41V / 42V)>1" holds, and in the second suction zone S2 where the entire fiber accumulation step is performed, the magnitude relationship of "(41V / 42V)≥1" holds.

[0426] In the high-weight portion preferential fiber accumulation step, the supply of the fiber material to at least a portion of the collecting recess 40 may be suppressed. Figure 17 、 Figure 18 、 Figure 21 and Figure 22) function, suppresses the supply of fiber material to both ends of the collecting recess 40 in the barrel axis direction Y1, and as a result, in the high grammage portion priority fiber accumulation step (first suction area S1), an excess amount of fiber material exceeding the height of the ring plate 38 can be accumulated in the central portion of the high grammage portion corresponding portion 410 in the barrel axis direction Y1. In the manufacturing method using the manufacturing apparatus 1A, in the high grammage portion priority fiber accumulation step, the partition plate 43 is used to accumulate the excess fiber material in the central portion of the high grammage portion corresponding portion 410 in the barrel axis direction Y1, and then, when the fiber accumulation step (entire fiber accumulation step) is about to end or has just ended, the scraper roller 45 is used to scrape the excess fiber material accumulated in the high grammage portion corresponding portion 410 and accumulate it in the low grammage portion corresponding portion 420.

[0427] The high-weight portion priority fiber accumulation step and the entire fiber accumulation step can be used to vary the amount of fiber material supplied to the collecting recess 40. For example, the amount of fiber material supplied to the collecting recess 40 can be set such that the relationship of "high-weight portion priority fiber accumulation step > entire fiber accumulation step" is established. This, in conjunction with the effects of the characteristic structure of the present invention, can further increase the degree of bias in the absorbent body.

[0428] As a method of making different the amount of fiber material supplied to the gathering recess 40 in the high-weight portion priority fiber accumulation process and the entire fiber accumulation process, for example, a partition component can be arranged inside the pipe 51 (the supply passage 50 containing the raw material of the fiber material), and the interior can be divided into a part corresponding to the first suction area S1 for implementing the high-weight portion priority fiber accumulation process and a part corresponding to the second suction area S2 for implementing the entire fiber accumulation process, and the method of making different the amount of fiber material supplied to each other in the two parts.

[0429] In the high-weight portion preferential fiber accumulation step, a water-absorbing polymer may be supplied to the accumulation recess 40. The manufacturing apparatus 1A is as described above. Figure 17 and Figure 18 As shown, a water-absorbent polymer introduction portion 54 for introducing water-absorbent polymer particles into the supply passage 50 is provided in the duct 51 . The water-absorbent polymer introduction portion 54 supplies the water-absorbent polymer to the collecting recess 40 , thereby obtaining an absorbent body containing the water-absorbent polymer.

[0430] As mentioned above, the present invention (fifth and sixth inventions) has been described based on preferred embodiments thereof. However, the present invention is not limited to the above embodiments and can be modified appropriately without departing from the gist of the present invention.

[0431] Regarding the above-mentioned embodiments of the present invention (fifth and sixth inventions), the following contents are further disclosed.

[0432] <1B>

[0433] A method for manufacturing an absorbent body, which uses a fiber accumulation device to manufacture an absorbent body having a high-weight portion with a relatively large weight of fiber material and a relatively small low-weight portion in one direction, wherein the method for manufacturing the absorbent body

[0434] The fiber accumulation device includes a fixed drum and a rotating drum, wherein the rotating drum is arranged to be rotatable around the outer periphery of the fixed drum, and the outer periphery of the rotating drum is provided with a collecting recess for collecting the fiber material, so that the fiber material transported by the air flow generated by suction from the side of the fixed drum is accumulated on the bottom surface of the collecting recess.

[0435] The gathering recess has a high-weight portion corresponding portion forming the high-weight portion and a low-weight portion corresponding portion forming the low-weight portion in the circumferential direction of the tube.

[0436] The manufacturing method of the absorbent body comprises:

[0437] A fiber accumulation step of supplying fiber material in a scattered state to the outer periphery of the rotating drum while rotating the rotating drum around the outer periphery of the fixed drum, so that the fiber material accumulates in the collecting recess in a predetermined suction area in the drum circumferential direction; and

[0438] After the fiber accumulation process, a scraping roller arranged opposite to the outer periphery of the rotating drum is used to scrape the fiber material accumulated on the portion corresponding to the high-weight portion, and the scraped fiber material is again accumulated on the portion corresponding to the low-weight portion in a re-fiber accumulation process.

[0439] The fiber accumulation process comprises: a high-weight portion priority fiber accumulation process for causing the fiber material to be preferentially accumulated on the portion corresponding to the high-weight portion; and a fiber accumulation process for causing the fiber material to be accumulated on the entire portion corresponding to the high-weight portion and the portion corresponding to the low-weight portion, which is implemented in an area of ​​the suction area different from the implementation area of ​​the high-weight portion priority fiber accumulation process.

[0440] In the high-basic-weight-portion-preferential fiber accumulation step, the difference in flow rate of the air flow between the portion corresponding to the high-basic-weight portion and the portion corresponding to the low-basic-weight portion is made larger than in the entire fiber accumulation step.

[0441] <2B>

[0442] The method for producing an absorbent body as described in <1B> above, wherein:

[0443] In the fiber accumulation step, the flow rate of the air flow in the portion corresponding to the low basic weight portion is made uneven in the cylinder axis direction.

[0444] <3B>

[0445] The method for producing an absorbent body as described in <2B> above, wherein:

[0446] In the fiber accumulation step, the flow rate of the air flow in the central portion of the low basic weight portion corresponding portion in the cylindrical axis direction is made smaller than the flow rates of the air flow at both ends of the low basic weight portion corresponding portion in the cylindrical axis direction.

[0447] <4B>

[0448] The method for producing an absorbent body according to any one of <1B> to <3B>, wherein:

[0449] In the high-weight portion preferential fiber deposition process, the flow rate of the air flow in at least a portion of the portion corresponding to the high-weight portion is made greater than the flow rate of the air flow in the portion corresponding to the low-weight portion.

[0450] In the entire fiber covering process, the flow rate of the air flow in at least a portion of the portion corresponding to the high grammage portion is made the same as or greater than the flow rate of the air flow in the portion corresponding to the low grammage portion.

[0451] <5B>

[0452] The method for producing an absorbent body according to any one of <1B> to <4B>, wherein:

[0453] The high-weight portion preferential fiber accumulation step and the entire fiber accumulation step are carried out in this order.

[0454] <6B>

[0455] The method for producing an absorbent body according to any one of <1B> to <5B>, wherein:

[0456] In the high-weight portion preferential fiber accumulation step, supply of the fiber material to at least a portion of the collecting recess is suppressed.

[0457] <7B>

[0458] The method for producing an absorbent body according to any one of <1B> to <6B>, wherein:

[0459] The amount of the fiber material supplied to the collecting recess is made different between the high-weight portion preferential fiber accumulation step and the entire fiber accumulation step.

[0460] <8B>

[0461] The method for producing an absorbent body according to any one of <1B> to <7B>, wherein:

[0462] In the high-weight portion of the absorbent body, both end portions in a direction perpendicular to the one direction have a fiber material with a weight smaller than that of the central portion sandwiched between the both end portions.

[0463] In the fiber accumulation step, the flow rate of the air flow at both ends of the high-weight portion corresponding to the high-weight portion in the cylindrical axis direction is made smaller than the flow rate of the air flow at the central portion in the cylindrical axis direction of the high-weight portion corresponding to the high-weight portion.

[0464] <9B>

[0465] The method for producing an absorbent body according to any one of <1B> to <8B>, wherein:

[0466] In the high-weight portion preferential fiber accumulation step, a water-absorbing polymer is supplied to the accumulation recessed portions.

[0467] <10B>

[0468] A manufacturing device for an absorbent body, which can be used to manufacture an absorbent body having a high-weight portion with a relatively large amount of fiber material and a relatively small low-weight portion in one direction, wherein the manufacturing device for the absorbent body

[0469] The invention comprises a fixed drum and a rotating drum, wherein the rotating drum is arranged to be rotatable around the outer periphery of the fixed drum, and the outer periphery of the rotating drum is provided with a collecting recess for collecting fiber materials. As the rotating drum rotates, the fiber materials conveyed by the air flow generated by suction from the side of the fixed drum are deposited on the bottom surface of the collecting recess in a predetermined suction area in the circumferential direction of the drum.

[0470] The gathering recess has a high-weight portion corresponding portion forming the high-weight portion and a low-weight portion corresponding portion forming the low-weight portion in the circumferential direction of the tube.

[0471] The suction area has, in the circumferential direction of the tube: a first suction area that preferentially accumulates the fiber material in the portion corresponding to the high grammage portion; and a second suction area that accumulates the fiber material in both the portion corresponding to the high grammage portion and the portion corresponding to the low grammage portion.

[0472] The first suction area makes the difference in the flow rate of the air flow between the portion corresponding to the high-weight portion and the portion corresponding to the low-weight portion larger than that of the second suction area.

[0473] It also has a scraping roller arranged opposite to the outer periphery of the rotating drum, and the scraping roller is configured to scrape the fiber material accumulated in the corresponding part of the high-weight part and accumulate the scraped fiber material in the corresponding part of the low-weight part.

[0474] <11B>

[0475] The manufacturing apparatus of the absorbent body as described in <10B> above, wherein

[0476] In the first suction area, the flow rate of the air flow in at least a portion of the portion corresponding to the high-weight portion is greater than the flow rate of the air flow in the portion corresponding to the low-weight portion.

[0477] In the second suction area, the flow rate of the air flow in at least a portion of the high-weight portion corresponding portion is the same as or greater than the flow rate of the air flow in the low-weight portion corresponding portion.

[0478] <12B>

[0479] The manufacturing apparatus of the absorbent body as described in <10B> or <11B> above, wherein

[0480] A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder.

[0481] The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening.

[0482] The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction.

[0483] In the portion of the rotating cylinder opposite to the outer periphery of the fixed cylinder, a non-air-permeable opening sealing component is arranged corresponding to the portion corresponding to the low-weight portion, and the portion of the opposite portion corresponding to the portion corresponding to the high-weight portion is not provided with the opening sealing component.

[0484] In the first suction region, the opening closing member overlaps the opening of the first suction region corresponding portion, thereby hindering suction of the low basic weight portion corresponding portion.

[0485] <13B>

[0486] The manufacturing apparatus of the absorbent body as described in <12B> above, wherein

[0487] In the first suction region, when the opening sealing member overlaps the opening of the first suction region corresponding portion, a gap exists between the peripheral edge of the opening and the opening sealing member.

[0488] <14B>

[0489] The apparatus for producing an absorbent body according to any one of <10B> to <13B>, wherein

[0490] Regarding the flow rate of the air flow, the relationship of size of the high-weight portion corresponding portion>the end portion in the cylindrical axis direction of the low-weight portion corresponding portion>the central portion in the cylindrical axis direction of the low-weight portion corresponding portion holds true.

[0491] <15B>

[0492] The apparatus for producing an absorbent body according to any one of <10B> to <14B>, wherein

[0493] At least a portion of the high basic weight portion corresponding portion has a recessed portion deeper than that of the low basic weight portion corresponding portion.

[0494] <16B>

[0495] The apparatus for manufacturing an absorbent body according to any one of <10B> to <15B>, wherein

[0496] The length of the first suction region in the cylinder circumferential direction is less than or equal to 2 / 3 of the length of the suction region in the cylinder circumferential direction.

[0497] <17B>

[0498] The apparatus for manufacturing an absorbent body according to any one of <10B> to <16B>, wherein

[0499] A member for suppressing the supply of the fiber material to at least a portion of the collecting recess is provided.

[0500] <18B>

[0501] The manufacturing apparatus of the absorbent body as described in <17B> above, wherein

[0502] The member for suppressing the supply of the fiber material is a partition plate that physically blocks the supply of the fiber material.

[0503] <19B>

[0504] The manufacturing apparatus of the absorbent body as described in <18B> above, wherein

[0505] A pipe is provided which is arranged to cover the suction area and has a supply passage for a raw material including a fiber material.

[0506] A pair of the partition plates are arranged on both sides in the cylinder axis direction across the collecting recess in the interior of the duct.

[0507] <20B>

[0508] The manufacturing apparatus of the absorbent body as described in <19B> above, wherein

[0509] The opposing surface of each of the pair of partition plates is inclined relative to the radial direction of the rotating drum and extends from the outer side to the inner side in the radial direction.

[0510] The distance between the facing surface of one partition plate and the facing surface of the other partition plate of the pair of partition plates gradually decreases from the outer side to the inner side in the radial direction of the rotating drum.

[0511] <21B>

[0512] The manufacturing apparatus of the absorbent body as described in <19B> or <20B> ​​above, wherein

[0513] The partition plate is arranged so that at least a portion of the partition plate overlaps with a portion where the supply passage and the suction region intersect (an opening of the duct on the suction region side).

[0514] <22B>

[0515] The apparatus for producing an absorbent body according to any one of <10B> to <21B>, wherein

[0516] A pipe is provided which is arranged to cover the suction area and has a supply passage for a raw material including a fiber material therein.

[0517] The scraper roller is arranged inside the duct on the downstream side of the suction region (the second suction region) in the rotation direction of the rotating drum.

[0518] <23B>

[0519] The apparatus for producing an absorbent body according to any one of <10B> to <22B>, wherein

[0520] The rotation of the scraper roller can be adjusted.

[0521] <24B>

[0522] The apparatus for producing an absorbent body according to any one of <10B> to <23B>, wherein

[0523] a duct having a supply passage for a raw material including a fiber material and arranged so as to cover the suction area; and a guide member for guiding the scattered fiber material scraped by the scraper roller to a desired position of the collecting recess,

[0524] The guide member extends from a surface of the inner surface of the duct that faces the collecting recessed portion toward the collecting recessed portion.

[0525] <25B>

[0526] The manufacturing apparatus of the absorbent body as described in <24B> above, wherein

[0527] The guide member is provided inside the duct at a position upstream of the scraper roller in the rotation direction of the rotary drum.

[0528] <26B>

[0529] The apparatus for producing an absorbent body according to any one of <10B> to <25B>, wherein

[0530] The first suction area and the second suction area are configured so that the flow rates of the airflow can be adjusted independently.

[0531] All the structures of only one embodiment described above can be used together as appropriate within the scope of the present invention. The embodiments within the scope of the first to fourth inventions or the fifth to sixth inventions can naturally be used together, and the first to fourth inventions and the fifth to sixth inventions can also be used together.

[0532] Industrial applicability

[0533] According to the present invention (the first to fourth inventions), it is possible to provide an absorbent body in which the degree of deviation of the fiber material is large in the direction corresponding to the flow direction during production.

[0534] Furthermore, according to the present invention (fifth to sixth inventions), it is possible to provide an absorbent body in which the degree of unevenness of the fiber material is large and the basis weight of the low basis weight portion is uniform.

Claims

1. A fiber accumulation device comprising a fixed drum and a rotating drum, the rotating drum being arranged to be rotatable around the outer periphery of the fixed drum, the outer periphery of the rotating drum being provided with a collecting recess for accumulating fiber material, the rotating drum being rotated to convey the collecting recess in a conveying direction along the circumferential direction of the drum, and the fiber material conveyed by the air flow generated by suction from the fixed drum side being deposited on the bottom surface of the collecting recess in a prescribed suction area in the circumferential direction of the drum, thereby producing a fiber accumulation body having a plurality of portions with different gram weights in the conveying direction, the fiber accumulation device being characterized by: The gathering recess has a plurality of fiber accumulation areas corresponding to a plurality of parts of the fiber accumulation body having different gram weights in the circumferential direction of the tube, the plurality of fiber accumulation areas including a first fiber accumulation area and a second fiber accumulation area forming a part with a higher gram weight than the first fiber accumulation area. The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface. A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder. The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening. The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction. A first non-air-permeable opening sealing member corresponding to the first fiber accumulation area and a second non-air-permeable opening sealing member corresponding to the second fiber accumulation area are arranged on the outer circumference of the rotating cylinder facing the fixed cylinder. During the conveying process of the collecting recess in the first suction area, the first opening closing member and the second opening closing member overlap the opening corresponding to the first suction area, thereby reducing the flow rate of the air flow in the first fiber accumulation area and the second fiber accumulation area. In the first suction region, the first opening closing member overlaps the opening of the first suction region corresponding portion, and the first suction region corresponding portion is spaced apart from the first opening closing member by a predetermined spacing distance G1. In the first suction region, when the second opening closing member overlaps the opening of the first suction region corresponding portion, the first suction region corresponding portion is separated from the second opening closing member by a predetermined spacing distance G2, and The relationship of the spacing distance G1 < the spacing distance G2 holds true.

2. The fiber deposition device according to claim 1, wherein: The spacing distance G1 and the spacing distance G2 are respectively greater than 0 mm and less than 3 mm.

3. The fiber deposition device according to claim 1 or 2, wherein: With respect to the length of the first opening closing member in the conveying direction orthogonal to the conveying direction, the length of the opening portion in the conveying direction orthogonal to the conveying direction of the portion corresponding to the first suction area that overlaps with the first opening closing member in the first suction area is not less than 10% and not more than 90%. Relative to the length of the second opening sealing member in the conveying orthogonal direction, the length of the opening portion in the conveying orthogonal direction of the first suction area corresponding portion overlapping with the second opening sealing member in the first suction area is greater than 10% and less than 90%.

4. The fiber deposition device according to claim 1 or 2, wherein: A ratio of an area of ​​the opening of the first suction region corresponding portion to an area of ​​the first suction region corresponding portion is 5% or more and 80% or less.

5. The fiber deposition device according to claim 1 or 2, wherein: The rotating drum includes: a drum body disposed opposite to the outer peripheral portion of the fixed drum; and an outer layer portion disposed farther from the fixed drum than the drum body. The first opening sealing member and the second opening sealing member are respectively arranged in the cylinder body at positions spaced a predetermined distance from the outer layer portion toward the cylinder body.

6. The fiber deposition device according to claim 5, wherein: The outer layer portion includes: a recess bottom forming plate which forms the bottom of the collecting recess and is formed by an air-permeable component having a plurality of suction holes through which the air flow can pass; and a recess dividing plate which is a component for forming a groove-shaped recess in the fiber-accumulating body.

7. The fiber deposition device according to claim 5, wherein: The outer layer portion includes a suction adjustment plate that is a member for adjusting a flow rate of the air flow in the collecting recess.

8. The fiber deposition device according to claim 1 or 2, wherein: The collecting recess has, in addition to the first fiber accumulation area and the second fiber accumulation area, a suction non-restriction area where suction is not restricted.

9. The fiber deposition device according to claim 8, wherein: The suction non-restriction area does not have the first opening closing member and the second opening closing member.

10. A fiber accumulation device comprising a fixed drum and a rotating drum, the rotating drum being arranged to be rotatable around the outer periphery of the fixed drum, the outer periphery of the rotating drum being provided with a collecting recess for accumulating fiber material, the rotating drum being rotated to convey the collecting recess in a conveying direction along the circumferential direction of the drum, and the fiber material conveyed by the air flow generated by suction from the fixed drum side being deposited on the bottom surface of the collecting recess in a prescribed suction area in the circumferential direction of the drum, thereby producing a fiber accumulation body having a plurality of portions with different gram weights in the conveying direction, the fiber accumulation device being characterized by: The gathering recess has a plurality of fiber accumulation areas corresponding to a plurality of parts of the fiber accumulation body having different gram weights in the circumferential direction of the tube, the plurality of fiber accumulation areas including a first fiber accumulation area and a second fiber accumulation area forming a part with a higher gram weight than the first fiber accumulation area. The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface. A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder. The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening. The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction. A first non-air-permeable opening sealing member corresponding to the first fiber accumulation area and a second non-air-permeable opening sealing member corresponding to the second fiber accumulation area are arranged on the outer circumference of the rotating cylinder facing the fixed cylinder. During the conveying process of the collecting recess in the first suction area, the first opening closing member and the second opening closing member overlap the opening corresponding to the first suction area, thereby reducing the flow rate of the air flow in the first fiber accumulation area and the second fiber accumulation area. The first opening sealing member is longer in the conveying direction orthogonal to the conveying direction than the opening corresponding to the first suction area, and in the first suction area, the first opening sealing member is overlapped with the opening and extends over the entire length of the opening in the conveying direction. The second opening closing component is shorter in length in the conveying orthogonal direction than the opening corresponding to the first suction area. When the second opening closing component overlaps with the opening in the first suction area, there is a portion of the opening in the conveying orthogonal direction that is not covered by the second opening closing component.

11. The fiber deposition device according to claim 10, wherein: The length of the first opening sealing member in the direction perpendicular to the conveyance is not less than 110% and not more than 1000% of the length of the opening of the first suction region corresponding portion in the direction perpendicular to the conveyance.

12. The fiber deposition device according to claim 10 or 11, wherein: The length of the second opening sealing member in the direction perpendicular to the conveyance is equal to or greater than 50% and less than 100% of the length of the opening of the first suction region corresponding portion in the direction perpendicular to the conveyance.

13. The fiber deposition device according to claim 10 or 11, wherein: In the first suction area, when the first opening sealing member overlaps the opening of the first suction area corresponding portion, the first suction area corresponding portion and the first opening sealing member are separated by a distance greater than 0 mm and less than 3 mm. In the first suction area, when the second opening sealing member overlaps the opening of the first suction area corresponding portion, the first suction area corresponding portion and the second opening sealing member are separated by a distance greater than 0 mm and less than 3 mm.

14. The fiber deposition device according to claim 10 or 11, wherein: A ratio of an area of ​​the opening of the first suction region corresponding portion to an area of ​​the first suction region corresponding portion is 5% or more and 80% or less.

15. The fiber deposition device according to claim 10 or 11, wherein: The rotating drum includes: a drum body disposed opposite to the outer peripheral portion of the fixed drum; and an outer layer portion disposed farther from the fixed drum than the drum body. The first opening sealing member and the second opening sealing member are respectively arranged in the cylinder body at positions spaced a predetermined distance from the outer layer portion toward the cylinder body.

16. The fiber deposition device according to claim 15, wherein: The outer layer portion includes: a recess bottom forming plate which forms the bottom of the collecting recess and is formed by an air-permeable component having a plurality of suction holes through which the air flow can pass; and a recess dividing plate which is a component for forming a groove-shaped recess in the fiber-accumulating body.

17. The fiber deposition device according to claim 15, wherein: The outer layer portion includes a suction adjustment plate that is a member for adjusting a flow rate of the air flow in the collecting recess.

18. The fiber deposition device according to claim 10 or 11, wherein: The collecting recess has, in addition to the first fiber accumulation area and the second fiber accumulation area, a suction non-restriction area where suction is not restricted.

19. The fiber deposition device according to claim 18, wherein: The suction non-restriction area does not have the first opening closing member and the second opening closing member.

20. A method for manufacturing an absorbent body, comprising using a fiber deposition device to manufacture an absorbent body having a plurality of portions having different grammages in one direction, wherein: The fiber accumulation device includes a fixed drum and a rotating drum, the rotating drum being arranged to be rotatable around the outer periphery of the fixed drum, and having a collecting recess on the outer periphery of the rotating drum for accumulating fiber materials, and while the rotating drum is rotated to convey the collecting recess in a conveying direction along the circumferential direction of the drum, the fiber materials conveyed by the air flow generated by suction from the side of the fixed drum are deposited on the bottom surface of the collecting recess in a prescribed suction area in the circumferential direction of the drum. The collecting recess has a plurality of fiber accumulation areas corresponding to the plurality of parts of the absorbent body having different gram weights in the circumferential direction of the tube. The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface. A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder. The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening. The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction. A plurality of non-air-permeable opening sealing members are arranged in the circumferential direction of the drum in a portion of the rotating drum facing the outer periphery of the fixed drum, corresponding to at least a portion of the plurality of fiber accumulation areas of the collecting recess. During the conveying process of the collecting recess in the first suction area, the opening of the collecting recess is overlapped with the opening of the corresponding portion of the first suction area, thereby reducing the flow rate of the air flow in the fiber accumulation area corresponding to the opening of the collecting recess. The plurality of opening sealing members arranged in the circumferential direction of the cylinder are respectively spaced apart from the first suction area corresponding portion by a predetermined spacing distance in a state where the openings of the first suction area corresponding portion are overlapped with the first suction area corresponding portion in the first suction area, and In the plurality of opening sealing members arranged in the circumferential direction of the cylinder, the spacing distances are different from each other, and the plurality of opening sealing members are arranged in a manner such that the spacing distances gradually change from one side to the other side in the circumferential direction of the cylinder. The method comprises the step of supplying the fiber material in a scattered state to the outer periphery of the rotating cylinder while rotating the rotating cylinder around the outer periphery of the fixed cylinder, and depositing the fiber material in the collecting recess in the suction area. In the fiber accumulation step, in the first suction region, among the plurality of fiber accumulation regions corresponding to the plurality of opening-closing members, the flow rate of the air flow is greater in the fiber accumulation region having a longer spacing therebetween.

21. The method for manufacturing an absorbent body according to claim 20, wherein: A plurality of the openings are arranged in the cylinder axis direction in the portion corresponding to the first suction area, and a plurality of the opening closing members are arranged in the cylinder axis direction in the portion of the rotating cylinder facing the outer periphery of the fixed cylinder. During the conveying process of the collecting recess in the first suction area, the plurality of opening closing members arranged in the cylinder axis direction overlap with the plurality of the openings arranged in the cylinder axis direction. The plurality of opening-sealing members arranged in the cylinder axis direction are spaced apart from the first suction region corresponding portion by a predetermined spacing distance in a state where the openings of the first suction region corresponding portion overlap in the first suction region, and The plurality of opening-sealing components arranged in the cylinder axis direction have different spacing distances from each other, and the plurality of opening-sealing components are arranged in such a manner that the spacing distance gradually changes from one side to the other side in the cylinder axis direction.

22. A method for manufacturing an absorbent body, comprising using a fiber deposition device to manufacture an absorbent body having a plurality of portions having different basis weights in one direction, wherein: The fiber accumulation device includes a fixed drum and a rotating drum, the rotating drum being arranged to be rotatable around the outer periphery of the fixed drum, and having a collecting recess on the outer periphery of the rotating drum for accumulating fiber materials, and while the rotating drum is rotated to convey the collecting recess in a conveying direction along the circumferential direction of the drum, the fiber materials conveyed by the air flow generated by suction from the side of the fixed drum are deposited on the bottom surface of the collecting recess in a prescribed suction area in the circumferential direction of the drum. The collecting recess has a plurality of fiber accumulation areas corresponding to the plurality of parts of the absorbent body having different gram weights in the circumferential direction of the tube. The suction region includes, in the cylinder circumferential direction, a first suction region where suction from the fixed cylinder side can be performed locally and a second suction region where suction can be performed over the entire surface. A first suction region corresponding portion corresponding to the first suction region and a second suction region corresponding portion corresponding to the second suction region are arranged on the outer periphery of the fixed cylinder. The first suction region corresponding portion is formed of a non-air-permeable member partially provided with an opening, and the air flow can pass through the first suction region corresponding portion in the thickness direction only through the opening. The second suction region corresponding portion does not include any non-air-permeable member, and the air flow can pass through the entire area of ​​the second suction region corresponding portion in the thickness direction. A plurality of non-air-permeable opening sealing members are arranged in the circumferential direction of the drum in a portion of the rotating drum facing the outer periphery of the fixed drum, corresponding to at least a portion of the plurality of fiber accumulation areas of the collecting recess. During the conveying process of the collecting recess in the first suction area, the opening of the collecting recess is overlapped with the opening of the corresponding portion of the first suction area, thereby reducing the flow rate of the air flow in the fiber accumulation area corresponding to the opening of the collecting recess. The plurality of opening-sealing components arranged in the circumferential direction of the cylinder have different lengths in the conveying direction perpendicular to the conveying direction of the opening-sealing components, and the plurality of opening-sealing components are arranged in such a manner that the lengths in the conveying direction perpendicular to the conveying direction of the opening-sealing components gradually change from one side to the other side of the circumferential direction of the cylinder. The method comprises the step of supplying the fiber material in a scattered state to the outer periphery of the rotating cylinder while rotating the rotating cylinder around the outer periphery of the fixed cylinder, and depositing the fiber material in the collecting recess in the suction area. In the fiber accumulation step, in the first suction area, among the fiber accumulation areas corresponding to the plurality of opening closing members, the shorter the length of the opening closing member in the direction perpendicular to conveyance, the greater the flow rate of the air flow in the fiber accumulation area.

23. The method for manufacturing an absorbent body according to claim 22, wherein: A plurality of the openings are arranged in the cylinder axis direction at a portion corresponding to the first suction area, and a plurality of the opening closing members are arranged in the cylinder axis direction at a portion of the rotating cylinder opposite to the outer periphery of the fixed cylinder. During the conveying process of the collecting recess in the first suction area, the plurality of opening closing members arranged in the cylinder axis direction overlap with the plurality of the openings arranged in the cylinder axis direction. Among the multiple opening closing components arranged in the cylinder axis direction, the lengths in the conveying direction orthogonal to the conveying direction of the opening closing components are different from each other, and the multiple opening closing components are arranged in a manner such that the lengths in the conveying direction orthogonal to the opening closing components gradually change from one side to the other side of the cylinder axis direction.

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