JP7428497B2 - Absorbent manufacturing method - Google Patents

Description

The present invention relates to a method for continuously manufacturing a plurality of sheet pieces by cutting a strip-shaped raw material sheet in two directions that intersect with each other, and a method for manufacturing an absorbent body containing the sheet pieces.

BACKGROUND ART Absorbent bodies containing pulp fibers and synthetic fibers are known as absorbent bodies used in absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads. Regarding such an absorbent body, for example, Patent Document 1 describes an absorbent body that includes hydrophilic fibers and a piece of nonwoven fabric as an aggregate of synthetic fibers, and as a manufacturing method of the absorbent body, the fibers are bonded together. A manufacturing method is described that includes the steps of pulverizing a nonwoven fabric having a three-dimensional structure using a cutter mill method to obtain nonwoven fabric pieces, and mixing the nonwoven fabric pieces with hydrophilic fibers.

Japanese Patent Application Publication No. 2002-301105

As described in Patent Document 1, when nonwoven fabric pieces are manufactured by crushing nonwoven fabric using a cutter mill method, it is difficult to form nonwoven fabric pieces of a desired size, and it is difficult to form nonwoven fabric pieces of a desired size. Variations occur. As a result, the structure of the absorbent body including the formed nonwoven fabric pieces may become uneven, which may cause a foreign body sensation during use.

In addition, sheet pieces such as the aforementioned nonwoven fabric pieces are bulkier and have better compression recovery properties than fibers such as pulp, and have the property of being easily deformed by external force and easily returning to their original state when the external force is removed. Therefore, the absorbent body containing the sheet piece has excellent physical properties such as flexibility, fit, and compression recovery. However, the absorbent body incorporated in absorbent articles such as disposable diapers is frequently subjected to loads from various directions while the absorbent article is being worn. A similar load is applied to the sheet piece, and as a result of repeated deformation and restoration due to compression of the sheet piece, the sheet piece becomes flattened and the various physical properties originally possessed by the absorbent body containing the sheet piece deteriorate. was there. Patent Document 1 does not describe the problem of physical property deterioration that accompanies the use of such sheet pieces, and naturally does not describe a method for solving the problem.

The object of the present invention is to provide a method for manufacturing a sheet piece that can efficiently produce a sheet piece that is bulky, has excellent compression recovery properties, is excellent in durability, and does not easily deteriorate in physical properties with use, and an absorbent material containing the sheet piece. The present invention relates to providing a method for manufacturing a body.

The present invention transports a belt-shaped raw material sheet containing synthetic fibers, partially applies stiffening treatment to the raw material sheet, and makes the treated part of the raw material sheet stiffer than the peripheral part of the treated part. a first cutting step of transporting the raw material sheet that has undergone the rigidity imparting step and cutting the raw material sheet in a first direction to obtain a narrow sheet; The method includes a second cutting step of conveying the sheet and cutting the narrow sheet in a second direction intersecting the first direction to obtain a plurality of sheet pieces.

The present invention also provides a method for manufacturing an absorbent body containing a plurality of sheet pieces, comprising a step of conveying the sheet pieces manufactured by the above-described manufacturing method of the present invention to a predetermined stacking section by air flow and stacking them. A method for manufacturing an absorbent body having the following steps.

According to the present invention, there is provided a method for manufacturing a sheet piece that can efficiently produce a sheet piece that is bulky, has excellent compression recovery properties, is excellent in durability, and does not easily deteriorate in physical properties with use, and an absorbent material containing the sheet piece. A method of manufacturing a body is provided.

FIG. 1 is a schematic perspective view of an embodiment of an absorbent body manufactured by the absorbent body manufacturing method of the present invention. FIGS. 2(a) and 2(b) are schematic perspective views of an embodiment of a sheet piece manufactured by the sheet piece manufacturing method of the present invention, respectively. FIG. 3 is a schematic cross-sectional view taken along line II in FIG. 2(a). FIG. 4 is a diagram illustrating the compression recovery property of a sheet piece. FIG. 4(a) is a diagram taking an example of an embodiment of a high-rigidity sheet piece, and FIG. It is a figure which took the sheet piece which does not have as an example. FIG. 5 is a schematic perspective view of another embodiment of a highly rigid sheet piece manufactured by the sheet piece manufacturing method of the present invention. FIG. 6 is a schematic perspective view of an embodiment of a manufacturing apparatus that can be used to carry out the method for manufacturing an absorbent body of the present invention. FIG. 7 is a diagram showing an embodiment of the sheet piece manufacturing method of the present invention carried out in the second supply mechanism (sheet piece manufacturing apparatus) of the manufacturing apparatus shown in FIG. 6. FIG. 8 is a diagram showing another embodiment of the sheet piece manufacturing method of the present invention. FIG. 9 is a diagram showing still another embodiment of the sheet piece manufacturing method of the present invention. FIG. 10 is a diagram showing still another embodiment of the sheet piece manufacturing method of the present invention. FIG. 11 is a diagram showing still another embodiment of the sheet piece manufacturing method of the present invention, and FIG. b) is a schematic side view of the sheet seen from the side.

Hereinafter, the present invention will be described based on preferred embodiments thereof with reference to the drawings. In addition, in the description of the following drawings, the same or similar parts are given the same or similar symbols. The drawings are basically schematic, and the ratio of each dimension may differ from the actual one.

FIG. 1 shows an absorbent body 10 that is an embodiment of the absorbent body manufactured by the absorbent body manufacturing method of the present invention. The absorbent body 10 is used as a component of an absorbent article, and has a vertical direction X corresponding to the front-back direction of a wearer of the absorbent article and a horizontal direction Y orthogonal to the vertical direction X. Further, the absorbent body 10 has two surfaces 10a and 10b that face each other, and one of these two surfaces 10a and 10b is a surface that faces the wearer's skin when the absorbent article is worn (skin-facing surface). The other side is the surface (non-skin facing surface) that faces the side opposite to the skin side (the side of clothing such as shorts) when the absorbent article is worn.

The term "absorbent article" here includes a wide range of articles used to absorb bodily fluids (urine, soft stool, menstrual blood, sweat, etc.) discharged from the human body, including so-called deployable disposable diapers with adhesive tape, Includes pants-type disposable diapers, sanitary napkins, sanitary shorts, incontinence pads, etc. An absorbent body in an absorbent article typically includes a liquid-absorbent absorbent core and a liquid-permeable core wrap sheet that covers the outer surface of the absorbent core. Can be used as a core.

An absorbent article including the absorbent body 10 typically includes a liquid-permeable top sheet that can come into contact with the wearer's skin when worn, a liquid-impermeable or water-repellent back sheet, and a space between these sheets. and a liquid-retaining absorbent body interposed therein. As the top sheet, various nonwoven fabrics or porous synthetic resin sheets can be used, and as the back sheet, synthetic resin films made of polyethylene, polypropylene, polyvinyl chloride, etc., or composites of synthetic resin films and nonwoven fabrics can be used. Materials etc. can be used. The absorbent article may further include various members depending on the specific use of the absorbent article. Such members are known to those skilled in the art. For example, when the absorbent article is applied to a disposable diaper or a sanitary napkin, one or more pairs of leak-proof cuffs can be arranged on both sides of the skin-facing surface of the top sheet in the longitudinal direction.

As shown in FIG. 1, the absorbent core 10 contains a plurality of sheet pieces 11 and a plurality of hydrophilic fibers 12F. As the hydrophilic fiber 12F, various types conventionally used in absorbent bodies for absorbent articles can be used without particular limitation, such as pulp fiber, rayon fiber, cotton fiber, etc. The species can be used alone or in combination of two or more species. In addition to the sheet piece 11 and the hydrophilic fibers 12F, the absorbent body 10 may further contain an absorbent material such as a water absorbent polymer.

The sheet pieces 11 may be distributed uniformly throughout the absorbent body 10 or may be unevenly distributed. In the absorbent core 10 shown in FIG. 1, the sheet pieces 11 are unevenly distributed in the center of the absorbent core 10 in the longitudinal direction X and on one surface 10b side.

The sheet pieces 11 included in the absorbent body 10 include a plurality of types of sheet pieces having different rigidities. FIG. 2 shows an example of the plurality of types of sheet pieces, and FIG. 2(b) is a low-rigidity sheet piece 11L having relatively low rigidity. The high-rigidity sheet piece 11H has a high-rigidity portion 120, whereas the low-rigidity sheet piece 11L does not have this, and this difference is manifested in the difference in rigidity.

In addition, below, the embodiment of the sheet piece based on this invention, such as the high-rigidity sheet piece 11H and the low-rigidity sheet piece 11L, is also collectively called "the sheet piece 11." The description of the sheet piece 11 herein applies to all embodiments of the sheet piece unless otherwise specified. Further, hereinafter, embodiments of the high-rigidity sheet piece 11H including the high-rigidity sheet piece 11HA are collectively referred to as the "high-rigidity sheet piece 11H." The description of the highly rigid sheet piece 11H in this specification applies to all embodiments of the highly rigid sheet piece unless otherwise specified.

As shown in FIG. 3, the sheet piece 11 is a fiber aggregate in which a plurality of fibers 11F are gathered and integrated. As described later, the sheet piece 11 is made by cutting a strip-shaped raw material sheet (raw material sheet 8 in the method for manufacturing the absorbent body 10 described later), typically a nonwoven fabric, mainly composed of fibers 11F, in two mutually intersecting directions. It is manufactured by cutting, so-called cross-cutting. By manufacturing the sheet pieces 11 by cross-cutting the raw material sheet, it is possible to simultaneously manufacture a plurality of sheet pieces 11 in which sheet pieces 11 of the designed shape and size are mixed in the designed ratio, Moreover, it becomes possible to make the absorber 10 contain a plurality of sheet pieces 11 manufactured according to the design.

The constituent fibers 11F of the sheet piece 11 include synthetic fibers. The fibers 11F may include fibers other than synthetic fibers, but typically include only synthetic fibers. As the material for the fibers 11F, a non-water-absorbing thermoplastic resin is preferably used, and specific examples thereof include polyethylene, polypropylene, polyethylene terephthalate, and the like. The fibers 11F are typically short fibers (fibers with a fiber length of less than 80 mm) made of one or more of these thermoplastic resins.

The sheet piece 11 (11H, 11L) shown in FIG. 2 has a rectangular parallelepiped shape, and has a longitudinal direction LD and a lateral direction SD. Such a rectangular parallelepiped-shaped sheet piece 11 typically has two non-cut surfaces 111 which are opposed to each other and which are made of the surface of the raw material sheet, and which intersect, specifically orthogonally cross, these two non-cut surfaces 111. It has four cut surfaces 112 formed by cutting the sheet. The uncut surface 111 is not a surface formed by cutting the raw material sheet, but is a surface that the raw material sheet originally had. The uncut surface 111 typically has a larger area than the cut surface 112, as shown in FIG. The uncut surface 111 is defined by two short sides 111a that face each other and two long sides 111b that intersect (specifically, perpendicularly intersect) each of these two short sides 111a. It should be noted that among the plurality of sheet pieces 11 obtained by cutting the raw material sheet, the sheet pieces 11 located on both sides along the conveyance direction of the raw material sheet (direction indicated by symbol MD in FIG. 7 etc.) have 4 One of the two cut surfaces 112 is a surface that the raw material sheet originally had (an end surface of the raw material sheet) and is not the cut surface 112 .

The dimensions of the sheet piece 11 may be appropriately set depending on the use of the sheet piece 11, and are not particularly limited. For example, when the outer shape of the sheet piece 11 is a rectangular parallelepiped shape as shown in FIG. 2 and is used in an absorbent body for an absorbent article such as the absorbent body 10, the dimensions of the sheet piece 11 should be set as follows. Can be done.
The length L1 of the sheet piece 11 in the transverse direction SD, that is, the length L1 of the short side 111a (see FIG. 2), is preferably 0.5 mm or more, more preferably 1 mm or more, and more preferably 10 mm or less, and more preferably is 5 mm or less.
The length L2 in the longitudinal direction LD of the sheet piece 11, that is, the length L2 of the long side 111b (see FIG. 2), is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 10 mm or less, more preferably It is 5 mm or less.
The thickness T (see FIG. 2) of the sheet piece 11 is preferably 0.5 mm or more, more preferably 1 mm or more.
Note that the sheet piece 11 may have a square or diamond shape in which each side has the same length when the uncut surface 111 is viewed from above.

One of the main features of the absorber 10 is that the sheet piece 11 includes a highly rigid sheet piece 11H. The high-rigidity sheet piece 11H has a high-rigidity portion 120 and other portions (low-rigidity portions 121), as shown in FIGS. 2(a) and 3. The high-rigidity portion 120 has high rigidity compared to the low-rigidity portion 121, and is a hard portion that does not easily collapse.

In the high-rigidity sheet piece 11HA shown in FIG. 2(a), the high-rigidity portion 120 extends from one side of the sheet piece 11HA to the other side. The central portion in the transversal direction SD extends continuously and linearly from one side to the other of the pair of opposing short sides 111a, 111a. In addition, as shown in FIG. 3, the high-rigidity portion 120 is present in the entire thickness direction Z of a predetermined portion (in the illustrated form, the central portion in the transverse direction SD) of the high-rigidity sheet piece 11HA, and has two opposing parts. The high-rigidity portion 120 present on one of the two non-cut surfaces 111 and the high-rigidity portion 120 present on the other have substantially the same shape and dimensions in plan view. In the high-rigidity sheet piece 11HA, the portion other than the high-rigidity portion 120 is a low-rigidity portion 121, and the low-rigidity portions 121 are located on both sides of the high-rigidity portion 120 in the lateral direction SD.

The high-rigidity portion 120 is typically a fused portion in which the constituent fibers 11F of the high-rigidity sheet piece 11H are fused together and compacted. In the high-rigidity portion 120, which is the fused portion, the fibers 11F may lose their original fiber form and become a film. The high-rigidity portion 120, which is a fused portion, is formed by subjecting the raw material sheet to stiffening treatment, as will be described later. Typically, the stiffening treatment is performed on the constituent fibers of the raw material sheet. (that is, the fiber 11F) is a compression process that involves melting. As the compression process involving melting of the fibers, for example, known embossing processes such as embossing process involving heat and ultrasonic embossing can be employed. On the other hand, the low-rigidity portion 121 is an unprocessed portion (non-fused portion) that has not been subjected to the stiffening treatment described below, and substantially maintains the original fiber form of the raw material sheet.

Because the high-rigidity sheet piece 11H has the high-rigidity portion 120, the high-rigidity sheet piece 11H has excellent compression recovery properties and durability compared to the low-rigidity sheet piece 11L that does not have the high-rigidity portion 120. That is, as shown in FIG. 4(a), a load F is applied to the high-rigidity sheet piece 11H from both outsides in the longitudinal direction LD, and the sheet piece 11H is moved in the longitudinal direction LD (the direction in which the high-rigidity portion 120 extends). ) When the load F is removed after the sheet piece 11H is buckled and deformed, the sheet piece 11H quickly returns to its original shape. In addition, since the highly rigid sheet piece 11H has excellent durability, it does not easily deteriorate even if such buckling deformation and restoring are repeated multiple times, and physical properties such as compression recovery properties are unlikely to deteriorate with use. On the other hand, the low-rigidity sheet piece 11L that does not have the high-rigidity part 120 has the same rigidity as the whole low-rigidity part 121 of the high-rigidity sheet piece 11H, as shown in FIG. 4(b). If the sheet piece 11L is subjected to buckling deformation in the same manner as the highly rigid sheet piece 11H and then the load F is removed, the sheet piece 11L may not return to its original state completely, or the operation may be repeated multiple times. In this case, even if it completely returns to its original state the first few times, there is a risk that it will collapse after fewer times than the sheet piece 11H.

It is also important that the high-rigidity portion 120 exists only in a part of the high-rigidity sheet piece 11H as shown in the figure, and not in all of it. That is, if the entire sheet piece 11 is the high-rigidity part 120, specifically, for example, the entire sheet piece 11 is subjected to a compression process that involves melting the constituent fibers 11F, so that the sheet piece 11 If the entire sheet piece 11 has the same rigidity as the high-rigidity part 120, the bulk of the sheet piece 11 will be reduced and the deformation under load will be reduced compared to the case where only a part of the sheet piece 11 is the high-rigidity part 120. There is a risk that the degree of freedom of the process will be lost, and furthermore, it is disadvantageous in terms of manufacturing cost. In the high-rigidity sheet piece 11H, the above-mentioned disadvantages are prevented because the high-rigidity portions 120 are partially present.

As described above, the high-rigidity portion 120 only needs to be partially present in the high-rigidity sheet piece 11H, and the pattern (shape and arrangement in plan view) of the high-rigidity portion 120 is one as shown in FIG. 2(a). The pattern is not limited to a continuous straight line, and may include, for example, a pattern including a curved line or a discontinuous line, a pattern in which a plurality of high-rigidity parts are arranged in a scattered manner, etc., but the effect of the high-rigidity part 120 can be surely expressed. From this point of view, it is preferable that the high-rigidity portion 120 has a linear shape in plan view and extends from one side of the high-rigidity sheet piece 11H to the other side, as shown in FIG. 2(a). "Extending" here includes not only the form in which the high rigidity part 120 is continuous in one direction as shown in FIG. ) are arranged intermittently in one direction, and the plurality of slightly elevated rigid parts as a whole extend in one direction. In the latter form, the plan view shape of each of the plurality of small height rigid parts is not particularly limited, and can be circular, quadrangular, etc., and the interval between two adjacent small height rigid parts is preferably It is 1 mm or less.

The length (i.e., width) W (see FIG. 3) of the high-rigidity portion 120 extending in one direction in the direction perpendicular to the extending direction thereof is determined by the external shape and dimensions of the sheet piece 11 on which the high-rigidity portion 120 is formed. It is not particularly limited, and may be adjusted as appropriate. For example, when the sheet piece 11 has a rectangular shape in plan view on the uncut surface 111 and its dimensions (lengths L1, L2, thickness T) are within the ranges described above, the sheet piece 11 has a high rigidity. The width W of the portion 120 is preferably 0.5 mm or more, more preferably 1 mm or more, and preferably 5 mm or less, more preferably 3 mm or less. In addition, when the high rigidity part 120 extending in one direction is an aggregate of the above-mentioned small high rigidity parts, the width W of the high rigidity part 120 here is the high rigidity part 120 in the small high rigidity part. corresponds to the length in the direction perpendicular to the extending direction.

Although the extending direction of the high-rigidity section 120 is not particularly limited, from the viewpoint of further enhancing the effect of improving the physical properties of the high-rigidity sheet piece 11H, the high-rigidity section 120 is arranged to intersect with the orientation direction of the constituent fibers 11F of the high-rigidity sheet piece 11H. The orientation direction is preferably perpendicular to the orientation direction, and more preferably perpendicular to the orientation direction. For example, in the case of the high-rigidity sheet piece 11HA shown in FIG. 2(a), the high-rigidity portion 120 extends in the longitudinal direction LD of the sheet piece 11HA. It is preferable to orient in a direction intersecting the LD, and more preferably in a direction perpendicular to the longitudinal direction LD, that is, in the lateral direction SD.

The orientation direction of the constituent fibers 11F of the high-rigidity sheet piece 11H typically corresponds to the conveyance direction of the raw material sheet during production of the sheet piece 11 (high-rigidity sheet piece 11H). Therefore, if the high-rigidity portion 120 is formed in a direction intersecting (preferably perpendicular to) the conveyance direction of the raw material sheet when manufacturing the sheet piece 11, the high-rigidity portion 120 will be formed in the finally obtained high-rigidity sheet piece 11H. may intersect (preferably be perpendicular to) the orientation direction of the constituent fibers 11F of the sheet piece 11H.

In the high-rigidity sheet piece 11HA shown in FIG. 2(a), the high-rigidity portion 120 extends in one direction, but a plurality of high-rigidity portions 120 may exist and extend in any direction. In the high-rigidity sheet piece 11HB shown in FIG. 5, the high-rigidity portion 120 extends in two directions, the longitudinal direction LD and the lateral direction SD of the sheet piece 11HB, and on each of the two opposing non-cut surfaces 111. , two high-rigidity parts 120 that are line-of-sight are orthogonal to each other. The high-rigidity portion 120 extending in the longitudinal direction LD is located at the center of the high-rigidity sheet piece 11HB in the transverse direction SD, and the high-rigidity portion 120 extending in the transverse direction SD is located in the longitudinal direction of the sheet piece 11HB. It is located at the center in direction LD. As shown in FIG. 5, when a plurality of high rigidity portions 120 intersect with each other on each of the two opposing surfaces (specifically, the non-cut surface 111) of the high rigidity sheet piece 11H, the two surfaces This is preferable because the physical properties such as compression recovery properties of the sheet piece 11 are significantly improved compared to the case where only one high-rigidity portion 120 is present in each. In particular, it is more preferable that at least one of the plurality of high-rigidity parts that intersect with each other intersects with the orientation direction of the constituent fibers F of the high-rigidity sheet piece 11H.

The method for manufacturing a sheet piece of the present invention is to produce the above-mentioned high-rigidity sheet piece 11H, that is, the high-rigidity sheet piece 11H, which has a high-rigidity portion 120 in a part thereof, has excellent compression recovery properties and excellent durability, and is suitable for use. A plurality of sheet pieces 11 are manufactured, including sheet pieces in which physical property deterioration is unlikely to occur. Hereinafter, the method for manufacturing a sheet piece of the present invention will be described with reference to the drawings based on one embodiment thereof, along with the method for manufacturing an absorbent body of the present invention in which the manufacturing method is partially adopted.

FIG. 6 shows the main parts of a manufacturing apparatus 1, which is an embodiment of a manufacturing apparatus that can be used to carry out the method for manufacturing an absorbent body of the present invention. The manufacturing apparatus 1 is a manufacturing apparatus for the absorbent body 10 described above. The manufacturing method of the absorbent body 10 using the manufacturing apparatus 1 includes a manufacturing process of a sheet piece 11, and a stacking process in which a plurality of sheet pieces 11 manufactured in the manufacturing process are conveyed to a predetermined stacking part by an air flow and stacked. It has a process.

The manufacturing apparatus 1 includes a rotary drum 2 in which a stacking recess 22 as the stacking part is formed on an outer circumferential surface 2f, and a flow for conveying raw materials (sheet pieces 11, hydrophilic fibers 12F) for the absorbent body 10 on the outer circumferential surface 2f. The ducts 3A and 3B each have a passage 30 therein, and while the rotating drum 2 is rotated in the direction 2R around the rotation axis along the circumferential direction 2Y of the drum, the passage 30 is filled by suction from the inside of the rotating drum 2. The raw materials carried by the generated air flow (vacuum air) are stacked in the stacking recess 22. A first supply mechanism 4 for supplying the hydrophilic fibers 12F is connected to the duct 3A, and a second supply mechanism 5 for supplying the sheet pieces 11 is connected to the duct 3B. A vacuum conveyor 6 is disposed below the rotating drum 2 to receive the stack of raw materials released from the stacking recess 22, that is, the absorbent body 10 (absorbent core), and convey it to the next process.

The rotating drum 2 includes a cylindrical drum main body 20 made of a rigid metal body, and an outer peripheral member 21 that is arranged to overlap the outer peripheral part of the drum main body 20 and forms an outer peripheral surface 2f of the rotating drum 2. ing. The outer peripheral member 21 receives power from a prime mover such as a motor and rotates in one direction 2R along the drum circumferential direction 2Y around a horizontal rotation axis. The main body 20 is fixed and does not rotate. Both ends of the drum body 20 in the axial direction are hermetically sealed by side walls (not shown) and a sealing material such as felt.

The outer peripheral member 21 includes an air-permeable porous plate 23 that forms the bottom of the accumulating recess 22, that is, a fiber stacking surface for raw materials, and a breathable porous plate 23 that forms a portion of the outer peripheral surface 2f of the rotating drum 2 other than the fiber stacking surface. or a non-ventilated pattern forming plate 24. In the manufacturing apparatus 1, the pattern forming plates 24 have an annular shape that continuously extends over the entire length in the drum circumferential direction 2Y, and are provided in pairs at both ends of the rotating drum 2 in the rotational axis direction. A porous plate 23 is located between the plates 24, 24.

The porous plate 23 transmits the airflow generated by suction from the inside of the device (inside the rotating drum 2) to the outside of the device (outside the rotating drum 2), and the air is carried along with the airflow. It is a breathable plate that retains raw materials without allowing it to pass through, and allows only air to pass through. A large number of suction holes passing through the porous plate 23 in the thickness direction are formed throughout the porous plate 23. During the passage, the suction hole acts as a permeation hole for the air flow. As the porous plate 23, for example, a mesh plate made of metal or resin, or a plate made of metal or resin in which a large number of pores are formed by etching or punching can be used. Further, as the pattern forming plate 24, for example, a plate made of metal such as stainless steel or aluminum, or a resin plate can be used.

As shown in FIG. 6, the inside of the drum body 20 is partitioned into a plurality of spaces A, B, and C in the drum circumferential direction 2Y. Further, a pressure reduction mechanism (not shown) is connected to the drum body 20 to reduce the pressure inside the drum body 20 . This pressure reduction mechanism includes an exhaust pipe (not shown) connected to a side wall (not shown) constituting the drum body 20 and an exhaust fan (not shown) connected to the exhaust pipe. There is. The plurality of spaces A, B, and C within the drum body 20 are independent from each other, and the negative pressure (suction force) in these plurality of spaces can be adjusted independently by the pressure reducing mechanism.

The rotating drum 2 has a predetermined range in the circumferential direction 2Y of the drum, specifically, a space A whose outer circumferential portion is covered with ducts 3A and 3B is a fiber stacking area in which raw materials can be stacked by suction from the inside. It is considered a zone. When the outer circumferential member 21 is rotated around the rotation axis while maintaining the negative pressure in the space A, while the accumulating recess 22 formed in the outer circumferential member 21 passes over the space A, the accumulation recess 22 Negative pressure in the space A acts on the bottom (porous plate 23), and air is sucked through a large number of suction holes formed in the bottom. By suction through the suction hole, the raw materials (sheet pieces 11, hydrophilic fibers 12F) that have been conveyed through the flow path 30 in the duct 3 are guided to the accumulation recess 22 and stacked on the bottom thereof. On the other hand, normally, the space B of the rotating drum 2 is set to a weaker negative pressure or zero pressure (atmospheric pressure) than the space A, and the space C is set to the transfer position of the fiber pile in the stacking recess 22 and its position. Since the area includes the front and rear, the pressure is set to zero or positive pressure.

The vacuum conveyor 6 is disposed at a position opposite to an endless air permeable belt 61 that spans over a driving roll and a driven roll (not shown), and a portion of the rotating drum 2 where the space C exists, with the air permeable belt 61 in between. It is configured to include a vacuum box (not shown). As shown in FIG. 6, a belt-shaped core wrap sheet 13 is introduced onto the breathable belt 61, and the absorbent body 10, which is a stacked fiber product released from the accumulation recess 22, is transferred onto the core wrap sheet 13. It is designed so that

As shown in FIG. 6, the duct 3A extends continuously from the first supply mechanism 4 to the rotating drum 2, and has an opening on the upstream side in the raw material supply direction and an opening on the downstream side (rotating drum 2 side). A flow path 30 for the raw material (hydrophilic fiber 12F) exists between both openings. A polymer dispersion pipe (not shown) for supplying water-absorbing polymer particles to the flow path 30 may be arranged on the top plate of the duct 3, and when the absorber 10 contains water-absorbing polymer particles, the polymer Use a spray tube. The duct 3B is configured similarly to the duct 3A, except that it extends continuously from the second supply mechanism 5 to the rotating drum 2.

The absorbent body 10 contains two types of raw materials (core forming material), sheet pieces 11 and hydrophilic fibers 12F, and the manufacturing apparatus 1 corresponds to this by supplying the hydrophilic fibers 12F into a duct as a core forming material supply mechanism. It is provided with a first supply mechanism 4 (hydrophilic fiber manufacturing device) that supplies the sheet pieces 11 into the duct 3A, and a second supply mechanism 5 (sheet piece manufacturing device) that supplies the sheet pieces 11 into the duct 3B.

The first supply mechanism 4 (hydrophilic fiber manufacturing device) is arranged at an opening on the opposite side of the rotating drum 2 in the duct 3A. The first supply mechanism 4 is configured in the same manner as the supply mechanism for fiber materials in this type of pulp fiber stacking device, and is used for defibrating a belt-shaped raw material sheet 7 in which a plurality of hydrophilic fibers 12F are accumulated. It is equipped with a spinning machine 41. The raw material sheet 7 is a sheet-like material mainly composed of hydrophilic fibers 12F, and is typically made of pulp fibers, which are the hydrophilic fibers 12F.

The second supply mechanism 5 (sheet piece manufacturing device) cuts the strip-shaped raw material sheet 8 in which the constituent fibers 11F of the sheet piece 11 are accumulated in two directions (first direction D1 and second direction D2) that intersect with each other. This is an apparatus for manufacturing a sheet piece 11 having a rectangular shape in plan view on a non-cutting surface 111 (see FIG. 2), and as shown in FIGS. 6 and 7, an object to be cut (raw material sheet 8) is a first cutting mechanism 53 for cutting a material in a first direction D1; and a first cutting mechanism 53 for cutting a material to be cut in a first direction D1; A second cutting mechanism 56 that cuts the width sheet 9) in the second direction D2 is provided. The strip-shaped raw material sheet 8 is conveyed in its longitudinal direction by a known conveying means included in the second supply mechanism. The symbol MD in the figure represents the transport direction (Machine Direction) of the object to be cut by the second supply mechanism 5, and the symbol CD represents the transport orthogonal direction (Cross machine Direction) that is perpendicular to MD. The raw material sheet 8 is a sheet-like material mainly composed of the constituent fibers 11F (see FIG. 3) of the sheet piece 11, and is typically a nonwoven fabric made by various manufacturing methods.

“First direction D1”, which is one of the cutting directions of the raw material sheet 8, is a direction along the conveyance direction MD of the raw material sheet 8 in the second supply mechanism 5. The term "direction along the conveyance direction MD" as used herein means a case where the angle formed with the conveyance direction MD is less than 45 degrees. In the illustrated embodiment, the first direction D1 and the conveying direction MD coincide with each other, and the angle between the two directions D1 and MD is zero. Further, the "second direction D2", which is another one of the cutting directions of the raw material sheet 8, is a direction that intersects the first direction D1, and in the illustrated embodiment, the "second direction D2" is a direction that intersects the first direction D1. The direction MD) and the second direction D2 are orthogonal to each other, the angle between both directions D1 and D2 is 90 degrees, and the second direction D2 and the transport orthogonal direction CD coincide.

The first cutting mechanism 53 includes a cutter roll 54 and an anvil roll 55, as shown in FIG. Both rolls 54 and 55 each have a substantially cylindrical shape, are rotatably supported around rotational axes, and are arranged so that their rotational axes are aligned parallel to each other, with their circumferential surfaces facing each other and rotating in opposite directions. has been done. A cutter blade 54C (see FIG. 7) is disposed on the circumferential surface of the cutter roll 54, whereas the circumferential surface of the anvil roll 55 is smooth and has no cutter blade disposed thereon. In the illustrated embodiment, as described above, the first direction D1, which is the direction in which the object to be cut (raw material sheet 8) is cut by the first cutting mechanism 53, coincides with the conveyance direction MD of the object to be cut, so the cutter roll 54 The cutter blade 54C extends in the circumferential direction of the roll 54 in accordance with the cutting direction, and extends over the entire circumferential length of the roll 54 on the circumferential surface thereof. As shown in FIG. 7, a plurality of cutter blades 54C are arranged on the circumferential surface of the cutter roll 54 at predetermined intervals C1 in the transport orthogonal direction CD (ie, the second direction D2).

The second cutting mechanism 56 includes a cutter roll 57 and an anvil roll 58, as shown in FIG. Both rolls 57 and 58 each have a substantially cylindrical shape, are rotatably supported around rotational axes, and are arranged so that their rotational axes are parallel to each other and their circumferential surfaces face each other to rotate in opposite directions. has been done. A cutter blade 57C (see FIG. 7) is disposed on the circumferential surface of the cutter roll 57, whereas the circumferential surface of the anvil roll 58 is smooth and has no cutter blade disposed thereon. In the illustrated embodiment, as described above, the second direction D2, which is the direction in which the object to be cut (the narrow sheet 9) is cut by the second cutting mechanism 56, coincides with the transport orthogonal direction CD, so that the cutter roll 57 The blade 57C extends in the direction of the rotation axis of the roll 57 in accordance with the cutting direction, and extends from the center in the direction of the rotation axis to both outer sides in the same direction on the circumferential surface of the roll 57. . As shown in FIG. 7, a plurality of cutter blades 57C are arranged on the circumferential surface of the cutter roll 57 at predetermined intervals C2 in the circumferential direction of the roll 57.

The process of manufacturing the sheet piece 11, which is part of the method for manufacturing the absorbent body 10, is performed by the second supply mechanism 5. In the method for manufacturing the sheet piece 11 using the second supply mechanism 5, before the strip-shaped raw material sheet 8 is cross-cut by the two cutting mechanisms 53 and 56 described above, the strip-shaped raw material sheet 8 is partially subjected to a stiffening process. It is characterized in that the processed portion is made into a high-rigidity portion 120 that is more rigid than the surrounding portion. In order to carry out this stiffening process, the second supply mechanism 5 includes a stiffening mechanism 50 upstream of the first cutting mechanism 53 in the transport direction MD, as shown in FIGS. 6 and 7.

The configuration of the rigidity imparting mechanism 50 may vary depending on the content of the rigidity imparting process (form of the high rigidity portion 120). The stiffening process performed by the second supply mechanism 5 of the manufacturing apparatus 1 is a process of fusing the constituent fibers of the raw material sheet 8, and correspondingly, the stiffening mechanism 50 is configured as shown in FIGS. 6 and 7. As shown, it includes a pair of heat rolls 51 and 52 that can heat the object to be processed (raw material sheet 8). Both rolls 51 and 52 each have a substantially cylindrical shape, are rotatably supported around rotational axes, and are arranged so that their rotational axes are parallel to each other and their circumferential surfaces face each other to rotate in opposite directions. has been done. Both rolls 51 and 52 are each equipped with a heating means (not shown), and the heating means can heat the circumferential surfaces of both rolls 51 and 52 to a predetermined temperature. As shown in FIG. 7, on the circumferential surface of the heat roll 51, which is one of the rolls 51 and 52, a convex portion 50H extending in the direction of the rotational axis of the roll 51 is provided with a predetermined shape in the circumferential direction of the roll 51. Multiple locations are placed at intervals. The circumferential surface of the other heat roll 52 may be provided with a protrusion 50H, or may be smooth without a protrusion 50H. The convex portion 50H extends parallel to the transport orthogonal direction CD (second direction D2), and can contact the raw material sheet 8 over the entire length of the transport orthogonal direction CD.

The stiffening mechanism 50 can be appropriately selected depending on the content of the stiffening process to be performed. For example, when the stiffening process carried out by the stiffening mechanism 50 is a process of fusing the constituent fibers of the raw material sheet 8, heat is applied to the object to be processed (the raw material sheet 8) using the heat roll described above. The applying means is not limited to this, and for example, a means called an impulse seal or the like, that is, a means for applying a current to a linear heater and instantaneously heating the heater to seal the object to be processed, etc. can be used.

A method of manufacturing the sheet piece 11 carried out by the second supply mechanism 5 will be described. First, as shown in FIGS. 6 and 7, a strip-shaped raw material sheet 8 containing synthetic fibers (fibers 11F) such as thermoplastic fibers is conveyed between a pair of heat rolls 51 and 52 that constitute the stiffening mechanism 50. and partially undergoes a stiffening treatment to make the treated portion a high-rigidity portion 120 having higher rigidity than the peripheral portion of the treated portion (rigidity imparting step). The raw material sheet 8 introduced between a pair of rotating heat rolls 51 and 52 is compressed in the thickness direction by a convex portion 50H heated to a predetermined temperature, and the compressed portion, that is, the convex portion 50H in a plan view of the raw material sheet 8 In the overlapped portion, the constituent fibers (fibers 11F) of the raw material sheet 8 are melted and fused to each other, forming a high-rigidity portion 120 consisting of a fused portion. Portions of the raw material sheet 8 that do not come into contact with the convex portions 50H are not subjected to rigidity imparting treatment and become low-rigidity portions 121.

In the form shown in FIG. 7, in the rigidity imparting step, the raw material sheet 8 is subjected to a rigidity imparting process such that the high rigidity portion 120 extends in a direction intersecting the conveyance direction MD of the raw material sheet 8. 50H compression processing is performed. As shown in FIG. 7, the convex portion 50H contacts the raw material sheet 8 in a direction perpendicular to the conveying direction MD, that is, parallel to the orthogonal conveying direction CD, and along the entire length of the orthogonal conveying direction CD. The high-rigidity portion 120 formed by the above is parallel to the orthogonal conveyance direction CD and extends over the entire length of the raw material sheet 8 in the orthogonal conveyance direction CD. In the raw material sheet 8, a plurality of linear high-rigidity portions 120 extending in the transport direction CD in plan view are arranged intermittently in the transport direction MD.

In the form shown in FIG. 7, the raw material sheet 8 is thus subjected to rigidity imparting treatment so that the high-rigidity portion 120 extends in a direction intersecting (specifically, orthogonal to) the conveyance direction MD of the raw material sheet 8. Therefore, if the constituent fibers (fibers 11F) of the raw material sheet 8 are oriented in the transport direction MD, the high-rigidity portion 120 in the finally obtained high-rigidity sheet piece 11H is Intersects (orthogonally) with the orientation direction of the constituent fibers. The advantages of the high-rigidity portion 120 intersecting the orientation direction of the constituent fibers of the high-rigidity sheet piece 11H are as described above.

Next, the raw material sheet 8 that has undergone the stiffening process, that is, the raw material sheet 8 on which the high-rigidity portion 120 has been formed, is conveyed and introduced between the cutter roll 54 and anvil roll 55 that constitute the first cutting mechanism 53. , to obtain a narrow sheet 9 by cutting in the first direction D1 (first cutting step). In the form shown in FIG. 7, the cutter blade 54C of the cutter roll 54 is parallel to the transport direction MD, so the first direction D1 is parallel to the transport direction MD. The plurality of narrow sheets 9 obtained by cutting the raw material sheet 8 by the cutter blade 54C are introduced into the next process (second cutting process) in a state of being arranged in parallel in the transport orthogonal direction CD. As shown in an enlarged view in FIG. 7, each of the plurality of narrow sheets 9 has a plurality of high-rigidity portions 120 arranged intermittently in the transport direction MD in a plan view. The width (length in the transport orthogonal direction CD) of the narrow sheet 9 substantially matches the interval C1 between the two cutter blades 54C, 54C adjacent to each other in the transport orthogonal direction CD. Further, the width of the narrow sheet 9 corresponds to the distance between two opposing cut surfaces 112 formed by cutting by two cutter blades 54C adjacent to each other in the transport orthogonal direction CD.

Next, a plurality of narrow sheets 9 (raw material sheets 8 that have undergone the first cutting process) are conveyed and introduced between the cutter roll 57 and anvil roll 58 that constitute the second cutting mechanism 56, and the second A plurality of sheet pieces 11 are obtained by cutting in the direction D2 (second cutting step). In the form shown in FIG. 7, the cutter blade 57C of the cutter roll 57 is in a direction intersecting the conveyance direction MD, specifically, parallel to the orthogonal conveyance direction CD, so the second direction D2 is parallel to the orthogonal conveyance direction CD. It is. Each of the plurality of sheet pieces 11 thus obtained has two opposing cut surfaces 112 formed by cutting by two cutter blades 57C adjacent to each other in the transport direction MD. The two cut surfaces 112, along with the two opposing cut surfaces 112 previously formed in the first cutting step, are formed by the end surface of the sheet piece 11 having a rectangular shape in plan view on the non-cut surface 111 (the thickness of the sheet piece 11). form a surface (along the direction). Moreover, the plurality of sheet pieces 11 obtained in this way include a high-rigidity sheet piece 11H having a high-rigidity portion 120. FIG. 7 shows an enlarged view of a high-rigidity sheet piece 11HC, which is an embodiment of a high-rigidity sheet piece 11H that can be included in the plurality of sheet pieces 11 obtained through the second cutting process. In the high-rigidity sheet piece 11HC, one high-rigidity portion 120 that is linear in plan view extends over the entire length of the sheet piece 11HC in the lateral direction SD on the non-cut surface 111 of the sheet piece 11HC.

The plurality of sheet pieces 11 manufactured by the second supply mechanism 5 as described above are supplied to the flow path 30 in the duct 3B, and are accumulated in the accumulation recess 22 formed on the outer peripheral surface 2f of the rotating drum 2. Ru. On the other hand, in the first supply mechanism 4, a plurality of hydrophilic fibers 12F are manufactured from the strip-shaped raw material sheet 7, and are accumulated in the accumulation recess 22 via the flow path 30 in the duct 3A. In this way, the plurality of sheet pieces 11 and the hydrophilic fibers 12F are accumulated in the accumulation recess 22, and the absorbent body 10 is formed. The absorbent body 10 formed in the stacking recess 22 is transported in a predetermined direction below the rotating drum 2 to the vicinity of the core wrap sheet 13 by movement of the collecting recess 22 as the rotating drum 2 rotates. Thereafter, the mold is released from the stacking recess 22 and transferred onto the core wrap sheet 13. Thereafter, the core wrap sheet 13 is folded so as to cover the entire outer surface of the absorbent core 10, and is conveyed to the next process (for example, a cutting process of cutting the absorbent core 10 into product unit lengths).

In the method of manufacturing the sheet piece 11 carried out by the second supply mechanism 5 described above, 1) the formation pattern of the high-rigidity portion 120 in the rigidity imparting step, specifically, the circumference of the heat roll 51 constituting the rigidity imparting mechanism 50; 2) the pattern (planar view shape and arrangement) of the convex portions 50H formed on the surface and in contact with the raw material sheet 8 that is the object to be processed, 2) the interval C1 of the cutter blade 54C used in the first cutting step, and 3) the third 2. By appropriately adjusting the interval C2 of the cutter blades 57C used in the cutting process, the shape of the high-rigidity sheet piece 11H included in the plurality of sheet pieces 11 finally obtained (presence or absence of the high-rigidity part 120, pattern, etc.) ), the ratio of the highly rigid sheet piece 11H to the sheet piece 11, etc. can be adjusted.

For example, in the second supply mechanism 5 shown in FIG. 7, a high-rigidity portion 120 is formed in the raw material sheet 8 in the rigidity imparting step in parallel to the transport direction CD, so that the plurality of sheet pieces obtained in the second cutting step 11 includes high-rigidity sheet pieces 11H in which the high-rigidity portion 120 extends only in the direction intersecting the conveyance direction MD of the raw material sheet 8, specifically, in the conveyance orthogonal direction CD, and FIG. A high-rigidity sheet piece 11HC shown in is an example thereof.

Further, in the second supply mechanism 5 shown in FIG. 7, after forming the convex portions 50H in the raw material sheet 8 in the rigidity imparting step in parallel to the transport direction CD, the cutter blade 54C is used in the first cutting step in the transport direction MD ( Then, in the second cutting step, the cutter blade 57C cuts the sheet piece 11 ( When a plurality of high-rigidity sheet pieces 11H) are manufactured at the same time, the pattern of the convex portions 50H is not changed, and the size relationship between the interval C1 between the cutter blades 54C and the interval C2 between the cutter blades 57C is adjusted as appropriate. It is also possible to obtain a "sheet piece in which the high-rigidity portion 120 extends in the longitudinal direction LD" such as the high-rigidity sheet piece 11HA shown in FIG. 2(a), or a high-rigidity sheet piece 11HC shown in FIG. It is also possible to obtain "a sheet piece in which the high-rigidity portion 120 extends in the lateral direction SD". In other words, whether the high-rigidity portion 120 in the plan view extends in the longitudinal direction LD of the sheet piece 11 or in the lateral direction SD can be adjusted by adjusting the magnitude relationship of the intervals C1 and C2. be.

Further, the plurality of sheet pieces 11 obtained in the second cutting step may include a sheet piece 11 that does not have the high-rigidity portion 120, that is, a low-rigidity sheet piece 11L shown in FIG. 2(b). It is possible. For example, in the second supply mechanism 5 shown in FIG. 7, the high-rigidity portion 120 is formed in the raw material sheet 8 in the rigidity imparting step in parallel to the transport direction CD, so the high-rigidity portion 120 is formed in the subsequent second cutting step as well. The narrow sheet 9 is cut in the same direction as , and the cutting width (length along the conveyance direction MD) of the narrow sheet 9 is shorter than the interval between two high rigidity parts 120 adjacent in the conveyance direction MD. do it. By doing so, the high-rigidity sheet piece 11H and the low-rigidity sheet piece 11L may coexist in the plurality of sheet pieces 11 obtained in the second cutting step. In addition, by appropriately adjusting the size relationship between the cutting width of the narrow sheet 9 and the interval between the high-rigidity parts 120, all of the plurality of sheet pieces 11 obtained in the second cutting process can be cut into high-rigidity sheet pieces. It is also possible to set it as 11H.

8 to 11 show other embodiments of the second supply mechanism (sheet piece manufacturing device) that can be employed in the manufacturing device 1. Regarding other embodiments to be described later, components different from those of the second supply mechanism 5 (see FIG. 7) described above will be mainly explained, and similar components will be given the same reference numerals and explanations will be omitted. The description of the second supply mechanism 5 applies as appropriate to components that are not particularly described.

The second supply mechanism 5A shown in FIG. 8 differs from the second supply mechanism 5 shown in FIG. 7 in the pattern of convex portions 50H formed on the circumferential surface of the heat roll 51. In the second supply mechanism 5A, as shown in FIG. 8, the convex portions 50H include a plurality of protrusions extending parallel to the conveyance direction MD of the raw material sheet 8 and a plurality of convex portions extending parallel to the conveyance direction CD. It is formed in a lattice shape. According to the second supply mechanism 5A, in the rigidity imparting step, the high rigidity portion 120 extends in two directions: the conveyance direction MD of the raw material sheet 8 and the direction intersecting the conveyance direction MD (specifically, the conveyance orthogonal direction CD). The raw material sheet 8 can be subjected to rigidity imparting treatment as shown in FIG. The highly rigid sheet piece 11HB shown in FIG. 5 can be manufactured by the second supply mechanism 5A.

Further, in the second supply mechanism 5A in which the high rigidity portion 120 can be formed in both the conveyance direction MD and the direction intersecting the conveyance direction MD (the conveyance orthogonal direction CD), the interval between the adjacent convex portions 50H in each of the two directions is By appropriately adjusting the interval C1 between the cutter blades 54C and the interval C2 between the cutter blades 57C, four of the following (1) to (4) can be obtained in the plurality of sheet pieces 11 obtained in the second cutting step. It is possible for more than one of the types to be included. The sheet pieces 11 shown in (1) to (4) below have different rigidities due to differences in the presence or absence of the high-rigidity portion 120, the arrangement of the high-rigidity portion 120, and the like. By containing two or more types of sheet pieces 11 having different rigidities in the absorbent body 10, the compression recovery properties of the absorbent body 10 can be adjusted more easily than when only one type of sheet piece 11 is contained. This can be done easily and precisely.

(1) Sheet piece 11 (high-rigidity sheet piece 11H) in which the high-rigidity portion 120 extends only in the direction intersecting the conveyance direction MD of the raw material sheet 8 (the conveyance orthogonal direction CD)
(2) Sheet piece 11 in which the high-rigidity portion 120 extends only in the conveyance direction MD of the raw material sheet 8 (high-rigidity sheet piece 11H)
(3) Sheet piece 11 (high-rigidity sheet piece 11H) in which the high-rigidity portion 120 extends only in two directions: the conveyance direction MD of the raw material sheet 8 and the direction intersecting the conveyance direction MD (transfer direction CD)
(4) Sheet piece 11 without high-rigidity portion 120 (low-rigidity sheet piece 11L)

In the second supply mechanism 5B shown in FIG. 9, a convex portion 50H formed on the circumferential surface of the heat roll 51 extends in a direction that is not perpendicular to but intersects with the conveyance direction MD of the raw material sheet 8. Specifically, the convex portion 50H of the second supply mechanism 5B extends obliquely to the direction of the rotation axis of the heat roll 51, and forms an angle with the rotation axis of more than 0 degrees and less than 90 degrees. Therefore, in the method of manufacturing the sheet piece 11 carried out in the second supply mechanism 5B, the high rigidity portion 120 is arranged so that the high rigidity portion 120 extends in a direction that is not perpendicular to the conveyance direction MD but intersects with the conveyance direction MD. The raw material sheet 8 is subjected to rigidity imparting treatment so that the angle formed by the transport direction MD is greater than 0 degrees and less than 90 degrees, preferably greater than or equal to 30 degrees and less than 60 degrees. A high-rigidity sheet piece 11HD shown in FIG. 9 is an example of a high-rigidity sheet piece 11H that can be manufactured by such a manufacturing method, and a high-rigidity portion 120 in a plan view is located in the longitudinal direction LD and short side of the sheet piece 11HD. It extends in a direction that is not orthogonal to both directions SD but intersects them.

According to the manufacturing method of the sheet piece 11 shown in FIG. 9, the high-rigidity portion 120 is formed in a direction that is not orthogonal to but intersects with the conveyance direction MD of the raw material sheet 8 in the rigidity imparting step, and the raw material sheet 8 is By cutting in two directions, ie, the transport direction CD (in other words, producing sheet pieces 11 having a rectangular shape in plan view on the uncut surface 111), a plurality of narrow sheets 9 are cut in the second cutting process. It becomes possible to mix the high-rigidity sheet piece 11H and the low-rigidity sheet piece 11L that does not have the high-rigidity portion 120 in the plurality of sheet pieces 11 that are manufactured simultaneously by one cutting process. In this way, when multiple types of sheet pieces 11 having different rigidities are manufactured at the same time, in the subsequent stacking process of sheet pieces 11, these multiple types of sheet pieces 11 are stacked in the stacking recess 22 in a mixed state. Therefore, it becomes possible to uniformly contain a plurality of types of sheet pieces 11 in the absorber 10.

In the second supply mechanism 5C shown in FIG. 10, in the second cutting step, the narrow sheet 9 is cut in a direction that is not perpendicular to but intersects with the conveying direction MD (first direction D1). That is, in the method for manufacturing the sheet piece 11 carried out by the second supply mechanism 5C, the second cutting direction D2 is a direction that does not intersect orthogonally with the conveyance direction MD (first direction D1) of the narrow sheet 9 but intersects with it. It is. Therefore, in the method for manufacturing sheet pieces 11 carried out by the second supply mechanism 5C, each of the plurality of sheet pieces 11 finally obtained has a parallelogram shape in plan view on the uncut surface 111 (see FIG. 2). Or it has a diamond shape. A high-rigidity sheet piece 11HE shown in FIG. 10 is an example of a high-rigidity sheet piece 11H that can be manufactured by such a manufacturing method, and a linear high-rigidity portion 120 is formed between a pair of opposing sides of the sheet piece 11HE. It extends between.

According to the manufacturing method of the sheet piece 11 shown in FIG. 10, in the stiffening step, a high-rigidity portion 120 is formed in the transport orthogonal direction CD that is perpendicular to the transport direction MD of the raw material sheet 8, and the raw material sheet 8 is formed in the transport direction MD. By cutting in two directions that are not orthogonal to this but intersecting with this, high rigidity It becomes possible to mix the sheet piece 11H and the low-rigidity sheet piece 11L that does not have the high-rigidity portion 120, and the same effect as the method for manufacturing the sheet piece 11 shown in FIG. 9 can be achieved.

The second supply mechanism 5D shown in FIG. 11 has a high rigidity portion between the first cutting mechanism 53 and the second cutting mechanism 56 that causes a phase shift of the high rigidity portions 120 of the plurality of narrow sheets 9. The structure is basically the same as the second supply mechanism 5 shown in FIG. 7 except that the phase shift inducing mechanism 59 is arranged. As shown in FIG. 11, the high-rigidity part phase shift inducing mechanism 59 includes a conveyance path changing roll 590 that is cylindrical and has a smooth circumferential surface. The conveyance path changing roll 590 is arranged at an intermediate position in the conveyance path of the narrow sheet 9 between the first cutting mechanism 53 and the second cutting mechanism 56, with its axial direction matching the conveyance orthogonal direction CD. ing. Further, as shown in FIG. 11(b), the conveyance path changing roll 590 forms a nip portion (nearest portion) of the pair of rolls 54 and 55 forming the first cutting mechanism 53 and the second cutting mechanism 56. It is disposed above or below (below in the form shown in FIG. 11) an imaginary straight line (not shown) connecting the nip portion (nearest portion) of the pair of rolls 57 and 58. This imaginary straight line corresponds to the shortest conveyance path among the conveyance paths for the narrow sheet 9 that connects the first cutting mechanism 53 and the second cutting mechanism 56.

In the method for manufacturing sheet pieces 11 using the second supply mechanism 5D, between the first cutting step and the second cutting step, the high rigidity portions 120 of the plurality of narrow sheets 9 obtained in the first cutting step are The process includes a step of causing a phase shift between the two. That is, in the second supply mechanism 5D, as shown in FIG. 91 is a pair of rolls that constitute the second cutting mechanism 56 from the nip portion (nearest portion) of the pair of rolls 54 and 55 that constitute the first cutting mechanism 53 without contacting the conveyance path changing roll 590 57 and 58, and the remaining narrow sheet 92 of the plurality of narrow sheets 9 is conveyed to the second cutting mechanism 56 while contacting the conveyance path changing roll 590. transported towards. The narrow sheet 92 goes from the first cutting mechanism 53 to the second cutting mechanism 56 via the conveyance path changing roll 590, compared to the narrow sheet 91 which does not go through the conveying path changing roll 590. The length of the portion extending over the cutting mechanism 56 (conveyance length) is long. Therefore, the phase of the high rigidity portion 120 of the narrow sheet 91 and the narrow sheet 92, in other words, the high rigidity portion that reaches the nip portion (nearest portion) of the pair of rolls 57, 58 of the second cutting mechanism 56. 120 occurs, and as a result, the cutting positions of the sheets 91 and 92 by the second cutting mechanism 56 differ. As a result, in the second cutting process performed by the second cutting mechanism 56, there are some high-height pieces in the plurality of sheet pieces 11 that are simultaneously manufactured by cutting the plurality of narrow sheets 9 (91, 92) once. It is possible to mix a plurality of types of sheet pieces 11 that differ from each other in the presence or absence of the rigid portion 120 or in the form of the highly rigid sheet piece 11H. In the form shown in FIG. 11, a high-rigidity sheet piece 11H and a low-rigidity sheet piece 11L without a high-rigidity portion 120 are simultaneously manufactured by cutting the plurality of narrow sheets 9 (91, 92) once.

Although the present invention has been described above based on its preferred embodiments, the present invention is not limited to the above-described embodiments, and can be modified as appropriate without departing from the spirit of the present invention.

1 Absorbent manufacturing device 2 Rotating drum 3A, 3B duct 4 First supply mechanism (hydrophilic fiber manufacturing device)
5, 5A, 5B, 5C, 5D Second supply mechanism (sheet piece manufacturing device)
50 Rigidity imparting mechanism 51, 52 Heat roll
50H Convex portion 53 First cutting mechanism 54 Cutter roll 54C Cutter blade 55 Anvil roll 56 Second cutting mechanism 57 Cutter roll 57C Cutter blade 58 Anvil roll 59 Highly rigid part phase shift inducing mechanism 590 Conveying path changing roll 6 Vacuum conveyor 7 Hydrophilic fiber raw material sheet 8 Raw material sheet for sheet pieces 9, 91, 92 Narrow sheet 10 Absorber 11 Sheet pieces 11H, 11HA, 11HB, 11HC, 11HD, 11HE High rigidity sheet piece 11L Low rigidity sheet piece 111 Uncut surface 112 Cut surface 120 High rigidity part 121 Low rigidity part 11F Constituent fibers of sheet piece 12F Hydrophilic fibers 13 Core wrap sheet

Claims (14)

A method for producing an absorbent body each containing a plurality of sheet pieces and a plurality of hydrophilic fibers, the method comprising:
The method for manufacturing the absorbent body includes the step of manufacturing the sheet piece,
In the manufacturing process of the sheet piece, a belt-shaped raw material sheet containing only synthetic fibers is conveyed, a stiffening treatment is partially applied to the raw material sheet, and the treated portion is attached to the peripheral portion of the treated portion. A rigidity imparting step to create a high-rigidity part with high rigidity compared to the
a first cutting step of transporting the raw material sheet that has undergone the stiffening step and cutting the raw material sheet in a first direction to obtain a narrow sheet;
a second cutting step of conveying the narrow sheet and cutting the narrow sheet in a second direction intersecting the first direction to obtain a plurality of sheet pieces ;
A method for manufacturing an absorbent body , wherein the plurality of sheet pieces obtained in the second cutting step include a sheet piece that does not have the high rigidity portion . The method for manufacturing an absorbent body according to claim 1, wherein the stiffening process is a process of fusing constituent fibers of the raw material sheet to each other. The absorbent body according to claim 1 or 2, wherein in the stiffening step, the stiffening process is performed on the raw material sheet so that the high-rigidity portion extends in a direction intersecting the conveyance direction of the raw material sheet. Production method. 2. The method according to claim 1, wherein in the stiffening step, the stiffening process is performed on the raw material sheet so that the high-rigidity portion extends in two directions: a conveying direction of the raw material sheet and a direction crossing the conveying direction. 2. The method for manufacturing the absorbent body according to 2. The method for manufacturing an absorbent body according to any one of claims 1 to 4, wherein the first direction is parallel to the conveyance direction of the raw material sheet. Any one of claims 1 to 5, wherein the plurality of sheet pieces obtained in the second cutting step include those in which the high rigidity portion extends from one side of the sheet piece to another side. A method for manufacturing an absorbent body as described in . Any one of claims 1 to 6, wherein the plurality of sheet pieces obtained in the second cutting step include those in which the high rigidity portion extends only in a direction intersecting the conveyance direction of the raw material sheet. A method for manufacturing the absorbent body according to item 1. According to any one of claims 1 to 7, the plurality of sheet pieces obtained in the second cutting step include those in which the high-rigidity portion extends only in the conveyance direction of the raw material sheet. A method for manufacturing an absorbent body . The plurality of sheet pieces obtained in the second cutting step include those in which the high-rigidity portion extends only in two directions: a conveyance direction of the raw material sheet and a direction intersecting the conveyance direction. A method for producing an absorbent body according to any one of Items 1 to 8. The method for manufacturing an absorbent body according to any one of claims 1 to 9 , wherein the constituent fibers of the raw material sheet are oriented in the same direction as the conveyance direction of the raw material sheet. The method for manufacturing an absorbent body according to any one of claims 1 to 9, wherein the high-rigidity portion intersects with the orientation direction of the constituent fibers of the sheet piece. In the rigidity imparting step, the raw material sheet is subjected to the rigidity imparting treatment so that the high rigidity portion extends in a direction that is not orthogonal to but intersects with the conveyance direction of the raw material sheet, or the second cutting step The method for manufacturing an absorbent body according to any one of claims 1 to 11, wherein the second direction is a direction that is not perpendicular to but intersects with the first direction. 1 . The method of claim 1 , further comprising a step of causing a phase shift of the high rigidity portions of the plurality of narrow sheets obtained in the first cutting step between the first cutting step and the second cutting step. The method for producing an absorbent body according to any one of items 1 to 12. 14. The method for manufacturing an absorbent body according to claim 1, further comprising the step of transporting the plurality of sheet pieces by airflow to a predetermined stacking section and stacking them.

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