JP6139039B1 - Method for manufacturing absorbent article - Google Patents

Abstract

A composite sheet comprising a first sheet on which a plurality of convex portions are formed and a second sheet laminated on the first sheet is used as the absorbent article (1). The manufacturing method of the absorbent article includes a step of heat-treating the first sheet (P12) to recover the bulk, and a region where the first roll (52 and the second roll (53) are engaged with each other. (B1), a plurality of convex portions are formed on one surface of the first sheet in contact with the first roll, and a plurality of concave portions are formed on the other surface of the first sheet in contact with the second roll. And the other side of the first sheet in which the shape of the plurality of concave portions is relaxed away from the second roll so that the convex portions are solid while one surface of the first sheet is in contact with the first roll. The surface of the second sheet (P13) is joined to one surface of the second sheet (P13) to form a composite sheet (P10). It overlaps with the region corresponding to the convex part in the thickness direction.

Description

  The present invention relates to a method for manufacturing an absorbent article.

  As a constituent member of an absorbent article such as a sanitary napkin or a disposable diaper, a composite sheet composed of a plurality of sheets is known. A composite sheet is used for the surface sheet of an absorbent article, for example. The properties required for the composite sheet include liquid permeability, but particularly the properties required for the composite sheet that touches the wearer's skin include softness (cushioning property) and good touch. Therefore, in recent years, a composite sheet having a plurality of hook-shaped or island-shaped convex portions protruding in a direction away from the surface of the base portion on a substantially flat base portion is used. Since the composite sheet having the ridge-like or island-like convex portions has a relatively soft convex portion and is easy to fit on the skin surface, the wearer tends to feel softness and good touch. In particular, a composite sheet that uses a bulk-recoverable sheet that recovers its bulk by heat treatment and has a convex portion formed by utilizing the phenomenon of bulk recovery improves the softness and feel compared to other methods. Has been done.

  A method for producing a composite sheet using such a bulk recoverable sheet is disclosed in Patent Document 1. In the method for manufacturing a composite sheet, two sheets are partially joined to form a large number of joined portions, and one sheet has convex portions formed at portions other than the joined portions. In the manufacturing method, a bulk-recoverable sheet whose bulk is recovered by heat treatment is used for at least one of both sheets. Then, one of the two sheets (bulk-recoverable sheet) is supplied to the meshing portion of the pair of tooth space rolls. Next, the sheet is held as it is along one peripheral surface portion of the pair of rolls and moved from the meshing portion, and the other of the two sheets is supplied so as to be superimposed on one side, and the two sheets are Join to form a composite sheet. At that time, the anti-net surface at the time of manufacturing the bulk recoverable sheet is set as a surface facing the overlapping sheets, and the bulk recoverable sheet is subjected to heat treatment before or after joining both sheets. At this time, a convex part is formed in one (bulk-recoverable sheet) of the two sheets, and the two sheets are joined at a place other than the convex part.

JP 2008-155602 A

  By the way, the composite sheet manufactured with the manufacturing method of patent document 1 has the space where a fiber density is remarkably low compared with the periphery in a convex part, ie, a hollow area | region. However, the hollow region is a gap formed between the first sheet and the second sheet. When there is a hollow region in the convex part, for example, when the composite sheet is used for the top sheet of the absorbent article, the liquid excreted on the skin side surface of the top sheet is absorbed by the convex part. Then, the inside of the hollow region cannot be moved, and the region around the hollow region, that is, the region near the surface of the convex portion is moved. Therefore, in the composite sheet, the liquid movement path in the convex portion is limited by the hollow region, and the liquid permeability of the composite sheet may be reduced. In other words, since the convex portion has a hollow area that prevents the liquid from moving, the composite sheet in which the convex portion is formed by utilizing the phenomenon of bulk recovery improves softness and touch, but decreases liquid permeability. There is a risk of it.

  An object of the present invention is a method of manufacturing an absorbent article using a composite sheet in which convex portions are formed by utilizing the phenomenon of bulk recovery, and can achieve both softness and touch in the composite sheet and liquid permeability. It is providing the manufacturing method of an absorbent article.

  The manufacturing method of the absorbent article of this invention is as follows. (1) Absorbent article using a composite sheet comprising a first sheet having a plurality of convex portions formed on one surface and a second sheet laminated on the other surface of the first sheet. A bulk recovery step of recovering the bulk by heat-treating the first sheet, and the heat-treated first sheet, the tooth portion and groove portion of the first roll, and the second roll Supplying to the area | region where a tooth | gear part and a groove part mutually mesh | engage, a some convex part is formed in the said one surface of the said 1st sheet | seat which contact | connects a said 1st roll, and the said 1st which contact | connects a said 2nd roll Forming each of the plurality of concave portions on the other surface of the sheet, and maintaining the state where the one surface of the first sheet is in contact with the first roll. The plurality of recesses away from the second roll so that the inside of the plurality of recesses is solid A joining step of joining the other surface of the first sheet having a relaxed shape to one surface of the second sheet to form the composite sheet, and A method for manufacturing an absorbent article, wherein a joint between the other surface and the one surface of the second sheet overlaps with a region corresponding to each of the plurality of convex portions of the first sheet in the thickness direction. .

  In the manufacturing method of the present absorbent article, the first sheet is recovered in the bulk recovery process, and the first sheet is sandwiched between the first roll and the second roll in the formation process. A convex portion is formed on one surface of one sheet, and a concave portion is formed on the other surface (back surface). Thereafter, in the joining step, the shape of the concave portion separated from the second roll is relaxed by the repulsive force (or elastic force) of the constituent fibers of the first sheet while maintaining the shape of the convex portion with the first roll. Thus, a dent smaller than the recess (shallow and narrow) is formed, and the dent and the second sheet are joined at the joint. In this way, the gap between the first sheet and the second sheet is obtained by joining the depression, that is, the region corresponding to the convex portion on the other surface of the first sheet and the second sheet. It can suppress that a hollow area | region is formed in the convex part. Thereby, a convex part can be formed in a solid shape. In addition, the region corresponding to the convex portion on the other surface of the first sheet and the second sheet are not only in contact with each other in shape but also joined (example: adhesive), so in subsequent steps The first sheet can be separated from the second sheet so that the hollow region is not formed later. That is, it can suppress that a hollow area | region is formed later in the convex part of a composite sheet, Therefore A convex part can be maintained solid. Thereby, it is possible to achieve both softness and touch due to the solid convex portion and improvement of liquid permeability.

In the manufacturing method of the present absorbent article, (2) the other surface of the first sheet is an anti-net surface at the time of manufacturing the first sheet, and the one surface of the second sheet is The anti-net surface at the time of manufacturing the second sheet, and in the joining step, the anti-net surface of the first sheet and the anti-net surface of the second sheet are joined. The manufacturing method of the absorbent article as described in 1) may be sufficient.
A sheet produced by depositing fibers on a fiber support such as a net is the surface that was in contact with the net (fiber support) when the sheet was manufactured, that is, the net surface and the anti-net surface opposite the net surface. And having. In the portion on the side opposite to the net surface of the sheet, the fiber density of the constituent fibers is low compared to the portion on the net surface side, the constituent fibers can be easily moved, and therefore bulk recovery is easy and fluffing is easy. So, in the manufacturing method of this absorbent article, when joining a 1st sheet | seat and a 2nd sheet | seat, the anti-net surfaces of both sheets are joined. For this reason, the fiber density is high on one surface of the first sheet, that is, the portion on the net surface side. Therefore, when the convex portion is formed in the forming process, there are many constituent fibers that cause plastic deformation such as bending. As a result, the shape of the convex portion can be more easily maintained even after the forming process. On the other hand, since the fiber density is low on the other side of the first sheet, that is, the portion on the side opposite to the net surface, there are few constituent fibers that cause plastic deformation such as bending when the recess is formed in the forming process. In addition, the bulk is greatly recovered by the heat treatment, and elastic deformation is easily performed in the thickness direction. As a result, when the second roll is separated from the concave portion in the joining process, the constituent fibers can be returned almost to the original state by the repulsive force (or elastic force) of the constituent fibers in the concave portion, that is, the shape of the concave portion is relaxed. Thus, the dent can be made small and fluffed. Thereby, while forming a convex part in one side of the 1st sheet, the other side can be made into a small hollow. And, in the portion of the second sheet on the side opposite to the net surface, since the fiber density is low and deformation is easy, the portion on the side opposite to the net surface of the second sheet and the portion on the side opposite to the net of the first sheet Can be easily joined. At that time, since the constituent fibers of the joining surfaces of both sheets can easily move with each other, the formation of a hollow region in the convex portion can be more reliably suppressed. That is, it can suppress more reliably that a hollow region is formed in the convex part of a composite sheet, and can form a solid structure in a convex part more reliably.

In the manufacturing method of the present absorbent article, (3) the plurality of convex portions are continuously extended along the conveyance direction MD of the first sheet, and between the convex portions adjacent to each other in the plurality of convex portions. A base portion is continuously extended along the transport direction MD, and the manufacturing method of the absorbent article performs intermittent compression along the transport direction MD in the base portion, The method for manufacturing an absorbent article according to the above (1) or (2) may further include an intermittent joining step for joining the first sheet and the second sheet.
When joining the first sheet and the second sheet, for example, at a location where the diffusion in the thickness direction of the adhesive for joining is insufficient, there is a risk that only the constituent fibers in the surface region of each sheet may be joined. is there. In that case, the region between the adjacent convex portions, that is, the base portion (concave portion) of the first sheet on which the convex portion is not formed naturally recovers the bulk due to the elastic force of the first sheet, and the like. There is a possibility that the unevenness of the unevenness disappears and the softness and the like are lowered. Therefore, in the method for manufacturing an absorbent article, the base of the first sheet is joined to the second sheet by intermittent compression (squeezing). Thus, the shape of the convex portion can be more stably formed by intermittently joining the base portion of the first sheet and the second sheet around the convex portion. Thereby, the solid structure in a convex part can be formed more stably. Moreover, since the 1st sheet | seat and the 2nd sheet | seat are squeezed in the area | region around a convex part, when the part of the skirt of a convex part is pulled to the pressing part side, ie, the 2nd sheet | seat side, the whole convex part Is pressed against the second sheet. Furthermore, the region of the second sheet that faces the convex portion of the first sheet comes close to the first sheet side. Accordingly, the bottom of the convex portion (the other surface of the first sheet) is pressed against one surface of the second sheet, and there is a gap between the first sheet and the second sheet. However, the gap can be eliminated. Thereby, the inside of a convex part can be made more solid. In addition, when the joining is continuous, the entire base portion of the first sheet becomes hard, and the texture may become worse, or it may be difficult to move the liquid in the part melted by joining, In this manufacturing method, since joining is intermittent, such a situation can be avoided.

In the manufacturing method of the present absorbent article, (4) the temperature of the outer peripheral surface including the tooth portion of the first roll is higher than room temperature, and has the lowest melting point among the materials constituting the first sheet. The manufacturing method of the absorbent article according to any one of (1) to (3) above, which is a first predetermined temperature lower than the melting point of the material.
In the manufacturing method of the present absorbent article, since the outer peripheral surface of the first roll has the first predetermined temperature, that is, the first surface of the first sheet is heated, The first surface can be easily formed into a convex shape. Thereby, the shape of a some convex part can be stably formed in one surface of a 1st sheet | seat. By stabilizing the shape of the convex portion, the solid structure in the convex portion can be formed more stably.

(5) The temperature of the outer peripheral surface including the tooth portion of the second roll is a second predetermined temperature that is equal to or higher than normal temperature and lower than the first predetermined temperature. The manufacturing method of the absorbent article as described in 4) may be sufficient.
When the temperature of the outer peripheral surface of the second roll is set to be equal to or higher than the first predetermined temperature, a concave portion is stably formed on the other surface of the first sheet. Then, even if the other surface of the first sheet is separated from the outer peripheral surface of the second roll, the shape of the concave portion remains as it is, and a gap is generated between the first sheet and the second sheet, and the convex portion May not become solid. Therefore, in the manufacturing method of the present absorbent article, in the forming step, a second roll having a second predetermined temperature lower than the first predetermined temperature is applied to the inside of the convex portion that is restored in bulk. . Thereby, it is possible to make the other surface of the first sheet in contact with the second roll into a concave shape while maintaining the bulk recovered state, that is, the other surface of the first sheet has a repulsive force (or elasticity). It is possible to make the shape concave while maintaining the force. And since the other surface of the 1st sheet | seat is maintained in the state holding the repulsive force (or elastic force), in the joining process, the other surface of the 1st sheet | seat is separated from the outer peripheral surface of a 2nd roll. When released, the recess can be relaxed to a recess smaller than the recess by the repulsive force. Thereby, the hollow and the 2nd sheet can be joined stably, and the situation where a crevice arises between the 1st sheet and the 2nd sheet can be controlled more certainly. That is, it can suppress more reliably that a hollow area | region is formed in the convex part of a composite sheet, Therefore A convex part can be made more solid reliably.

In the manufacturing method of the present absorbent article, (6) the uppermost end in the vertical direction of the second roll is below the virtual horizontal plane passing through the uppermost end in the vertical direction of the first roll. The manufacturing method of the absorbent article as described in the above (4) or (5) may be used.
The temperature of a 1st roll is said predetermined temperature higher than normal temperature. Therefore, the object that is vertically above the first roll is heated by the heat of the first roll, and there is a possibility that the temperature is about the same as that of the first roll. So, in the manufacturing method of this absorbent article, the 2nd roll is arrange | positioned below the 1st roll in the perpendicular direction. Therefore, it is possible to prevent the temperature of the second roll from being affected by the first roll and reaching the same temperature as the first roll. Thereby, after forming a recessed part in the other surface of a 1st sheet | seat at a formation process, the recessed part can be easily recovered to a substantially flat shape. As a result, it is possible to prevent a gap from being generated between the first sheet and the second sheet. That is, it can suppress more reliably that a hollow area | region is formed in the convex part of a composite sheet, Therefore A convex part can be made more solid reliably.

(7) Absorption as described in any one of said (1) thru | or (6) with which the material of the outer peripheral surface containing the said tooth | gear part of a said 2nd roll consists of dielectrics. The manufacturing method of a property article may be sufficient.
In the manufacturing method of this absorbent article, the material of the outer peripheral surface of the second roll is made of a dielectric. Therefore, when the other surface of the first sheet moves away from the outer peripheral surface of the second roll, the other surface of the first sheet is caused by static electricity generated by friction between the outer peripheral surface of the second roll and the first sheet. The constituent fibers of the surface are lifted, and the recess can be made into a smaller depression or a flatter shape. Accordingly, the first sheet and the second sheet can be more reliably joined, that is, no gap can be generated between the two sheets. As a result, it can suppress more reliably that a hollow area | region is formed in the convex part of a composite sheet, and can make a convex part solid more reliably.

In the manufacturing method of the present absorbent article, (8) each of the first roll and the second roll has the tooth portion and the groove portion continuously extended on the outer peripheral surface along the rotation direction. In the forming step, a speed at which the first sheet is supplied to the meshing region is equal to or less than an outer peripheral speed of the first roll, according to any one of (1) to (7) above. The manufacturing method of an absorbent article may be sufficient.
If the supply speed (feed speed) of the first sheet exceeds the outer peripheral speed of the first roll, wrinkles will occur in the first sheet. Therefore, in the manufacturing method of the absorbent article, the first sheet supply speed (feed speed) is set to be equal to or less than the outer peripheral speed of the first roll, thereby more reliably preventing wrinkles on the first sheet. Thus, the convex portion can be formed more reliably.

In the manufacturing method of the present absorbent article, (9) any one of the above (1) to (8), wherein in the forming step, the outer peripheral speed of the second roll is faster than the outer peripheral speed of the first roll. The manufacturing method of the absorbent article as described in one item | term may be sufficient.
In the manufacturing method of the present absorbent article, since the outer peripheral speed of the second roll is faster than the outer peripheral speed of the first roll, the second roll scrubs the first sheet on the first roll. The deformation amount of the portion on the other surface side of one sheet can be increased. As a result, the constituent fibers on the other surface side of the first sheet can be more easily moved and deformed, so that a gap is generated between the first sheet and the second sheet, that is, in the convex portion of the composite sheet. The formation of the hollow region can be more reliably suppressed, so that the convex portion can be made more solid.

In the manufacturing method of the present absorbent article, (10) in the forming step, the first sheet is pressed against a bottom portion of the groove portion of the second roll by a top portion of the tooth portion of the first roll. Absorbency as described in any one of said (1) thru | or (9) which is compressed, is not pressed by the top part of the said tooth part of the said 2nd roll, and is not pressed against the bottom part of the said groove part of the said 1st roll. It may be a method for manufacturing an article.
In the manufacturing method of the present absorbent article, the first sheet is pressed against the bottom of the groove portion of the second roll by the top of the tooth portion of the first roll and compressed, so that they are adjacent to each other on one surface. The base between the convex portions can be formed stably. In addition, the first sheet is not compressed by being pressed against the bottom of the groove portion of the first roll by the top portion of the tooth portion of the second roll, so that a concave portion can be temporarily formed to assist in the formation of the convex portion. The shape can be easily recovered (or bulk recovered) by the elastic force of the concave portion temporarily formed in the convex portion. Thereby, while being able to form the shape of a convex part stably, it can suppress that a 1st sheet | seat leaves | separates from a 2nd sheet | seat, and a clearance gap arises. It can suppress that a hollow area | region is formed in the convex part of a composite sheet, and can make a convex part solid.

(11) The absorptivity according to any one of (1) to (10), wherein the second roll rotates in a rotating state with the first sheet. It may be a method for manufacturing an article.
In the manufacturing method of this absorbent article, since the second roll rotates in accordance with the displacement amount of the first sheet, the first sheet has wrinkles and widths without adjusting the speed of the second roll. Can be made difficult to generate. Thereby, generation | occurrence | production of the wrinkle in a 1st sheet | seat can be suppressed more reliably, and a convex part can be formed more reliably.

  According to the present invention, there is provided a method for manufacturing an absorbent article in which convex portions are formed by utilizing the phenomenon of bulk recovery, and the manufacture of an absorbent article capable of achieving both softness and touch in a composite sheet and liquid permeability. A method can be provided.

It is a figure which shows a part of structural example of the absorbent article which concerns on embodiment. It is a figure which shows the structural example of the surface sheet of the absorbent article which concerns on embodiment. It is a figure which shows typically the structural example of the manufacturing apparatus of the absorbent article which concerns on embodiment. It is a figure which shows typically the structural example of the roll of a manufacturing apparatus. It is a figure which illustrates typically the manufacturing method of the absorptive article concerning an embodiment. It is a figure which illustrates typically the manufacturing method of the absorptive article concerning an embodiment. It is a figure which illustrates typically the manufacturing method of the absorptive article concerning an embodiment. It is a figure which illustrates typically the manufacturing method of the absorptive article concerning an embodiment.

  The absorbent article according to the present embodiment will be described with reference to the drawings, taking a sanitary napkin as an example. However, the type and application of the absorbent article are not particularly limited, and examples include sanitary products and sanitary products such as panty liners, disposable diapers (tape type, pants type), incontinence pads, and sweat removing sheets. These may be human subjects or non-human animals such as pets. The liquid which the absorbent article is to be absorbed is not particularly limited, and examples thereof include liquid excrement and body fluid of the wearer.

  FIG. 1 is a diagram illustrating a configuration example of the absorbent article 1, and shows a plan view in a state where the absorbent article 1 is developed. The absorbent article (sanitary napkin) 1 has a longitudinal direction L, a width direction W, and a thickness direction T orthogonal to each other, a main body portion 1A extending in the longitudinal direction L, and a width direction at a substantially central portion of the longitudinal direction L. A pair of flap portions 1B and 1B extending on both sides of W are provided. The absorbent article 1 has a central axis CL extending in the longitudinal direction L through the center in the width direction W, and a central axis CW extending in the width direction W through the center in the longitudinal direction L of the pair of flap portions 1B, 1B. . In FIG. 1, the upper side is the front of the absorbent article 1 and the lower side is the rear of the absorbent article 1. In addition, since the longitudinal direction L, the width direction W, and the thickness direction T of the absorbent article 1 and the longitudinal direction, the width direction, and the thickness direction of each material of the absorbent article 1 described later coincide, The longitudinal direction L, the width direction W, and the thickness direction T are used in common for the property article 1 and each material thereof. Further, “plan view” refers to viewing the developed absorbent article 1 in the thickness direction T from the upper surface side. “Skin side” and “non-skin side” refer to the side closer to the wearer's skin surface and the far side in the thickness direction T when the absorbent article 1 is worn by the wearer of the absorbent article 1. Each means. A direction toward the central axis CL and a direction away from the central axis CL are defined as directions inside and outside the width direction W, respectively. A direction toward the central axis CW and a direction away from the central axis CW are defined as the inner and outer directions of the longitudinal direction L, respectively. These definitions are also commonly used for each material of the absorbent article 1. Further, in the present specification, in the case of “solid” with respect to the convex portion described later, there is no hollow region (a space where the fiber density is significantly lower than the surroundings) that prevents the movement of the liquid in the convex portion. That means.

  The absorbent article 1 includes at least a top sheet 2, a back sheet 3, and an absorbent body 4. The top sheet 2 is a liquid-permeable sheet located on the skin side of the wearer. Examples of the surface sheet 2 include any liquid-permeable sheet such as a liquid-permeable nonwoven fabric or woven fabric, a synthetic resin film in which liquid-permeable holes are formed, and a composite sheet thereof. The back sheet 3 is a liquid-impermeable sheet located on the non-skin side of the wearer. Examples of the back sheet 3 include liquid-impermeable sheets such as liquid-impermeable nonwoven fabrics and synthetic resin films, composite sheets thereof, and SMS nonwoven fabrics. An exterior sheet 9 that reinforces the back sheet 3 and improves the touch may be laminated on the non-skin side of the back sheet 3. Examples of the exterior sheet 9 include the same material as the back sheet 3, a water-repellent nonwoven fabric, a synthetic resin film, and any water-repellent sheet such as a composite sheet thereof. The absorber 4 is a liquid-absorbing and liquid-holding material located between the top sheet 2 and the back sheet 3. Examples of the absorbent body 4 include pulp fibers, synthetic fibers, and absorbent polymers. The absorber 4 and the top sheet 2 and the back sheet 3 are respectively joined by an adhesive, and the top sheet 2 and the back sheet 3 are joined by an adhesive at their peripheral portions. As an adhesive for bonding between the top sheet 2, the absorber 4 and the back sheet 3, a known material generally used in the absorbent article 1, for example, a thermoplastic adhesive can be used.

  Next, the top sheet 2 will be further described. The top sheet 2 is formed from the composite sheet 10. FIG. 2 is a diagram illustrating a configuration example of the composite sheet 10 (surface sheet 2) according to the embodiment. 2A is a partial plan view of the composite sheet 10, and FIG. 2B is a cross-sectional view taken along the line IIb-IIb 'of FIG. The composite sheet 10 includes a first sheet 12 and a second sheet 13. However, one direction of the thickness direction T is upward and the other direction is downward.

  The first sheet 12 has a first upper surface 12E (one surface) that is an upward surface in the thickness direction T and a first lower surface 12F (the other surface) that is a downward surface, The sheet extends in the direction L and the width direction W. The first sheet 12 is continuous along the longitudinal direction L between the plurality of convex portions 15 continuously extending along the longitudinal direction L on the first upper surface 12E and the convex portions 15 adjacent to each other. And a base 16 that is extended to the outside. It can be said that the convex portion 15 is a protruding portion that protrudes upward in the thickness direction T from the base portion 16 of the first upper surface 12E. The first sheet 12 is bonded to the second sheet 13 by the bonding portion 14 on the first lower surface 12F. As a dimension of the convex part 15, width 0.25-5 mm, height 0.25-5 mm, and pitch 0.5-10 mm are mentioned, for example.

  The second sheet 13 has a second upper surface 13E (one surface) that is an upward surface in the thickness direction T, and a second lower surface 13F (the other surface) that is a downward surface. The sheet extends in the direction L and the width direction W. The second sheet 13 is bonded to the first sheet 12 by the bonding portion 14 on the second upper surface 13E. The second sheet 13 may be slightly raised upward in the thickness direction T at the convex portion 15. That is, the boundary between the first sheet 12 and the second sheet 13 may be slightly convex in the convex portion 15.

  The joining portion 14 joins the first lower surface 12F of the first sheet 12 and the second upper surface 13E of the second sheet 13, and is an adhesive exemplified by a hot melt adhesive in the present embodiment. Although not shown in the figure, the thickness direction T diffuses upward and downward. The joint portion 14 overlaps with a region corresponding to each of the plurality of convex portions 15 of the first sheet 12 in the thickness direction T. In other words, at least a part of the joint part 14 is included in at least a part of the region of each convex part 15 when viewed from above in the thickness direction T, that is, in plan view. However, the joining portion 14 is not particularly limited as long as the first sheet and the second sheet 13 can be joined. For example, a thin conductive material is applied and the first sheet and the second sheet 13 are formed by induction heating. May be heat-welded.

  Thus, since the first lower surface (the other surface) 12F of the convex portion 15 and the second upper surface (the one surface) 13E of the second sheet 13 are joined by the joint portion 14, the convex portion 15 and the first surface The formation of a gap with the second sheet 13 can be suppressed, and the inside of the convex portion 15 can be made solid. Thereby, the whole convex part 15 can be made into the movement path | route of a liquid, and the liquid permeability of the composite sheet 10 can be improved. Moreover, since the some sheet-like convex part 15 is formed in the composite sheet 10, the softness and touch which a wearer feels can be improved. In this way, the composite sheet 10 achieves both softness, touch and liquid permeability. In this case, since the convex portion 15 is a solid shape, from the viewpoint of liquid permeability, the distance between the first lower surface 12F of the first sheet 12 and the second upper surface 13E of the second sheet 13 is the base portion. It is within 5% of the height in the thickness direction T of the convex portion 15 from 16, and preferably within 1%.

  In the present embodiment, the pattern of the joint portion 14 is a plurality of linear patterns (stripe patterns) extending along the longitudinal direction L and arranged in parallel with each other in the width direction W. The dimensions of the stripe pattern include, for example, a width of 0.5 to 2 mm and a pitch of 1 to 4 mm. However, the pattern of the joint portion 14 is not particularly limited as long as it overlaps the region corresponding to the convex portion 15 and the thickness direction T, and may be an omega pattern, a web pattern, or a spiral pattern. In addition, if it is each said pattern, the area | region where the junction part 14 is not included in the area | region of the convex part 15 may exist in a few area | regions among the whole areas of the composite sheet 10. FIG.

  The composite sheet 10 further includes a pressing unit 17 in the present embodiment. The pressing part 17 is intermittently arranged along the longitudinal direction L in each base part 16. The pressing parts 17 may be arranged at equal intervals in the longitudinal direction L in the base part 16 or may be arranged at non-equal intervals. In the bases 16 adjacent to each other in the width direction W, they may be the same position in the longitudinal direction L or may not be the same position. In the present embodiment, the base 16 is arranged in a checkered pattern. Moreover, the shape of the pressing unit 17 in a plan view is arbitrary such as an ellipse. The pressing unit 17 is formed by sandwiching and compressing from above the first sheet 12 and below the second sheet 13 in the thickness direction T, and joining the first sheet 12 and the second sheet 13 together. To do. In addition, the composite sheet 10 does not need to include the pressing part 17.

  In the present embodiment, the first sheet 12 is manufactured by depositing fibers on a fiber support such as a net, and a surface that is in contact with the net (fiber support) at the time of manufacture is referred to as a net surface, The surface opposite to the net surface is referred to as an anti-net surface. The first upper surface 12E and the first lower surface 12F of the first sheet 12 are a net surface and an anti-net surface at the time of manufacturing the first sheet 12, respectively. Furthermore, the second upper surface 13E and the second lower surface 13F of the second sheet 13 are an anti-net surface and a net surface when the second sheet 13 is manufactured, respectively. Therefore, in the present embodiment, the anti-net surface of the first sheet 12 and the anti-net surface of the second sheet 13 are joined.

  The basic weight of the convex part 15 and the base part 16 in the 1st sheet | seat 12 is substantially the same. The fiber density of the convex portion 15 is lower than the fiber density of the base portion 16. The fiber density of the base part 16 is lower than the fiber density of the pressing part 17. Since the fiber density of the convex part 15 is low, a wearer can feel softness. Either the basis weight of the first sheet 12 or the basis weight of the second sheet 13 may be higher or the same.

The first sheet 12 is liquid permeable and uses a bulk-recoverable sheet that recovers its bulk by a predetermined heat treatment. In the absorbent article 1, the bulk of the first sheet 12 is recovered. Examples of the bulk recoverable sheet include nonwoven fabrics such as air-through nonwoven fabrics, air laid nonwoven fabrics, needle punched nonwoven fabrics, and spunlace nonwoven fabrics. Examples of the basis weight include 10 to 200 g / m ² . Moreover, as a constituent fiber of the 1st sheet | seat 12, a polyester-type or polyolefin-type fiber, or those composite fibers are mentioned, for example. Examples of the composite fibers include core / sheath fibers such as polyethylene terephthalate (PET) / polyethylene (PE) and polypropylene (PP) / polyethylene (PE). In this embodiment, a fiber having a core / sheath structure of polyethylene terephthalate (PET) / polyethylene (PE) is used. Examples of the fineness of the fiber include 1 to 20 dtex.

  As long as the second sheet 13 is liquid permeable, a bulk-recoverable sheet may or may not be used. In the present embodiment, from the viewpoint of softness, a core / sheath structure fiber of polyethylene terephthalate (PET) / polyethylene (PE), which is the same bulk recovering nonwoven fabric as the first sheet 12, is used. In the absorbent article 1, the second sheet 13 is recovered in bulk. However, a sheet different from the first sheet 12 may be used.

  Next, the structure of the manufacturing apparatus 50 of the absorbent article 1 according to the present embodiment will be described. FIG. 3 is a diagram schematically illustrating a configuration example of the manufacturing apparatus 50 for the absorbent article 1. FIG. 4 is a diagram schematically illustrating a configuration example of a roll of the manufacturing apparatus 50. The manufacturing apparatus 50 includes a first heat treatment apparatus 51, a first roll 52, a second roll 53, a second heat treatment apparatus 54, an adhesive application apparatus 55, a joining roll 56, and a main body production apparatus. 57. The manufacturing apparatus 50 has a conveyance direction MD, a transverse direction CD perpendicular to the conveyance direction MD and along the conveyance surface, and a vertical direction TD perpendicular to the conveyance direction MD and the transverse direction CD, regarding conveyance of the material of the composite sheet 10 and the like. . Here, the longitudinal direction, the width direction, and the thickness direction of the composite sheet 10 and the material (member) constituting the composite sheet 10 are all the same as the transport direction MD, the transverse direction CD, and the vertical direction TD. Therefore, also in the composite sheet 10 and the material constituting it, the transport direction MD, the transverse direction CD, and the vertical direction TD are used in the longitudinal direction, the width direction, and the thickness direction, respectively.

  The first heat treatment apparatus 51 is an apparatus for performing heat treatment on a sheet whose volume is recovered by heat treatment. In the present embodiment, the first heat treatment apparatus 51 is supplied with a first sheet P12a that is a material for the first sheet 12 and is bulk-recovered by a predetermined heat treatment. The first heat treatment apparatus 51 forms the first sheet P12b by carrying out the predetermined heat treatment on the first sheet P12a to restore the bulk while conveying the first sheet P12a in the conveyance direction MD. .

  In the present embodiment, the first heat treatment apparatus 51 conveys the first sheet P12a while adjusting the tension by, for example, nip rolls provided at both ends of the conveyance path in the apparatus. Examples of the heat treatment method include a method of supplying hot air to either one of the first sheets P12a (example: anti-net surface) or both surfaces. At this time, since the first sheet P12a does not contact the conveyor belt, it is easy to recover the bulk uniformly. However, the 1st heat processing apparatus 51 is not limited to this example, For example, you may mount and convey the 1st sheet | seat P12a on a sheet | seat support member like a conveyor belt. Examples of the heat treatment method include a method of supplying hot air to a surface (example: anti-net surface) opposite to the surface in contact with the sheet support member in the first sheet P12a. At this time, the surface to which hot air is supplied is easier to recover the bulk than the other surface.

  The first roll 52 and the second roll 53 sandwich the sheet in the meshing area of the tooth portion and the groove portion of the both, and form a plurality of convex portions on one surface of the sheet, and a plurality of concave portions on the other surface. Form. In the present embodiment, the first roll 52 is disposed to face the second roll at a first predetermined position on the outer peripheral surface of the first roll 52. The first roll 52 is continuously extended along the rotation direction between the plurality of tooth portions 52a continuously extending along the rotation direction and the tooth portions 52a adjacent to each other on the outer peripheral surface thereof. Grooved portion 52b. The second roll 53 is continuously extended along the rotation direction between the plurality of tooth portions 53a continuously extending along the rotation direction and the tooth portions 53a adjacent to each other on the outer peripheral surface thereof. Grooved portion 53b. As indicated by imaginary lines EL1, EL2 (FIG. 4), the teeth and grooves of both rolls are arranged to mesh with each other. The tooth portion 52a and groove portion 52b of the first roll 52 and the tooth portion 53a and groove portion 53b of the second roll 52 hold the first sheet P12b in the meshing region B1 where both mesh with each other. A plurality of convex portions are formed on one surface of the sheet P12b, and a plurality of concave portions are formed on the other surface. Accordingly, the first roll 52 and the second roll 53 form the first sheet P12b that has passed through the meshing region B1, that is, the first sheet P12c. The outer peripheral surfaces of the first roll 52 and the second roll 53 can be set to a desired temperature. At least the outer peripheral surface of the first roll 52 is made of, for example, metal (example: stainless steel), and at least the outer peripheral surface of the second roll 53 is made of, for example, a dielectric (example: synthetic resin).

  The second heat treatment apparatus 54 is an apparatus for performing heat treatment on a sheet whose bulk is recovered by heat treatment. In the present embodiment, as the material for the second sheet 13, the second sheet P13a that is recovered in bulk by a predetermined heat treatment is used. The second heat treatment apparatus 54 is supplied with the second sheet P13a, performs the predetermined heat treatment on the second sheet P13a while conveying the second sheet P13a in the conveyance direction MD, and recovers the bulk. The second sheet P13b is formed.

  Similarly to the first heat treatment apparatus 51, the second heat treatment apparatus 54 conveys the second sheet P13a while adjusting the tension by, for example, a nip roll, and supplies hot air to both surfaces of the second sheet P13a, for example. Heat treatment is performed. However, for example, the second sheet P13a is placed on a sheet support member such as a conveyor belt and conveyed, and hot air is supplied to the surface of the second sheet P13a opposite to the surface in contact with the sheet support member. Heat treatment may be performed.

  The adhesive application device 55 applies the adhesive in a predetermined pattern to one surface of the second sheet P13b. Although there is no restriction | limiting in particular in an adhesive agent, For example, a hot-melt-adhesive agent is mentioned. The predetermined pattern corresponds to each of the plurality of convex portions of the first sheet P12c when the other surface of the first sheet P12c and the one surface of the second sheet P13c are joined in a later step. The region and the adhesive are set so as to overlap in the thickness direction T. Thereby, the adhesive application device 55 forms the second sheet P13b to which the adhesive is applied, that is, the second sheet P13c.

  The joining roll 56 sandwiches and joins two sheets to the facing area between the outer peripheral surface of the joining roll 5 and the tooth portion and groove portion of the first roll 52. In the present embodiment, the joining roll 56 is disposed to face the first roll 52 at a second predetermined position different from the first predetermined position on the outer peripheral surface of the first roll 52. The joining roll 56 includes pins 56p disposed intermittently along the rotation direction and the rotation axis direction at the base portion 56q of the outer peripheral surface thereof. As indicated by imaginary lines EL1 and EL2 (FIG. 4), the pin 56p of the joining roll 56 and the tooth portion 52a of the first roll 52 are arranged to face each other. The pin 56p and the base portion 56q of the joining roll 56 and the tooth portion 52a and the groove portion 52b of the first roll 52 sandwich the first sheet P12c and the second sheet P13c in the facing region B2 where both face each other. Then, the other surface of the first sheet P12c and the one surface of the second sheet P13c are brought into close contact with each other and bonded by the bonding portion 14 (example: adhesive). Thereby, the 1st roll 52 and the 2nd roll 53 form the laminated body of the 1st sheet | seat P12c and the 2nd sheet | seat P13c, ie, the composite sheet P10. In the present embodiment, the pin 56p of the joining roll 56 and the tooth portion 52a of the first roll 52 pinch the first sheet P12c and the second sheet P13c and compress (squeeze) them, so that they are compressed. In the case where the compressed portion 17 that can be the compressed portion 17 is not formed, the joining roll 56 may be an anvil roll (a roll that does not have the pin 56p). In that case, a pressing part becomes hard too much and the possibility of having a bad influence on softness and touch can be controlled. The outer peripheral surface of the joining roll 56 can be set to a desired temperature. In the joining roll 56, at least the outer peripheral surface is made of, for example, metal (example: stainless steel).

  The main body manufacturing apparatus 57 is supplied with a composite sheet P10 that is a material for the topsheet 2. And the composite sheet P10, the absorber (not shown) which is the material for the absorber 4 separately prepared (manufactured), and the back material sheet which is the material for the back sheet 3 separately prepared (manufactured) (Not shown) are stacked in this order, joined together, and cut into products. Thereby, the main body manufacturing apparatus 57 continuously forms the absorbent article P1. The method for forming the absorbent article P1 is not particularly limited as long as the composite sheet P10 is used as the material for the topsheet 2, and various known methods can be used.

  Next, the manufacturing method of the absorbent article 1 which concerns on this Embodiment is demonstrated with reference to FIGS. However, FIGS. 5-8 is sectional drawing which illustrates typically the manufacturing method of the absorbent article which concerns on embodiment. This manufacturing method includes a first bulk recovery step S1 (FIG. 5), a formation step S2 (FIGS. 6 to 7), a second bulk recovery step S3, a coating step S4, and a joining step S5 (FIG. 8). ) And a main body manufacturing process S6.

  In the first bulk recovery step S1, the first sheet P12a unwound from the first material roll (not shown) is heat-treated by the first heat treatment apparatus 51 to recover the bulk. The material of the first sheet P12a is the same as the material of the first sheet 12, and in this embodiment, fibers of a core / sheath structure of polyethylene terephthalate (PET) / polyethylene (PE) (high density) are used. . At this time, as shown in FIG. 5A, one surface 20a of the first sheet P12a is a net surface having a high density of constituent fibers, and the other surface 20b is an anti-net surface having a low density of constituent fibers. is there. In the first heat treatment apparatus 51, one surface 20a and the other surface 20b of the first sheet P12a are exposed to hot air or a heated atmosphere. Thereby, as shown in FIG. 5B, the bulk of the first sheet P12a is recovered, and the first sheet P12b is formed. The first sheet P12b has a substantially constant basis weight as compared with the first sheet P12a, but has a thicker thickness, and the density of the constituent fibers is generally reduced. In this case, compared with the case where the first sheet P12a is placed on the conveyor belt and the hot air is allowed to pass through, both surfaces of the first sheet P12a can be exposed to the hot air or the heating atmosphere almost equally. The entire sheet P12a can be more uniformly recovered, and can be softer and more comfortable to the touch.

  The temperature of the heat treatment (hot air or atmosphere) at this time is a material having the lowest melting point among the materials constituting the first sheet P12a from the viewpoint of recovering bulk considering the material that can be used as the first sheet P21a. The processing temperature is lower than the melting point and higher than the temperature (the melting point −50 degrees). From the viewpoint of stably recovering the bulk of the first sheet P12a, the lower limit of the treatment temperature is preferably higher than the (melting point-30 ° C) temperature, more preferably (the melting point-20 ° C). high. On the other hand, the upper limit of the treatment temperature is preferably lower than the temperature of (the melting point−5 degrees), more preferably (the melting point−), from the viewpoint of surely eliminating the possibility of melting the material having the lowest melting point. 10 degrees). In the present embodiment, fibers of a core / sheath structure of polyethylene terephthalate (PET) / polyethylene (PE) (high density) are used as the material of the first sheet P12a, and the melting point of high density polyethylene (HDPE) is 140. For example, the processing temperature is set to 130 ° C.

  Next, in the forming step S2, the first sheet P12b is supplied to the meshing region B1. As shown in FIG. 6, the first roll 52 and the second roll 53 form a plurality of convex portions 21 on one surface 20a of the first sheet P12b in contact with the first roll 52, and adjacent convex portions. A base portion 23 is formed between the portions 21, and a plurality of concave portions 22 are formed on the other surface 20 b of the first sheet P <b> 12 b that contacts the second roll 53. As a result, the first sheet P12c is formed. The one surface 20 a and the other surface 20 b correspond to the first upper surface 12 E and the first lower surface 12 F of the composite sheet 10, and the convex portion 21 and the base portion 23 correspond to the convex portion 15 and the base portion 16.

  At this time, in the first sheet P12b, the portion between the tooth portions 52a of the first roll 52 is moved from the other surface 20b side to the one surface 20a side by the tooth portion 53a of the second roll 53. In other words, the first roll 52 is pushed out toward the bottom 52s of the groove 52b. At this time, the part of the first sheet P12b corresponding to the top part 53t of the tooth part 53a of the second roll 53 does not contact the bottom part 52s, and therefore the first sheet P12b does not contact the bottom part 52s. In other words, the first sheet P12b does not hit the bottom of the groove 52b. However, “not touching the bottom” means not only when there is a gap between the first sheet P12b and the bottom 52s, but also when the first sheet 12b touches the bottom 52s, or when the bottom 52s does not deform plastically. Includes cases where it is lightly compressed. Further, in the first sheet P12b, the portion between the tooth portions 53a of the second roll 53 is moved from one surface 20a side to the other surface 20b side by the tooth portions 52a of the first roll 52, that is, Pushed toward the bottom 53 s of the second roll 53. At this time, the first sheet P12b may or may not contact the bottom 53s. In other words, the first sheet P12b may or may not touch the bottom of the groove 52b. Thus, a convex shape on one surface 20a of the first sheet P12b, that is, the convex portion 21 can be formed, the base portion 23 can be formed between the adjacent convex portions 21, and the other surface of the first sheet P12b A concave shape 20b, that is, a concave portion 22 can be formed.

  As a preferable aspect in the present embodiment, the base portion 23 of the first sheet P12b is pressed against the bottom portion 53s of the second roll 53 by the top portion 52t of the tooth portion 52a of the first roll 52 and compressed. The shape of the base 23 is fixed by heat welding or plastic deformation of the constituent fibers by the compression. Thereby, the convex part 21 of the 1st sheet | seat P12b can be stably fixed to the up-down direction TD substantially in the base 23 of the both sides of the cross direction CD in the convex part 21. FIG. As a result, the shape of the convex portion 21 on the one surface 20a side in the first sheet P12b can be stabilized.

  At that time, in the first sheet P12b, the convex portion 21 of the first sheet P12b is not pressed against the bottom 52s of the first roll 52 and is not compressed. Therefore, since heat welding and plastic deformation of the constituent fibers do not occur, the convex portion 21 and the concave portion 22 of the first sheet P12b are not substantially fixed in the vertical direction TD. As a result, when the tooth portion 53a of the second roll 53 is removed, the recess 22 of the first sheet P12b can return to the state before being bitten by the tooth portion 53a due to the repulsive force (or elastic force) of the constituent fibers. Is in a state. That is, it can be seen that the plurality of recesses 22 on the other surface 20b of the first sheet P12c in contact with the second roll 53 are temporarily formed in a state where they can be recovered to the original state (not recessed). it can.

  Thereafter, the other surface 20b of the first sheet P12c is pulled away from the second roll 53 while maintaining one surface 20a of the first sheet P12c in contact with the first roll 52. At this time, as shown in FIG. 7, the one surface 20 a of the first sheet P <b> 12 c continues to contact the first roll 52, so that a plurality of one surfaces 20 a of the first sheet P <b> 12 c in contact with the first roll 52 are provided. The convex portion 21 is stably maintained. On the other hand, since the other surface 20b of the first sheet P12c is pulled away from the second roll 53, the plurality of recesses 22 on the other surface 20b of the first sheet P12c in contact with the second roll 53 are in the original state ( It will recover to a state where it is not recessed.

  In the present embodiment, as a preferable aspect, considering the material that can be used as the first sheet P21b, the temperature of the outer peripheral surface including the tooth portion 52a of the first roll 52 is higher than normal temperature (example: 25 ° C.). The first predetermined temperature lower than the melting point of the material having the lowest melting point among the materials constituting the first sheet 12, that is, the first sheet P12b. Thus, when the temperature of the outer peripheral surface of the 1st roll 52 is made high, the shape of the convex part 21 by the side of the one surface 20a in the 1st sheet | seat P12b can be stabilized more according to a shaping effect. In addition, since a part of the heat of the first roll 52 is stored in a portion inside the surface of the one surface 20a in the first sheet P12b, the other surface 20b is pulled away from the second roll 53. Thus, when the recess 22 recovers to its original state, recovery by the repulsive force (or elastic force) can be assisted by the effect of bulk recovery by heat. The lower limit of the first predetermined temperature is preferably higher than the temperature of (the melting point−60 degrees), more preferably the temperature of the melting point−50 degrees, from the viewpoint of further stabilizing the shape of the convex portion 21. Is also expensive. On the other hand, the upper limit of the first predetermined temperature is that the first sheet P12b is entirely heated, and the shapes of the plurality of recesses 22 on the other surface 20b of the first sheet P12b are stabilized, so that the original state From the viewpoint of preventing the recovery from becoming impossible, the temperature is preferably lower than the (melting point−20 degrees) temperature, and more preferably lower than the (melting point−30 degrees) temperature.

  In the present embodiment, as a more preferable aspect, considering the material that can be used as the first sheet P21b, the temperature of the outer peripheral surface including the tooth portion 53a of the second roll 53 is normal temperature (example: 25 ° C.) or more, The second predetermined temperature is lower than the first predetermined temperature. Thus, when the temperature of the outer peripheral surface of the second roll 53 is made lower than the temperature of the outer peripheral surface of the first roll 52, the shaping effect is almost lost, and the effect of bulk recovery becomes stronger. The plurality of recesses 22 on the other surface 20b of the sheet P12b can be easily restored to the original state. The upper limit of the second predetermined temperature is preferably (from the viewpoint of facilitating recovery of the concave portion 22 to its original state, preferably (the melting point of the material having the lowest melting point among the materials constituting the first sheet P12b is -70 degrees). ), More preferably lower than (the melting point-80 ° C). Preferably, the second roll 53 may not be heated.

  In this case, the difference between the temperature of the outer peripheral surface including the tooth portion 52a of the first roll 52 and the temperature of the outer peripheral surface including the tooth portion 53a of the second roll 53 is preferably 50 degrees or more, and preferably 60 degrees or more. More preferably, 70 degrees or more is still more preferable. By providing a difference between the temperature of the outer peripheral surface of the first roll 52 and the temperature of the outer peripheral surface of the second roll 53, the plurality of convex portions 21 are more reliably formed on one 20a surface of the first sheet P12b. Can be formed stably, and the plurality of recesses 22 on the other surface 20b can be temporarily formed in a state where they can be easily recovered to the original state (not recessed).

  In the present embodiment, fibers of a core / sheath structure of polyethylene terephthalate (PET) / polyethylene (PE) (high density) are used as the material of the first sheet P12b, and the melting point of high density polyethylene (HDPE) is 140. ℃. In this case, for example, the temperature of the outer peripheral surface including the tooth portion 52a of the first roll 52 is about 100 ° C., and the temperature of the outer peripheral surface including the tooth portion 53a of the second roll 53 is normal temperature (example: about 25 ° C., provided that The temperature difference between the outer peripheral surfaces of the first roll 52 and the second roll 53 is about 75 ° C.

  In the present embodiment, as a preferable aspect, the material of the outer peripheral surface including the tooth portion 53a of the second roll 53 is made of a dielectric material such as a synthetic resin having no conductivity. In this embodiment, nylon is used. Therefore, when the first sheet P12c is separated from the second roll 53, the other surface 20b of the first sheet P12c is caused by static electricity generated by friction between the outer peripheral surface of the second roll 53 and the first sheet P12c. These constituent fibers are attracted to the second roll 53. Thereby, the constituent fibers of the other surface 20b of the first sheet P12c are lifted in the direction of the second roll 53, and the recess 22 can be restored to a smaller recess or a flat shape. Thereby, in both joining process S5 mentioned later, both material sheets can be joined so that a crevice may not arise more between the 1st sheet P12c and the 2nd sheet 13c. As a result, the inside of the convex part 21 of the composite sheet P10 can be made more solid. In addition, when a temperature difference is made between the outer peripheral surface of the first roll 52 and the outer peripheral surface of the second roll 53, the dielectric, particularly synthetic resin, has a larger specific heat than the metal. It is difficult for the temperature of the second roll 53 to rise due to the heat of the first roll 52, and thus the temperature difference between the outer peripheral surfaces of the first roll 52 and the second roll 53 can be easily maintained.

  Next, in the second bulk recovery step S3, as in the first bulk recovery step S1 shown in FIG. 5, the second sheet P13a unwound from the second material roll (not shown) The heat treatment is performed by the second heat treatment apparatus 54 to recover the bulk. The material of the second sheet P13a is the same as the material of the second sheet 13, and in this embodiment, fibers of a core / sheath structure of polyethylene terephthalate (PET) / polyethylene (PE) (high density) are used. . At this time, one surface 30a of the second sheet P13a is an anti-net surface having a low density of constituent fibers, and the other surface 30b is a net surface having a high density of constituent fibers. In the second heat treatment apparatus 54, one surface 30a and the other surface 30b of the second sheet P13a are exposed to hot air or a heated atmosphere. Thereby, the bulk of the second sheet P13a is recovered, and the second sheet P13b is formed. The second sheet P13b has a substantially constant basis weight as compared with the second sheet P13a, but the thickness is increased, and the density of the constituent fibers is reduced as a whole. In this case, both surfaces of the second sheet P13a can be exposed to hot air or a heated atmosphere substantially equally, and the second sheet P13a can be more uniformly recovered and softened. The one surface 30a and the other surface 30b correspond to the second upper surface 13E and the second lower surface 13F of the composite sheet 10.

  The temperature of the heat treatment at this time is lower than the melting point of the material having the lowest melting point among the materials constituting the second sheet P13a and higher than the temperature of (melting point −50 degrees) from the viewpoint of bulk recovery. Processing temperature. In the present embodiment, a fiber having a core / sheath structure of polyethylene terephthalate (PET) / polyethylene (HDPE) is used as the material of the second sheet P13a, the melting point of the high-density polyethylene is 140 ° C., and the processing temperature is 130 ° C. To do.

  Next, in the application step S <b> 4, the heat-treated second sheet P <b> 13 b is supplied to the adhesive application device 55. The second sheet P13b is coated with an adhesive in a predetermined pattern on one surface 30a. In the present embodiment, the predetermined pattern is a stripe pattern having a predetermined width extending along the transport direction MD as shown in FIG. 2 and arranged in the transverse direction CD at a predetermined interval. Each of the plurality of convex portions 21 of the first sheet P12c is obtained when the other surface 20b of the first sheet P12c and the one surface 30a of the second sheet P13c are joined in a later step. And the adhesive and the adhesive are set so as to overlap in the vertical direction TD. However, the width and interval of the adhesive in the joint portion 14 may be the same as or different from the width and interval of the convex portion 21.

  Next, in the joining step S5, the first sheet P12c and the second sheet P13c are supplied to the facing area B2. At that time, the state where one surface 20a of the first sheet P12c is in contact with the first roll 52 is maintained, and the plurality of convex portions 21 are maintained. On the other hand, the other surface 20b of the first sheet P12c is separated from the second roll 53, and the shapes of the plurality of recesses 22 are relaxed (the recesses are reduced). Then, as shown in FIG. 8, the first sheet P12c and the second sheet P13c are sandwiched between the base part 56q of the joining roll 56, the pin 56p, and the tooth part 52a of the first roll 52, and the first sheet P12c. The other surface 20b of the second sheet and the one surface 30a of the second sheet P13c are brought into close contact with each other and bonded by the bonding portion 14 (adhesive). A composite sheet P10 that is a laminate of the first sheet P12c and the second sheet P13c is formed. The composite sheet P10 is substantially the composite sheet 10. At this time, the distance between one surface 20a of the first sheet P12c and the other surface 20b of the second sheet P13c is within 5% of the height in the vertical direction TD of the convex portion 21 from the base 23, preferably Therefore, the convex portion 21 can have a solid shape. Thereby, the permeability of the liquid in the whole convex part 21 can be improved.

  In the present embodiment, as a preferred aspect, when the first sheet P12c and the second sheet P13c are joined, the anti-net surfaces of both sheets are joined. Therefore, since the fiber density is high on one surface 20a of the first sheet P12c, that is, the portion on the net surface side, when the convex portion 21 is formed in the forming step S2, the constituent fiber that causes plastic deformation such as bending is not formed. Many. As a result, the shape of the convex portion 21 can be stably maintained even after the forming step S2. Further, since the fiber density is low on the other surface 20b of the first sheet P12c, that is, the portion on the side opposite to the net surface, the bulk is greatly recovered and elastic deformation is easily performed in the vertical direction TD. Further, when the recess 22 is formed in the forming step S2, there are few constituent fibers that cause plastic deformation such as bending. As a result, when the second roll 53 is separated in the joining step S5, the shape of the concave portion 22 can be made smaller by the repulsive force (or elastic force) of the constituent fibers of the concave portion 22, and the surface of the concave portion 22 can be fluffed. it can. Thereby, the other surface 20b can be made into a smaller hollow, forming the convex part 21 stably in one surface 20a of the 1st sheet | seat P12c. And the part by the side of the anti-net surface of the 2nd sheet | seat P13c and the part of the anti-net surface of the 1st sheet | seat P12c can be joined more easily. At that time, since the fiber density is low in the portions on the opposite net surface side of both sheets, the deformation is easy, so that the constituent fibers of both sheets can easily move to each other, and a hollow region is formed in the convex portion 21. Can be suppressed more reliably. That is, it can suppress more reliably that a hollow area | region is formed in the convex part 21 of the composite sheet P10, and can form a solid structure in the convex part 21 more reliably.

  In the present embodiment, as a preferred aspect, the first sheet P12c and the second sheet P13c are further held and compressed (squeezed) by the pin 56p of the joining roll 56 and the tooth portion 52a of the first roll 52. And the pressing part 27 is formed in the location compressed. That is, in the base 23 of the first sheet P12c, the compression in the vertical direction TD is intermittently performed along the conveyance direction MD, so that the first sheet P12c and the second sheet P13c are intermittently joined. In addition, the bonding of the bonding portion 14 (adhesive) is also strengthened. In this case, it can be said that joining process S5 includes the intermittent joining process which joins intermittently to conveyance direction MD by the pressing part 27 in addition to joining of the junction part 14 (adhesive). The pressing unit 27 corresponds to the pressing unit 17 of the composite sheet 10.

  By providing the squeezing part 27 in this way, even if there is a place where the joint is weak in the joint part 14 between the first sheet P12c and the second sheet P13c, the place where the joint is weak can be compensated. For example, if the adhesive in the vertical direction TD of the adhesive at the base portion 23 is not sufficiently diffused and the bonding is weak, the first sheet P12c naturally recovers its bulk due to its own elastic force and the like, and the unevenness of the unevenness may be reduced. I can think. Then, the shape of the convex part 21 can be maintained more stably by intermittently joining the base part 23 of the first sheet P12c to the second sheet P13c around the convex part 21 by the pressing part 27. Thereby, the solid structure in the convex part 21 can be maintained more stably. Moreover, when the pressing part 27 is continuous, the entire base part 23 of the first sheet P12c becomes hard and the texture becomes worse, or the movement of the liquid in the part melted by pressing becomes difficult. In embodiment, since the pressing part 27 is intermittent, such a situation can be avoided. Moreover, since the 1st sheet | seat P12c and the 2nd sheet | seat P13c are squeezed in the area | region around the convex part 21, the skirt part of the convex part 21 is pulled to the pressing part 27 side, ie, the 2nd sheet | seat P13c side. As a result, the entire convex portion 21 is pressed against the second sheet P13c. Furthermore, the area | region which opposes the convex part 21 of the 1st sheet | seat P12c in the 2nd sheet | seat P13c comes to adjoin to the 1st sheet | seat P12c side. Accordingly, the bottom portion of the convex portion 21 (the other surface 20b of the first sheet P12c) is pressed against the one surface 30a of the second sheet P13c, and the first sheet P12c and the second sheet P13c. Even if there is a gap between the two, the gap can be crushed. Thereby, the inside of the convex part 21 can be made more solid.

  In the present embodiment, the temperature of the outer peripheral surface including the pins 56p of the joining roll 56 is higher than the normal temperature (example: 25 ° C.) from the viewpoint of ease of forming the compressed portion 27 and not melting the sheet. The third predetermined temperature is lower than the melting point of the material having the lowest melting point among the materials constituting the first sheet P12c and the second sheet P13c. Preferably, it is higher than the temperature of (the melting point−60 degrees) and lower than the temperature of the (melting point−30). In the present embodiment, a core / sheath structure fiber of polyethylene terephthalate (PET) / polyethylene (HDPE) is used as the material of the first sheet P12c and the second sheet P13c, and the melting point of high-density polyethylene (HDPE) is 140. As the temperature, the third predetermined temperature is 100 ° C.

  Next, in the main body manufacturing step S <b> 6, the composite sheet P <b> 10 that is a material sheet for the top sheet 2 is supplied to the main body manufacturing apparatus 57. A separately prepared (manufactured) absorbent body for the absorber 4 and a separately prepared (manufactured) back surface material sheet for the back sheet 3 are supplied to the main body manufacturing apparatus 57. The composite sheet P10, the absorbent body, and the back surface material sheet are laminated in this order and joined to each other, and cut into products one by one, whereby the absorbent article P1 is continuously formed.

  An absorbent article can be manufactured as described above.

  As described above, in the manufacturing method of the present absorbent article, in the forming step S2, the convex portion 21 is formed on one surface 20a of the first sheet P12b, and the concave portion 22 is formed on the other surface (back surface) 20b. Form. Thereafter, in the joining step S5, while maintaining the shape of the convex portion 21 with the first roll 52, the shape of the concave portion 22 separated from the second roll 53 is the repulsive force of the constituent fibers of the first sheet P12c (or Relieved by the elastic force), the concave portion 22 becomes a smaller (shallow and narrow) dent, and the dent and the second sheet P13c are joined by the joining portion 14. In this way, by joining the depression (which is formed by recovering the recess 22), that is, the region corresponding to the projection 21 on the other surface 20b of the first sheet P12c and the second sheet P13c. Further, it is possible to suppress the formation of a gap that may be generated between the first sheet P12c and the second sheet P13c, that is, the hollow region in the convex portion 21. Thereby, the convex part 21 can be formed in a solid shape. In addition, the region corresponding to the convex portion 21 on the other surface 20b of the first sheet P12c and the second sheet 13c are not only in contact with each other in shape but also joined at the joining portion 14 (example: Therefore, the first sheet P12c can be partially separated from the second sheet P13c in the subsequent process, so that the hollow region is not formed later. That is, it can suppress that a hollow area | region is formed in the convex part 21 of the composite sheet P10, Therefore The convex part 21 can be made solid. Thereby, the softness and touch by the solid convex part 21 and the improvement of liquid permeability can be made compatible.

  In addition, when teeth and grooves are formed in the rotation axis direction of the roll, thereby forming a convex portion on the sheet along the transverse direction CD, even if the convex portion is formed in the forming process, it is conveyed in the subsequent process. It is difficult to maintain the shape of the convex portion by the tension applied to the sheet in the direction MD. Therefore, in a preferred aspect of the present embodiment, the first roll 52, the second roll 53, and the joining roll 56 are formed with teeth and grooves along the rotation direction thereof, thereby along the conveyance direction MD. The convex portion 21 is formed on the first sheet P12. Therefore, in the joining step and the subsequent steps, the shape of the convex portion 21 can be hardly crushed by the tension in the transport direction MD and can be easily maintained. That is, the softness and the touch due to the shape of the convex portion can be maintained while maintaining the liquid permeability by the solid portion of the convex portion.

  In a preferred aspect of the present embodiment, the second roll 53 rotates with the first sheet P12b. Therefore, without adjusting the speed of the second roll 53 according to the speed of the first roll 52, it is possible to make it difficult to generate wrinkles and widths in the first sheet P12b. Thereby, generation | occurrence | production of the wrinkle in the 1st sheet | seat P12b can be suppressed more reliably, and in a joining process S, a convex part can be more reliably formed solid.

  In a further preferred aspect of the present embodiment, the uppermost end in the vertical direction of the second roll 53 is an imaginary horizontal plane passing through the uppermost end in the vertical direction of the first roll 52 (in the example of FIG. 3, the second sheet P13a). ~ P13c and the plane including the composite sheet P10) is preferably on the lower side in the vertical direction. The reason is as follows. As described above, the temperature of the first roll 52 may be set to the first predetermined temperature higher than the normal temperature. Therefore, the air around the first roll 52 is heated by the heat of the first roll 52, becomes low density, and moves vertically upward. When this happens, there is a risk that the object located vertically above the first roll 52 will have a temperature comparable to that of the first roll 52. However, by disposing the second roll 53 below the first roll 52 in the vertical direction, the temperature of the second roll 53 is influenced by the first roll 52 and the first roll It is possible to prevent the temperature from becoming as high as 52. Thereby, after forming the other surface of the first sheet P12b into a concave shape in the forming step S2, the concave portion can be easily restored to a substantially flat shape. As a result, it is possible to prevent a gap from being formed between the first sheet and the second sheet, and it is possible to more reliably make the convex portion of the composite sheet P10 solid.

The basis weight, thickness, and fiber density of the sheet in the above embodiment are obtained by the following method.
(1) Basis weight of sheet: A sheet is cut into a size of 5 cm × 5 cm to be a sample, and the mass is measured after a drying treatment in an atmosphere of 100 ° C. or higher. Divide the measured mass by the area of the sample to calculate the basis weight of the sample. A value obtained by averaging the basis weights of 10 samples is defined as the basis weight of the sheet.
(2) the thickness of the sheet: using thickness gauge with a measuring element of 15cm ² (the Ltd. Daiei Chemical Seiki Seisakusho Model FS-60DS), the thickness of the sheet under the conditions of measuring load of 3 g / cm ² Measure the thickness. The thickness of three places is measured with one sample, and the average value of the three places is taken as the thickness of the sheet.
(3) Sheet fiber density: The sheet fiber density is calculated by dividing the weight of the sheet obtained by the above method by the thickness of the sheet obtained by the above method.

  The absorbent article of the present invention is not limited to the above-described embodiments, and can be appropriately combined and changed within a range not departing from the object and spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Absorbent article 52 1st roll 53 2nd roll P10 Composite sheet P12 1st sheet P13 2nd sheet

Claims (11)

Method of manufacturing an absorbent article using a composite sheet comprising: a first sheet having a plurality of convex portions formed on one surface; and a second sheet laminated on the other surface of the first sheet. Because
A bulk recovery step of recovering the bulk by heat-treating the first sheet;
The heat-treated first sheet is supplied to a region where the teeth and grooves of the first roll and the teeth and grooves of the second roll are engaged with each other, and the first sheet is in contact with the first roll. Forming a plurality of convex portions on the one surface of the sheet, and forming a plurality of concave portions on the other surface of the first sheet in contact with the second roll;
While maintaining the state where the one surface of the first sheet is in contact with the first roll, the inside of each of the plurality of convex portions is separated from the second roll so as to be solid. A joining step of joining the other surface of the first sheet, in which the shape of a plurality of recesses is relaxed, to one surface of the second sheet to form the composite sheet;
With
A joint portion between the other surface of the first sheet and the one surface of the second sheet overlaps with a region corresponding to each of the plurality of convex portions of the first sheet in a thickness direction. ,
Manufacturing method of absorbent article. The other surface of the first sheet is an anti-net surface at the time of manufacturing the first sheet,
The one surface of the second sheet is an anti-net surface at the time of manufacturing the second sheet,
In the joining step, the anti-net surface of the first sheet and the anti-net surface of the second sheet are joined.
The manufacturing method of the absorbent article of Claim 1. The plurality of convex portions are continuously extended along the conveyance direction MD of the first sheet, and a base portion is continuous along the conveyance direction MD between the convex portions adjacent to each other in the plurality of convex portions. Extended,
The manufacturing method of the absorbent article further includes an intermittent joining step of joining the first sheet and the second sheet by performing intermittent compression along the transport direction MD at the base. ,
The manufacturing method of the absorbent article of Claim 1 or 2. The temperature of the outer peripheral surface including the tooth portion of the first roll is a first predetermined temperature that is higher than normal temperature and lower than the melting point of the material having the lowest melting point among the materials constituting the first sheet. Is,
The manufacturing method of the absorbent article as described in any one of Claims 1 thru | or 3. The temperature of the outer peripheral surface including the tooth portion of the second roll is a second predetermined temperature that is equal to or higher than normal temperature and lower than the first predetermined temperature.
The manufacturing method of the absorbent article of Claim 4. An uppermost end in the vertical direction of the second roll is below the virtual horizontal plane passing through an uppermost end in the vertical direction of the first roll,
The manufacturing method of the absorbent article of Claim 4 or 5. The material of the outer peripheral surface including the tooth portion of the second roll is made of a dielectric.
The manufacturing method of the absorbent article as described in any one of Claims 1 thru | or 6. In each of the first roll and the second roll, the tooth portion and the groove portion are continuously extended along the rotation direction on the outer peripheral surface,
In the forming step, a speed at which the first sheet is supplied to the meshing area is equal to or less than an outer peripheral speed of the first roll.
The manufacturing method of the absorbent article as described in any one of Claims 1 thru | or 7. In the forming step, the outer peripheral speed of the second roll is faster than the outer peripheral speed of the first roll.
The manufacturing method of the absorbent article as described in any one of Claims 1 thru | or 8. In the forming step, the first sheet is compressed by being pressed against the bottom of the groove portion of the second roll by the top portion of the tooth portion of the first roll, and the tooth portion of the second roll. The top of the first roll is not pressed against the bottom of the groove and is not compressed,
The manufacturing method of the absorbent article as described in any one of Claims 1 thru | or 9. The second roll rotates in a rotating state with the first sheet;
The manufacturing method of the absorbent article as described in any one of Claims 1 thru | or 10.

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