JP7438686B2 - Method for manufacturing sheet member for absorbent article and absorbent article - Google Patents

Description

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

Conventionally, absorbent articles such as pants-type disposable diapers are known. In such an absorbent article, in order to improve breathability when worn, holes may be provided on the surface of a sheet member such as a nonwoven fabric that constitutes the absorbent article. For example, Patent Document 1 discloses a disposable wearing article that includes a perforated nonwoven fabric in which a large number of holes penetrating the front and back sides are provided at intervals.

JP2018-57810A

Absorbent articles such as disposable diapers are usually provided with a stretchable elastic member such as thread rubber to give them elasticity, but this thread rubber etc. is provided on the sheet member that constitutes the disposable diaper. In some cases, it may protrude outward from the through hole (ventilation hole). Users who visually recognize the rubber thread etc. that have protruded from the through-holes may have negative feedback, such as that the absorbent product is defective or that the elasticity is not working properly and a good fit cannot be obtained. It is easier to make an impression.

The present invention has been made in view of the conventional problems as described above, and an object thereof is to provide a sheet member for an absorbent article in which the elastic member does not protrude from the through hole.

The main invention for achieving the above purpose is:
a conveying step of respectively conveying a first continuous sheet body provided with a plurality of through holes and a second continuous sheet body;
Between the first continuous sheet body and the second continuous sheet body laminated on one side in the thickness direction of the first continuous sheet body, the first continuous sheet body or the second continuous sheet body is a bonding area forming step of forming a plurality of bonding areas for attaching the elastic member stretched in the conveyance direction;
The stretched elastic member is cut between the two joining regions adjacent in the conveying direction, and the cut elastic member is transferred from the through hole to the other side of the first sheet continuous body in the thickness direction. an elastic member cutting step of contracting the elastic member along the conveying direction so as not to protrude to the side;
has
The bonding area includes a first bonding area and a second bonding area adjacent to the first bonding area on the downstream side in the conveyance direction,
In the cutting step, the elastic member is cut at a position closer to the first bonding area than the second bonding area in the conveyance direction,
The sheet member for an absorbent article is an exterior body of a tape-type disposable diaper,
The elastic member is a crotch gather elastic member that imparts elasticity to the crotch region of the exterior body,
The method for producing a sheet member for an absorbent article is characterized in that in the elastic member cutting step, at least a portion of the crotch gather elastic member is cut .
Other features of the present invention will become apparent from the description of this specification and the accompanying drawings.

According to the present invention, it is possible to provide a sheet member for an absorbent article in which the elastic member does not protrude from the through hole.

FIG. 1 is a schematic perspective view of a diaper 1 according to a first embodiment. FIG. 2 is a schematic plan view of the diaper 1 in an expanded and stretched state, viewed from the skin side. 3 is a schematic cross-sectional view taken along line AA in FIG. 2. FIG. FIG. 2 is a schematic side view illustrating a manufacturing apparatus 100 that manufactures a sheet member 2. FIG. FIG. 3 is a flow diagram showing the manufacturing process of the sheet member 2. FIG. 5 is a schematic plan view showing an example of the arrangement of bonding regions 50. FIG. FIGS. 7A to 7C are diagrams illustrating the mechanism by which an elastic member pops out from a through hole in a conventional stretchable sheet member provided with a through hole. FIG. 6 is a diagram illustrating a state of cutback when the elastic member 3 is cut at a position close to a joining region 50 (first joining region 501) provided on the upstream side in the conveyance direction. FIG. 7 is a diagram illustrating how cutback occurs when the elastic member 3 is cut at a position close to the bonding region 50 (second bonding region 502) provided on the downstream side in the conveyance direction. It is a schematic sectional view of the sheet member 2 in this embodiment. FIGS. 11A to 11C are schematic explanatory diagrams illustrating a conventional method for forming a perforated nonwoven fabric. 12A to 12C are schematic explanatory diagrams illustrating the method for forming the perforated nonwoven fabric of this embodiment. FIG. 4 is a schematic cross-sectional view illustrating a case where the diameter of the through hole 40 is made different on one side and the other side in the thickness direction. FIG. 7 is a schematic plan view of a diaper 5 according to a second embodiment in an unfolded and stretched state. 15 is a schematic cross-sectional view taken along line BB in FIG. 14. FIG. FIG. 2 is a schematic side view illustrating a manufacturing apparatus 200 that manufactures the sheet member 6. FIG. 5 is a schematic plan view showing an example of the arrangement of bonding regions 50. FIG. FIG. 7 is a schematic plan view illustrating a modification of the bonding region 50. FIG. 19A and 19B are explanatory diagrams of the function of attaching the elastic member 3 by the welded portion pair 52S.

From the description of this specification and the attached drawings, at least the following matters will become clear.
a conveyance step of respectively conveying a first continuous sheet body provided with a plurality of through holes and a second continuous sheet body, and one of the first continuous sheet body and the first continuous sheet body in the thickness direction; A plurality of bonding areas are formed between the second continuous sheet body stacked on the side and the elastic member stretched in the conveyance direction of the first continuous sheet body or the second continuous sheet body. cutting the stretched elastic member between two bonding areas adjacent to each other in the conveying direction, and transporting the cut elastic member from the through hole into the first sheet continuous body; A method of manufacturing a sheet member for an absorbent article, comprising: cutting an elastic member along the conveyance direction so as not to protrude to the other side in the thickness direction.

According to such a method of manufacturing a sheet member for an absorbent article, it is possible to make it difficult for the elastic member to pop out from the through hole provided in the sheet member. Therefore, when an absorbent article is manufactured using the sheet member, it becomes difficult to visually recognize that the elastic member (rubber thread, etc.) protrudes from the through hole. This can make it difficult for the user to get the impression that the absorbent article is defective or that the elasticity is not working properly and a good fit cannot be obtained.

In this method of manufacturing a sheet member for an absorbent article, the bonding area has a first bonding area and a second bonding area adjacent to the first bonding area on the downstream side in the conveying direction, and the cutting In the step, it is preferable that the elastic member is cut at a position closer to the first bonding area than to the second bonding area in the conveyance direction.

According to such a method of manufacturing a sheet member for an absorbent article, the shrinkage force when the elastic member contracts (cuts back) from the cut position toward the joining region can be made relatively small. This makes it difficult for the elastic member to get caught on the outer edge of the through hole, making it easier to prevent the elastic member from jumping out of the through hole.

In this method of manufacturing a sheet member for an absorbent article, it is desirable that the height of the portion where the outer edge of the through hole protrudes in the thickness direction is 0.2 mm or less.

According to such a method of manufacturing a sheet member for an absorbent article, when the elastic member shrinks (cut back), it is possible to prevent the elastic member from getting caught on the outer edge of the through hole. Therefore, it is possible to effectively prevent the elastic member from popping out from the through hole.

In this method of manufacturing a sheet member for an absorbent article, it is desirable that the diameter of the through hole is three times or less the diameter of the elastic member.

According to such a method of manufacturing a sheet member for an absorbent article, it is possible to provide a sheet member in which the elastic member does not easily pop out from the through hole while ensuring good air permeability.

In this method of manufacturing a sheet member for an absorbent article, it is desirable that the diameter of the through hole is smaller than twice the diameter of the elastic member.

According to such a method of manufacturing a sheet member for an absorbent article, it becomes more difficult for the elastic member to pass through the through-hole during the contraction (cutback) operation of the elastic member. Thereby, it is possible to highly accurately prevent the elastic member from popping out from the through hole.

In this method of manufacturing a sheet member for an absorbent article, it is preferable that the diameter of the through hole on the one side in the thickness direction is smaller than the diameter of the through hole on the other side in the thickness direction. .

According to such a method of manufacturing a sheet member for an absorbent article, the elastic member is prevented from protruding from one side (skin side) to the other side (non-skin side) in the thickness direction of the through hole, and The through-holes can be easily recognized on the non-skin side), making it easier for the user to recognize that the material has good breathability.

In this method of manufacturing a sheet member for an absorbent article, the through hole is formed by passing a pin through the first continuous sheet from one side to the other side in the thickness direction, and the through hole is formed by passing a pin through the first continuous sheet from one side to the other side in the thickness direction. When forming the holes, it is desirable that the pins be heated to a temperature that is higher than the softening point and lower than the melting point of the thermoplastic fibers contained in the first continuous sheet.

According to such a method of manufacturing a sheet member for an absorbent article, the pin part can be pushed in and pulled out while heating the first continuous sheet, so that the pin part can be pushed into the first continuous sheet which has become soft due to heating. This facilitates the insertion of the through-hole, and the shape of the formed through-hole is easily maintained.

In this method of manufacturing a sheet member for an absorbent article, when forming the through holes, the pins are heated to a temperature closer to the softening point than the melting point of the thermoplastic fibers included in the first sheet continuous body. It is desirable that it be heated to such an extent that

According to such a method of manufacturing a sheet member for an absorbent article, by opening the holes by heating the pin portion as low as possible, the fibers in the opening portion are easily contracted, and the diameter of the through hole is reduced. It becomes easier.

In this method of manufacturing a sheet member for an absorbent article, the bonding area includes a first bonding area and a second bonding area adjacent to the first bonding area on the downstream side in the conveyance direction, Preferably, an adhesive is provided between the first bonding area and the second bonding area in the direction of the bonding.

According to such a method of manufacturing a sheet member for an absorbent article, since the elastic member is lightly fixed by the adhesive, wobbling is less likely to occur when the elastic member contracts. Therefore, when the elastic member contracts, it becomes less likely to be caught on the outer edge of the through hole, and it becomes easier to prevent the elastic member from jumping out of the through hole.

In this method of manufacturing a sheet member for an absorbent article, the sheet member for an absorbent article is a waist member of a pants-type disposable diaper, and the elastic member is a fit gather elastic member that imparts elasticity to the waist member. Preferably, at least a portion of the fit gather elastic member is cut in the elastic member cutting step.

According to such a method of manufacturing a sheet member for an absorbent article, it is possible to provide a sheet member that can be used to manufacture a pants-type disposable diaper in which the fit gather elastic member does not protrude from the through hole in the waist region.

In such a method for manufacturing a sheet member for an absorbent article, the sheet member for an absorbent article is an exterior body of a tape-type disposable diaper, and the elastic member is a crotch gather that imparts elasticity to the crotch region of the exterior body. It is preferable that the crotch gather elastic member is an elastic member, and that at least a portion of the crotch gather elastic member is cut in the elastic member cutting step.

According to such a method of manufacturing a sheet member for an absorbent article, it is possible to provide a sheet member that can be used to manufacture a tape-type disposable diaper in which the crotch gather elastic member does not protrude from the through hole in the crotch region.

Further, a first sheet member having vertical and horizontal directions that intersect with each other and having a plurality of through holes on its surface, and a second sheet member laminated closer to the skin than the first sheet member; an elastic member provided between the first sheet member and the second sheet member in a state extending in the left-right direction; and a plurality of elastic members attached to the first sheet member and the second sheet member. an absorbent article comprising a sheet member having a joint portion, wherein the elastic member cut between the two horizontally adjacent joint portions extends from the through hole to the first sheet member. The absorbent article is characterized in that the absorbent article is contracted along the left-right direction so as not to protrude to the non-skin side.

According to such an absorbent article, it becomes difficult to visually recognize that the elastic member (rubber thread, etc.) protrudes from the through hole. This can make it difficult for the user to get the impression that the absorbent article is defective or that the elasticity is not working properly and a good fit cannot be obtained.

In such an absorbent article, it is preferable that a plurality of the elastic members are provided at intervals in the vertical direction, and that the plurality of elastic members are cut at different positions in the left-right direction.

According to such an absorbent article, marks of cutting the elastic member become less noticeable on the non-skin side surface of the absorbent article (first sheet member), and the appearance of the absorbent article can be improved.

In such an absorbent article, it is desirable that the height of the portion where the outer edge of the through hole protrudes toward the skin side is 0.2 mm or less.

According to such an absorbent article, when the elastic member contracts (cuts back), it is possible to prevent the elastic member from getting caught on the outer edge of the through hole. Therefore, it is possible to realize an absorbent article in which the elastic member is unlikely to pop out from the through hole.

In such an absorbent article, it is desirable that the diameter of the through hole is three times or less the diameter of the elastic member.

According to such an absorbent article, it is possible to realize an absorbent article in which the elastic member does not easily pop out from the through hole while ensuring good air permeability.

For such an absorbent article, it is desirable that the diameter of the through hole is smaller than twice the diameter of the elastic member.

According to such an absorbent article, when the elastic member contracts (cuts back), it becomes more difficult for the elastic member to pass through the through hole. Thereby, it is possible to realize an absorbent article in which the elastic member is prevented from popping out from the through hole with high precision.

In such an absorbent article, it is desirable that the diameter of the through hole on the skin side is smaller than the diameter of the through hole on the non-skin side.

According to such an absorbent article, while suppressing the elastic member from protruding from one side (skin side) to the other side (non-skin side) in the thickness direction of the through-hole, The through-holes can be easily recognized, and the user can easily recognize that the absorbent article has good air permeability.

In such an absorbent article, the first sheet member is a nonwoven fabric containing thermoplastic fibers, and the proportion of the portion where the thermoplastic fibers are not melted at the outer edge of the through hole is the same as the thermoplastic fibers. It is desirable that the percentage of the melted portion be greater than the percentage of the melted portion.

According to such an absorbent article, the rigidity at the outer edge of the through hole can be reduced. Therefore, when the elastic member shrinks (cut back), it is less likely to be caught on the outer edge, and the elastic member is less likely to pop out from the through hole. Furthermore, an absorbent article that has a good texture in the region where the through holes are formed can be realized.

In such an absorbent article, the sheet member is a waist member of a pants-type disposable diaper, the elastic member is a fit gather elastic member that imparts elasticity to the waist member, and the fit gather elastic member is It is preferable that at least a portion of it is cut at a predetermined position in the left-right direction.

According to such an absorbent article, it is possible to realize a pants-type disposable diaper in which the fit gather elastic member does not protrude from the through hole in the waist region.

In such an absorbent article, the sheet member is an exterior body of a tape-type disposable diaper, the elastic member is a crotch gather elastic member that imparts elasticity to the crotch region of the exterior body, and the crotch gather It is desirable that at least a portion of the elastic member is cut at a predetermined position in the vertical direction.

According to such an absorbent article, it is possible to realize a tape-type disposable diaper in which the crotch gather elastic member does not protrude from the through hole in the crotch region.

Such an absorbent article has a longitudinal direction along the up-down direction in the unfolded state, and in the longitudinal direction, the ventral end of the absorbent article in the unfolded state and the stretchability of the crotch gather elastic member. The distance between the dorsal end of the absorbent article in the unfolded state and the ventral end of the part where the elasticity of the crotch gather elastic member is acting is determined by It is desirable that the distance between

According to such an absorbent article, even if the elastic member is cut at any point in the ventral region in the longitudinal direction, the crotch gather elastic member can be made difficult to pop out from the through hole.

===First embodiment===
As an absorbent article according to the first embodiment, a pants-type disposable diaper 1 for infants (hereinafter also simply referred to as "diaper 1") will be described as an example. However, the absorbent article according to the first embodiment is not limited to the above, and can also be applied to disposable diapers for adults.

<Basic configuration of pants-type disposable diaper 1>
FIG. 1 is a schematic perspective view of a diaper 1 according to a first embodiment. FIG. 2 is a schematic plan view of the diaper 1 in an unfolded and stretched state, viewed from the skin side. FIG. 3 is a schematic cross-sectional view taken along line AA in FIG. 2. The "stretched state" of the diaper 1 is a state in which the diaper 1 is stretched without wrinkles, and the dimensions of each member constituting the diaper 1 (for example, the abdominal part 20 described later) match the dimensions of the member alone, or It is in a state of elongation until it reaches a length close to that.

The diaper 1 has an absorbent main body 10, an abdominal part 20, and a back part 30. The absorbent body 10 is placed in the wearer's crotch area. The ventral side part 20 and the dorsal side part 30 also serve as a "sheet member 2" that is placed around the wearer's waist. As shown in FIG. 1, the pants-shaped diaper 1 has an up-down direction, a left-right direction, and a thickness direction that are orthogonal to each other. In the thickness direction, the side that comes into contact with the wearer is called the skin side, and the side that does not come into contact with the wearer is called the non-skin side. Moreover, in FIGS. 2 and 3, the diaper 1 in the unfolded and stretched state has a longitudinal direction, a width direction, and a thickness direction that are orthogonal to each other. The longitudinal direction is the direction along the up-down direction in the pants-shaped state of FIG. 1, and the width direction is the direction along the left-right direction in the pants-shaped state.

In the unfolded diaper 1 shown in FIG. 2, the central part of the abdominal part 20 in the width direction overlaps one longitudinal end of the absorbent main body 10, and the other longitudinal end of the absorbent main body 10 overlaps with the central part of the abdominal part 20 in the width direction. The center portion of the back side portion 30 in the width direction overlaps with the portion. The diaper 1 in the unfolded state is folded in half at approximately the central portion C10 in the longitudinal direction, and both sides of the ventral side portion 20 and the back side portion 30 in the width direction (horizontal direction) are joined by welding or the like. The diaper 1 is in a pants-like state as shown in FIG.

The absorbent body 10 includes an absorbent body 11, a liquid-permeable top sheet (not shown) disposed closer to the skin than the absorbent body 11, and a liquid-impermeable top sheet disposed closer to the non-skin side than the absorbent body 11. An example of this is a back sheet (not shown). The absorbent body 11 absorbs and retains excreta such as urine, and can be exemplified by liquid absorbent fibers such as pulp containing super absorbent polymer (SAP) molded into a predetermined shape.

As shown in FIG. 3, the ventral side part 20 and the dorsal side part 30 each include skin-side nonwoven fabrics 21 and 31 disposed on the skin side in the thickness direction, and skin-side nonwoven fabrics 21 and 31 that are less thick than the skin-side nonwoven fabrics 21 and 31, respectively. It has non-skin side nonwoven fabrics 22, 32 arranged on the skin side, fit gather elastic members 23, 33, and cover nonwoven fabrics 24, 34. The skin-side nonwoven fabrics 21, 31 and the non-skin-side nonwoven fabrics 22, 32 are arranged closer to the non-skin side than the absorbent main body 10. The cover nonwoven fabrics 24 and 34 are arranged closer to the skin than the absorbent body 10, and have a shorter length in the longitudinal direction (up and down direction) than the skin side nonwoven fabrics 21 and 31, etc. covering the ends.

The skin-side nonwoven fabrics 21, 31, the non-skin-side nonwoven fabrics 22, 32, and the cover nonwoven fabrics 24, 34 are nonwoven fabrics containing thermoplastic resin fibers. Examples include single fibers of thermoplastic resins such as polypropylene (PP) and polyethylene (PE), and composite fibers such as a sheath-core structure of PP and PE.

The plurality of fit gather elastic members 23, 33 are arranged in a line in the vertical direction between the skin-side nonwoven fabrics 21, 31 and the non-skin-side nonwoven fabrics 22, 32, and are attached in a state of being stretched in the left-right direction. . This gives the ventral side part 20 and the dorsal side part 30 elasticity along the left-right direction. In addition, as the fit gather elastic members 23 and 33, thread-like rubber, spandex, etc. can be illustrated.

In addition, a plurality of through holes 40 are formed in the abdominal part 20 and the back part 30 in the thickness direction thereof to penetrate the non-skin side nonwoven fabrics 22, 32. That is, the non-skin side nonwoven fabrics 22 and 32 in this embodiment are perforated nonwoven fabrics having a plurality of holes. It is assumed that the through holes 40 are formed in a predetermined pattern throughout the non-skin side nonwoven fabrics 22, 32. For example, in the diaper 1, as shown in FIG. 2, circular holes are discretely arranged at predetermined intervals in a so-called staggered arrangement. However, the shape and number of the through holes 40, and the arrangement of the through holes 40 are not particularly limited, and are not limited to the example shown in FIG. 2.

By providing such a through hole 40, good breathability of the abdominal part 20 and the back part 30 is ensured when the diaper 1 is worn. Note that the through hole 40 may be formed only in either the ventral side portion 20 or the dorsal side portion 30. Moreover, the through-hole 40 may be formed so as to penetrate both the skin-side nonwoven fabrics 21, 31 and the non-skin-side nonwoven fabrics 22, 32 in the thickness direction.

<Method for manufacturing sheet member 2>
The manufacturing direction of the sheet member 2 that constitutes the abdominal part 20 (dorsal part 30) of the diaper 1 will be described. As shown in FIG. 3, the ventral part 20 and the dorsal part 30 have substantially the same structure, so below, the ventral part 20 will be explained, and the dorsal part 30 will be explained. The explanation will be omitted.

The abdominal part 20 in this embodiment is formed by forming the elastic sheet member 2 into a predetermined shape. Specifically, the sheet member 2 is a sheet-like member in which a plurality of ventral portions 20, 20, . . . are continuous in a predetermined direction (direction corresponding to the left-right direction). In the following description, in the method for manufacturing the sheet member 2, a continuous body of nonwoven fabric corresponding to the non-skin side nonwoven fabric 22 provided with a plurality of through holes 40, 40, . . . is referred to as a first continuous sheet body 2A. Similarly, a continuous body of nonwoven fabric corresponding to the skin-side nonwoven fabric 21 is referred to as a second continuous sheet body 2B. Further, a continuous elastic member corresponding to the fit gather elastic member 23 is referred to as an elastic member 3.

FIG. 4 is a schematic side view illustrating the manufacturing apparatus 100 that manufactures the sheet member 2. As shown in FIG. FIG. 5 is a flow diagram showing the manufacturing process of the sheet member 2. As shown in FIG. The manufacturing apparatus 100 shown in FIG. 4 continuously manufactures the sheet member 2 (ventral side part 20 of the diaper 1) by sequentially performing each step (S101 to S103) shown in FIG. The manufacturing apparatus 100 includes a transport mechanism 110, a bonding area forming mechanism 120, and an elastic member cutting mechanism 130.

First, a conveyance step is performed in which various base materials constituting the sheet member 2 are conveyed in a predetermined conveyance direction (S101). In addition, in the manufacturing apparatus 100, the conveyance direction is a direction along the left-right direction of the diaper 1 (abdominal part 20). In the conveyance process, the first sheet continuous body 2A in which the non-skin-side nonwoven fabrics 22 are continuous in the conveyance direction is conveyed from the upstream side to the downstream side in the conveyance direction at a predetermined conveyance speed by a conveyance mechanism 110 equipped with a plurality of conveyance rollers. be done. Similarly, the second sheet continuous body 2B in which skin-side nonwoven fabrics 21 are continuous in the conveyance direction is conveyed by the conveyance mechanism 110 from the upstream side to the downstream side in the conveyance direction at a predetermined conveyance speed. Further, the elastic member 3 in which the fit gather elastic members 23 are continuous in the transport direction is transported by the transport mechanism 110 from the upstream side to the downstream side in the transport direction at a predetermined transport speed.

In addition, in FIG. 4, it is assumed that a plurality of through holes 40, 40, . . . are formed in advance in the non-skin side nonwoven fabric 22 (first sheet continuous body 2A). That is, the first sheet continuous body 2A is supplied to the manufacturing apparatus 100 as a perforated nonwoven fabric. However, the first continuous sheet body 2A may be supplied as a non-perforated nonwoven fabric, and the through holes 40 may be formed while being conveyed in the conveyance direction. A method for forming the through hole 40 in this case will be explained later.

Next, a joining region forming step is performed to form a plurality of joining regions 50, 50, . . . for attaching the elastic member 3 to the first continuous sheet body 2A and the second continuous sheet body 2B (S102). As shown in FIG. 4, the first continuous sheet body 2A and the second continuous sheet body 2B are conveyed so as to be stacked in the thickness direction. Then, the elastic member 3 is placed between the first continuous sheet body 2A and the second continuous sheet body 2B in the thickness direction in a state where it is stretched in the conveying direction at a predetermined stretching magnification, and is stretched through the joining region 50. Then, it is attached so as to be sandwiched between the first continuous sheet body 2A and the second continuous sheet body 2B.

In the bonding region forming step, the bonding region 50 is formed by applying a bonding material such as a hot melt adhesive to each base material transported in the transport direction by the bonding region forming mechanism 120. In FIG. 4, a sheet member adhesive application section 122 and an elastic member adhesive application section 123 are provided as the bonding region forming mechanism 120. Then, the sheet member adhesive application unit 122 applies a bonding material to the opposing surfaces of the first continuous sheet body 2A and the second continuous sheet body 2B that are being conveyed, and the elastic member adhesive application unit 123 applies a bonding material to the opposing surfaces of the first continuous sheet body 2A and the second continuous sheet body 2B that are being conveyed. A bonding material is applied to the surface of the elastic member 3 .

FIG. 6 is a schematic plan view showing an example of the arrangement of the bonding region 50. A sheet cutting position EC indicated by a broken line in FIG. 6 represents a position where the sheet member 2 is cut in a later process (a process of manufacturing the diaper 1 using the sheet member 2). That is, the abdominal part 20 (diaper 1) is formed by cutting the sheet member 2 at two sheet cutting positions EC and EC adjacent to each other in the conveying direction.

The joining regions 50 are formed at at least two locations between two sheet cutting positions EC, EC adjacent to each other in the conveyance direction. In the example of FIG. 6, two joining regions 50, a first joining region 501 and a second joining region 502, are formed between two adjacent sheet cutting positions EC, EC. The second bonding area 502 is provided at a predetermined interval on the downstream side of the first bonding area 501 in the conveyance direction, and these bonding areas 50 allow the elastic member 3 stretched in the conveyance direction to It is attached between the first continuous sheet body 2A and the second continuous sheet body 2B. This gives the sheet member 2 elasticity along the conveyance direction (the left-right direction of the diaper 1).

In addition, in FIG. 6, the joining area 50 is formed by a plurality of rectangular joining parts lined up in the direction perpendicular to the conveying direction (also called the "CD direction"), but the shape and size of the joining area 50 may vary. is not limited to the example shown in FIG. Furthermore, other bonding areas may be provided in addition to the first bonding area 501 and the second bonding area 502.

Next, an elastic member cutting step is performed in which the elastic member 3 stretched in the transport direction is cut between the two bonding regions 50, 50 adjacent in the transport direction (S103). The elastic member is cut using the elastic member cutting mechanism 130. The elastic member cutting mechanism 130 includes a pair of cutter rolls 131 and an anvil roll 132. The cutter roll 131 and the anvil roll 132 both have rotating shafts along the CD direction, and are provided at positions facing each other in the thickness direction of the sheet member 2 (see FIG. 4). Then, by sandwiching the conveyed sheet member 2 between a cutter blade provided on the circumferential surface of the cutter roll 131 and an anvil provided on the circumferential surface of the anvil roll 132, only the elastic member 3 is cut. .

For example, in FIG. 6, the elastic member 3 in the stretched state is cut at the elastic member cutting position CP between the first bonding area 501 and the second bonding area 502 that are adjacent to each other in the conveyance direction. Then, the cut elastic member 3 contracts in the upstream direction in the conveying direction from the elastic member cutting position CP toward the first joining region 501, and also contracts in the conveying direction from the elastic member cutting position CP toward the second joining region 502. contraction downstream of. The operation in which the cut elastic member 3 contracts in this manner is also called "cutback." In FIG. 6, some of the plurality of elastic members 3, 3 are cut back to prevent the sheet member 2 from exhibiting elasticity in the left-right direction (conveyance direction) in a predetermined region. . This region is a region that is overlapped and joined to the absorbent main body 10 in the manufacturing process of the diaper 1, and by weakening the elasticity in the left-right direction in this region, the absorbent main body 10 contracts in the left-right direction. Storage is suppressed, making it difficult for excrement such as urine to leak.

Note that the cutting position CP represents the position where the elastic member 3 in the stretched state is first cut. For example, when the elastic member 3 is cut at multiple locations in the conveyance direction by the elastic member cutting mechanism 130, the position where the elastic member 3 is first cut among the multiple locations is set as the cutting position CP. do.

Moreover, in FIG. 6, the cutting positions CP are provided at the same position in the conveyance direction (left-right direction). That is, FIG. 6 shows an example in which a plurality of elastic members 3, 3, . However, the cutting positions CP in the conveyance direction may be different for each of the plurality of elastic members 3, 3.... By shifting the cutting positions in the left-right direction for each of the plurality of elastic members 3, the marks of cutting the elastic members 3 on the ventral side 20 (non-skin side non-woven fabric 22) of the diaper 1 are less noticeable, and the appearance of the diaper 1 is improved. can be improved.

Through such operations, the sheet member 2 having elasticity in the left-right direction (conveyance direction) is manufactured. Although not shown in FIG. 4, various processes for manufacturing the diaper 1 are performed on the downstream side of the manufacturing apparatus 100 in the transport direction. For example, in the process of joining the absorbent body 10 to the sheet member 2 (ventral side part 20 and dorsal side part 30), the absorbent body 10 is folded in two at a predetermined position in the CD direction (approximately the central part C10 in the longitudinal direction described above). In the process, the sheet members 2 and 2 (ventral side part 20 and dorsal side part 30) stacked on each other in the thickness direction are placed at a predetermined position in the conveyance direction (corresponding to both sides of the ventral side part 20 and dorsal side part 30 in the left and right direction). A step of joining the sheet member 2 at the sheet cutting position EC, a step of cutting the sheet member 2 at the sheet cutting position EC, etc. are performed. As a result, a pants-shaped diaper 1 as shown in FIG. 1 is manufactured.

<About the through hole 40>
Conventionally, when manufacturing the sheet member 2 (ventral side part 20, dorsal side part 30) as described above, if the sheet member 2 is provided with a plurality of through holes 40, the elastic member 3 is cut back. When doing so, there was a problem in that the elastic member 3 jumped out from the through hole 40 to the outside of the sheet member 2. 7A to 7C are diagrams illustrating the mechanism by which an elastic member pops out from a through-hole in a conventional stretchable sheet member (perforated nonwoven fabric) provided with through-holes.

FIG. 7A shows a perforated nonwoven fabric NW1 (corresponding to the first continuous sheet body 2A) and a nonwoven fabric NW2 (corresponding to the second continuous sheet body 2B) laminated in the thickness direction, and a rubber thread S (elastic A cross section of a member (corresponding to member 3) viewed from the CD direction is shown. The rubber thread S is arranged in an extended state in the conveyance direction. The perforated nonwoven fabric NW1 is provided with through holes h. A protrusion hp protruding toward one side in the thickness direction is formed near the outer edge of the through hole h, as shown in FIG. 7A. This protrusion hp is a so-called "burr" and is conventionally formed naturally when a through hole is formed in a nonwoven fabric.

When the rubber thread S is cut and contracted (cut back) in the conveying direction from the state shown in FIG. As shown in 7B, the rubber thread S may sometimes jump out of the perforated nonwoven fabric NW1 while deforming into an Ω-shape from the through hole h. That is, the rubber thread S may jump out from one side to the other side in the thickness direction of the perforated nonwoven fabric NW1. The stronger the contraction force of the rubber thread S, the greater the impact when caught on the protrusion hp, and the easier it is for the rubber thread S to pop out from the through hole h.

Furthermore, as the perforated nonwoven fabric NW1 is transported or bent during the diaper manufacturing process, the cut end of the rubber thread S protrudes from the through hole h to the outside of the perforated nonwoven fabric NW1, as shown in FIG. 7C. There is a risk. When a diaper is manufactured using such a sheet member, rubber can be visually seen protruding from the ventilation holes (through holes h). Therefore, the user is likely to have a negative impression that the diaper is defective or that the diaper does not have sufficient elasticity to provide a good fit.

On the other hand, in this embodiment, when manufacturing the sheet member 2, when cutting back the elastic member 3 in the above-mentioned elastic member cutting step (S103), the through hole 40 of the non-skin side nonwoven fabric 22 is cut back. The elastic member 3 can be made difficult to pop out. Specifically, when cutting the elastic member 3 between two joining regions 50, 50 adjacent to each other in the transport direction, the joining region 50 provided on the upstream side in the transport direction is The elastic member 3 is cut at a position close to the joined region 50.

FIG. 8 is a diagram illustrating how cutback occurs when the elastic member 3 is cut at a position close to the joining region 50 (first joining region 501) provided on the upstream side in the conveyance direction. FIG. 9 is a diagram illustrating how cutback occurs when the elastic member 3 is cut at a position close to the joining region 50 (second joining region 502) provided on the downstream side in the conveyance direction. 8 and 9, similarly to FIG. 6, the first bonding area 501 and the second bonding area 502 are arranged adjacent to each other from the upstream side to the downstream side in the conveyance direction. The intermediate position between the first bonding area 501 and the second bonding area 502 in the transport direction is defined as C50. Further, it is assumed that the sheet member 2 is being transported from the upstream side to the downstream side in the transport direction at a predetermined speed V1.

In FIG. 8, the elastic member 3 is cut on the upstream side of the intermediate position C50 in the conveyance direction. That is, in the conveyance direction, the distance between the cutting position CP of the elastic member 3 and the first bonding area 501 is shorter than the distance between the cutting position CP of the elastic member 3 and the second bonding area 502. Therefore, as shown by the arrow in FIG. 8, the contraction speed V31 of the elastic member 3 moving from the cutting position CP toward the upstream side in the conveying direction (the first bonding area 501) is lower than the contraction speed V31 from the cutting position CP toward the downstream side in the conveying direction (the second bonding area 501). The shrinkage speed V32 toward the region 502) is smaller than the shrinkage speed V32 toward the region 502).

At this time, the sheet member 2 continues to move downstream in the conveyance direction at a speed V1. Therefore, if WD1 is the relative contraction amount of the elastic member 3 moving upstream in the conveyance direction per unit time with respect to the sheet member 2, then WD1=V31+V1. Further, if WD2 is the relative amount of contraction of the elastic member 3 moving downstream in the conveyance direction per unit time, then WD2=V32-V1 (see FIG. 8).

In contrast, in FIG. 9, the elastic member 3 is cut downstream of the intermediate position C50 in the conveyance direction. That is, in the conveyance direction, the distance between the cutting position CP of the elastic member 3 and the first bonding area 501 is longer than the distance between the cutting position CP of the elastic member 3 and the second bonding area 502. Therefore, as shown by the arrow in FIG. The contraction speed V34 toward the area 502) is higher than the contraction speed V34 toward the region 502).

If WD3 is the relative contraction amount of the elastic member 3 moving upstream in the conveying direction per unit time with respect to the sheet member 2, then WD3=V33+V1. Furthermore, if the relative contraction amount of the elastic member 3 moving downstream in the conveying direction per unit time is WD4, then WD4=V34-V1 (see FIG. 9).

Comparing FIG. 8 and FIG. 9, it can be seen that the amount of contraction of the elastic member 3 per unit time toward the upstream side in the conveyance direction is smaller in FIG. 8 (WD1<WD3). This is because the contraction speed V31 of the elastic member 3 toward the upstream side in the conveyance direction in FIG. 8 is smaller than the contraction speed V33 of the elastic member 3 toward the upstream side in the conveyance direction in FIG. That is, the elastic member 3 is cut at a position closer to the bonding area 50 (first bonding area 501) provided on the upstream side in the conveyance direction than to the bonding area 50 (second bonding area 502) provided on the downstream side in the conveyance direction. By doing so, the contraction force of the elastic member 3 toward the upstream side in the conveyance direction can be reduced.

In FIG. 7, it has been explained that when the rubber thread S contracts, the stronger the contraction force is, the more likely it is to be caught on the protrusion hp on the outer edge of the through hole h, and the rubber thread is more likely to pop out. By weakening the contraction force of the elastic member 3, it is possible to easily prevent the elastic member 3 from popping out from the through hole 40.

As is clear from FIGS. 8 and 9, the contraction force of the elastic member 3 toward the downstream side in the conveyance direction is relatively smaller than the contraction force toward the upstream side in the conveyance direction (WD1>WD2, WD3>WD4). . Therefore, if the elastic member 3 can be prevented from popping out of the through hole 40 on the upstream side in the conveyance direction, the possibility that the elastic member 3 will pop out from the through hole 40 on the downstream side in the conveyance direction is low.

Further, an adhesive may be provided between the first bonding area 501 and the second bonding area of the sheet member 2 in the conveyance direction. For example, an adhesive may be applied between the first bonding area 501 and the second bonding area so as to have adhesive strength that allows the elastic member 3 to be cut back. If the elastic member 3 is lightly fixed to the sheet member 2 with such an adhesive, when the elastic member 3 is cut back (shrinked) in the conveyance direction, the elastic member 3 will not move in the CD direction or other direction. It becomes difficult to shake in the direction. That is, since the adhesive functions like a steady rest, the contraction movement of the elastic member 3 is easily stabilized, and the elastic member 3 is less likely to be caught on the outer edge 40e of the through hole 40. This makes it easier to prevent the elastic member 3 from popping out of the through hole 40.

In addition to adjusting the cutting position of the elastic member 3, it is also possible to prevent the elastic member 3 from popping out from the through hole 40 by adjusting the shape of the through hole 40 as follows. .

FIG. 10 is a schematic cross-sectional view of the sheet member 2 in this embodiment, and corresponds to FIG. 7. In FIG. 10, the outer edge 40e of the through hole 40 hardly protrudes in the thickness direction. To be precise, the protrusion height h40e of the outer edge portion 40e protruding in the thickness direction is equal to or less than a predetermined position. That is, no large protrusion (burr) is formed on the outer edge portion 40e. With such a through hole 40, when the elastic member 3 contracts, it becomes difficult to get caught on the outer edge 40e of the through hole 40. Therefore, the elastic member 3 is prevented from protruding from the through hole 40 to the outside of the first continuous sheet body 2A (non-skin side nonwoven fabric 22) (from one side in the thickness direction to the other side).

Here, a method for forming the through hole 40 will be briefly described. FIGS. 11A to 11C are schematic explanatory diagrams illustrating a conventional method for forming a perforated nonwoven fabric. 12A to 12C are schematic explanatory diagrams illustrating the method for forming the perforated nonwoven fabric of this embodiment.

Conventionally, when forming holes (through holes) in nonwoven fabric, the nonwoven fabric is sandwiched from both sides in the thickness direction between a needle-shaped pin part for making the hole in the nonwoven fabric and a groove part into which the pin part is inserted. The method was common. In FIG. 11A, a pin portion 141 and a pin support base 142 that supports the pin portion are provided on the upper side in the thickness direction of the nonwoven fabric, and a substantially trapezoidal groove portion 145 is provided on the lower side in the thickness direction of the nonwoven fabric. At this time, in order to soften the fibers of the nonwoven fabric, it is preferable that the pin part 141 be heated to a predetermined temperature, or that heated air be force-fed from a blower connected to the groove part 145.

Then, as shown in FIG. 11B, by moving the pin part 141 and the pin support base 142 downward and inserting them into the groove part 145, an opening is formed in the nonwoven fabric by the pin part 141. At this time, an opening is formed in the nonwoven fabric at the part where the tip of the pin part 141 contacts, but the fibers are compressed in the part sandwiched between the pin support base 142 and the groove part 145, and at the outer edge of the opening, A protrusion (burr) protruding downward in the thickness direction is formed. Thereafter, as shown in FIG. 11C, by moving the pin part 141 and the pin support base 142 upward, the pin part 141 that has penetrated the nonwoven fabric is pulled out. At this time, since the fibers are compressed in the protrusion (burr) formed at the outer edge of the aperture, the shape of the aperture and its outer edge is easily maintained when the pin part 141 is pulled out. Therefore, in the perforated nonwoven fabric formed by the conventional method, protrusions (burrs) tend to remain on the outer edges of the perforations.

In contrast, in the present embodiment, the pin portion 143 is made of a needle or the like having a uniform thickness (diameter), and the groove portion 146 into which the pin portion 143 is inserted has a size that is approximately the same as the diameter of the pin portion 143. The through hole 40 is formed by sandwiching the nonwoven fabric from both sides in the thickness direction with a cylindrical groove 146 having a diameter of . Specifically, a pin portion 143 is provided on the upper side in the thickness direction of the first continuous sheet body 2A (non-skin side nonwoven fabric 22), and a groove portion 146 is provided on the lower side in the thickness direction of the first continuous sheet body 2A. By moving the pin portion 143 downward and inserting it into the groove portion 146 (see FIG. 12A), the through hole 40 is formed (see FIG. 12B). In this embodiment, since the radial clearance between the pin part 143 and the groove part 146 is small, about 0.3 to 0.5 mm, in FIG. When sandwiched between the two, the fibers of the nonwoven fabric are cut to form the through holes 40. That is, when inserting the pin portion 143 into the groove portion 146, the outer edge portion of the through hole 40 is not easily compressed in the thickness direction. Therefore, in this embodiment, a protrusion (burr) at the outer edge of the opening as shown in FIG. 11B is unlikely to be formed. Thereafter, by moving the pin part 143 upward, the pin part 143 that has penetrated the first sheet continuous body 2A is pulled out (see FIG. 12C).

In this way, it is possible to suppress the protrusion in the thickness direction at the outer edge 40e of the through hole 40, and it is possible to form a perforated nonwoven fabric without large protrusions (burrs). In addition, in the through-hole 40 formed by the above-mentioned method, the maximum value of the height h40e at which the outer edge portion 40e protrudes in the thickness direction as shown in FIG. 10 was 0.2 mm. That is, in the present embodiment, the protrusion height h40e in the thickness direction of the outer edge portion 40e of the through hole 40 formed in the first sheet continuous body 2A (non-skin side nonwoven fabric 22) is suppressed to 0.2 mm or less. (h40e≦0.2mm). If the protrusion height h40e is 0.2 mm or less, it is possible to effectively prevent the elastic member 3 from protruding from the through hole 40 as described with reference to FIG.

Further, by adjusting the size of the diameter D40 of the through hole 40, it is possible to prevent the elastic member 3 from popping out from the through hole 40. For example, by setting the size relationship between the diameter D40 of the through hole 40 and the diameter d3 of the elastic member 3 within a predetermined range, it is possible to easily suppress the elastic member 3 from popping out. Specifically, when the elastic member 3 pops out from the through hole 40, the elastic member 3 that is in the middle of being cut back deforms into an Ω-shape as shown in FIG. 7B and pops out from the through hole 40. Therefore, if the diameter D40 of the through hole 40 is smaller than the diameter 2×d3 of two elastic members 3 (D40<2×d3), the Ω-shaped elastic member 3 will pass through the through hole 40. Since this is less likely to occur, it is possible to suppress the elastic member 3 from popping out with high precision. Note that the through hole 40 is not necessarily formed in a perfect circle shape, but may be formed in an elliptical shape or the like. Moreover, the sizes of the plurality of through holes 40, 40, . . . may be different. In such a case, the diameter D40 is the average value of the diameters of the through holes 40. Further, the diameter d3 of the elastic member 3 represents the diameter of the elastic member 3 in a natural state (unstretched state).

However, since the through-hole 40 has a function as a ventilation hole of the diaper 1, it is desirable that the diameter D40 of the through-hole 40 is as large as possible in order to maintain breathability. When manufacturing the sheet member 2 using the manufacturing method of this embodiment, when the diameter D40 of the through hole 40 is four times the diameter d3 of the elastic member 3, the occurrence rate of the elastic member 3 popping out is 20% or more. there were. Here, the "incidence rate of the elastic member 3 popping out" represents the percentage of the number of the elastic members 3 that were visually recognized as popping out when 100 ventral parts 20 (diapers 1) were manufactured. In this case, a package containing about 10 to 20 diapers 1 will contain a plurality of diapers 1 with elastic members 3 protruding from them, which may cause anxiety to the user who purchased the package. There is a risk.

On the other hand, when the diameter D40 of the through hole 40 was three times the diameter d3 of the elastic member 3, the occurrence rate of the elastic member 3 popping out was 1% or less. In this case, there is a low possibility that a diaper 1 in which the elastic member 3 is protruding will be included in a package containing about 10 to 20 diapers 1, making it difficult to cause anxiety to the user. .

Therefore, by setting the diameter D40 of the through hole 40 to be less than or equal to the diameter 3×d3 of three elastic members 3 (D40≦3×d3), the elastic member can be passed through the through hole 40 while ensuring good air permeability. It is possible to provide a diaper 1 in which 3 does not easily pop out.

Further, the diameter D40 of the through hole 40 may be different on one side and the other side in the thickness direction. Specifically, it is preferable that the diameter D40B on the other side (non-skin side) in the thickness direction is larger than the diameter D40A on one side (skin side) in the thickness direction (D40A<D40B). FIG. 13 is a schematic cross-sectional view showing a case where the diameter of the through hole 40 is made different on one side and the other side in the thickness direction.

As shown in FIG. 13, by making the diameter D40A of the through hole 40 on one side (skin side) in the thickness direction as small as possible, the elastic member 3 to be cut back can be prevented from popping out from the through hole 40 as described above. becomes easier to suppress. On the other hand, by increasing the diameter D40B of the through hole 40 on the other side (non-skin side) in the thickness direction, the through hole 40 that is visible on the non-skin surface in the waist portion 20 of the diaper 1 becomes more conspicuous. . Therefore, it is possible to easily make the user aware that the waist portion 20 has good breathability.

When forming such a through hole 40 in the first sheet continuous body 2A (non-skin side nonwoven fabric 22), the pin part 143 explained in FIG. 12 is heated and the hole is opened under a predetermined temperature condition. is desirable. By using the heated pin portion 143, the through hole 40 can be formed while heating the first continuous sheet body 2A. The temperature of the heated pin portion 143 is preferably higher than the softening point of the thermoplastic resin fibers included in the first sheet continuous body 2A and lower than the melting point of the thermoplastic resin fibers. By setting the temperature below the melting point, thermal damage to the first sheet continuous body 2A caused by the heated pin portion 143 can be suppressed, and by setting the temperature above the softening point, the fibers are softened and the through holes 40 are formed in the first continuous sheet body 2A. It is possible to reduce the frictional resistance when forming. Moreover, it is more preferable to set the temperature to such a level that the thermoplastic resin fibers do not harden. By setting the temperature to a level that does not harden the thermoplastic resin fibers, it is possible to reduce the possibility that the nonwoven fabric becomes hard at the outer edge portion 40e of the through hole 40. The softening point can be measured according to JIS K7196 (Softening temperature test method by thermomechanical analysis of thermoplastic films and sheets). As a result, the pin part 143 can be pushed in and pulled out while heating the first continuous sheet body 2A, making it easy to insert the pin part 143 into the first continuous sheet body 2A, which has become soft due to heating, and to prevent the formation. This makes it easier to maintain the shape of the through hole 40.

Furthermore, it is more desirable that the temperature of the pin portion 143 be closer to the softening point than the melting point of the thermoplastic resin fibers included in the first continuous sheet body 2A. That is, it is desirable that the heating temperature of the pin portion 143 be as low as possible within the temperature range between the melting point and the softening point of the thermoplastic resin fiber. Specifically, in the first continuous sheet body 2A of this embodiment, the pin portions 143 are heated to about 120° C. to 135° C. to form the through holes 40. In this way, by lowering the heating temperature as much as possible, when the temperature of the softened thermoplastic fibers drops, the fibers in the open hole portions tend to shrink, and the diameter D40 of the through holes 40 tends to become smaller. Also,
As shown in FIG. 12C, when the pin portion 143 is pulled out on the other side (non-skin side) in the thickness direction, the temperature on one side (skin side) in the thickness direction of the first sheet continuous body 2A tends to drop first. Therefore, the fibers are more likely to shrink on the skin side of the through hole 40. Therefore, the diameter D40A of the through hole 40 on one side (skin side) in the thickness direction tends to be smaller than the diameter D40B of the through hole 40 on the other side (non-skin side) in the thickness direction. As a result, a through hole 40 having a shape as shown in FIG. 13 is formed.

Further, in the through hole 40 formed in this manner, the proportion of the portion where the thermoplastic fibers are not melted is larger than the proportion of the portion where the thermoplastic fibers are melted at the outer edge portion 40e. In the part where the thermoplastic fibers are not melted, the flexibility of the fibers is easily maintained and the rigidity is difficult to increase, so the higher the proportion of the unmelted part, the lower the rigidity at the outer edge 40e of the through hole 40 can be. Therefore, when the elastic member 3 is cut back, it is less likely to be caught on the outer edge portion 40e, and the elastic member 3 is less likely to pop out from the through hole 40. Furthermore, since the flexibility of the non-skin side nonwoven fabric 22 in the region where the through holes 40 are formed is easily maintained, the diaper 1 can have a good feel to the touch.

===Second embodiment===
In the second embodiment, a tape-type disposable diaper 5 (hereinafter also referred to as "diaper 5") will be described as an absorbent article.

<Basic configuration of tape-type disposable diaper 5>
FIG. 14 is a plan view of the diaper 5 of the second embodiment in an expanded and stretched state. FIG. 15 is a cross-sectional view taken along line BB shown in FIG. The diaper 5 has a vertical direction and a horizontal direction that are perpendicular to each other, and has a back waist region 5A, a crotch region 5B, and a ventral waist region 5C arranged in the vertical direction. The longitudinal direction of the diaper 5 is a direction corresponding to the up-down direction (longitudinal direction) of the diaper 1, and the lateral direction of the diaper 5 is a direction corresponding to the left-right direction (width direction) of the diaper 1. Moreover, as shown in FIG. 15, the direction in which the materials constituting the diaper 5 are laminated is referred to as the thickness direction. In the thickness direction, the side that contacts the wearer is called the skin side, and the opposite side is called the non-skin side.

As shown in FIGS. 14 and 15, the diaper 5 includes an absorbent core 11 that absorbs excrement, a liquid-permeable skin-side sheet 12 located closer to the skin than the absorbent core 11, and an absorbent core 11 and a skin-side sheet 12 located closer to the skin than the absorbent core 11. A liquid-permeable intermediate sheet 13 located between the sheets 12, a liquid-impermeable leak-proof sheet 14 located on the non-skin side of the absorbent body 11, and a liquid-impermeable leak-proof sheet 14 located on the non-skin side of the leak-proof sheet 14. It has an exterior sheet 15 and a pair of side sheets 16 provided on both sides of the skin-side sheet 12 in the lateral direction. Moreover, a pair of fastening tapes 17 extend from the back waist region 5A to both laterally outward sides. Further, on both sides of the diaper 5 in the lateral direction, leg-stretchable members (for example, thread rubber, etc.) that stretch in the vertical direction are arranged, so that the diaper 5 fits around the wearer's legs. Furthermore, a pair of leakage prevention walls 18 that stand up on the skin side are provided on both sides of the absorbent body 11 in the lateral direction. The structure of the absorbent core 11 in the diaper 5 is substantially the same as the absorbent core 11 of the first embodiment.

In the crotch area 5B, a plurality of crotch gather elastic members 35 such as thread rubber are attached between the leak-proof sheet 14 and the exterior sheet 15 in the thickness direction in a state of being stretched along the longitudinal direction. Due to the elasticity exhibited by the crotch gather elastic member 35, when the diaper 5 is worn, a force is exerted against the wearer's crotch area to press the absorbent body 11 from the non-skin side to the skin side. This makes it easier for the absorbent body 11 to come into close contact with the wearer's skin in the crotch area, improving the fit of the crotch area, and making it easier to suppress leakage of excrement.

In the diaper 5 of the second embodiment, the exterior sheet 15 is a perforated nonwoven fabric similar to the non-skin side nonwoven fabric 22 of the first embodiment, and the surface thereof has holes that penetrate the exterior sheet 15 in the thickness direction. A plurality of through holes 40 are formed. The through holes 40 provided in the exterior sheet 15 of the second embodiment have substantially the same configuration as the through holes 40 of the first embodiment.

<Method for manufacturing sheet member 6>
Among the members constituting the diaper 5, the leak-proof sheet 14 and the exterior sheet 15, which are laminated in the thickness direction, and the crotch gather elastic member 35 provided therebetween correspond to the exterior body of the diaper 5. Hereinafter, the exterior body will be referred to as a "sheet member 6" (see FIG. 15), and a method for manufacturing the sheet member 6 will be described.

In the second embodiment, the sheet member 6 is a sheet-like member in which a plurality of leak proof sheets 14 and an exterior sheet 15 are continuous in a predetermined direction (direction corresponding to the vertical direction in FIG. 14). In the method for manufacturing the sheet member 6, a continuous body of nonwoven fabric corresponding to the exterior sheet 15 provided with a plurality of through holes 40, 40, . . . is referred to as a first continuous sheet body 6A. A continuous body of liquid-impermeable sheets corresponding to the leak-proof sheet 14 is referred to as a second continuous sheet body 6B, and a continuous elastic member corresponding to the crotch gather elastic member 35 is referred to as an elastic member 7.

FIG. 16 is a schematic side view illustrating a manufacturing apparatus 200 for manufacturing the sheet member 6. As shown in FIG. The basic configuration of the manufacturing apparatus 200 is substantially the same as that of the manufacturing apparatus 100 of the first embodiment, and includes a transport mechanism 210, a bonding area forming mechanism 220, and an elastic member cutting mechanism 230. Then, using the manufacturing apparatus 200, the sheet member 6 is manufactured by performing the same steps (S101 to S103) as the manufacturing process of the sheet member 2 (see FIG. 5).

First, in the conveyance step (S101), the first continuous sheet 6A is conveyed from the upstream side to the downstream side in the conveyance direction at a predetermined conveyance speed by the conveyance mechanism 210 including a plurality of conveyance rollers. In addition, in the manufacturing apparatus 200, the conveyance direction is a direction along the longitudinal direction of the diaper 5. Similarly, the second continuous sheet 6B and the elastic member 7 are transported by the transport mechanism 210 from the upstream side to the downstream side in the transport direction at a predetermined transport speed.

Next, a joining region forming step is performed to form a plurality of joining regions 50, 50, . . . for attaching the elastic member 7 to the first continuous sheet body 6A and the second continuous sheet body 6B (S102). As shown in FIG. 16, the first continuous sheet body 6A and the second continuous sheet body 6B are conveyed so as to be stacked in the thickness direction. Then, the elastic member 7 is disposed between the first continuous sheet body 6A and the second continuous sheet body 6B in the thickness direction in a state where it is stretched in the conveying direction at a predetermined stretching magnification, and is stretched through the joining region 50. Then, it is attached so as to be sandwiched between the first continuous sheet body 6A and the second continuous sheet body 6B. The method of forming the bonding region 50 is substantially the same as in the first embodiment.

FIG. 17 is a schematic plan view showing an example of the arrangement of the bonding region 50. A sheet cutting position EC shown by a broken line in FIG. 17 represents a position where the sheet member 6 is cut in a subsequent process (a process of manufacturing the diaper 5 using the sheet member 6).

In the second embodiment, one or more joining regions 50 are formed on both sides of the sheet cutting position EC in the conveyance direction. In the example of FIG. 17, a first bonding area 511 is formed on the upstream side in the conveying direction with respect to the sheet cutting position EC, and a second bonding area 512 is formed on the downstream side in the conveying direction. The elastic member 7, which is stretched along the conveying direction, is attached between the first continuous sheet body 6A and the second continuous sheet body 6B by these joining regions 50. Note that, similarly to the first embodiment, an adhesive may be provided between the first bonding area 511 and the second bonding area 512 in the conveyance direction.

Next, an elastic member cutting step is performed in which the elastic member 7 stretched in the transport direction is cut between the two bonding regions 50, 50 adjacent in the transport direction (S103). Cutting of the elastic member is performed using an elastic member cutting mechanism 230 that includes a pair of cutter rolls 231 and an anvil roll 232. In FIG. 17, the elastic member 7 in the stretched state is cut at the elastic member cutting position CP between the first bonding area 511 and the second bonding area 512 adjacent in the conveying direction. The cut elastic member 7 is cut back from the elastic member cutting position CP to the upstream side and the downstream side in the conveyance direction, and in the area between the first bonding area 511 and the second bonding area 512, the elastic member 7 Stretchability is no longer expressed. That is, only a portion of the crotch region 5B of the diaper 5 is given elasticity.

In this elastic member cutting step (S103), similarly to the first embodiment, by appropriately adjusting the elastic member cutting position CP, the elastic member 7 to be cut back (contracted) is attached to the first sheet continuous body 6A. It can be suppressed from popping out from the provided through hole 40. Specifically, the elastic member 7 is cut at a position closer to the first bonding area 511 than the second bonding area 512 in the conveyance direction. In the case of FIG. 17, if the intermediate position in the conveyance direction between the first bonding area 511 and the second bonding area 512 is C51, it is preferable that the intermediate position of the elastic member cutting position CP is upstream of C51 in the conveyance direction. .

In this way, as explained in FIG. 8, the amount of contraction of the elastic member 7 per unit time can be made relatively small. That is, with respect to the sheet member 6 that is transported at a predetermined transport speed V2 in the transport direction, the elastic member 7 cut at the elastic member cutting position CP contracts at a speed V72 in the transport direction downstream. The speed V71 of contraction toward the upstream side can be reduced. Therefore, the contraction force of the elastic member 7 can be reduced as a whole. Thereby, when the elastic member 7 is cut back, it becomes difficult to catch on the outer edge 40e of the through hole 40, and it becomes easier to prevent the elastic member 7 from popping out from the through hole 40.

Note that the portion of the elastic member 7 (crotch gather elastic member 35) where the elasticity acts in the conveyance direction is also referred to as the "effective length portion" of the elastic member. As shown in FIG. 14, in the longitudinal direction, the distance d35f between the ventral end of the diaper 5 and the ventral end of the effective length portion of the crotch gather elastic member 35 is equal to the distance d35f between the dorsal end of the diaper 5 and It is larger than the distance d35b between the effective length portion of the crotch gather elastic member 35 and the dorsal end. That is, the effective length portion of the crotch gather elastic member 35 is provided closer to the back side than the center in the longitudinal direction of the diaper 5. Therefore, when the diaper 5 is worn, the absorbent core 11 easily fits the wearer's body on the buttocks side, making it easier to suppress leakage of excrement. Moreover, with such a configuration, by cutting the elastic member 7 (crotch gather elastic member 35) within the dorsal waist region 5A (see FIG. 17), it is possible to suppress the contractile force of the elastic member 7 to a small level. can. Therefore, it is easy to adjust the position of the elastic member cutting position CP, and it becomes easy to realize the diaper 5 in which the crotch gather elastic member 35 does not easily pop out from the through hole 40.

===Modification example of joining area 50===
In the embodiment described above, the bonding region 50 was formed using adhesive means such as hot melt adhesive, but the method of forming the bonding region 50 is not limited to this. For example, the joining region 50 may be formed using a welding means such as ultrasonic welding. Note that since ultrasonic welding is a known technique, a description of ultrasonic welding will be omitted in this specification.

FIG. 18 is a schematic plan view illustrating a modified example of the bonding region 50. FIG. 18 is a diagram showing a modified version of the joining region described in FIG. 6 of the first embodiment. In this modification, a welded area 50 is formed by a plurality of welded parts 52, 52 that are discretely arranged in the conveyance direction and a direction (CD direction) orthogonal to the conveyance direction. Each welding part 52 is formed into a substantially rectangular shape by ultrasonic welding, and joins the first continuous sheet body 2A and the second continuous sheet body 2B in the thickness direction, and also connects a pair of welded parts adjacent in the CD direction. The elastic member 3 is attached to the sheet member 2 by sandwiching the elastic member 3 from both sides in the CD direction between the pair of parts 52S.

19A and 19B are explanatory diagrams of the function of attaching the elastic member 3 by the welded portion pair 52S, and are schematic enlarged views of section C in FIG. 18. As shown in FIG. 19A, a pair of welded parts 52, 52 forming a welded part pair 52S are lined up with an interval GH50 in the CD direction. The distance GH50 is set to be the same as or slightly larger than the diameter d3t of the elastic member 3 when expanded to a predetermined expansion ratio (GH50≧d3t). That is, the elastic member 3 in the stretched state is arranged between the welded portion pair 52S in the CD direction.

From this state, when the elastic member 3 is relaxed from the stretched state, the elastic member 3 contracts in the transport direction and expands in the CD direction, as shown in 19B, and the diameter d3 in the natural state is the CD of the welded portion pair 52S. The distance in the direction is larger than the distance GH50 (d3>GH50). As a result, the elastic member 3 is pressed in the CD direction by the welded parts 52, 52. As a result, the elastic member 3 is attached to the sheet member 2.

In the diaper 1 in the pants-type state shown in FIG. 1, the fit gather elastic member 32 (elastic member 3) is in a natural state relaxed from the above-mentioned stretched state. In addition, in the pants-shaped diaper 1, both sides of the ventral part 20 (dorsal part 30) in the left-right direction are joined by welding or the like, so the ventral part 20 is stretched in the left-right direction when the diaper 1 is worn. Even if this happens, the fit gather elastic member 32 will not come off from the abdominal part 20.

It is also possible to form the joining region 50 in the diaper 5 of the second embodiment by the pair of welded parts 52S as described above.

===Other embodiments===

Although the embodiments of the present invention have been described above, the above-described embodiments are intended to facilitate understanding of the present invention, and are not intended to be interpreted as limiting the present invention. Further, the present invention can be modified and improved without departing from the spirit thereof, and it goes without saying that the present invention includes equivalents thereof.

1 Diaper (first embodiment) (pants-type disposable diaper, absorbent article),
2 sheet member (first embodiment),
2A first sheet continuous body (non-skin side nonwoven fabric),
2B second sheet continuous body (skin side nonwoven fabric),
3 Elastic member (fit gather elastic member),
5 Diaper (second embodiment) (tape-type disposable diaper, absorbent article),
6 sheet member (second embodiment),
6A first sheet continuous body (exterior sheet),
6B second sheet continuous body (liquid impermeable sheet),
7 Elastic member (crotch gather elastic member),
10 absorbent body,
11 Absorbent body, 12 Skin side sheet, 13 Intermediate sheet, 14 Leak proof sheet,
15 exterior sheet, 16 side sheet, 17 fastening tape, 18 leakage prevention wall,
20 ventral part,
21 skin side nonwoven fabric, 22 non-skin side nonwoven fabric, 23 fit gather elastic member,
24 Cover nonwoven fabric,
30 dorsal part,
31 skin side nonwoven fabric, 32 non-skin side nonwoven fabric, 33 fit gather elastic member,
34 Cover nonwoven fabric, 35 Crotch gather elastic member,
40 through hole, 40e outer edge,
50 joint area,
501 first bonding area, 502 second bonding area,
511 first bonding area, 512 second bonding area,
52 welded part, 52S welded part pair,
100 manufacturing device (first embodiment),
110 conveyance mechanism,
120 junction region formation mechanism,
122 sheet member adhesive application section, 123 elastic member adhesive application section,
130 elastic member cutting mechanism,
131 cutter roll, 132 anvil roll,
141 pin part, 142 pin support base, 143 pin part,
145 Groove, 146 Groove,
200 manufacturing device (second embodiment),
210 transport mechanism,
220 junction region formation mechanism,
222 sheet member adhesive application section, 223 elastic member adhesive application section,
230 elastic member cutting mechanism,
231 cutter roll, 232 anvil roll,

Claims (8)

a conveying step of respectively conveying a first continuous sheet body provided with a plurality of through holes and a second continuous sheet body;
Between the first continuous sheet body and the second continuous sheet body laminated on one side in the thickness direction of the first continuous sheet body, the first continuous sheet body or the second continuous sheet body is a bonding area forming step of forming a plurality of bonding areas for attaching the elastic member stretched in the conveyance direction;
The stretched elastic member is cut between the two joining regions adjacent in the conveying direction, and the cut elastic member is transferred from the through hole to the other side of the first sheet continuous body in the thickness direction. an elastic member cutting step of contracting the elastic member along the conveying direction so as not to protrude to the side;
has
The bonding area includes a first bonding area and a second bonding area adjacent to the first bonding area on the downstream side in the conveyance direction,
In the elastic member cutting step, the elastic member is cut at a position closer to the first bonding area than the second bonding area in the conveyance direction,
The sheet member for an absorbent article is an exterior body of a tape-type disposable diaper,
The elastic member is a crotch gather elastic member that imparts elasticity to the crotch region of the exterior body,
A method for manufacturing a sheet member for an absorbent article, characterized in that in the elastic member cutting step, at least a portion of the crotch gather elastic member is cut. The method for manufacturing a sheet member for an absorbent article according to claim 1,
A method for manufacturing a sheet member for an absorbent article, characterized in that the height of a portion of the outer edge of the through hole protruding in the thickness direction is 0.2 mm or less. The method for manufacturing a sheet member for an absorbent article according to claim 1,
A method for manufacturing a sheet member for an absorbent article, wherein the diameter of the through hole is three times or less the diameter of the elastic member. The method for manufacturing a sheet member for an absorbent article according to claim 3,
A method for manufacturing a sheet member for an absorbent article, wherein the diameter of the through hole is smaller than twice the diameter of the elastic member. The method for manufacturing a sheet member for an absorbent article according to claim 1,
A method for manufacturing a sheet member for an absorbent article, wherein a diameter of the through hole on the one side in the thickness direction is smaller than a diameter of the through hole on the other side in the thickness direction. The method for manufacturing a sheet member for an absorbent article according to any one of claims 1 to 5, comprising:
The through hole is formed by passing a pin through the first sheet continuous body from one side to the other side in the thickness direction,
When forming the through holes, the pins are heated to a temperature that is higher than the softening point and lower than the melting point of the thermoplastic fibers contained in the first continuous sheet. A method for manufacturing a sheet member for articles. The method for manufacturing a sheet member for an absorbent article according to claim 6,
When forming the through hole, the pin is heated to a temperature closer to the softening point than the melting point of the thermoplastic fibers included in the first continuous sheet. A method for manufacturing a sheet member for absorbent articles. The method for producing a sheet member for an absorbent article according to any one of claims 1 to 7,
The bonding area includes a first bonding area and a second bonding area adjacent to the first bonding area on the downstream side in the conveyance direction,
A method for manufacturing a sheet member for an absorbent article, characterized in that an adhesive is provided between the first bonding area and the second bonding area in the conveyance direction.

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