Method and apparatus for manufacturing a composite expansion and contraction member

Abstract

Even when variations in processing conditions, non-uniformity of materials, or the like occur, it is possible to form a non-elastic region by eliminating or reducing the elastic stretchability in a predetermined portion of the composite sheet in which the elastic member is disposed, while suppressing the occurrence of holes or cuts in the composite sheet. 【Solution means】 The manufacturing method of the composite expansion and contraction member 10 includes conveying a composite sheet 10A in which a plurality of elastic members 13 are disposed between sheets 11 and 12 along the extending direction of the elastic member 13, and pressing the composite sheet 10A between a first roll 5 having a plurality of convex portions 4P and a second roll 6 to cut the elastic member 13 and form a non-elastic region 15 in the composite sheet 10A. The method also includes a step of forming a forward hole suppression region 16 for suppressing the occurrence of holes in the composite sheet 10A at a boundary portion between the non-elastic region 15 and an elastic region 14 adjacent to the downstream side in the conveyance direction of the non-elastic region 15.

Description

[Technical field]

[0001] The present invention relates to a method and an apparatus for manufacturing a composite elastic member. [Background technology]

[0002] Conventionally, in absorbent articles such as disposable diapers, composite elastic members having elasticity in a predetermined direction have been used to improve the adhesion of predetermined parts such as the waist and torso to the wearer, and a known composite elastic member is configured in such a way that a plurality of thread-like or strip-like elastic members are arranged in a stretched state on a non-stretch sheet that does not inherently have elasticity, such as a nonwoven fabric or a plastic film. In addition, composite elastic members are not only those in which the entire sheet has elasticity, but also those in which elasticity is imparted only to necessary parts and which have non-elastic regions that have no elasticity.

[0003] For example, Patent Document 1 describes a method for manufacturing a composite elastic member having a non-elastic region, in which a composite sheet having a plurality of elastic members arranged in a stretched state between a first roll having a large number of projections arranged on its surface and a second roll facing the first roll is passed, and the elastic members of the composite sheet are cut by applying pressure between the projections of the first roll and the second roll and by heating with both rolls. Patent Document 1 relates to an improved technology for a pants-type disposable diaper that includes an exterior body and an absorbent body that is arranged in the center of the skin-facing side of the exterior body and includes a liquid-retaining absorbent core, and the composite elastic member is used in the exterior body of the diaper. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2002-273808 A Summary of the Invention [Problem to be solved by the invention]

[0005] In a method for manufacturing a composite expansion and contraction member having an inelastic region, it is preferable that the elastic member disposed on the composite sheet can be cut without damaging the composite sheet. However, in the conventional method for manufacturing a composite expansion and contraction member having an inelastic region, perforations may occur in the composite sheet. Regarding the method for manufacturing a composite expansion and contraction member having an inelastic region described in Patent Document 1, there is still room for improvement in the occurrence of perforations in the composite sheet due to fluctuations in processing conditions or unevenness in materials. Also, when the basis weight of the material is reduced, etc., the perforations may deteriorate when the breaking strength of the sheet decreases.

[0006] Therefore, an object of the present invention relates to forming an inelastic region by suppressing the occurrence of perforations and cuts in the composite sheet and disappearing or reducing the elastic stretchability at a predetermined portion of the composite sheet where the elastic member is disposed, even when fluctuations in processing conditions or unevenness in materials occur.

Means for Solving the Problems

[0007] The present invention relates to a method for manufacturing a composite expansion and contraction member in which an elastic region exhibiting elastic stretchability and an inelastic region substantially not exhibiting elastic stretchability are alternately formed in one direction. As an embodiment, while conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, the composite sheet is pressurized between a first roll and a second roll provided with a plurality of convex portions, thereby cutting the elastic members to form the inelastic region in the composite sheet, and at the boundary between the inelastic region and the elastic region adjacent to the downstream side in the conveying direction of the inelastic region, a step of forming a perforation suppression region for suppressing perforations in the composite sheet is preferably provided. As one embodiment, the first roll has a pressing portion provided with a plurality of convex portions on a part of the circumferential surface in the circumferential direction, and the pressing portion includes a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region that is located in front of the cutting region in the rotation direction of the first roll and in which a plurality of second convex portions for pressing the composite sheet are formed. It is preferable that the front edge of the second convex portion in the rotation direction has a convex curved shape toward the rotation direction.

[0008] The present invention also relates to a method for manufacturing a composite stretch member in which an elastic region that exhibits elastic stretchability and an inelastic region that substantially does not exhibit elastic stretchability are alternately formed in the conveying direction. As one embodiment, while conveying a composite sheet having a plurality of sheets and a plurality of elastic members arranged between the sheets along the extending direction of the elastic members, the composite sheet is pressed between a first roll and a second roll each provided with a plurality of convex portions, thereby cutting the elastic members to form the inelastic region in the composite sheet, and forming a front hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveying direction of the inelastic region. It is preferable to include this step. As one embodiment, the first roll has a pressing portion provided with a plurality of convex portions on a part of the circumferential surface in the circumferential direction, and the pressing portion includes a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region that is located in front of the cutting region in the rotation direction of the first roll and in which a plurality of second convex portions for pressing the composite sheet are formed. It is preferable that the front edges of the first convex portion and the second convex portion are straight lines along the rotation axis direction of the first roll, and the length of the edge of the second convex portion is shorter than the length along the rotation axis direction of the front edge of the first convex portion.

[0009] Furthermore, the present invention relates to a pant diaper including the composite stretch member manufactured by the above method.

[0010] Furthermore, the present invention relates to a manufacturing apparatus used for manufacturing a composite expansion and contraction member in which an elastic region exhibiting elastic expansion and contraction and an inelastic region substantially not exhibiting elastic expansion and contraction are alternately formed in one direction. As one embodiment, while conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, the composite sheet is pressed between a first roll having a plurality of convex portions and a second roll, thereby cutting the elastic members to form the inelastic regions in the composite sheet, and at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveying direction of the inelastic region, it is preferable to include pressing means for forming a forward hole suppression region for suppressing the formation of holes in the composite sheet. As one embodiment, the first roll has a pressing portion having a plurality of convex portions in a part of the circumferential direction on the circumferential surface, and the pressing portion has a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region located in front of the cutting region in the rotational direction of the first roll and having a plurality of second convex portions for pressing the composite sheet, and it is preferable that a front edge portion of the second convex portion in the forward direction of the rotational direction has a convex curved shape toward the rotational direction.

[0011] Furthermore, the present invention relates to a manufacturing apparatus used for manufacturing a composite expansion and contraction member in which an elastic region exhibiting elastic expansion and contraction and an inelastic region substantially not exhibiting elastic expansion and contraction are alternately formed in one direction. As one embodiment, while conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, the composite sheet is pressed between a first roll having a plurality of convex portions and a second roll, thereby cutting the elastic members to form the inelastic regions in the composite sheet, and at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveying direction of the inelastic region, it is preferable to include pressing means for forming a forward hole suppression region for suppressing the formation of holes in the composite sheet. As one embodiment, the first roll has a pressing portion provided with a plurality of convex portions on a part of the circumferential surface in the circumferential direction, and the pressing portion includes a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region that is located in front of the cutting region in the rotational direction of the first roll and in which a plurality of second convex portions for pressing the composite sheet are formed. The front edge of the first convex portion and the second convex portion in the rotational direction is a straight line along the rotational axis direction of the first roll, and it is preferable that the length of the edge of the second convex portion is shorter than the length along the rotational axis direction of the front edge of the first convex portion.

Effect of the Invention

[0012] According to the present invention, even when fluctuations in processing conditions or unevenness in materials occur, it is possible to form an inelastic region by suppressing the occurrence of holes in the composite sheet and eliminating or reducing the elastic stretchability at a predetermined portion of the composite sheet where the elastic member is disposed.

Brief Description of the Drawings

[0013]

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DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, the present invention will be described with reference to the drawings in its preferred embodiments. The manufacturing apparatus 1 for a composite expansion and contraction member shown in FIG. 1 is a manufacturing apparatus used for implementing a method for manufacturing a composite expansion and contraction member 10 according to an embodiment of the present invention. The method for manufacturing the composite expansion and contraction member 10 of the present embodiment is, for example, a method for manufacturing a composite expansion and contraction member used for a pants-type disposable diaper, and as shown in FIG. 3, an elastic region 14 that exhibits elastic stretchability and a non-elastic region 15 that substantially does not exhibit elastic stretchability are alternately formed in one direction to manufacture the composite expansion and contraction member 10. In the following description, the direction in which the sheets 11 and 12 are conveyed will be described as the MD (Machine Direction) direction, and the direction orthogonal to the MD direction will be described as the CD (Cross machine Direction) direction. Note that the extending direction of the elastic member 13 described later coincides with the MD direction. Also, the rotational axis direction A described later coincides with the CD direction.

[0015] The manufacturing apparatus 1 for a composite expansion and contraction member shown in FIG. 1 preferably includes a composite sheet manufacturing means 2 and a pressing means 3.

[0016] The composite sheet manufacturing means 2 is arranged on the upstream side in the MD direction from the pressing means 3, and includes a conveying means (not shown) for the sheets 11 and 12, a conveying means (not shown) for the elastic members 13, an adhesive applying means (not shown) for applying an adhesive to the sheet 11, and a pair of upper and lower nip rolls 23 and 23 where each of the constituent members 11, 12, and 13 of the composite sheet 10A converges. The configuration of the composite sheet manufacturing means 2 is basically the same as that in a manufacturing apparatus for this type of stretchable sheet (a sheet having a plurality of elastic members arranged in an extended state on the sheet).

[0017] In the composite sheet manufacturing means 2, as shown in FIG. 1, while continuously conveying the strip-shaped sheet 11 supplied from a raw material roll (not shown) in the MD direction indicated by the reference in FIG. 1, an adhesive such as a hot melt adhesive is applied to one surface (the surface facing the sheet 12) of the sheet 11 by an adhesive applying means, and the sheet 11 to which the adhesive is applied is conveyed between a pair of nip rolls 23 and 23. Also, a predetermined tension is applied to each of the plurality of filamentous elastic members 13 to extend them at a predetermined elongation rate, and the plurality of elastic members 13 in the extended state are conveyed between a pair of nip rolls 23 and 23. Separately, a strip-shaped sheet 12 having the same length as the sheet 11 in the CD direction is conveyed between a pair of nip rolls 23 and 23 from above the sheet 11. The CD direction is a direction orthogonal to the MD direction and is parallel to the rotation axes 51 and 61 of the rolls 5 and 6 described later. In this way, two strip-shaped sheets 11 and 12 and a plurality of elastic members 13 in the extended state are fed between a pair of nip rolls 23 and 23 and pressed between both rolls 23 and 23, so that each of the members 11, 12, and 13 is crimped to each other via the adhesive, and a composite sheet 10A having a plurality of sheets 11 and 12 and a plurality of elastic members 13 arranged between the sheets 11 and 12 is obtained. Note that the adhesive may be applied to the sheet 12, may be applied to both the sheet 11 and the sheet 12, or may be applied to the plurality of elastic members 13. The elastic members 13 are arranged along the MD direction. In other words, the extending direction of the elastic members 13 coincides with the MD direction.

[0018] The pressing means 3 included in the manufacturing apparatus 1 presses the composite sheet 10A manufactured using the composite sheet manufacturing means 2 to cut the elastic member 13 and form the inelastic region 15 in the composite sheet 10A, and at the boundary between the inelastic region 15 and the elastic region 14 adjacent to the downstream side in the MD direction of the inelastic region 15, it is used to form the forward hole suppression region 16 for suppressing the perforation of the composite sheet 10A. As shown in FIG. 1, the pressing means 3 includes a first roll 5 having a plurality of convex portions 4P protruding from its peripheral surface, and a second roll 6 facing the first roll 5. The peripheral surface of the second roll 6 has no uneven shape and is smooth. Note that the first roll 5 is provided with a pressing mechanism by hydraulic pressure or pneumatic pressure at its bearing portion, and it is possible to apply a desired pressure to the composite sheet 10A inserted between the two rolls 5 and 6.

[0019] The surfaces of the nip rolls 23, 23 preferably use a non-sticking material or are non-stick treated because, depending on the types of the sheets 11, 12, etc., the hot melt adhesive may penetrate the sheets 11, 12 and contaminate the roll surface.

[0020] As shown in FIG. 1, the pressing means 3 includes a first roll 5 having a rotating body 52 rotatably supported about the rotation axis 51 in the rotation direction R1, and a second roll 6 having a cylindrical rotating body 62 rotating synchronously with the roll 5 in the direction R2 about the rotation axis 61. When both rolls 5 and 6 are rotating, the elastic member 13 of the composite sheet 10A supplied between the two rolls 5 and 6 is pressed by the pressing portion 4 of the roll 5 and the peripheral surface of the roll 6. The two rolls 5 and 6 are provided so as to rotate synchronously by the driving force from the driving means (not shown) being transmitted to their rotation axes 51 and 61.

[0021] Both rolls 5 and 6 are composed of a rigid body made of metal such as various tool steels (steel) like die steel. In the present embodiment, heating means (not shown) such as a heater is attached to each of the two rolls 5 and 6, and heat is transmitted to the composite sheet 10A passing between the two rolls 5 and 6 by heat conduction from the heating means. However, in the present invention, such heating means is not essential, and the heating means may not be attached to either of the two rolls 5 and 6, or may be attached to only one of them.

[0022] From the viewpoints of improving the cutability of the elastic member 13 of the composite sheet 10A supplied between the two rolls 5 and 6 by the pressure portion 4 and preventing the melting of the composite sheet 10A, the heating temperature of the pressure portion 4 of the first roll 5 by the heating means is preferably 50°C or higher and 170°C or lower, more preferably 70°C or higher and 150°C or lower. When non-woven fabrics are used as the sheets 11 and 12, the upper limit of the heating temperature of the pressure portion 4 is preferably set to be equal to or lower than the melting point of its constituent material.

[0023] In the pressing means 3, as shown in FIG. 1, the belt-shaped composite sheet 10A obtained by using the composite sheet manufacturing means 2 is passed between the first roll 5 rotating in the direction R1 and the second roll 6 rotating in the rotation direction R2, and the composite sheet 10A is pressed by the pressing between the pressure portion 4 of the first roll 5 and the peripheral surface of the second roll 6, and a front hole suppression region 16 and a non-elastic region 15 are formed in the composite sheet 10A, and the target composite expansion and contraction member 10 is obtained (see FIG. 3).

[0024] Regarding the first roll 5 which is one of the main features of the present invention, as shown in FIG. 1, on a part of the circumferential surface of the first roll 5 in the circumferential direction, there is a pressing portion 4 having a plurality of convex portions 4P for pressing the elastic member 13. More specifically, the first roll 5 has one or more (two places in the illustrated embodiment) processed portions 53 formed to protrude in the circumferential direction R on its circumferential surface, and the pressing portion 4 is formed on the upper surface of each processed portion 53. The pressing portion 4 is provided with a plurality of convex portions 4P for pressing the elastic member at intervals in the circumferential direction. In the preferred embodiment, the protruding height of the convex portion 4P from the base surface is constant.

[0025] The pressing portion 4 of the present embodiment has a cutting region 41 in which a plurality of first convex portions 4Q for forming the non-elastic region 15 are formed, and a pre-pressing region 42 in which a plurality of second convex portions 4R for forming the front hole suppression region 16 are formed (see FIG. 2).

[0026] In the cutting region 41 in the present embodiment, as shown in FIG. 2, a large number of the first convex portions 4Q are dispersedly arranged. By pressing the composite sheet 10A with the first convex portions 4Q, each elastic member 13 is cut at a plurality of locations to form the non-elastic region 15 (see FIG. 3). It is preferable that when the composite sheet 10A passes through the cutting region 41, at least two or more of the first convex portions 4Q are arranged side by side in the circumferential direction R of the first roll 5 with respect to each elastic member 13. That is, when assuming a straight line extending in the circumferential direction R of the first roll 5 on the cutting region 41, it is preferable that the straight line intersects at least two or more of the first convex portions 4Q regardless of the position where the straight line is moved from one end to the other end of the cutting region 41. By doing so, the elastic member 13 can be cut more reliably.

[0027] In the present invention, from the viewpoint of more reliably cutting the elastic member 13, it is preferable that the front edge of the first convex portion 4Q in the rotation direction R1 is a straight line along the rotation axis direction A of the first roll 5. In this embodiment, the planar shape of the first convex portion 4Q is an oval shape extending in the rotation axis direction A, but it is not limited thereto, and it may be a rhombus shape, a circular shape, an elliptical shape, a rectangular shape, or the like. The oval shape in this embodiment includes, as shown in FIG. 2, a shape having curves at both ends on both sides in the rotation axis direction A and connecting the ends with a straight line.

[0028] In the pre-pressurization region 42 in this embodiment, as shown in FIG. 2, a plurality of second convex portions 4R are arranged. The second convex portion 4R is a convex portion 4P that is located at the foremost portion in the rotation direction R1 of the first roll 5 and first contacts the composite sheet 10A among the plurality of convex portions 4P constituting the pressing portion 4. The second convex portion 4R has an oval shape inclined with respect to the rotation direction R1 in a plan view, and the front edge portion in the rotation direction R1 of the first roll 5 has a convex curved shape toward the rotation direction R1 (see FIG. 2). When the second convex portion 4R has such a shape, it is preferable in that the second convex portion 4R can uniformly press the plurality of elastic members 13 in the front hole suppression region 16. Note that the second convex portion 4R may be arranged singly instead of plurally. In this embodiment, by pressing the composite sheet 10A with the second convex portion 4R, a front hole suppression region 16 for suppressing the formation of holes in the composite sheet 10A is formed at the boundary between the inelastic region 15 and the elastic region 14 adjacent to the downstream side in the conveyance direction of the inelastic region 15 (see FIG. 3). Note that the elastic member 13 in the front hole suppression region 16 may or may not be cut by being pressed by the second convex portion 4R, but from the viewpoint of making use of the stretchability of the elastic member 13 other than the inelastic region 15, it is preferable that the elastic member 13 in the front hole suppression region 16 is not cut. As shown in FIG. 2, it is preferable from the viewpoint of suppressing the cutting of the elastic member 13 that the length Lb of the second convex portion 4R along the rotation direction R1 of the first roll 5 is longer than the length La of the first convex portion 4Q along the rotation direction R1.

[0029] By configuring and arranging the pressing portion 4 of the first roll 5 that presses the composite sheet 10A with a plurality of elastic members 13 disposed between the sheets in this manner, a non-elastic region 15 can be formed at a predetermined portion of the composite sheet 10A where the elastic members 13 are disposed. That is, with respect to the composite sheet 10A passing between the first roll 5 and the second roll 6, the first convex portion 4Q, which is a convex portion 4P other than the second convex portion 4R, contacts the composite sheet 10A and cuts a plurality of elastic members 13 in the composite sheet 10A. Due to this cutting, each elastic member 13 in the stretched state has its stretched state released and contracts in the front and rear directions in the MD direction from the cutting position. In this way, a non-elastic region 15 that does not exhibit elastic stretchability is formed, and a composite stretchable member is manufactured in which an elastic region 14 that exhibits elastic stretchability and a non-elastic region 15 that does not exhibit elastic stretchability are alternately formed in the MD direction.

[0030] However, if the breaking strength of at least one of the sheets 11 and 12 used for the composite sheet 10A is low, holes may occur in the composite sheet 10A due to contact with the second convex portion 4R that first contacts the composite sheet 10A. Therefore, in the present embodiment, the front edge of the second convex portion 4R that first contacts the composite sheet 10A in the rotation direction R1 is formed in a convex curved shape toward the rotation direction R1. With such a configuration, the portion where the second convex portion 4R and the composite sheet 10A first come into contact, which is the most impactful on the composite sheet 10A, becomes a point, and the portion (the starting point of the hole formation) where an impact force is applied to the fibers of the composite sheet 10A can be made extremely small. Therefore, the occurrence of holes in the composite sheet 10A can be suppressed. That is, by adopting the combination of the cutting region 41 and the pre-pressing region 42, even when variations in processing conditions or unevenness in materials occur, while suppressing the occurrence of holes in the composite sheet, a non-elastic region can be reliably formed by eliminating or reducing the elastic stretchability at a predetermined portion of the composite sheet where the elastic members are disposed.

[0031] The planar shape of the second convex portion 4R in this embodiment is different from that of the first convex portion 4Q. Specifically, the planar shape of the second convex portion 4R is an oval shape inclined in the rotation direction R1, but it is not limited to this. The second convex portion 4R only needs to have a convex curved shape at the front edge in the rotation direction R1 facing the rotation direction R1. For example, it may have the shapes shown in FIGS. 6(a) to (l). From the viewpoint of making the indentation of the second convex portion 4R less noticeable and improving the appearance, it is also preferable that the shape is as shown in FIG. 6(b). Note that for the second convex portion 4R shown in FIG. 6(k), the front edge in the rotation direction R1 is also a convex curved shape facing the rotation direction R1. Also, as shown in FIGS. 6(c) and (d), the pre-pressurized region 42 may have a plurality of rows of the second convex portion array.

[0032] When a plurality of elastic members 13 are arranged at intervals in the CD direction, from the viewpoint of suppressing damage to the elastic members 13 in the front hole suppression region 16 and making use of the elasticity of the elastic members 13 other than the inelastic region 15, the second convex portion 4R is preferably arranged so as not to press the elastic members 13. More specifically, for example, it is preferably arranged so as to press between the elastic members 13. More specifically, it is preferable that all of the second convex portion 4R is arranged so as to press between the elastic members 13 (see FIG. 14). Note that the second convex portion 4R is preferably arranged so as not to press an elastic member with a high contribution to elasticity. For example, when an elastic sheet 70 described later is used for at least one of the sheets 11 and 12, the second convex portion 4R is preferably arranged so as to press between the elastic members 13 rather than between the elastic filaments 73.

[0033] As shown in FIG. 2, a large number of convex portions 4P are dispersedly arranged in the cutting region 41 of the pressing portion 4 and are arranged in a staggered pattern. More specifically, as shown in FIG. 2, the first convex portion 4Q is arranged to have a first convex portion array 41A in which a plurality of first convex portions 4Q are arranged in series along the rotation axis direction A at a certain interval. In the pre-pressurization region 42, a plurality of second convex portions 4R are arranged so as to have a second convex portion row 42A in which the second convex portions are in series along the rotation axis direction A at regular intervals. In the post-pressurization region 43 described later, a plurality of third convex portions 4S are arranged so as to have a third convex portion row 43A in which the third convex portions are in series along the rotation axis direction A at regular intervals.

[0034] Since the pressing portion 4 comes into contact in order from the one located in front of the rotation direction R1 of the roll 5, within the cutting region 41, there is a time when the adjacent first convex portion rows 41A simultaneously press the composite sheet 10A. However, since there is no convex portion row adjacent to the third convex portion 4S that comes into contact last in the rearward direction of the conveyance direction, the time for pressing only with the third convex portion 4S becomes long. Therefore, due to the contact with the third convex portion 4S that comes into contact last, holes are likely to occur in the composite sheet 10A. Thus, from the viewpoint of suppressing the occurrence of holes in the composite sheet 10A, the pressing portion 4 of the present embodiment has a post-pressurization region 43. As shown in FIG. 2, a plurality of third convex portions 4S are arranged in the post-pressurization region 43. The third convex portion 4S is the convex portion 4P that is located at the rearmost part of the rotation direction R1 of the first roll 5 and comes into contact with the composite sheet 10A last among the plurality of convex portions 4P that constitute the pressing portion 4. The third convex portion 4S has an oval shape that is inclined in the rotation direction R1 in a plan view, and the rear edge portion in the rotation direction R1 of the first roll 5 has a convex curved shape toward the opposite direction of the rotation direction R1 (see FIG. 2). With such a configuration, the portion where the third convex portion 4S, which applies the most load to the composite sheet 10A, and the composite sheet 10A come into contact last becomes a point, and the portion where force is applied to the fibers of the composite sheet 10A (the starting point of hole formation) can be made extremely small, so that the occurrence of holes in the composite sheet 10A can be suppressed. Note that the third convex portion 4S may be arranged singly instead of plurally.

[0035] In this embodiment, by pressing the composite sheet 10A with the third convex portion 4S, a rear hole formation suppression region 17 for suppressing the formation of holes in the composite sheet 10A is formed at the boundary between the inelastic region 15 and the elastic region 14 adjacent to the upstream side in the conveyance direction of the inelastic region 15 (see FIG. 3). Note that the elastic member 13 in the rear hole formation suppression region 17 may or may not be cut by being pressed by the third convex portion 4S. However, from the viewpoint of making use of the stretchability of the elastic member 13 other than the inelastic region 15, it is preferable that the elastic member 13 in the rear hole formation suppression region 17 is not cut. As shown in FIG. 2, it is preferable that the length Lc of the third convex portion 4S along the rotation direction R1 of the first roll 5 is longer than the length La of the first convex portion 4Q along the rotation direction R1 from the viewpoint of suppressing the cutting of the elastic member 13.

[0036] When the plurality of elastic members 13 are arranged at intervals in the CD direction, from the viewpoint of suppressing damage to the elastic member 13 in the rear hole formation suppression region 17 and making use of the stretchability of the elastic member 13 other than the inelastic region 15, the third convex portion 4S is preferably arranged so as not to press the elastic member 13, for example, to press between the elastic members 13. More specifically, it is preferable that all of the third convex portions 4S are arranged so as to press between the elastic members 13 (see FIG. 14).

[0037] From the viewpoint of suppressing the cutting of the elastic member 13 and suppressing the occurrence of holes in the composite sheet 10A, the pressure at which the pressing portion 4 presses the composite sheet 10A is preferably 70 N / mm or more and 1800 N / mm or less in terms of line pressure, and more preferably set to 80 N / mm or more and 1400 N / mm or less. Here, the line pressure refers to a numerical value indicating the pressure applied between a pair of rolls, and is a value obtained by dividing the pressure applied between the first roll 5 and the second roll 6 by the length of the contact line ignoring the crushing of the rolls when the first roll 5 and the second roll 6 are brought into contact.

[0038] From the viewpoint of suppressing the occurrence of holes in the composite sheet 10A, it is preferable that the distance W1 between the second convex portion 4R and the first convex portion 4Q adjacent to the second convex portion 4R is shorter than the distance W2 between adjacent first convex portions 4Q (see FIG. 4). That is, it is preferable that the distance W1 between the second convex portion row 42A and the first convex portion row 41A is shorter than the distance W2 between the first convex portion rows 41A. With such a configuration, the impact force when the convex portion 4P pressing the composite sheet 10A changes from the second convex portion 4R to the first convex portion 4Q can be suppressed, so that the occurrence of holes in the composite sheet 10A can be suppressed. From the viewpoint of achieving such an effect, the distance W1 between the second convex portion 4R and the first convex portion 4Q adjacent to the second convex portion 4R is preferably 0.1 mm or more, more preferably 0.2 mm or more, preferably 5 mm or less, more preferably 1 mm or less, preferably 0.1 mm or more and 5 mm or less, more preferably 0.2 mm or more and 1 mm or less. From the same viewpoint, the distance W2 between adjacent first convex portions 4Q is preferably 0.2 mm or more, more preferably 0.3 mm or more, preferably 10 mm or less, more preferably 5 mm or less, preferably 0.2 mm or more and 5 mm or less, more preferably 0.3 mm or more and 10 mm or less.

[0039] From the viewpoint of suppressing the occurrence of holes in the composite sheet 10A, it is also preferable that the distance W3 between the third convex portion 4S and the first convex portion 4Q adjacent to the third convex portion 4S is shorter than the distance W2 between adjacent first convex portions 4Q (see FIG. 5). That is, it is preferable that the distance W3 between the third convex portion row 43A and the first convex portion row 41A is shorter than the distance W2 between the first convex portion rows 41A. With such a configuration, the impact force when the convex portion 4P pressing the composite sheet 10A changes from the first convex portion 4Q to the third convex portion 4S can be suppressed, so that the occurrence of holes in the composite sheet 10A can be suppressed. From the viewpoint of achieving such an effect, the distance W3 between the third convex portion 4S and the first convex portion 4Q adjacent to the third convex portion 4S is preferably 0.1 mm or more, more preferably 0.2 mm or more, preferably 5 mm or less, more preferably 1 mm or less, preferably 0.1 mm or more and 5 mm or less, more preferably 0.2 mm or more and 1 mm or less.

[0040] <Measurement Methods for Spacing W1, Spacing W2, and Spacing W3> Observe the surface of the pressing portion 4 of the first roll 5 with a microscope, and measure the spacing between the adjacent first convex portion rows 41A and the second convex portion rows 42A, the spacing between the adjacent first convex portion rows 41A, or the spacing between the adjacent first convex portion row 41A and the third convex portion row 43A, respectively, and set the measured distance of the spacing as the spacing W1, the spacing W2, or the spacing W3.

[0041] From the viewpoint of improving the appearance of the composite expansion and contraction member 10, it is preferable that the maximum value of the total length of the second convex portions 4R along the rotation axis direction A is smaller than the minimum value of the total length of the first convex portions 4Q along the rotation axis direction A. With such a configuration, the length along the rotation axis direction A for pressing the composite sheet 10A by the second convex portions 4R can be made smaller than the length along the rotation axis direction A for pressing the composite sheet 10A by the first convex portions 4Q, so that the appearance of the composite expansion and contraction member 10 can be improved. From the viewpoint of achieving such an effect, the maximum value of the total length of the second convex portions 4R along the rotation axis direction A is preferably 10 mm or more, more preferably 20 mm or more, preferably 120 mm or less, more preferably 100 mm or less, preferably 10 mm or more and 120 mm or less, more preferably 20 mm or more and 100 mm or less. From the same viewpoint, the minimum value of the total length of the first convex portions 4Q along the rotation axis direction A is preferably 11 mm or more, more preferably 21 mm or more, preferably 125 mm or less, more preferably 105 mm or less, preferably 11 mm or more and 125 mm or less, more preferably 21 mm or more and 105 mm or less.

[0042] From the viewpoint of improving the appearance of the composite expansion and contraction member 10, it is also preferable that the maximum value of the total length of the third convex portions 4S along the rotation axis direction A is smaller than the minimum value of the total length of the first convex portions 4Q along the rotation axis direction A. With such a configuration, the length along the rotation axis direction A for pressing the composite sheet 10A by the third convex portions 4S can be made smaller than the length along the rotation axis direction A for pressing the composite sheet 10A by the first convex portions 4Q, so that the appearance of the composite expansion and contraction member 10 can be improved. From the perspective of achieving such an effect, the maximum value of the total length of the third convex portions 4S along the rotation axis direction A is preferably 10 mm or more, more preferably 20 mm or more, preferably 120 mm or less, more preferably 100 mm or less, preferably 10 mm or more and 120 mm or less, and more preferably 20 mm or more and 100 mm or less. From the same perspective, the minimum value of the total length of the first convex portions 4Q along the rotation axis direction A is preferably 11 mm or more, more preferably 21 mm or more, preferably 125 mm or less, more preferably 105 mm or less, preferably 11 mm or more and 125 mm or less, and more preferably 21 mm or more and 105 mm or less.

[0043] <Calculation (measurement) method for the maximum value of the total length of the second convex portions 4R along the rotation axis direction A and the maximum value of the total length of the third convex portions 4S along the rotation axis direction A> Observe the surface of the pressing portion 4 of the first roll 5 with a microscope, obtain the sum of the lengths L4 of the respective convex portions along the rotation axis direction A of each second convex portion 4R constituting the second convex portion row 42A, and set this as the maximum value of the total length of the second convex portions 4R along the rotation axis direction A. The total length of the second convex portions 4R is obtained by finding the sum of the portions existing within the length range of the pressing portion 4 along the rotation axis direction A. In calculating the maximum value of the total length of the third convex portions 4S along the rotation axis direction A, it is obtained in the same manner as the total length of the second convex portions 4R, except that the sum of the lengths L5 of the respective convex portions along the rotation axis direction A of the third convex portions 4S is obtained. <Calculation (measurement) method for the minimum value of the total length of the first convex portions 4Q along the rotation axis direction A> Observe the surface of the pressing portion 4 of the first roll 5 with a microscope, obtain the sum of the total lengths L3 of each first convex portion 4Q constituting the first convex portion row 41A, and set this as the minimum value of the total length of the first convex portions 4Q along the rotation axis direction A. When the total length of the first convex portions 4Q along the rotation axis direction A varies depending on the first convex portion row 41A, the smallest value among the total lengths of the first convex portions 4Q along the rotation axis direction A is set as the minimum value of the total length of the first convex portions 4Q along the rotation axis direction A. The total length of the first convex portions 4Q is obtained by finding the sum of the portions existing within the length range of the pressing portion 4 along the rotation axis direction A, in the same manner as the total length of the second convex portions 4R or the third convex portions 4S.

[0044] The protruding height from the base surface of the first convex portion 4Q, the second convex portion 4R, and the third convex portion 4S is preferably 0.1 mm or more, more preferably 0.2 mm or more, preferably 1.5 mm or less, more preferably 1.0 mm or less, preferably 0.1 mm or more and 1.5 mm or less, and more preferably 0.2 mm or more and 1.0 mm or less.

[0045] As the elastic member 13 to be used, for example, various materials and forms of elastic members (for example, filamentous ones) conventionally used in absorbent articles can be used. Examples of the forming material of the elastic member 13 include polyurethane elastic fibers (spandex), natural rubber, synthetic rubber, and the like. When the filamentous elastic member 13 is in a thread form, its thickness is preferably 150 dtex or more and 1500 dtex or less, and more preferably 200 dtex or more and 1300 dtex or less. The elongation ratio of the elastic member 13 is preferably 1.1 times or more and 10.0 times or less of its natural length. Further, as the elastic member 13, the elastic filament 73 described later can also be used.

[0046] As the adhesive to be used, for example, various adhesives conventionally used in absorbent articles can be used. For example, a hot-melt type adhesive can be preferably used. Examples of the hot-melt type adhesive include styrene-based and olefin-based ones. As the styrene-based hot-melt adhesive, styrene-butadiene-styrene copolymer (SBS), styrene-isoprene-styrene copolymer (SIS), styrene-ethylene-butylene-styrene copolymer (SEBS) which is a hydrogenated product of SBS, and a blend type hot-melt adhesive obtained by blending two or more of these are preferably used.

[0047] It is preferable that at least one of the sheets 11 and 12 constituting the composite sheet 10A has stretchability in one direction, and in a state of being stretched at least in the one direction, a high basis weight portion having a relatively high basis weight and a low basis weight portion having a relatively low basis weight are alternately arranged in the one direction, which is a stretchable sheet 70. In the present embodiment, the stretchable sheet 70 is used as the sheet 11. As the stretchable sheet 70, a stretchable sheet 70 in which elastic filaments 73 arranged to extend in one direction are joined between two fiber sheets 71 and 72 as shown in FIG. 7 can be used. The two fiber sheets 71 and 72 are stretchable in the one direction in which the elastic filaments 73 extend. When the above-described stretchable sheet 70 is used as a sheet constituting the composite sheet 10A, the one direction in which the elastic filaments 73 extend is made to coincide with the MD direction. As the fiber sheets 71 and 72, for example, non-woven fabrics can be used. Since the stretchable sheet 70 has a weak breaking strength, holes are likely to occur, and the effects of the present invention can be more exhibited. Note that the stretchable sheet 70 may include a sheet other than a stretchable sheet having stretchability in one direction (for example, a non-stretchable sheet), on the premise that it has stretchability in one direction.

[0048] In the present invention, "having stretchability in one direction" specifically refers to that the maximum elongation in one direction of the sheet (for example, the stretchable sheet 70) is preferably 50% or more.

[0049] The "maximum elongation" referred to here is the elongation rate when the measurement object (for example, the stretchable sheet 70) is extended to a length (the length immediately before the material breaks) that cannot be extended any further, and is obtained by the following formula (1). Maximum elongation (%) = {(length after elongation - length before elongation) / length before elongation} × 100... (1) The maximum elongation can be measured by the following procedure. In the natural state (the contracted state of the elastic member) of the measurement object, marks are made at intervals of 50 mm in the Y direction, and the interval between these marks is measured and taken as the "length before elongation". Next, the measurement object is extended in its stretching direction until immediately before the material of the measurement object breaks, and the interval between the marks in such an extended state is measured and taken as the "length after elongation". Then, these measured values are substituted into the formula (1) to calculate the maximum elongation.

[0050] As the sheet constituting the stretchable sheet 70, for example, (1) a stretchable nonwoven fabric in which a stretchable fiber layer is integrated on both sides or one side of an elastic fiber layer, (2) a stretchable nonwoven fabric in which a stretchable fiber layer is integrated on both sides or one side of a net-shaped elastic sheet, (3) a stretchable nonwoven fabric in which a stretchable fiber layer is integrated on both sides or one side of an elastic sheet made of an elastic film, (4) a stretchable nonwoven fabric in which a large number of elastic filaments arranged so as to extend in one direction without intersecting each other are integrated with a stretchable fiber layer, etc. can be preferably used. The "stretchable fiber layer" as used herein includes, in addition to a fiber layer that is stretchable before being integrated with an elastic material, a fiber layer that becomes stretchable by mechanical processing or the like after being integrated with an elastic material. Examples of the method of integrating the elastic fiber layer and the stretchable fiber layer include a method of laminating them and entangling the fibers by water jet entanglement or air through, a method of joining them by heat embossing, an adhesive, ultrasonic waves, etc.

[0051] The stretchable sheet 70 corresponds to the stretchable nonwoven fabric of the above (4). The stretchable sheet 70 having the above-described configuration can be manufactured, for example, according to the method described in JP-A-2009-61743. Specifically, for example, while a plurality of molten elastic filaments 73 spun from a spinning nozzle are drawn and stretched at a predetermined speed, before the elastic filaments 73 are solidified, the elastic filaments 73 are fused to the fiber sheets 71, 72 so that the elastic filaments 73 are arranged in one direction without intersecting each other, and then the two sheets 71, 72 to which the elastic filaments 73 are fused are stretched along the extending direction of the elastic filaments 73, whereby the above-described stretchable sheet 70 can be manufactured. The stretchable sheet 70 has stretchability in one direction in which the elastic filaments 73 extend throughout.

[0052] Examples of the forming material of the elastic filament 73 include natural rubber, synthetic rubbers such as EVA rubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, and neoprene rubber, polyurethane, and thermoplastic elastomers. The thickness of the elastic filament 73 is preferably 30 μm or more and 200 μm or less, and more preferably 50 μm or more and 130 μm or less. The elongation ratio of the elastic filament 73 is preferably 1.1 times or more and 10.0 times or less of its natural length.

[0053] From the viewpoints of thickness, design property, etc., the basis weight of the fiber sheets 71 and 72 constituting the stretchable sheet 70 is preferably 3 g / m 2 or more, more preferably 5 g / m 2 or more, and preferably 30 g / m 2 or less, more preferably 10 g / m 2 or less, and preferably 3 g / m 2 or more and 30 g / m 2 or less, more preferably 5 g / m 2 or more and 10 g / m 2 or less.

[0054] From the viewpoints of suppressing the perforation of the composite sheet 10A and thickness, design property, etc., the basis weight of the stretchable sheet 70 is preferably 6 g / m 2 or more, more preferably 8 g / m 2 or more, and preferably 60 g / m 2 or less, more preferably 45 g / m 2 or less, and preferably 6 g / m 2 or more and 60 g / m 2 or less, more preferably 8 g / m 2 or more and 45 g / m 2 or less.

[0055] From the viewpoint of preventing breakage during sheet use, the breaking strength of the stretchable sheet 70 is preferably 3 N / 50 mm or more, more preferably 5 N / 50 mm or more, and preferably 90 N / 50 mm or less, more preferably 70 N / 50 mm or less, and preferably 3 N / 50 mm or more and 90 N / 50 mm or less, more preferably 5 N / 50 mm or more and 70 N / 50 mm or less.

[0056] 〔Measurement method of breaking strength〕 Cut out a measurement piece in a rectangular shape with a length of 50 mm in the CD direction and 300 mm in the MD direction, which is perpendicular to the CD direction, from the composite sheet 10A. Use this cut-out measurement piece as a measurement sample. Attach this measurement sample to the chuck of a tensile testing machine (for example, the tensilon tensile testing machine "RTA-100" manufactured by Orientec Co., Ltd.) so that the MD direction becomes the tensile direction. Note that the distance between the chucks is 100 mm. Then, pull the measurement sample at a speed of 300 mm / min, and define the maximum load point until the measurement sample breaks as the breaking strength.

[0057] In the present invention, it is also preferable that at least one of the sheets 11 and 12 is a non-stretchable sheet 75. The "non-stretchable sheet" as used herein refers to a sheet whose maximum elongation is preferably less than 50%, more preferably 0%. As the non-stretchable sheet 75, non-woven fabrics, resin films, etc. obtained by various manufacturing methods can be used. Examples of non-woven fabrics include spunbond non-woven fabrics, air-through non-woven fabrics, needle-punched non-woven fabrics, etc. The non-stretchable sheet 75 may have a single-layer structure or a laminated structure in which two or more sheets are laminated.

[0058] When at least one of the sheets 11 and 12 is a non-stretchable sheet 75, from the viewpoints of suppressing the formation of holes in the composite sheet 10A and viewpoints such as thickness and designability, the basis weight of the non-stretchable sheet 75 is preferably 6 g / m 2 or more, more preferably 8 g / m 2 or more, preferably 50 g / m 2 or less, more preferably 45 g / m 2 or less, preferably 6 g / m 2 or more and 50 g / m 2 or less, more preferably 8 g / m 2 or more and 45 g / m 2 or less.

[0059] When at least one of the sheets 11 and 12 is the non-stretchable sheet 75, from the viewpoint of preventing breakage during sheet use, the breaking strength of the non-stretchable sheet 75 is preferably 5 N / 50 mm or more, more preferably 10 N / 50 mm or more, preferably 100 N / 50 mm or less, more preferably 90 N / 50 mm or less, preferably 5 N / 50 mm or more and 100 N / 50 mm or less, more preferably 10 N / 50 mm or more and 90 N / 50 mm or less.

[0060] The composite elastic member 10 manufactured in this way is an elastic stretchable sheet. Such a composite elastic member 10 contributes to improving the fit of the diaper, for example, by being disposed at the waist portion of a pant-type diaper. In the disposable diaper, it is preferable that the end portion of the absorber of the disposable diaper overlaps with the inelastic region 15 formed by the pressing portion 4 in the composite elastic member 10. With such a configuration, the contraction of the absorber by the elastic member 13 is suppressed, and the leakage prevention effect is improved.

[0061] Next, the pressing portion 4a, which is another embodiment, will be described with reference to the drawings based on its preferred embodiment. As long as there is no contradiction, the configuration of the aforementioned manufacturing apparatus 1 can be appropriately applied to the pressing portion 4a. Hereinafter, the components different from those in the embodiments shown in FIGS. 1 to 7 will be mainly described, and the same components will be denoted by the same reference numerals and the description thereof will be omitted. For the components not particularly described, the description of the components of the manufacturing apparatus 1 will be appropriately applied.

[0062] In the above-described pressing portion 4, the second convex portion 4R had a convex curved shape with the front edge in the rotation direction R1 of the first roll 5 facing the rotation direction R1. However, the second convex portion 4Ra of the pressing portion 4a of the present embodiment has a straight line extending along the rotation axis direction A at the front edge in the rotation direction R1. Specifically, the second convex portion 4Ra of the manufacturing apparatus 1a has an oval shape extending in the CD direction in a plan view, and the front edge in the rotation direction R1 of the second convex portion 4Ra is a straight line along the rotation axis direction A that is shorter than the front edge in the rotation direction R1 of the first convex portion 4Q (see FIGS. 8 and 10). Even in such a configuration, the portion where the second convex portion 4Ra and the composite sheet 10A first come into contact, which is the most impactful on the composite sheet 10A, becomes shorter with respect to the first convex portion 4Q, and the portion where an impact force is applied to the fibers of the composite sheet 10A (the starting point of the perforation) can be reduced, so that the occurrence of perforations in the composite sheet 10A can be suppressed. That is, even when the strength of the composite sheet is weak, the non-elastic region can be surely formed by suppressing the occurrence of perforations in the composite sheet and disappearing or reducing the elastic stretchability in a predetermined portion of the composite sheet where the elastic member is disposed.

[0063] In the present embodiment, by pressing the composite sheet 10A with the second convex portion 4Ra, a front perforation suppression region 16a for suppressing the perforation of the composite sheet 10A is formed at the boundary between the non-elastic region 15 and the elastic region 14 adjacent to the downstream side in the conveyance direction of the non-elastic region 15 (see FIG. 9). Note that the elastic member 13 in the front perforation suppression region 16a may or may not be cut. From the viewpoint of making use of the stretchability of the elastic member 13 other than the non-elastic region 15, it is preferable that the elastic member 13 in the front perforation suppression region 16a is not cut. As shown in FIG. 8, it is preferable that the length Lb of the second convex portion 4Ra along the rotation direction R1 of the first roll 5 is longer than the length La of the first convex portion 4Q along the rotation direction R1 from the viewpoint of suppressing the cutting of the elastic member 13.

[0064] From the perspective of suppressing the occurrence of holes in the composite sheet, the length L2 of the front edge of the second convex portion 4Ra in the rotation direction R1 is preferably 0.01 mm or more, more preferably 0.1 mm or more, preferably 5 mm or less, more preferably 4 mm or less, preferably 0.01 mm or more and 5 mm or less, more preferably 0.1 mm or more and 4 mm or less. From the same perspective as above, the length L1 of the front edge of the first convex portion 4Q in the rotation direction R1 is preferably 1 mm or more, more preferably 1.5 mm or more, preferably 10 mm or less, more preferably 5 mm or less, preferably 1 mm or more and 10 mm or less, more preferably 1.5 mm or more and 5 mm or less. From the same perspective as above, the length L2 of the front edge of the second convex portion 4Ra in the rotation direction R1 is preferably 1% or more, more preferably 10% or more, preferably 90% or less, more preferably 70% or less, preferably 1% or more and 90% or less, more preferably 10% or more and 70% or less with respect to the length L1 of the front edge of the first convex portion 4Q in the rotation direction R1. From the perspective of suppressing the occurrence of holes in the composite sheet, it is also preferable that the total length of the second convex portion 4Ra is shorter than the total length of the first convex portion 4Q.

[0065] The planar shape of the second convex portion 4Ra in the present embodiment was an oval shape extending in the CD direction, but it is not limited thereto. The second convex portion 4Ra only needs to have a straight line at the front edge in the rotation direction R1 that is shorter than the front edge of the first convex portion 4Q in the rotation direction R1. For example, the planar shape of the second convex portion 4Ra may be a triangular shape shown in Fig. 11(a) or a hexagonal shape shown in Fig. 11(b).

[0066] In the pressing part 4 described above, the third convex part 4S had a convex curved shape with the rear edge in the rotation direction R1 of the first roll 5 facing the direction opposite to the rotation direction R1. However, the rear edge of the third convex part 4Sa of the pressing part 4a of the present embodiment is a straight line extending along the rotation axis direction A. Specifically, the third convex part 4Sa of the manufacturing apparatus 1a has an oval shape extending in the CD direction in a plan view, and the rear edge of the third convex part 4Sa in the rotation direction R1 is a straight line along the rotation axis direction A that is shorter than the rear edge of the first convex part 4Q in the rotation direction R1. Even with such a configuration, the rear edge where the third convex part 4S of the third convex part 4Sa, which is the part where the most load is applied to the composite sheet 10A, comes into contact with the composite sheet 10A last, is shorter than the edge of the first convex part 4Q, and the part (the starting point of the hole) where force is applied to the fibers of the composite sheet 10A can be reduced. Therefore, the generation of holes in the composite sheet 10A can be suppressed.

[0067] In the present embodiment, by pressing the composite sheet 10A with the third convex part 4S, a rear hole suppression region 17a for suppressing the formation of holes in the composite sheet 10A is formed at the boundary between the inelastic region 15 and the elastic region 14 adjacent to the downstream side in the conveyance direction of the inelastic region 15. That is, the rear hole suppression region 17a is arranged at a position corresponding to the post-pressurization region 43a (see FIG. 8). Note that the elastic member 13 in the rear hole suppression region 17a may or may not be cut. However, from the viewpoint of making use of the stretchability of the elastic member 13 other than the inelastic region 15, it is preferable not to cut the elastic member 13 in the rear hole suppression region 17a.

[0068] The present invention is not limited to the above-described embodiments and can be appropriately changed. Also, the above-described embodiments may be combined. For example, in the third convex part 4S in the pressing part 4 described above, the rear edge in the rotation direction R1 of the first roll 5 was a convex curved shape facing the rotation direction R1. However, the rear edge in the rotation direction R1 of the third convex part 4S may be a straight line along the rotation axis direction A that is shorter than the rear edge in the rotation direction R1 of the first convex part 4Q. Further, in the third convex portion 4S in the pressing portion 4a described above, the edge portion behind the third convex portion 4S in the rotation direction R1 was a straight line along the rotation axis direction A that was shorter than the edge portion behind the first convex portion 4Q in the rotation direction R1. However, the edge portion behind the first roll 5 in the rotation direction R1 may be a convex curved shape toward the rotation direction R1. Furthermore, although two processing portions 53 were formed on the first roll 5, the number of processing portions 53 may be one or three or more.

[0069] The composite sheet 10A may be a sheet using the stretchable sheet 70 for at least one of the sheets 11 and 12 and introducing the elastic member 13 between the sheets 11 and 12 (see Fig. 12(a)), or may not introduce the elastic member 13 between the sheets 11 and 12 (see Fig. 12(b)). When using the stretchable sheet 70 for at least one of the sheets 11 and 12 and not introducing the elastic member 13, the elastic filament 73 corresponds to the elastic member 13 in the present invention. As the composite sheet 10A, the stretchable sheet 70 may be used alone (see Fig. 12(c)). In this case, the elastic filament 73 corresponds to the elastic member 13 in the present invention. The composite sheet 10A may be a composite sheet having a configuration in which the elastic member 13 is sandwiched between the sheets 11 and 12, and both of the sheets 11 and 12 sandwiching the elastic member 13 may be non-stretchable sheets 75 (see Figs. 12(d) and 13). The composite sheet 10A may be a composite sheet having a configuration in which the stretchable sheet 70 is sandwiched between two non-stretchable sheets 75 (see Fig. 12(e)). In this case, the elastic filament 73 corresponds to the elastic member 13 in the present invention. The stretchable sheet 70 may be a composite sheet having a configuration in which a non-stretchable sheet 75 is arranged in place of one of the fiber sheets 71 and 72 (see Fig. 12(f)). In this case, the elastic filament 73 corresponds to the elastic member 13 in the present invention. Note that in Figs. 12(a) to (f), for convenience of explanation, the state before the sheets 11 and 12 merge is shown.

[0070] Regarding the above-described embodiments, the present invention further discloses the following manufacturing method and manufacturing apparatus for a composite expansion and contraction member. <1> A method for manufacturing a composite expansion and contraction member in which an elastic region exhibiting elastic expansion and contraction and a non-elastic region substantially not exhibiting elastic expansion and contraction are alternately formed in one direction, while conveying a composite sheet having a plurality of sheets and a plurality of elastic members arranged between the sheets along the extending direction of the elastic members, the composite sheet is pressed between a first roll having a plurality of convex portions and a second roll, thereby cutting the elastic members to form the non-elastic regions in the composite sheet, and a forward hole suppression region for suppressing the formation of holes in the composite sheet is formed at the boundary between the non-elastic region and the elastic region adjacent to the downstream side in the conveying direction of the non-elastic region. The first roll has a pressing portion having a plurality of convex portions on a part of the circumferential surface in the circumferential direction, and the pressing portion has a cutting region in which a plurality of first convex portions for forming the non-elastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and having a plurality of second convex portions for pressing the composite sheet, and the second convex portion has a curved shape convex toward the rotation direction at the front edge in the rotation direction. A method for manufacturing a composite expansion and contraction member.

[0071] <2> The manufacturing method of the composite expansion and contraction member according to <1>, wherein the first convex portion and the second convex portion have different planar shapes. <3> The manufacturing method of the composite expansion and contraction member according to <1> or <2>, wherein the front edge of the first convex portion in the rotation direction is a straight line along the rotation axis direction of the first roll. <4> A method for manufacturing a composite expansion and contraction member in which an elastic region exhibiting elastic expansion and contraction and a non-elastic region substantially not exhibiting elastic expansion and contraction are alternately formed in one direction, While conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, the composite sheet is pressed between a first roll having a plurality of convex portions and a second roll, thereby cutting the elastic members to form the non-elastic regions in the composite sheet, and forming a front hole suppression region for suppressing the formation of holes in the composite sheet at the boundary between the non-elastic region and the elastic region adjacent to the downstream side in the conveyance direction of the non-elastic region. The first roll has a pressing portion with a plurality of convex portions on a part of the circumferential surface in the circumferential direction. The pressing portion has a cutting region where a plurality of first convex portions for forming the non-elastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and where a plurality of second convex portions for pressing the composite sheet are formed. The front edge of the first convex portion and the second convex portion in the rotation direction is a straight line along the rotation axis direction of the first roll, and the length of the edge of the second convex portion in the rotation axis direction is shorter than the length of the front edge of the first convex portion in the rotation axis direction. A method for manufacturing a composite elastic member. <5> A step of forming the non-elastic region and forming a rear hole suppression region for suppressing the formation of holes in the composite sheet at the boundary between the non-elastic region and the elastic region adjacent to the upstream side in the conveyance direction of the non-elastic region is provided. The pressing portion has a post-pressing region located behind the cutting region in the rotation direction and where a plurality of third convex portions for pressing the composite sheet are formed. The third convex portion has a rear edge in the rotation direction that has a convex curved shape facing opposite to the rotation direction or is a straight line along the rotation axis direction of the first roll and shorter than the rear edge of the first convex portion in the rotation direction. The method for manufacturing a composite elastic member according to <1> or <4> above. <6> The length of the second convex portion along the rotation direction of the first roll is longer than the length of the first convex portion along the rotation direction. The method for manufacturing a composite elastic member according to <1> or <4> above. <7> The length of the third convex portion along the rotation direction of the first roll is longer than the length of the first convex portion along the rotation direction. The method for manufacturing a composite elastic member according to <5> above. <8> The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein the maximum value of the total length of the second convex portions along the rotation axis direction of the first roll is smaller than the minimum value of the total length of the first convex portions along the rotation axis direction. <9> The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein the distance between the second convex portion and the first convex portion adjacent to the second convex portion is shorter than the distance between adjacent first convex portions. <10> The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein at least one of the sheets constituting the composite sheet has stretchability in one direction, and in a state of being stretched at least in the one direction, a high basis weight portion with a relatively high basis weight and a low basis weight portion with a relatively low basis weight are alternately arranged in the one direction, and it is a stretchable sheet. <11> The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein the composite sheet is a composite sheet having a configuration in which an elastic member is sandwiched between sheets, and any of the sheets is a non-stretchable sheet.

[0072] <12> The first roll is provided with a heating means inside. The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein the heating temperature of the pressing portion of the first roll by the heating means is 50°C or higher and 170°C or lower. <13> The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein the first convex portion contacts the composite sheet and cuts a plurality of the elastic members. <14> The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein the pressure at which the pressing portion presses the composite sheet is 70 N / mm or more and 1800 N / mm or less in line pressure. <15> The method for manufacturing a composite expansion and contraction member according to <1> or <4>, wherein the second convex portion presses between the elastic members. <16> A pant diaper comprising a composite stretchable member produced by the method according to <1> or <4> above. <17> A manufacturing apparatus used to manufacture a composite stretchable member in which an elastic region exhibiting elastic stretchability and a non-elastic region substantially not exhibiting elastic stretchability are alternately formed in one direction, while conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, and pressing the composite sheet between a first roll and a second roll each having a plurality of convex portions, thereby cutting the elastic members to form the non-elastic regions in the composite sheet, and forming a forward hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the non-elastic region and an elastic region adjacent to the downstream side in the conveying direction of the non-elastic region, the apparatus comprising pressing means. The first roll has a pressing portion having a plurality of convex portions on a part of the circumferential surface in the circumferential direction, the pressing portion having a cutting region in which a plurality of first convex portions for forming the non-elastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and having a plurality of second convex portions for pressing the composite sheet, the second convex portions having a front edge in the rotation direction that is convexly curved in the rotation direction, the manufacturing apparatus for a composite stretchable member. <18> The manufacturing apparatus for a composite stretchable member according to <17> above, wherein the first convex portion and the second convex portion have different planar shapes. <19> The manufacturing apparatus for a composite stretchable member according to <17> or <18> above, wherein the first convex portion has a front edge in the rotation direction that is a straight line along the rotation axis direction of the first roll.

[0073] <20> A manufacturing apparatus used to manufacture a composite stretchable member in which an elastic region exhibiting elastic stretchability and a non-elastic region substantially not exhibiting elastic stretchability are alternately formed in one direction, A composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets is conveyed along the extending direction of the elastic members, and the composite sheet is pressed between a first roll having a plurality of convex portions and a second roll, thereby cutting the elastic members to form the inelastic regions in the composite sheet, and a pressing means for forming a forward hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveyance direction of the inelastic region is provided. The first roll has a pressing portion having a plurality of convex portions on a part of the circumferential surface in the circumferential direction, and the pressing portion has a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and having a plurality of second convex portions for pressing the composite sheet. The first convex portion and the second convex portion have a front edge in the rotation direction that is a straight line along the rotation axis direction of the first roll, and the length of the edge of the second convex portion is shorter than the length along the rotation axis direction of the first roll of the first convex portion. A manufacturing apparatus for a composite elastic member. <21> The pressing portion has a post-pressing region located behind the cutting region in the rotation direction and having a plurality of third convex portions for pressing the composite sheet. The third convex portion has a rear edge in the rotation direction that has a convex curved shape facing opposite to the rotation direction or is a straight line along the rotation axis direction of the first roll that is shorter than the rear edge of the first convex portion in the rotation direction. The manufacturing apparatus for a composite elastic member according to <17> or <20>. <22> The length of the second convex portion along the rotation direction of the first roll is longer than the length of the first convex portion along the rotation direction. The manufacturing apparatus for a composite elastic member according to <17> or <20>. <23> The length of the third convex portion along the rotation direction of the first roll is longer than the length of the first convex portion along the rotation direction. The manufacturing apparatus for a composite elastic member according to <21>. <24> The manufacturing apparatus for a composite expansion and contraction member according to <17> or <20>, wherein the maximum value of the total length of the second convex portions along the rotation axis direction of the first roll is smaller than the minimum value of the total length of the first convex portions along the rotation axis direction. <25> The manufacturing apparatus for a composite expansion and contraction member according to <17> or <20>, wherein the distance between the second convex portion and the first convex portion adjacent to the second convex portion is shorter than the distance between adjacent first convex portions. <26> The manufacturing apparatus for a composite expansion and contraction member according to <17> or <20>, wherein the composite sheet is a composite sheet having a configuration in which an elastic member is sandwiched between sheets, and all of the sheets are non-elastic sheets. <27> The manufacturing apparatus for a composite expansion and contraction member according to <17> or <20>, wherein heating means is attached inside each of the first roll and the second roll. <28> The manufacturing apparatus for a composite expansion and contraction member according to <17> or <20>, wherein the second convex portion is located at the foremost part in the rotation direction among the convex portions and is the convex portion that first contacts the composite sheet.

[0074] <29> The manufacturing apparatus for a composite expansion and contraction member according to <17> or <20>, wherein the second convex portion is arranged to press between the elastic members. <30> The length of the front edge portion of the second convex portion in the rotation direction is 0.01 mm or more and 5 mm or less, and the length of the front edge portion of the first convex portion in the rotation direction is 1 mm or more and 10 mm or less. The manufacturing apparatus for a composite expansion and contraction member according to <20>, wherein the length of the front edge portion of the second convex portion in the rotation direction is 1% or more and 90% or less of the length of the front edge portion of the first convex portion in the rotation direction. <31> The manufacturing apparatus for a composite expansion and contraction member according to <21>, wherein the protruding height from the base surface of the first convex portion, the second convex portion, and the third convex portion is 0.1 mm or more and 1.5 mm or less.

Example

[0075] Hereinafter, the present invention will be described in more detail with reference to examples. However, the scope of the present invention is not limited to such examples.

[0076] [Example 1] A telescopic member having the same configuration as the composite telescopic member shown in FIG. 3 was prepared. First, a belt-like sheet 11 and a sheet 12, and an elastic member 13 to be introduced between both sheets 11 and 12 were prepared. Next, using the manufacturing apparatus 1, an adhesive such as a hot melt adhesive was applied to one surface (the surface facing the sheet 12) of the belt-like sheet 11 by an adhesive application means, and the belt-like sheets 11 and 12 and a plurality of elastic members 13 in an extended state were fed in, and the members 11, 12, and 13 were pressure-bonded to each other via the adhesive by pressing with nip rolls 23 and 23, thereby obtaining a belt-like composite sheet 10A. Then, by pressing the composite sheet 10A at the pressing portion 4 of the first roll 5, a composite telescopic member 10 in which an elastic region 14 and a non-elastic region 15 were alternately formed in one direction was manufactured. A front hole-suppressing region 16 and a rear hole-suppressing region 17 were formed in the composite telescopic member 10. The pressing portion 4 used was one having the same configuration as the pressing portion shown in FIG. 2. The linear pressure when pressing the composite sheet 10A at the pressing portion 4 was 646 N / mm 2 and the heating temperature of the pressing portion 4 of the first roll 5 was 100°C. As the sheet 11, a stretchable sheet 70 was used, and as the sheet 12, a non-stretchable sheet was used. The basis weight (when not extended) of the sheet 11 was 45 g / m 2 and the breaking strength was 30 N / 50 mm. The basis weight of the sheet 12 was 18 g / m 2 and the breaking strength was 32 N / 50 mm. As the elastic member 13, thread rubber was used.

[0077] [Example 2] A composite telescopic member was manufactured in the same manner as in Example 1, except that the linear pressure when pressing the composite sheet 10A at the pressing portion 4 was changed to 969 N / mm 2 .

[0078] [Example 3] The linear pressure when pressing the composite sheet 10A at the pressing part 4 was 1292 N / mm 2 A composite expansion and contraction member was manufactured in the same manner as in Example 1, except that the linear pressure was set to 1292 N / mm

[0079] 〔Example 4〕 A composite expansion and contraction member was manufactured in the same manner as in Example 1, except that a member having the same configuration as the pressing part shown in FIG. 8 was used The length of the front edge of the first convex part 4Q in the rotation direction R1 was 3 mm, and the length of the front edge of the second convex part 4Ra in the rotation direction R1 was 2 mm

[0080] 〔Comparative Example 1〕 A composite expansion and contraction member was manufactured in the same manner as in Example 1, except that a pressing part having only the cutting region 41 was used. Only the inelastic region 15 was formed in the obtained composite expansion and contraction member, and the front hole suppression region 16 and the rear hole suppression region 17 were not formed

[0081] 〔Evaluation〕 The composite expansion and contraction members obtained in Examples 1 to 4 and Comparative Example 1 were evaluated for the presence of holes and the cutting condition of the elastic member. Specifically, the composite expansion and contraction member 10 was set to the extended state, and the presence of holes in the inelastic region 15 and the cutting condition of the elastic member 13 were visually confirmed. This operation was performed 30 times. The results are shown in Table 1

[0082]

Table 1

[0083] As is clear from the results shown in Table 1, the composite expansion and contraction members 10 obtained in Examples 1 to 4 had a better hole condition compared to Comparative Example 1, while the cutting of the elastic member 13 was sufficient. From these results, it can be seen that it is preferable to provide the pre-pressing region 42 and the post-pressing region 43 in the pressing part 4 from the viewpoint of suppressing the occurrence of holes in the composite sheet and forming the inelastic region

Explanation of reference numerals

[0084] 1 Manufacturing apparatus 2 Composite sheet manufacturing means 3 Pressing means 4,4a Pressing part 4P Protrusion 4Q First protrusion 4R,4Ra Second protrusion 4S,4Sa Third protrusion 5 First roll 6 Second roll 10 Composite expansion and contraction member 10A Composite sheet 11 Sheet 12 Sheet 13 Elastic member 14 Elastic region 15 Non-elastic region 16,16a Front hole suppression region 17,17a Rear hole suppression region 23 Nipper roll 41 Cutting region 42,42a Pre-pressing region 43,43a Post-pressing region 70 Stretchable sheet

Claims

1. A method for manufacturing a composite expansion and contraction member in which an elastic region exhibiting elastic expansion and contraction and an inelastic region substantially not exhibiting elastic expansion and contraction are alternately formed in one direction, comprising: while conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, pressing the composite sheet between a first roll having a plurality of convex portions and a second roll, thereby cutting the elastic members to form the inelastic region in the composite sheet, and forming a forward hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveying direction of the inelastic region. The first roll has a pressing portion having a plurality of convex portions on a part of the circumferential surface in the circumferential direction, the pressing portion having a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and having a plurality of second convex portions for pressing the composite sheet, the second convex portion having a front edge in the rotation direction having a convex curved shape toward the rotation direction. A method for manufacturing a composite expansion and contraction member.

2. The method for manufacturing a composite expansion and contraction member according to claim 1, wherein the first convex portion and the second convex portion have different planar shapes.

3. The method for manufacturing a composite expansion and contraction member according to claim 1 or 2, wherein a front edge of the first convex portion in the rotation direction is a straight line along the rotation axis direction of the first roll.

4. A method for manufacturing a composite expansion and contraction member in which an elastic region exhibiting elastic expansion and contraction and an inelastic region substantially not exhibiting elastic expansion and contraction are alternately formed in one direction, comprising: while conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, pressing the composite sheet between a first roll having a plurality of convex portions and a second roll, thereby cutting the elastic members to form the inelastic region in the composite sheet, and forming a forward hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveying direction of the inelastic region. The first roll has a pressing portion provided with a plurality of convex portions on a part of the circumferential surface in the circumferential direction. The pressing portion has a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and provided with a plurality of second convex portions for pressing the composite sheet. The first convex portion and the second convex portion are such that the front edge in the rotation direction is a straight line along the rotation axis direction of the first roll, and the length of the edge of the second convex portion in the rotation axis direction is shorter than the length of the front edge of the first convex portion in the rotation axis direction. A method for manufacturing a composite stretchable member.

5. A step of forming the inelastic region and forming a rear hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the inelastic region and an elastic region adjacent to the upstream side in the conveyance direction of the inelastic region. The pressing portion has a post-pressing region located behind the cutting region in the rotation direction and provided with a plurality of third convex portions for pressing the composite sheet. The third convex portion is such that the rear edge in the rotation direction has a convex curved shape facing opposite to the rotation direction, or is a straight line along the rotation axis direction of the first roll and shorter than the rear edge of the first convex portion in the rotation direction. The method for manufacturing a composite stretchable member according to claim 1 or 4.

6. The maximum value of the total length of the second convex portions along the rotation axis direction of the first roll is smaller than the minimum value of the total length of the first convex portions along the rotation axis direction. The method for manufacturing a composite stretchable member according to claim 1 or 4.

7. The distance between the second convex portion and the first convex portion adjacent to the second convex portion is shorter than the distance between adjacent first convex portions. The method for manufacturing a composite stretchable member according to claim 1 or 4.

8. At least one of the sheets constituting the composite sheet is a stretchable sheet having stretchability in one direction, and in a state of being stretched at least in the one direction, a high basis weight portion having a relatively high basis weight and a low basis weight portion having a relatively low basis weight are alternately arranged in the one direction. The method for manufacturing a composite stretchable member according to claim 1 or 4.

9. The second convex portion presses between the elastic members. The method for manufacturing a composite stretchable member according to claim 1 or 4.

10. A manufacturing apparatus used for manufacturing a composite stretchable member in which an elastic region exhibiting elastic stretchability and an inelastic region substantially not exhibiting elastic stretchability are alternately formed in one direction. While conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, the composite sheet is pressed between a first roll and a second roll each having a plurality of convex portions, thereby cutting the elastic members to form the inelastic regions in the composite sheet, and forming a forward hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveyance direction of the inelastic region, the apparatus further comprising pressing means. The first roll has a pressing portion having a plurality of convex portions on a part of the circumferential surface in the circumferential direction, the pressing portion having a cutting region in which a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and in which a plurality of second convex portions for pressing the composite sheet are formed, the second convex portions having a front edge in the rotation direction which is a convex curve shape directed in the rotation direction, the apparatus for manufacturing a composite elastic member.

11. The apparatus for manufacturing a composite elastic member according to claim 10, wherein the first convex portion and the second convex portion have different planar shapes.

12. The apparatus for manufacturing a composite elastic member according to claim 10 or 11, wherein a front edge of the first convex portion in the rotation direction is a straight line along the rotation axis direction of the first roll.

13. A manufacturing apparatus used for manufacturing a composite elastic member in which elastic regions exhibiting elastic stretchability and inelastic regions substantially not exhibiting elastic stretchability are alternately formed in one direction, While conveying a composite sheet having a plurality of sheets and a plurality of elastic members disposed between the sheets along the extending direction of the elastic members, the composite sheet is pressed between a first roll and a second roll each having a plurality of convex portions, thereby cutting the elastic members to form the inelastic regions in the composite sheet, and forming a forward hole suppression region for suppressing the formation of holes in the composite sheet at a boundary portion between the inelastic region and an elastic region adjacent to the downstream side in the conveyance direction of the inelastic region, the apparatus further comprising pressing means. The first roll has a pressing portion provided with a plurality of convex portions on a part of the circumferential surface in the circumferential direction. The pressing portion has a cutting region where a plurality of first convex portions for forming the inelastic region are formed, and a pre-pressing region located in front of the cutting region in the rotation direction of the first roll and where a plurality of second convex portions for pressing the composite sheet are formed. The first convex portions and the second convex portions have an edge in the front in the rotation direction that is a straight line along the rotation axis direction of the first roll, and the length of the edge of the second convex portion is shorter than the length along the rotation axis direction of the first convex portion. A manufacturing apparatus for a composite expansion and contraction member.

14. The pressing portion has a post-pressing region located behind the cutting region in the rotation direction and where a plurality of third convex portions for pressing the composite sheet are formed. The third convex portions have an edge in the rear in the rotation direction that has a convex curved shape facing opposite to the rotation direction or is a straight line along the rotation axis direction of the first roll that is shorter than the edge in the rear in the rotation direction of the first convex portion. The manufacturing apparatus for a composite expansion and contraction member according to claim 10 or 13.

15. The maximum value of the total length of the second convex portions along the rotation axis direction of the first roll is smaller than the minimum value of the total length of the first convex portions along the rotation axis direction. The manufacturing apparatus for a composite expansion and contraction member according to claim 10 or 13.

16. The distance between the second convex portion and the first convex portion adjacent to the second convex portion is shorter than the distance between adjacent first convex portions. The manufacturing apparatus for a composite expansion and contraction member according to claim 10 or 13.

17. The second convex portions are arranged so as to press between the elastic members. The manufacturing apparatus for a composite expansion and contraction member according to claim 10 or 13.

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