Method for manufacturing stretchable sheet, stretchable sheet, device for manufacturing stretchable sheet, and anvil roll

Abstract

A method for manufacturing an elastic sheet comprises: a step for supplying first and second sheets (11, 12) and an elastic member (14); and a joining step for forming a pair of welded sections (jp) on both sides of the elastic member (14) and joining the first and second sheets (11, 12), the plurality of protrusions (231) of the anvil roll (23) having groove sections (232), and the grooves (232) being formed in a cross-section in the intersecting direction of the groove sections (232). When the intersection points of a line (X1) connecting the starting edges (232s) of the first side wall part (232iu) of the groove part (232) and a line (X2) extending the second side wall (232) toward the starting edges (232s) are set as a first intersection point and a second intersection point (Y1, Y2), the separation distance (W1) between the starting edges (232s) is longer than the distance (W2) between the first intersection point and the second intersection point (Y1, Y2).

Description

Technical Field

[0001] The present invention relates to a method for producing a stretchable sheet, a stretchable sheet, a stretchable sheet production apparatus, and an anvil roll. Background Art

[0002] As a method for manufacturing a stretchable sheet, a method is known in which an elastic member, such as a rubber thread, is sandwiched between sheets in an extended state by welds. For example, Patent Document 1 discloses a method in which a stretchable sheet includes an elastic member disposed in an extended state between a first sheet and a second sheet. The first sheet and the second sheet are joined by a plurality of welds located on either side of the elastic member. A porosity-varying region is formed between a pair of welds in the second sheet, where a portion of the constituent fibers are melted.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6997254 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] In the manufacturing method disclosed in Patent Document 1, a void ratio variation region is formed by welding using an ultrasonic weld. When the laminate is fed to the ultrasonic weld, the depth or width of the recess that houses the elastic member is adjusted so that no gaps exist between the first sheet, the elastic member, and the second sheet in the laminate. However, when adjusting the recess in Patent Document 1, when elastic members of multiple diameters are arranged on the stretchable sheet, there is no margin for the recess, which may cause the elastic member to be exposed or fall off. Furthermore, when manufacturing a stretchable sheet using a weld to clamp an elastic member such as a rubber thread, if the width between the welds is narrowed to securely secure the elastic member, the elastic member may break during the weld formation. On the other hand, if the width between the welds is increased without cutting the elastic member, there is a risk of the elastic member falling off during manufacturing, making it difficult to install multiple elastic members without cutting them during the stretchable sheet manufacturing process.

[0008] The present invention has been made in view of the above-mentioned problems, and its purpose is to suppress the cutting of the elastic member during the joining process of forming the welding portion pair in a method for manufacturing a stretchable sheet in which an elastic member is installed on the sheet by clamping the elastic member by a welding portion pair located on both sides of the elastic member, and to install the elastic member in a manner that prevents it from falling off.

[0009] Solutions to Problems

[0010] The main invention used to achieve the above-mentioned purpose is a method for manufacturing a stretchable sheet, wherein the stretchable sheet is stacked by sandwiching an elastic member between a first sheet and a second sheet, and is characterized in that the method for manufacturing the stretchable sheet comprises: a process of supplying the first sheet, the second sheet and the elastic member to an anvil roller rotating along the conveying direction, in a state where the elastic member is arranged in an extended state along the conveying direction between the first sheet and the second sheet; a process of forming a pair of welded portions on both sides of the elastic member in a cross direction orthogonal to the conveying direction to join the first sheet and the second sheet; and a process of cutting the elastic member, after the cutting process, the shrunk elastic member is clamped by the pair of welded portions, and the conveying direction of the elastic member is stretched. The position of the feeding direction is limited, and a plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, and the convex portion has a groove portion along the rotation direction of the anvil roller, and in the cross section of the groove portion along the cross direction, the groove portion has: a pair of first side wall portions extending from the starting edge of the groove portion to a prescribed position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, and in the cross section, when the intersection points of the line connecting the starting edges of the pair of first side wall portions along the cross direction and the line extending the pair of second side wall portions respectively toward the starting edge side are set as the first intersection point and the second intersection point, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

[0011] Other features of the present invention will be clarified from the description of this specification and the accompanying drawings.

[0012] Effects of the Invention

[0013] According to the present invention, in a method for manufacturing a stretchable sheet in which an elastic member is attached to a sheet by being sandwiched between a pair of welded portions located on both sides of the elastic member, the elastic member can be prevented from being cut during the joining step of forming the pair of welded portions, and can be attached in a manner that prevents the elastic member from falling off. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a diagram showing a state where the stretchable sheet 10 is stretched without wrinkles.

[0015] Figure 2 yes Figure 1 A schematic cross-sectional view of the portion indicated by A.

[0016] Figure 3 yes Figure 1 An enlarged view of the portion shown in B.

[0017] Figure 4AThis is a schematic perspective view of an absorbent article 1 using a stretchable sheet 10. Figure 4B This is a schematic plan view of the absorbent article 1 in the unfolded and stretched state as viewed from the skin side.

[0018] Figure 5 It is a schematic cross-sectional view of a stretchable sheet manufacturing apparatus 20 according to the present embodiment.

[0019] Figure 6 It is a schematic cross-sectional view of the ultrasonic welding device 22 .

[0020] Figure 7A It is an explanatory diagram of the surface of the anvil roller 23 . Figure 7B This is a schematic enlarged view of the closest portion between the anvil roller 23 and the horn 24 .

[0021] Figure 8A and Figure 8B 1 and 2 are diagrams for explaining a method of attaching the elastic member 14 via the welded portion j.

[0022] Figure 9 It is a cross-sectional view showing a cross section of the groove portion 232 along the intersecting direction.

[0023] Figure 10 It is a diagram illustrating the structure of the groove portion 232 .

[0024] Figures 11A to 11C Each of them is a diagram showing a modified example of the groove portion 232 .

[0025] Figure 12 It is a perspective view illustrating the convex portion 231 .

[0026] Figure 13 1 and 2 are views for explaining a joining process in a state where the first elastic member 14 a and the second elastic member 14 b are sandwiched therebetween.

[0027] Figure 14A 1 is a schematic cross-sectional view of a portion of the stretchable sheet 10 in a natural state where a pair of welded portions jp are formed.

[0028] Figure 14B 1 is a schematic cross-sectional view of another example of a portion where a pair of welded portions jp is formed in the stretchable sheet 10 in a natural state.

[0029] Figure 14C This is a microscopic image of an example of the inner weld portion jin and the outer weld portion jout in this embodiment.

[0030] Figure 14D This is a microscopic image of another example of the inner weld portion jin and the outer weld portion jout in this embodiment.

[0031] Figure 15It is a diagram illustrating the structure of the elastic member 14 .

[0032] Figure 16A This is a modified example of the anvil roller 23. Figure 16B It is an explanation Figure 16A FIG. 2 is a diagram of the groove portion 232 of the anvil roller 23.

[0033] Figure 17 This is a modified example of the stretch sheet 10 , and is a diagram showing a state in which the stretch sheet 10 is stretched without wrinkles. DETAILED DESCRIPTION

[0034] At least the following matters will become clear from the description of this specification and the accompanying drawings.

[0035] Method 1 is a method for manufacturing a stretchable sheet, wherein the stretchable sheet is stacked by sandwiching an elastic member between a first sheet and a second sheet, and is characterized in that the method for manufacturing the stretchable sheet comprises: a step of feeding the first sheet, the second sheet and the elastic member to an anvil roller rotating along the conveying direction, in a state where the elastic member is arranged in an extended state in a conveying direction between the first sheet and the second sheet; a step of forming a pair of welded portions on both sides of the elastic member in a cross direction orthogonal to the conveying direction to join the first sheet and the second sheet; and a step of cutting the elastic member, after the cutting step, the contracted elastic member is clamped by the pair of welded portions, and the position of the elastic member in the conveying direction is The position is restricted, and a plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, and the convex portion has a groove portion along the rotation direction of the anvil roller, and in the cross section of the groove portion along the cross direction, the groove portion has: a pair of first side wall portions extending from the starting edge of the groove portion to a prescribed position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, and in the cross section, when the intersection points of the line connecting the starting edges of the pair of first side wall portions along the cross direction and the line extending the pair of second side wall portions respectively toward the starting edge side are set as the first intersection point and the second intersection point, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

[0036] According to the stretchable sheet manufacturing method of embodiment 1, the distance between the starting edges of the first sidewalls defines the opening width of the groove, and the groove is configured so that the groove width increases from a predetermined position located on the inner side of the opening toward the opening. This structure allows the elastic member to be positioned so that it does not protrude from the groove during the joining process, facilitating the joining of the first and second sheets. By preventing the elastic member from being welded together during the joining process, breakage of the elastic member is avoided. Furthermore, by allowing the elastic member to be stably fed through the groove and performed during the joining process, the elastic member can be prevented from falling out during the process.

[0037] Method 2 is a method for manufacturing a stretchable sheet, wherein the stretchable sheet is formed by stacking a first sheet and a second sheet with an elastic member sandwiched therebetween, and the method is characterized in that the method comprises: in a state where the elastic member is extended in a conveying direction and is arranged between the first sheet and the second sheet, the first sheet, the second sheet, and the elastic member are fed to an anvil roller rotating in the conveying direction; in a cross direction orthogonal to the conveying direction, a pair of welded portions are formed on both sides of the elastic member to join the first sheet and the second sheet and a step of cutting the elastic member, wherein after the cutting step, the shrunk elastic member is clamped by the welding portion, and the position of the elastic member in the conveying direction is restricted. A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, and the convex portions have groove portions along the rotation direction of the anvil roller. In a cross section of the groove portion along the cross direction, the depth of the groove portion is greater than the height of the convex portion from the outer peripheral surface, and the length of the groove portion in the cross direction becomes shorter from the starting edge of the groove portion toward the inner side.

[0038] According to the stretchable sheet manufacturing method of embodiment 2, if the groove is shallow, the elastic member may be exposed and cut during the joining process. However, by having a sufficiently deep groove, the elastic member can be stably passed through the groove. In addition, because the length (width) in the cross direction decreases toward the inner side of the groove, the elastic member is less likely to fly out of the groove. This allows the joining process to be performed without cutting the elastic member.

[0039] Aspect 3 is the method for producing a stretchable sheet according to aspect 1 or 2, wherein the convex portion includes a plurality of grooves provided at intervals in the intersecting direction with respect to the elastic member.

[0040] According to the manufacturing method of the stretchable sheet as in method 3, by providing a plurality of grooves on the convex portion, even if the configuration of the elastic member is slightly deviated during manufacturing, as long as the elastic member is configured in any one of the plurality of grooves, the joining process can be carried out without cutting or falling off.

[0041] A fourth aspect is the method for producing a stretchable sheet according to the third aspect, wherein, in the cross section, the depth of the groove portion is equal to or greater than the spacing between the groove portions in the intersecting direction.

[0042] According to the method for producing a stretchable sheet as in embodiment 4, the groove portion has a deep depth, and thus the elastic member can pass through the groove portion more stably.

[0043] A fifth aspect is the method for producing a stretchable sheet according to the first aspect, wherein, in the cross section, the length of the groove portion in the intersecting direction decreases from the starting edge toward the back side.

[0044] According to the method for producing a stretchable sheet of embodiment 5, the shape of the groove allows the elastic member to easily enter the groove and is difficult to escape, thereby making it less likely that the elastic member will be cut or damaged during the feeding and joining steps.

[0045] Aspect 6 is the method for producing a stretchable sheet according to aspect 1, wherein, in the cross section, an angle formed by the pair of first side wall portions is at least twice an angle formed by the pair of second side wall portions.

[0046] According to the method for producing a stretchable sheet of embodiment 6, the shape of the groove allows the elastic member to easily enter the groove and is difficult to escape, thereby making it less likely that the elastic member will be cut or damaged during the feeding and joining steps.

[0047] Method 7 is a method for manufacturing a stretchable sheet described in Method 7, characterized in that, in the depth direction of the groove portion in the cross section, the length of the portion of the groove portion formed by the pair of second side wall portions is longer than the length of the portion formed by the pair of first side wall portions.

[0048] According to the manufacturing method of the stretchable sheet as in method 7, since the inner side (bottom side) of the groove is long, when the elastic member passes through the groove, the elastic member can be accommodated in the inner side of the groove, and the elastic member is unlikely to fly out of the groove.

[0049] Mode 8 is the method for producing a stretchable sheet according to any one of Modes 1 to 7, wherein the depth of the groove portion in the cross section is longer than the outer diameter of the elastic member when the elastic member is stretched to its maximum stretchable length in the conveying direction.

[0050] According to the method for producing a stretchable sheet as in aspect 8, the elastic member arranged in a stretched state is less likely to be exposed from the groove portion during the production process, and the joining process can be performed without cutting the elastic member.

[0051] Aspect 9 is the method for producing a stretchable sheet according to aspect 8, wherein the depth of the groove portion in the cross section is longer than the maximum outer diameter of the elastic member that has shrunk after the cutting step.

[0052] According to the method for producing a stretchable sheet as in aspect 9, since the groove portion has a sufficient depth, the elastic member is less likely to be exposed from the groove portion, and the joining step can be performed without cutting the elastic member.

[0053] Method 10 is a method for manufacturing a stretchable sheet described in any one of methods 1 to 6 and 8 to 9, characterized in that, in the cross-section, the area ratio occupied by the portion corresponding to the pair of first side wall portions in the depth direction of the groove portion is greater than the area ratio occupied by the portion corresponding to the pair of second side wall portions.

[0054] According to the method for manufacturing a stretchable sheet as in aspect 10, the wide groove structure on the first side wall side (starting edge side) allows the elastic member to easily enter the groove and be stably arranged.

[0055] Method 11 is a method for manufacturing a stretchable sheet described in Method 2, characterized in that the groove portion has: a pair of first side wall portions extending from the starting edge of the groove portion to a specified position located on the inner side; and a pair of second side wall portions extending from the specified position to the bottom of the groove portion. In the cross section, when the intersection points of a line connecting the starting edges of the pair of first side wall portions along the cross direction and a line extending the pair of second side wall portions respectively toward the starting edge side are set as first intersection points and second intersection points, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

[0056] According to the manufacturing method of the stretchable sheet of embodiment 11, the grooves have not only sufficient depth but also a wide opening width, making it easy to arrange the elastic member without protruding from the grooves. Therefore, the elastic member is more securely housed in the grooves and is less susceptible to being affected by the protrusions.

[0057] Method 12 is a method for manufacturing a stretchable sheet, wherein the stretchable sheet is stacked by sandwiching a plurality of elastic members between a first sheet and a second sheet, and is characterized in that the method for manufacturing the stretchable sheet comprises: a step of supplying the first sheet, the second sheet and the plurality of elastic members to an anvil roller rotating along the conveying direction, in a state where the plurality of elastic members are arranged at intervals along a cross direction orthogonal to the conveying direction between the first sheet and the second sheet, and the first sheet and the second sheet are extended along the conveying direction; forming a pair of welded portions on both sides of each of the elastic members in the cross direction orthogonal to the conveying direction, thereby joining the first sheet and the second sheet. a joining process of a second sheet; and a process of cutting the elastic member, wherein in the supply process, the plurality of elastic members supplied to the anvil roller include a first elastic member and a second elastic member having different thicknesses, and in the joining process, the pair of welded portions are formed on the first elastic member and the second elastic member respectively so as not to form a damaged portion in which a part of the surface is damaged, and, in the joining process, the pair of welded portions are formed so that the first elastic member and the second elastic member that have shrunk after the cutting process are clamped by the respective pairs of welded portions to limit the position of the first elastic member and the second elastic member in the conveying direction.

[0058] According to the manufacturing method of the stretchable sheet such as method 12, even if the first elastic member and the second elastic member have different thicknesses or elongation ratios in the stretched state, both can be joined without generating damaged portions on the surface, and the position in the conveying direction can be restricted without debonding.

[0059] Method 13 is a method for manufacturing a stretchable sheet described in Method 12, characterized in that a plurality of protrusions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, and the plurality of protrusions respectively have grooves along the rotation direction of the anvil roller. In the joining process, the pair of welded portions is formed in a state where the first elastic member and the second elastic member are not exposed from the grooves respectively arranged therein.

[0060] According to the manufacturing method of the stretchable sheet such as method 13, even if the first elastic member and the second elastic member have different thicknesses in the stretched state, since the welding portion pair is formed in a state where they are not exposed from the groove portion, any one of the elastic members can be fixed without being stepped on (cut off) by the welding portion pair.

[0061] Aspect 14 is the method for producing a stretchable sheet according to aspect 12 or 13, wherein the convex portion includes a plurality of the grooves provided at intervals in the intersecting direction with respect to one elastic member.

[0062] According to the manufacturing method of the stretchable sheet such as method 14, by providing a plurality of grooves on the convex portion relative to an elastic member, even if the configuration of the elastic member is somewhat offset during manufacturing, as long as the elastic member is configured in any one of the plurality of grooves, the joining process can be carried out without cutting or falling off.

[0063] Aspect 15 is the method for producing a stretchable sheet according to any one of aspects 12 to 14, wherein in a cross section of the groove portion along the intersecting direction, the depth of the groove portion is greater than or equal to the spacing between the groove portions in the intersecting direction.

[0064] According to the method for producing a stretchable sheet as in aspect 15, since the groove is deep, even when a plurality of elastic members having different thicknesses in a stretched state are arranged, the elastic members can pass through the groove more stably.

[0065] Method 16 is a method for manufacturing a stretchable sheet described in any one of methods 12 to 15, characterized in that, in the cross section of the groove portion along the cross direction, the depth of the groove portion is longer than the respective outer diameters of the first elastic member and the second elastic member when the first elastic member and the second elastic member are stretched to their maximum stretchable length in the conveying direction.

[0066] According to the method for manufacturing a stretchable sheet as in aspect 16, even if there is a variation in the stretched states of the first and second elastic members having different thicknesses, the above-described structure allows the elastic members to stably pass through the grooves and the process can be performed.

[0067] Aspect 17 is the method for producing a stretchable sheet according to any one of aspects 12 to 16, wherein the depth of the groove portion in the cross section is longer than the maximum outer diameter of each of the first elastic member and the second elastic member that are shrunk after the cutting step.

[0068] According to the method for manufacturing a stretchable sheet of aspect 17, since the groove has a sufficient depth, the first elastic member and the second elastic member are less likely to be exposed from the groove, and the joining step can be performed without cutting the elastic members.

[0069] Method 18 is a method for manufacturing a stretchable sheet described in any one of Methods 12 to 17, characterized in that a plurality of protrusions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, the protrusions having a groove portion along the rotation direction of the anvil roller, and in a cross section of the groove portion along the cross direction, the groove portion has: a pair of first side wall portions extending from the starting edge of the groove portion to a prescribed position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, and in the cross section, the area ratio of the portion of the groove portion corresponding to the pair of first side wall portions in the depth direction of the groove portion is larger than the area ratio of the portion corresponding to the pair of second side wall portions.

[0070] According to the manufacturing method of the stretchable sheet such as method 18, even when a plurality of elastic members of different thicknesses are arranged in a stretched state, the groove on the inner side (bottom side) can be adjusted while the groove on the starting edge side receives the elastic member and allows the thick elastic member to pass through, so that the joining process can be carried out more stably.

[0071] Method 19 is a stretchable sheet having mutually intersecting up-down directions and left-right directions, the stretchable sheet comprising: a first sheet; a second sheet joined to the first sheet by a plurality of welded portions; and an elastic member disposed between the first sheet and the second sheet and capable of stretching and contracting along the left-right directions, characterized in that the plurality of welded portions comprise a plurality of welded portion pairs, the plurality of welded portion pairs being located on both sides of the elastic member in the up-down direction, clamping the elastic member in a state of contraction along the left-right directions, and limiting the elastic member's relative movement to the first sheet and the second sheet. At the position in the left-right direction, in the cross-section along the up-down direction of the stretchable sheet at the position where the weld portion is formed, the pair of weld portions are provided on both sides of the elastic member in the up-down direction, and at least one of the pair of weld portions comprises: an inner weld portion including fibers having a molten solidified portion in which the constituent fibers constituting the first sheet and the second sheet are in a molten solidified state; and an outer weld portion located on the outside of the up-down direction relative to the inner weld portion and including only fibers having the molten solidified portion, and the average thickness of the inner weld portion is thicker than the average thickness of the outer weld portion.

[0072] According to the stretchable sheet of embodiment 19, the inner weld portion of the welded portion mitigates the problem of the weld portion becoming too hard. Furthermore, even if the positional restraint of the elastic member is weakened by the application of force to the inner weld portion, the outer weld portion can prevent the elastic member from being separated from between the first sheet and the second sheet. In addition, the thickness of the inner weld portion can easily buffer the force applied to the weld portion, thereby preventing the outer weld portion from breaking or peeling.

[0073] Aspect 20 is the stretchable sheet according to aspect 19, wherein, in a cross section of the stretchable sheet along the up-down direction, the welded portion pair includes both the inner welded portion and the outer welded portion.

[0074] According to the stretch sheet of aspect 20, excessive hardness of the welded portion can be alleviated on both sides of the elastic member in the vertical direction, and separation of the elastic member from between the first sheet and the second sheet can be suppressed.

[0075] Mode 21 is the stretchable sheet according to Mode 19 or 20, characterized in that, in a cross section of the stretchable sheet along the up-down direction, a portion having a gap is formed in at least one of between the elastic member and the first sheet and between the elastic member and the second sheet.

[0076] According to the stretch sheet of aspect 21, the elastic member is arranged without excessive contact with the first and second sheets to form gaps. This prevents the elastic member held by the weld from becoming too hard when the stretch sheet contracts.

[0077] Method 22 is a stretchable sheet described in any one of methods 19 to 21, characterized in that the elastic member is a filamentous elastic member formed by a collection of multiple elastic fibers, and in a cross-section along the up-down direction between the pair of welded portions of the elastic member in a state of being contracted along the left-right direction, there is a gap between the elastic fibers.

[0078] According to the stretchable sheet of aspect 22, even when external pressure is applied to the elastic member, the gaps can be compressed to generate a relief margin, and thus the elastic member is less likely to be cut.

[0079] Mode 23 is an absorbent article having vertical and horizontal directions intersecting each other, the absorbent article having an absorbent body and a pair of waist portions, characterized in that the absorbent article comprises: a first sheet; a second sheet joined to the first sheet by a plurality of welded portions; and an elastic member capable of stretching and contracting in the horizontal direction, wherein a plurality of the elastic members are arranged between the first sheet and the second sheet at intervals in the vertical direction, the plurality of welded portions including a plurality of welded portion pairs, the plurality of welded portion pairs being located on both sides of the elastic member in the vertical direction, sandwiching the elastic member in a state of contraction in the horizontal direction, and restricting the position of the elastic member in the horizontal direction relative to the first and second sheets, the plurality of elastic members including a first elastic member and a second elastic member having different thicknesses when the absorbent article is maximally stretched in the horizontal direction, and no damaged portion in which a portion of the surface of the first elastic member or the second elastic member is damaged is provided between the welded portion pairs adjacent to each other in the horizontal direction.

[0080] According to the absorbent article as in method 23, by having a first elastic member and a second elastic member with different thicknesses when stretched between the first sheet and the second sheet, parts with different stretching ratios can be provided, and the desired stress or stretch characteristics can be exerted on each part of the absorbent article.

[0081] Method 24 is a manufacturing device for a stretchable sheet, wherein the stretchable sheet is formed by stacking a first sheet and a second sheet with an elastic member sandwiched therebetween, and is characterized in that the manufacturing device for the stretchable sheet comprises: a supply section for supplying the first sheet, the second sheet and the elastic member to an anvil roller rotating along the conveying direction in a state in which the elastic member is arranged in an extended state along the conveying direction between the first sheet and the second sheet; a welding section forming section for forming a plurality of welding sections, wherein the plurality of welding sections form a welding section pair on both sides of the elastic member in a cross direction orthogonal to the conveying direction to join the first sheet and the second sheet; and a cutting section for cutting the elastic member, wherein after the elastic member is cut by the cutting section, the contracted elastic member is clamped by the welding section pair, and the The position of the elastic member in the conveying direction is restricted, and a plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, and the convex portion has a groove portion along the rotation direction of the anvil roller, and in a cross section of the groove portion along the intersection direction, the groove portion has: a pair of first side wall portions extending from the starting edge of the groove portion to a prescribed position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, and in the cross section, when the intersection points of a line connecting the starting edges of the pair of first side wall portions along the intersection direction and a line extending the pair of second side wall portions respectively toward the starting edge side are set as a first intersection point and a second intersection point, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

[0082] According to the stretchable sheet manufacturing apparatus of embodiment 24, the distance between the starting edges of the first sidewalls defines the opening width of the groove, and the groove is configured so that the groove width widens from a predetermined position located on the inner side of the opening toward the opening. With this manufacturing apparatus, the elastic member is arranged without protruding from the groove, facilitating the joining of the first and second sheets. By preventing the elastic member from being welded together, breakage of the elastic member is avoided. Furthermore, by manufacturing while allowing the elastic member to pass stably through the groove, it is possible to prevent the elastic member from falling out during manufacturing.

[0083] Method 25 is a manufacturing device for a stretchable sheet, wherein the stretchable sheet is stacked by sandwiching an elastic member between a first sheet and a second sheet, and is characterized in that the manufacturing device for the stretchable sheet comprises: a supply section for supplying the first sheet, the second sheet and the elastic member to an anvil roller rotating along the conveying direction in a state in which the elastic member is extended along the conveying direction and is arranged between the first sheet and the second sheet; a welding section forming section for forming a plurality of welding sections, wherein the plurality of welding sections form a pair of welding sections on both sides of the elastic member in a cross direction orthogonal to the conveying direction to join the A first sheet and a second sheet; and a cutting portion that cuts the elastic member, after the elastic member is cut by the cutting portion, the shrunk elastic member is clamped by the welding portion, and the position of the elastic member in the conveying direction is restricted, and a plurality of protrusions that protrude outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, the protrusions having grooves along the rotation direction of the anvil roller, and in a cross section of the groove along the cross direction, the depth of the groove is greater than the height of the protrusion from the outer peripheral surface, and the length of the groove in the cross direction becomes shorter from the starting edge of the groove toward the inner side.

[0084] According to the manufacturing device of the stretchable sheet such as method 25, if the groove is shallow, the elastic member may be exposed and broken when the joint is formed. However, with the manufacturing device having the above-mentioned structure, since the groove has a sufficient depth, the elastic member can pass stably through the groove, and the welded portion can be formed without cutting the elastic member.

[0085] Method 26 is a manufacturing device for a stretchable sheet, wherein the stretchable sheet is formed by stacking a first sheet and a second sheet with a plurality of elastic members sandwiched therebetween, and is characterized in that the manufacturing device for the stretchable sheet comprises: a supply section for supplying the first sheet, the second sheet and the plurality of elastic members to an anvil roller rotating along the conveying direction, in a state where the plurality of elastic members are arranged at intervals between the first sheet and the second sheet along a cross direction orthogonal to the conveying direction and are in an extended state along the conveying direction; and a welding section forming section for forming a plurality of welding sections, wherein the plurality of welding sections form welding sections on both sides of each of the elastic members in the cross direction orthogonal to the conveying direction. A pair of joining portions for joining the first sheet and the second sheet; and a cutting portion for cutting the elastic member, wherein the plurality of elastic members supplied to the anvil roller include a first elastic member and a second elastic member having different thicknesses, and wherein the pair of welding portions are formed for the first elastic member and the second elastic member respectively so as not to form a damaged portion in which a part of the surface is damaged, and wherein the pair of welding portions are formed in the welding portion forming portion so that the first elastic member and the second elastic member that are shrunk after being cut by the cutting portion are clamped by each pair of welding portions to limit the position of the first elastic member and the second elastic member in the conveying direction.

[0086] According to the manufacturing device of the stretchable sheet such as method 26, even if the first elastic member and the second elastic member have different thicknesses and elongation ratios in the stretched state, both can undergo the joining process without generating damaged portions on the surface, and the position of each elastic member in the conveying direction can be restricted without the elastic member falling off.

[0087] 18. The stretchable sheet manufacturing device of claim 17, wherein the stretchable sheet is laminated by sandwiching an elastic member between a first sheet and a second sheet, and wherein the outer peripheral surface of the anvil roller is provided with a plurality of protrusions protruding outward in the radial direction of the anvil roller, the protrusions having a groove portion along the rotation direction of the anvil roller, and a direction orthogonal to the rotation direction is taken as a cross direction, and in a cross section of the groove portion along the cross direction, the groove portion has: a pair of first side wall portions extending from a starting edge of the groove portion to a prescribed position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, and in the cross section, when the intersection points of a line connecting the starting edges of the pair of first side wall portions along the cross direction and a line extending the pair of second side wall portions respectively toward the starting edge side are set as first intersection points and second intersection points, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

[0088] According to the anvil roller of embodiment 27, by using such an anvil roller, when manufacturing a stretchable sheet, the first sheet and the second sheet can be easily joined without the elastic member protruding from the groove portion. By preventing the elastic member from being welded together, the elastic member can be prevented from being broken. In addition, by securely housing the elastic member in the groove portion, the elastic member can be prevented from falling out during manufacturing.

[0089] Method 28 is an anvil roller used in a manufacturing device for a stretchable sheet, wherein the stretchable sheet is formed by stacking a first sheet and a second sheet with an elastic component sandwiched therebetween, and is characterized in that a plurality of protrusions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller, the protrusions having a groove portion along the rotation direction of the anvil roller, and a direction orthogonal to the rotation direction is taken as a cross direction, and in a cross section of the groove portion along the cross direction, the depth of the groove portion is greater than the height of the protrusion from the outer peripheral surface, and the length of the groove portion in the cross direction becomes shorter from the starting edge of the groove portion toward the inner side.

[0090] With an anvil roller like embodiment 28, if the groove is shallow, the elastic member could be exposed and break during the joining process. However, by using this anvil roller, the groove is sufficiently deep, allowing the elastic member to pass through the groove stably. Furthermore, since the length (width) in the cross direction decreases toward the inner side of the groove, the elastic member is less likely to escape from the groove. Consequently, the elastic member can be prevented from breaking during the joining process.

[0091] Implementation Method

[0092] [Structure of the stretchable sheet 10]

[0093] Figure 1 It is a top view of the stretchable sheet 10 manufactured by the manufacturing method (manufacturing apparatus) of this embodiment. Figure 1 This is a diagram showing a state where the stretchable sheet 10 is stretched without wrinkles.

[0094] Figure 2 yes Figure 1 A schematic cross-sectional view of the portion indicated by A. Figure 3 yes Figure 1 An enlarged view of the portion shown in B.

[0095] The stretchable sheet 10 has a left-right direction (stretching direction), a thickness direction, and a top-bottom direction that are orthogonal to each other. Furthermore, the stretchable sheet 10 includes a first sheet 11 and a second sheet 12 stacked in the thickness direction, and includes a plurality of elastic members 14 (e.g., rubber threads) and a plurality of welded portions j interposed between the first sheet 11 and the second sheet 12.

[0096] Multiple elastic members 14 extend horizontally along the stretchable sheet 10 and are spaced apart vertically. The elastic members 14 are attached to the first sheet 11 and the second sheet 12 in an extended state. Thus, the stretchable sheet 10 is imparted with stretchability in the direction in which the elastic members 14 extend (the horizontal direction). In addition to filamentous natural rubber, various well-known synthetic rubbers such as styrene rubber, polyurethane rubber, ester rubber, polyurethane, and polyethylene can be used as the elastic members 14.

[0097] like Figures 1 to 3 As shown, the first sheet 11 and the second sheet 12 are intermittently joined by a plurality of welded portions j discretely arranged in the vertical and horizontal directions. The welded portions j can be formed using a well-known welding method such as ultrasonic welding or heat welding.

[0098] In this embodiment, the stretchable sheet 10 has a plurality of welded portions j arranged in a vertical direction. The plurality of welded portion rows R are arranged at intervals in the horizontal direction. Figure 1 As shown in FIG, the welded portion row R meanders in the left-right direction while extending in the up-down direction. Figure 3 As shown, the positions of the welded portions j adjacent to each other in the vertical direction are shifted in the horizontal direction.

[0099] On the other hand, since the vertical positions of the welded portions j adjacent to each other in the left-right direction are consistent, Figure 3 As shown, the spaces through which the elastic members 14 pass are aligned in the vertical direction between vertically adjacent welded portions j, allowing the elastic members 14 to be arranged in the horizontal direction. However, this is not limiting. The vertical positions of the welded portions j adjacent in the horizontal direction may be staggered, and the elastic members 14 may pass between welded portions j at different vertical positions. Even in these cases, horizontal stretchability can be imparted to the stretchable sheet 10.

[0100] Furthermore, the stretch sheet 10 of the present embodiment includes welded portion groups jG in which a predetermined number of welded portions j are densely packed in each welded portion row R, and the welded portion groups jG are arranged at intervals in the vertical direction.

[0101] like Figure 3 As shown, the two welds j located on either side of the elastic member 14 in the vertical direction are also referred to as a "weld pair jp." The elastic member 14, which is in a contracted state in the horizontal direction, is sandwiched by the weld pair jp, thereby restricting the horizontal position of the elastic member 14 relative to the first sheet 11 and the second sheet 12. The weld pair jp and the weld group jG will be described in detail later. Figure 3The planar shape of the weld portion j shown is a parallelogram, but the planar shape of the weld portion j is not particularly limited, and any shape such as a rectangle, an ellipse, or a circle can be adopted.

[0102] in addition, Figure 2 The stretch sheet 10 may be composed of two sheets. For example, a single sheet may be folded back, with the folded portion serving as the first sheet and the unfolded portion serving as the second sheet. Alternatively, a single sheet may be folded back to form a two-layered sheet. Furthermore, the stretch sheet 10 may be formed by stacking one or more other sheets on the first and second sheets 11 and 12. In other words, the stretch sheet 10 may be composed of three or more layers.

[0103] [Example of use of the stretchable sheet 10]

[0104] Figure 4A This is a schematic perspective view of a pants-type disposable diaper 1 (absorbent article) using a stretchable sheet 10 . Figure 4B The stretchable sheet 10 manufactured by the manufacturing method (manufacturing apparatus) of this embodiment is used as a component of absorbent articles such as disposable diapers, for example.

[0105] The shorts type disposable diaper 1 (hereinafter also referred to as "diaper") is Figure 4A When worn in a shorts-like configuration, the diaper 1 has vertical and horizontal directions that intersect each other. Furthermore, the diaper 1 comprises an absorbent body 2 that absorbs and retains excrement, and a pair of waist portions 3. The portion of the pair of waist portions 3 that contacts the wearer's ventral side is also referred to as the ventral waist portion 3F, and the portion that contacts the wearer's dorsal side is also referred to as the dorsal waist portion 3B. The ventral waist portion 3F and the dorsal waist portion 3B are joined at both sides in the horizontal direction by a pair of side seams SS.

[0106] like Figure 4B As shown in the unfolded state, the left-right center portion of the ventral waist portion 3F overlaps with one end portion in the longitudinal direction of the absorbent body 2, and the left-right center portion of the dorsal waist portion 3B overlaps with the other end portion in the longitudinal direction of the absorbent body 2. The unfolded diaper 1 is folded in half approximately at the center in the longitudinal direction, and the left-right side portions of the ventral waist portion 3F and the left-right side portions of the dorsal waist portion 3B are joined by welding or the like to form a pair of side joints SS, thereby forming the diaper 1 into a shorts-type shape.

[0107] A plurality of elastic members 5 are arranged at intervals in the vertical direction in the ventral waistline portion 3F and the dorsal waistline portion 3B. These elastic members 5 are configured to stretch and contract in the left-right direction of the diaper 1. Thus, the ventral waistline portion 3F and the dorsal waistline portion 3B can stretch and contract in the left-right direction of the diaper 1 and conform to the wearer's waist. A stretch sheet 10 can be used in the ventral waistline portion 3F and the dorsal waistline portion 3B. The stretch direction (left-right direction) of the stretch sheet 10 corresponds to the left-right direction of the diaper 1, and the vertical direction of the stretch sheet 10 corresponds to the vertical direction of the diaper 1.

[0108] When the stretch sheet 10 is used as a component of an absorbent article, the first sheet 11 and the second sheet 12 constituting the stretch sheet 10 can be made of soft sheets. Examples include nonwoven fabrics such as spunbond nonwoven fabrics and SMS (spunbond / meltblown / spunbond) nonwoven fabrics. Alternatively, at least one of the first sheet 11 and the second sheet 12 can be a stretch sheet (stretch film or stretch nonwoven fabric) that can stretch in the direction of expansion and contraction of the stretch sheet 10. Alternatively, a stretch film or stretch nonwoven fabric can be sandwiched between the first sheet 11 and the second sheet 12.

[0109] The stretch sheet 10 is not limited to use in the ventral waistline portion 3F and the dorsal waistline portion 3B. For example, the stretch sheet 10 can be used in the leg gathers located on either side of the absorbent body in the left-right direction of the diaper to help the disposable diaper fit the wearer's legs. Since the leg gathers expand and contract in the longitudinal direction of the absorbent body, the longitudinal direction of the absorbent body corresponds to the expansion and contraction direction of the stretch sheet 10.

[0110] In a belt-type disposable diaper (not shown), fastening tapes (hook members) extend from the rear waistline portion to both sides in the left-right direction. The side panels that attach the fastening tapes to the rear waistline portion can use the stretch sheet 10. Since the side panels expand and contract in the left-right direction of the diaper, the left-right direction of the diaper corresponds to the direction of expansion and contraction of the stretch sheet 10.

[0111] In addition, the stretch sheet 10 is not limited to shorts-type or belt-type disposable diapers, and can also be used as a component of absorbent articles such as liner-type disposable diapers, sanitary napkins for menstrual use, and shorts-type sanitary napkins for menstrual use. In addition, it is not limited to absorbent articles, and can also be used for masks or cleaning sheets, etc.

[0112] Manufacturing device and manufacturing method of stretchable sheet

[0113] (Structure of the manufacturing device 20 for stretchable sheet)

[0114] Figure 5 It is a schematic cross-sectional view of a stretchable sheet manufacturing apparatus 20 according to the present embodiment. Figure 6It is a schematic cross-sectional view of the ultrasonic welding device 22 . Figure 7A It is an explanatory diagram of the surface of the anvil roller 23 . Figure 7B This is a schematic enlarged view of the closest portion between the anvil roller 23 and the horn 24 .

[0115] Figure 8A and Figure 8B 1 and 2 are diagrams for explaining a method of attaching the elastic member 14 via the welded portion j.

[0116] The stretchable sheet manufacturing device 20 includes a conveying roller group 21 ( Figure 6 ), ultrasonic welding device 22, discharge roller 25, cutting roller 26, support roller 27, and nip rollers 31 and 32. The stretchable sheet 10 is manufactured as a continuous sheet that is continuous in the left-right direction. In the stretchable sheet manufacturing device 20, the direction in which the sheet is continuous is the conveying direction, and the direction orthogonal to the conveying direction (i.e., the vertical direction of the stretchable sheet 10) is the cross direction (also called CD direction).

[0117] like Figure 6 As shown, the conveying roller group 21 (supply unit) is arranged upstream of the ultrasonic welding device 22 in the conveying direction, and conveys the material constituting the stretchable sheet 10 and supplies it to the ultrasonic welding device 22. Specifically, the conveying roller group 21 includes a first conveying roller 211 for conveying the continuous body of the first sheet 11, a second conveying roller 212 for conveying the continuous body of the second sheet 12, and a third conveying roller 213 for conveying the continuous body of the plurality of elastic members 14.

[0118] The first to third transport rollers 211 to 213 rotate about rotation axes extending in the cross direction (CD) by a drive source (e.g., a motor) (not shown). The first to third transport rollers 211 to 213 may be a pair of rollers or individual rollers. Alternatively, the material may be supplied to the ultrasonic welding device 22 via a belt conveyor or the like.

[0119] Hereinafter, the continuum of the first sheet 11 , the continuum of the second sheet 12 , the continuum of the elastic member 14 , and the continuum of the stretch sheet 10 are also simply referred to as the first sheet 11 , the second sheet 12 , the elastic member 14 , and the stretch sheet 10 .

[0120] The ultrasonic welding device 22 (weld portion forming unit) forms the weld portion j of the stretchable sheet 10 and includes an anvil roller 23 rotating in the conveying direction and a horn 24 disposed at a predetermined position P23h in the rotation direction Dc23 of the anvil roller 23 .

[0121] The horn 24 is supported by an appropriate support member 24s so as to be substantially immovably positioned at the aforementioned predetermined position P23h. Furthermore, the horn 24 has a flat vibrating surface 24hs disposed opposite the outer peripheral surface 23s of the anvil roller 23. Furthermore, this surface 24hs vibrates in a direction that expands or contracts the gap between it and the outer peripheral surface 23s. The frequency of the vibration is, for example, a predetermined value of 20 kHz to 35 kHz, and the amplitude is, for example, a predetermined value of 1 micron to 30 microns. Consequently, the vibrating surface 24hs undergoes ultrasonic vibration, thereby ultrasonically welding the two sheets 11 and 12 passing between this surface 24hs and the outer peripheral surface 23s. In other words, the aforementioned welded portion j is formed on the two sheets 11 and 12. Furthermore, this vibration is generated by inputting an electrical signal of the aforementioned frequency into a piezoelectric element of a transducer (not shown) connected to the horn 24.

[0122] The anvil roller 23 is supported by a suitable supporting member (not shown) such as a bearing so as to be rotatable around a rotation axis along the CD direction. Furthermore, the roller 23 is driven to rotate by a driving force applied by a servo motor (not shown) serving as a driving source. Furthermore, the first sheet 11 conveyed from the first conveying roller 211, the second sheet 12 conveyed from the second conveying roller 212, and the elastic member 14 conveyed from the third conveying roller 213 are respectively wound around the outer peripheral surface 23s of the roller 23 substantially without relative sliding. Therefore, by the driven rotation of the anvil roller 23, the first sheet 11, the second sheet 12, and the elastic member 14 are conveyed along the outer peripheral surface 23s of the roller 23 at a conveying speed value that is the same as the circumferential speed value of the anvil roller 23. That is, the two continuous sheets 11, 12 and the elastic member 14 are conveyed along a conveying path that curves along the outer peripheral surface 23s.

[0123] Here, the circumferential speed (mpm) of the first conveying roller 211 of the first sheet 11 and the circumferential speed (mpm) of the conveying roller 212 of the second sheet 12 are approximately the same as the circumferential speed (mpm) of the anvil roller 23. Therefore, the first sheet 11 and the second sheet 12 are wound around the anvil roller 23 in a tensioned state, approximately without stretching or slacking. On the other hand, the circumferential speed (mpm) of the conveying roller 213 of the elastic member 14 is approximately one-half the elongation ratio of the circumferential speed (mpm) of the anvil roller 23. Therefore, the elastic member 14 is stretched to the aforementioned elongation ratio while passing between the third conveying roller 213 and the anvil roller 23, and is wound around the anvil roller 23 in this stretched state.

[0124] In this example, the order of winding on the anvil roller 23 is as follows: the first sheet 11 is wound first, the elastic member 14 is wound next, and finally the second sheet 12 is wound. Thus, the three are in a state where the elastic member 14 is inserted between the first sheet 11 and the second sheet 12 on the outer peripheral surface 23s of the anvil roller 23.

[0125] Moreover, if Figure 6 As shown, the outer peripheral surface 23s of the anvil roller 23 is provided with a plurality of protrusions 231 that protrude radially outward from the anvil roller 23. These protrusions 231, together with the horn 24, ultrasonically weld the material to form welded portions j. Therefore, the protrusions 231 are arranged to correspond to the arrangement pattern of the welded portions j in the stretchable sheet 10.

[0126] The plurality of projections 231 provided on the outer peripheral surface 23s of the anvil roller 23 have a plurality of grooves 232 along the rotation direction of the anvil roller 23. The elastic members 14 are arranged in the plurality of grooves 232 when forming the welded portion j, which will be described in detail later.

[0127] The discharge roller 25 is a roller that discharges the semi-finished stretch sheet having the welded portion j formed therein to the cutting step of the elastic member 14. The discharge roller 25 is rotated around a rotation axis along the CD direction by a driving source (not shown).

[0128] The cutter roller 26 and the support roller 27 (cutting portion) are rollers disposed facing each other on the downstream side in the transport direction of the ultrasonic welding device 22. The cutter roller 26 and the support roller 27 are rotated around a rotation axis along the CD direction by a driving source (not shown).

[0129] A cutting blade 261 is provided on the outer peripheral surface of the cutting roller 26 so as to protrude radially outward from the cutting roller 26. Figure 5 In the embodiment, two cutting blades 261 are provided on the cutting roller 26 at intervals in the rotational direction, but the number of cutting blades is not limited thereto. The spacing between the cutting blades 261 in the rotational direction corresponds to the spacing between the cutting positions of the elastic members 14. Furthermore, the plurality of elastic members 14 arranged in the CD direction (vertical direction) in the stretchable sheet 10 may be cut using either a single cutting blade 261 extending in the CD direction or a plurality of cutting blades 261 arranged in the CD direction provided for each elastic member 14.

[0130] The outer peripheral surface of the support roller 27 is provided with a support blade 271 that supports the cutting blade 261 of the cutting roller 26. However, the support roller 27 may not have the support blade 271, and may be a roller with a smooth outer peripheral surface or a roller with a groove portion that supports the cutting blade 261.

[0131] The pair of clamping rollers 31 and 32 are used to clamp the elastic member 14 when the cutting roller 26 and the support roller 27 cut the elastic member 14 to limit the shrinkage movement of the elastic member 14. Figure 5 In the stretchable sheet manufacturing device 20 shown, a pair of clamping rollers 31 and 32 are respectively provided on the downstream and upstream sides of the cutting roller 26 and the support roller 27, but the present invention is not limited to this. A manufacturing device may also be provided on only one of the downstream and upstream sides.

[0132] (Method for Manufacturing the Stretchable Sheet 10: Step of Supplying to the Anvil Roll)

[0133] In the method for manufacturing the stretchable sheet 10 using the manufacturing apparatus 20 having the above-described structure, first, Figure 6 As shown, the conveying roller group 21 (supply unit) supplies the first sheets 11 and 12 and the elastic member 14 to the anvil roller 23. Specifically, the elastic member 14 is supplied so that it is positioned outside the first sheet 11 and inside the second sheet 12 in the radial direction of the anvil roller 23. In this way, the elastic member 14 is arranged in an extended state in the conveying direction (left-right direction) between the first sheet 11 and the second sheet 12.

[0134] (Method for Manufacturing the Stretchable Sheet 10: Joining Step)

[0135] Next, the first and second sheets 11 and 12 and the elastic member 14 wound around the anvil roller 23 are conveyed to the ultrasonic welding device 22 by the rotation of the anvil roller 23 and pass between the anvil roller 23 and the horn 24. At this time, the ultrasonic welding device 22 (weld portion forming unit) ultrasonically welds (presses) the first sheet 11 and the second sheet 12 to form a plurality of weld portions j that are joined to each other.

[0136] Specifically, the first and second sheets 11 and 12 are melted and joined at positions corresponding to the convex portions 231 of the anvil roller 23 by ultrasonic vibrations from the horn 24. At this time, the elastic member 14 is located in the groove portion 232 of the anvil roller 23 (see Figure 7A 、 Figure 7B ), no ultrasonic welding is performed. Figure 6 In the drawings, for easy understanding of the drawings, the elastic member 14 is shown as being located on the convex portion 231 of the anvil roller 23. However, in reality, the elastic member 14 is located in the groove portion 232.

[0137] In addition, as described above, the plurality of welded portions j also serve to limit the position of the elastic member 14 relative to the left and right directions of the first sheet 11 and the second sheet 12, that is, to attach the elastic member 14 to the first sheet 11 and the second sheet 12. Figure 1 As shown in FIG. 1 , a plurality of welded portion pairs jp located on both sides of the elastic member 14 in the vertical direction of the stretchable sheet 10 are formed at intervals in the horizontal direction of the stretchable sheet 10 .

[0138] The weld forming unit for forming the weld j is not limited to the ultrasonic welding device 22; any device capable of press-bonding and joining multiple sheets together can be used. For example, a heat sealing device can also be used to form the weld j. The heat sealing device can be exemplified by a pair of heated rollers, one of which has a convex portion on its outer circumference corresponding to the weld j, and the other of which has a smooth outer circumference supporting the convex portion.

[0139] In addition, Figure 6 In the example, an ultrasonic welding device 22 using a non-rotating horn 24 is illustrated, but the present invention is not limited to this. For example, an ultrasonic welding device 22 composed of a pair of rollers (a horn roller and an anvil roller) may also be used. Alternatively, the horn side that performs ultrasonic vibrations may be a roller-shaped device, while the anvil side may be a non-rotating device having a flat surface that receives ultrasonic vibrations. Alternatively, the vibrating surface on the horn side may be a concave-convex surface, while the surface on the anvil side may be a smooth surface.

[0140] (Method for Manufacturing the Stretchable Sheet 10: Step of Cutting the Elastic Member 14)

[0141] The manufacturing method of the stretchable sheet 10 of this embodiment includes a step of cutting the elastic member 14 after forming the welded portion j and joining the first sheet 11 and the second sheet 12. Figure 5 As shown, the laminate 10' comprising the first and second sheets 11, 12 and the elastic member 14, with the welded portion j formed therein, is conveyed by the discharge roller 25 and passes between the cutter roller 26 and the support roller 27 (cutting section). At this time, the cutting blade 261 penetrates the laminate 10' supported by the support blade 271, and the elastic member 14 is cut.

[0142] In the step of cutting the elastic member 14 , the first sheet 11 and the second sheet 12 may be separated by cutting together with the elastic member 14 , or only the elastic member 14 may be cut without separating the first sheet 11 and the second sheet 12 .

[0143] For example, when the continuous body of the stretchable sheet 10 is cut into Figure 4A In the case of the component dimensions of the diaper 1 (absorbent article) shown in FIG. 1 , the first sheet 11 and the second sheet 12 can be separated by cutting together with the elastic member 14. Specifically, the absorbent body 2 is placed on the stretchable sheet 10 composed of the first sheet 11 and the second sheet 12, and the diaper 1 is folded in half at the center in the longitudinal direction. After forming a pair of side joints SS on both sides of the ventral waistline portion 3F and the dorsal waistline portion 3B in the left-right direction, the first sheet 11 and the second sheet 12 are separated by cutting together with the elastic member 14.

[0144] On the other hand, the stretchability may be partially removed from the stretch sheet 10. For example, when the stretch sheet 10 is used in the ventral waistline portion 3F and the dorsal waistline portion 3B, as in the diaper 1, the stretchability may be removed from the portion of the ventral waistline portion 3F or the dorsal waistline portion 3B that overlaps with the absorbent body 2, in order to ensure the flatness of the absorbent body 2. In this case, the elastic member 14 extending in the horizontal direction of the stretch sheet 10 can be cut at the center to separate the first sheet 11 and the second sheet 12. However, when the first sheet 11 and the second sheet 12 are separated together with the elastic member 14, no cut marks are left on the stretch sheet 10, thereby improving the appearance of the stretch sheet 10.

[0145] (Position restriction of elastic member 14)

[0146] Then, after the cutting process is performed by the cutting section, the shrunken elastic member 14 is clamped by the welding section jp, and the position of the elastic member 14 in the conveying direction (left-right direction) is restricted. Figure 8A As shown, in the cross direction (up and down direction, CD direction), the interval Dj between the welded portion pair jp located on both sides of the elastic member 14 is greater than the cross direction diameter D14 of the elastic member 14 stretched when the welded portion j is formed. Moreover, the interval Dj is made smaller than the cross direction diameter of the elastic member 14 in the natural length and no-load state. The elastic member 14 in the stretched state is thinner than the elastic member 14 in the natural state by the stretched portion. Therefore, after the continuous body of the elastic member 14 is cut after the welded portion j is formed, the stretched state of the elastic member 14 is relaxed, as shown in FIG. Figure 8B As shown, the elastic member 14 that is to be expanded in the cross direction while shrinking in the conveying direction is clamped by the welding portion pair jP. Thus, the left-right position of the elastic member 14 is restricted, and the elastic member 14 is installed on the sheet.

[0147] In this way, a stretchable sheet 10 is manufactured by stacking the first sheet 11 and the second sheet to clamp the elastic member 14. However, if the width between the welded portions is narrowed in order to reliably clamp the elastic member 14, the elastic member 14 may sometimes break. On the other hand, if the width between the clamped welded portions is expanded so as not to cut the elastic member 14, the elastic member 14 may fall off during manufacturing. In the manufacturing process of the stretchable sheet 10, it is difficult to fix a plurality of elastic members 14 without cutting them.

[0148] In this regard, in the present embodiment, in order to stably arrange the elastic member 14 in the grooves 232 provided in the convex portion 231 of the anvil roller 23 , each groove 232 has the following structure. Figure 9 2 is a cross-sectional view showing a cross section of the groove portion 232 along the intersecting direction. Figure 9As shown in this cross section, the groove portion 232 of this embodiment includes a pair of first side walls 232iu extending from a starting edge 232s of the groove portion 232 to a predetermined position P located on the inner side, and a pair of second side walls 232id extending from the predetermined position P to the bottom 232b of the groove portion 232. Furthermore, in this cross section, when the intersections of a line X1 connecting the starting edges 232s, 232s of the pair of first side walls 232iu in the intersecting direction and a line X2 extending the pair of second side walls 232id toward the starting edges 232s are defined as first intersection points Y1 and second intersection points Y2, a distance W1 separating the starting edges 232s, 232s of the pair of first side walls 232iu is longer than a distance W2 between the first intersection point Y1 and the second intersection point Y2 (W>1).

[0149] Here, the separation distance W1 between the starting edges 232s, 232s of the first side wall portion 232iu defines the opening width of the groove portion 232. In this embodiment, the groove portion 232 is configured so that the groove width (length in the cross direction) widens from a predetermined position P located on the inner side of the opening toward the opening. This structure facilitates the elastic member 14 to enter the groove portion 232. When the welded portion j is formed in the aforementioned joining process, it is easy to join the first sheet 11 and the second sheet 12 without the elastic member 14 being exposed from the groove portion 232. By preventing the elastic member 14 from being welded together during the joining process, the elastic member 14 is prevented from being cut. Furthermore, by performing the steps of stably feeding the elastic member 14 while passing through the groove portion 232 and the joining process, it is possible to prevent the elastic member 14 from falling off during each step. Furthermore, the separation distance (opening width) W1 is preferably 0.2 mm to 0.4 mm.

[0150] In addition, the depth D of the groove portion 232 is preferably greater than the height H of the convex portion 231 from the outer peripheral surface 23s of the anvil roller 23 (D ≥ H). Figure 9As shown, in this embodiment, the depth D of the groove 232 is approximately the same as the height H of the protrusion 231. However, the depth D of the groove 232 may also be deeper than the height H of the protrusion 231 (i.e., in this case, the groove 232 is formed to a position radially inward of the outer peripheral surface 23s). Furthermore, the length (width) of the groove 232 in the cross direction decreases from the starting edge 232s of the groove 232 toward the inner side. In other words, due to its shape that tapers toward the inner side, the elastic member 14 easily enters the groove 232 and is difficult to escape. If the groove 232 were shallow, the elastic member 14 might be exposed during placement, potentially breaking during the bonding process. However, by having a sufficient depth, as in the groove 232 of this embodiment, the elastic member 14 can pass through the groove 232 stably, making it less likely that the elastic member 14 will be cut or damaged during the bonding process. In addition, the depth D of the groove portion 232 is preferably 0.3 mm to 0.5 mm.

[0151] In addition, if Figure 9 As shown, the groove portion 232 of this embodiment has a structure in which the width (length) in the intersecting direction of the portion formed by the first side wall portion 232iu and the portion formed by the second side wall portion 232id is two-stage, but the present invention is not limited to this. If the depth D of the groove portion 232 is greater than the height H of the protrusion 231, for example, the groove portion 232 may have a shape that is not provided with the first side wall portion 232iu and the second side wall portion 232id, and is constantly narrowed toward the inner side at a predetermined inclination angle (so-called substantially V-shaped).

[0152] In addition, if Figure 7B As shown, during the feeding and joining steps, one of the first and second sheets 11, 12 (here, the first sheet 11) also enters the groove 232 along with the elastic member 14. Therefore, this sheet may be subjected to a pulling force during transport. Therefore, if the groove 232 is shallow, the sheet (the first sheet 11) may float, making it difficult to enter. Therefore, the deeper the groove 232, the easier it is for the first sheet 11 to enter the groove 232 along with the elastic member 14. In addition, if the height H of the protrusion 231 from the outer peripheral surface 23s is too high, the first sheet 11 that wants to move along the outer peripheral surface 23s (and the protrusion 231) will be difficult to enter the groove 232 due to the influence of being pulled. Therefore, the lower the height (H) of the protrusion 231 from the outer peripheral surface 23s and the deeper the depth (D) of the groove 232, the easier it is for the first sheet 11 to enter the groove 232.

[0153] Furthermore, the groove 232 of this embodiment not only has a sufficient depth (D) but also has a wide opening width (corresponding to W1), so the elastic member 14 can be easily disposed without being exposed from the groove 232. Therefore, the elastic member 14 can be more easily and securely accommodated in the groove 232, and the elastic member 14 is less likely to be affected by the protrusion 231.

[0154] In addition, if Figure 7B As shown, the convex portion 231 of the anvil roller 23 has a plurality of grooves 232 spaced apart in the cross direction relative to one elastic member 14. In this embodiment, there are seven grooves 232. Each convex portion 231 having the seven grooves 232 forms each welded portion group jG ( Figure 3 ). In addition, each convex portion 231 having a plurality of grooves 232 is provided at predetermined intervals in the cross direction, and is arranged along the cross direction (CD direction) while meandering along the rotation direction of the anvil roller 23. In the convex portion 231, by providing a plurality of grooves 232 relative to one elastic member 14, even if the arrangement of the elastic member 14 is slightly offset during the manufacture of the stretchable sheet 10 (during the supply process), as long as the elastic member 14 is arranged in any one of the seven grooves 232, the joining process can be carried out without cutting or falling off. In addition, the number of grooves 232 relative to one elastic member 14 is not limited to the above number.

[0155] In addition, if Figure 7B As shown, in a cross section of the groove 232 taken along the intersecting direction, the depth D of the groove 232 is greater than the spacing T between the grooves 232 in the intersecting direction. That is, the greater the depth D of the groove 232, the more stably the elastic member 14 can pass through the groove 232. Furthermore, the depth D of the groove 232 is not limited to being greater than the spacing T between the grooves 232; it can be any depth greater than the spacing T.

[0156] Figure 10 2 is a diagram illustrating the structure of the groove portion 232. Figure 10 As shown, in the cross section of the groove portion 232 along the intersecting direction, the angle θ1 formed by the pair of first side wall portions 232iu is preferably at least twice the angle θ2 formed by the pair of second side wall portions 232id. In the present embodiment, the angle θ1 is 55°, but is not limited thereto. The angle θ1 is preferably 45° to 135°. In the present embodiment, the angle θ2 is 25°, but is not limited thereto. The angle θ2 is preferably 15° to 55°. Due to the shape of the groove portion 232, the elastic member 14 can easily enter the groove portion 232 and is difficult to fly out, which can prevent the elastic member 14 from being cut or damaged during the supply process and the bonding process.

[0157] In addition, if Figure 10As shown, in the depth direction of the groove 232 in a cross-section of the groove 232 taken along the intersecting direction, the length L2 of the portion formed by the pair of second side walls 232id in the groove 232 is longer than the length L1 of the portion formed by the pair of first side walls 232iu (L2>L1). Because the length L2 of the portion formed by the pair of second side walls 232id, i.e., the length of the inner side (bottom side) of the groove 232, is longer, the elastic member 14 is easily accommodated in the inner side of the groove 232 when passing through the groove 232. As a result, the elastic member 14 is less likely to escape from the groove 232 during the bonding process.

[0158] Furthermore, the depth D of the groove portion 232 in a cross-section along the intersecting direction of the groove portion 232 is preferably greater than the outer diameter of the elastic member 14 when the elastic member 14 is stretched to its maximum stretchable length in the conveying direction. Thus, during manufacturing, the elastic member 14 disposed in a stretched state is less likely to be exposed from the groove portion 232, and the joining process can be performed without cutting the elastic member 14.

[0159] Furthermore, the depth D of the groove 232 in the cross section along the intersecting direction is preferably greater than the maximum outer diameter of the elastic member 14 that has shrunk after the cutting process. Thus, since the groove 232 has a sufficient depth, the elastic member 14 is unlikely to be exposed from the groove 232, and the joining process can be performed without cutting the elastic member 14.

[0160] The outer diameter of the elastic member 14 when stretched to its maximum extendable length and the maximum outer diameter of the elastic member 14 after contraction are each measured as follows. First, as a method for measuring the outer diameter of the elastic member 14 when stretched, the width of the elastic member 14 when the formed stretchable sheet 10 is stretched to its maximum extendable length is measured using a digital microscope (VHX7000 manufactured by Keyes Corporation). Ten similar measurements are performed, and the average value is defined as the outer diameter of the elastic member 14 when stretched to its maximum extendable length.

[0161] To measure the maximum outer diameter of the elastic member 14 after contraction, remove the elastic member 14 from the stretchable sheet 10 and measure the width of the elastic member 14 alone in its natural state using the aforementioned digital microscope. Repeat this measurement at ten locations, and the average value is taken as the maximum outer diameter after contraction.

[0162] Alternatively, the elastic member 14 of the stretchable sheet 10 can be measured at the location with the largest outer diameter in the cross section. In this case, a sample for cross-sectional measurement can be obtained by cutting the stretchable sheet 10 after solidifying it in liquid nitrogen. Alternatively, a commercially available cooling spray can be used for solidification. A magnified image of the sample is captured using a microscope (VHX7000 manufactured by Keyes) and measured.

[0163] Figures 11A to 11C They are diagrams showing modified examples of the groove portion 232. Figure 11A In the groove portion 232 shown in FIG, in a cross section of the groove portion 232 along the intersecting direction, a portion 232up ( Figure 11A The area ratio of the area indicated by the oblique lines in the figure) is greater than that of the portion 232dw ( Figure 11A Thus, since the first side wall portion 232iu side (starting edge 232s side) of the groove portion 232 has a wide structure, the elastic member 14 can easily enter the groove portion 232, and the elastic member 14 can be stably arranged.

[0164] exist Figure 11B In the groove portion 232 shown, the pair of first side walls 232iu are inclined so that the groove portion 232 narrows toward the inner side (predetermined position P) of the groove portion 232, but the pair of second side walls 232id are not inclined toward the inner side from the predetermined position P (the length (width) in the cross direction is not shortened). That is, unlike the groove portion 232 or the groove portion 232 of the present embodiment described above, Figure 11A Compared to the groove 232 shown in FIG. , the groove 232 has a wider area on the inner side of the groove 232. With this shape of the groove 232, even if the elastic member 14 made of rubber thread or the like is thick, it can be stably arranged in the groove 232, and the elastic member 14 can be prevented from being exposed from the groove 232.

[0165] Figure 11C The angle formed by the pair of first sidewalls 232iu of the groove 232 shown is 90 degrees, and the opening of the groove 232 is set wide. If the opening is wide, the elastic member 14 can easily enter, otherwise it will fall off during the process. However, since Figure 11C The second side wall 232id of the groove 232 shown is deep and narrows toward the inside. Therefore, the elastic member 14 entering from the wide first side wall 232iu is pressed against the second side wall 232id, thereby preventing debonding. This groove 232 allows the elastic member 14 to easily enter the groove 232 and prevents it from falling out.

[0166] Figure 12 : This is a three-dimensional diagram illustrating the protrusion 231. The length L5 of the protrusion 231 in the conveying direction corresponds to the length in the left-right direction of each welded portion j of the stretchable sheet 10 formed by the protrusion 231. In this embodiment, the length L5 of the protrusion 231 in the conveying direction is 1.5 mm, wherein the protrusion 231 has a shape in which the center of the conveying direction is pulled out after dividing the length L5 into three equal parts (so-called hollow shape). Therefore, Figure 12The length La shown is 0.5 mm (1.5 mm / 3). Furthermore, the length of the hollow portion need not be 1 / 3 of the length of the protrusion 231 in the transport direction. The length L5 of the protrusion 231 in the transport direction is preferably within the range of 0.2 mm to 3.0 mm. By making the protrusion 231 into the aforementioned hollow shape, the welded portion j can be prevented from becoming excessively hard.

[0167] In addition, in this embodiment, the length L6 ( Figure 12 ) is 0.25mm. In addition, the length L6 in the cross direction is preferably in the range of 0.2mm to 0.5mm. In addition, the length L5 of the convex portion 231 in the conveying direction is preferably longer than the length L6 in the cross direction (L5>L6). Since the elastic member 14 is arranged in the groove portion 232 (in the conveying direction) in the stretched state Figure 12 In the figure, the elastic member 14 is represented by an imaginary line (dashed line). Therefore, by lengthening the length L5 of the convex portion 231 in the conveying direction, the elastic member 14 is difficult to fall off, and the first sheet 11 and the second sheet 12 are reliably welded.

[0168] In addition, return Figure 7A It is preferable that the distance L7 between adjacent convex portions 231 in the conveying direction (i.e., corresponding to the distance between adjacent welded portion rows R in the horizontal direction of the stretchable sheet 10) is longer than the conveying direction length L5 of the convex portions 231 (L7>L5). If the distance L7 between adjacent convex portions 231 is too short, the horizontal spacing of the formed welded portion rows R becomes too short, and there is a possibility of consolidation of multiple welded portions j. However, by making the distance L7 longer than the conveying direction length L5 of the convex portions 231, the occurrence of consolidation is reduced.

[0169] Next, the elastic members 14 supplied in the aforementioned supply process will be described in detail. In this supply process, the elastic members 14 are supplied to the anvil roller 23 along with the first and second sheets 11, 12. More specifically, a plurality of elastic members 14, stretched in the conveyance direction, are supplied to the anvil roller 23 at intervals in the crosswise direction between the first and second sheets 11, 12. Furthermore, in this supply process, the plurality of stretched elastic members 14 supplied to the anvil roller 23 may include first elastic members 14a and second elastic members 14b of varying thicknesses.

[0170] Figure 13 14a and 14b are sandwiched between the first and second elastic members 14a and 14b. Figure 13As shown, in the joining process of this embodiment, the first elastic member 14a and the second elastic member 14b are joined while being accommodated in the respective grooves 232. In particular, even if the second elastic member 14b is thick in the stretched state, the grooves 232 of this embodiment are deep, so that the second elastic member 14b can be stably arranged by being pressed into the inner side of the grooves 232.

[0171] By securely positioning the first and second elastic members 14a, 14b in the grooves 232, the first and second elastic members 14a, 14b can each be joined together to form a pair of welded portions jp, preventing the formation of damaged portions where a portion of the surface is damaged. Furthermore, by forming the pairs of welded portions jp, the first and second elastic members 14a, 14b, which have shrunk after the cutting process, are sandwiched between the welded portions jp, thereby restricting the positions of the first and second elastic members 14a, 14b in the transport direction. Specifically, if the elastic member 14 is, for example, a rubber yarn, even if the first and second elastic members 14a, 14b have different yarn counts or different elongation ratios, the joining process can be performed without causing damaged portions on their surfaces. Furthermore, the positions of the first and second elastic members 14a, 14b in the transport direction can be restricted without causing them to fall off.

[0172] In addition, if Figure 13 As shown, in the joining process of this embodiment, the first elastic member 14a and the second elastic member 14b can form the welded portion pair jp without being exposed from the grooves 232 in which they are respectively arranged. Even when the first elastic member 14a and the second elastic member 14b have different thicknesses in the stretched state, the welded portion pair jp is formed without being exposed from the grooves 232 (in a state where they do not extend from the grooves 232 and contact the protrusions 231 during joining). Therefore, the first elastic member 14a and the second elastic member 14b are fixed without being stepped on (cut off) by the welded portion pair jp.

[0173] In addition, if Figure 13 As shown, in a cross section of the groove 232 along the intersecting direction, the depth D of the groove 232 is preferably greater than the spacing T of the groove 232 in the intersecting direction. Thus, due to the deep depth of the groove 232, even the elastic members 14 (the first elastic member 14a and the second elastic member 14b) having different thicknesses in the stretched state can pass through the groove 232 more stably.

[0174] Furthermore, it is preferable that the depth D of the groove 232, in a cross-section along the intersecting direction of the groove 232, is greater than the outer diameters of the first elastic member 14a and the second elastic member 14b when the first elastic member 14a and the second elastic member 14b are stretched to their maximum stretchable lengths in the conveying direction. With this configuration, even if the stretched states of the first elastic member 14a and the second elastic member 14b differ in thickness, the process of allowing the elastic members 14a and 14b to pass through the groove 232 can be performed stably.

[0175] Furthermore, the depth D of the groove 232 in a cross-section along the intersecting direction is preferably greater than the maximum outer diameter of each of the first and second elastic members 14a, 14b, which have shrunk after the cutting process. This sufficient depth of the groove 232 prevents the first and second elastic members 14a, 14b from being exposed, allowing the joining process to be performed without cutting the elastic members 14a, 14b. The method for measuring the maximum elongation and contraction of the first and second elastic members 14a, 14b is the same as that for the elastic member 14 described above.

[0176] In addition, in the cross section of the groove portion 232 along the intersecting direction, as shown in FIG. Figure 11A As shown in the modified example, if the groove portion 232 has a structure in which the area ratio of the portion 232up corresponding to the pair of first side wall portions 232iu in the groove portion 232 is larger than the area ratio of the portion 232dw corresponding to the pair of second side wall portions 232id, then even in the case where the first elastic member 14a and the second elastic member 14b of different thicknesses are arranged in the extended state, while the starting edge 232s side receives each elastic member 14a and 14b while the thick second elastic member 14b passes, adjustment can be performed on the inner side (232d2 side) of the groove portion 232, and the joining process can be performed more stably.

[0177] Next, the first elastic member 14a and the second elastic member 14b are connected to the diaper 1 ( Figure 4A and Figure 4B ) will be described accordingly. As described above, the diaper 1 ( Figure 4A 、 Figure 4B In the ventral waistline portion 3F and the dorsal waistline portion 3B, a plurality of elastic members 5 that expand and contract in the left-right direction of the diaper 1 are arranged at intervals in the vertical direction. The positions of the plurality of elastic members 5 in the left-right direction relative to the first sheet 11 and the second sheet 12 are controlled by a plurality of welded portion pairs jp (not shown) located on both sides of each elastic member 5 in the vertical direction.

[0178] The plurality of elastic members 5 of the diaper 1 include a first elastic member 5a (equivalent to the second elastic member 14b) and a second elastic member 5b (equivalent to the first elastic member 14a) having different thicknesses when the diaper 1 (absorbent article) is stretched to its maximum in the left-right direction (see Figure 4B ). The first elastic member 5a and the second elastic member 5b are similarly limited in their left-right positions relative to the first sheet 11 and the second sheet 12 by a plurality of welded portion pairs jp (not shown) located on both sides of the respective vertical directions. Figure 8B Similarly to the elastic member 14 described above, in each of the first elastic member 5a and the second elastic member 5b, no damaged portion in which a portion of the surface of the first elastic member 5a and the second elastic member 5b is damaged is provided between the pair of welded portions jp adjacent in the left-right direction.

[0179] By providing first and second elastic members 5a, 5b, which have different thicknesses when the diaper 1 (absorbent article) is stretched to its maximum in the left-right direction, between the first sheet 11 and the second sheet 12, it is possible to provide portions having different elongation ratios even when using elastic members 5 of the same thickness (count). Furthermore, by arranging elastic members 5 of different thicknesses (counts), such as thin elastic members 5 having a high elongation ratio or thick elastic members 5 having a low elongation ratio, it is possible to achieve desired stress or expansion characteristics at each portion of the diaper 1.

[0180] In addition, as the first elastic member 5a of the diaper 1, for example, a rubber thread with a thickness of 940 dtex and an elongation ratio of 2.7 times can be exemplified. As the second elastic member 5b of the diaper 1, a rubber thread with a thickness of 470 dtex and an elongation ratio of 2.3 times can be exemplified. In addition, the elastic member 5 may also have other elastic members that are different from the first elastic member 5a and the second elastic member 5b. For example, in order to make the diaper 1 fit more firmly to the waistline, among the multiple elastic members 5, one may also be on the inner side in the longitudinal direction (the lower side in the vertical direction, refer to FIG. 2 ) than the second elastic member 5b. Figure 4B) includes multiple lower elastic members that are thicker than the first elastic member 5a in the stretched state. Alternatively, the multiple elastic members 5 may further include elastic members 5 having different thicknesses and elongation ratios in the vertical direction, for example, between the second elastic member 5b and the lower elastic member. Examples include a rubber thread with a thickness of 620 dtex and an elongation ratio of 2.8, or a rubber thread with a thickness of 780 dtex and an elongation ratio of 2.7. In this way, by reliably positioning multiple elastic members 5 having different thicknesses and elongation ratios in the stretched state at desired positions relative to the waistline 3, the stress in the waistline 3 can be finely adjusted, thereby facilitating a better fit to the wearer's waist.

[0181] Furthermore, the stretchable sheet 10 manufactured by the manufacturing method of this embodiment also has the following structure. Figure 14A 1 is a schematic cross-sectional view of a portion of the stretchable sheet 10 where a weld pair jp is formed in a natural state (a state in which the elastic member 14 is contracted). Figure 14B 1 is a schematic cross-sectional view of another example of a portion of the stretchable sheet 10 in a natural state (a state in which the elastic member 14 is contracted) where the welded portion pairs jp are formed. Figure 14C This is a microscopic image of an example of the inner weld portion jin and the outer weld portion jout of this embodiment. Figure 14D This is a microscopic image of another example of the inner weld portion jin and the outer weld portion jout in this embodiment.

[0182] like Figure 14A As shown, the welded portion pair jp formed on the stretchable sheet 10 manufactured by the manufacturing method of this embodiment has: an inner welded portion jin ( Figure 14A The portion indicated by the dot pattern): comprising fibers having a melt-solidified portion in which the constituent fibers constituting the first sheet 11 and the second sheet 12 are in a melt-solidified state; and an outer weld portion jout ( Figure 14A The portion represented by the grid-like pattern (so-called quilting pattern) is located outside the inner welded portion in the vertical direction and includes only fibers having a melted and solidified portion.

[0183] Specifically, the inner weld jin and outer weld jout are formed as follows. According to the manufacturing method of the stretchable sheet 10 of this embodiment and the structure of the groove 232, even with first and second elastic members 14a and 14b of varying thicknesses, a weld j (weld pair jp) is formed without protruding from the groove 232. With respect to the convex portion 231, since the first and second sheets 11 and 12 are firmly welded, the thickness is thin, resulting in an outer weld jout composed solely of fibers with melted and solidified portions. Furthermore, the vibration of the horn 24 is transmitted from the cross-directional (vertical) end of the convex portion 231 to the first and second sheets 11 and 12 located at the cross-directional (vertical) end of the groove 232, forming the inner weld jin. The inner weld jin is composed of a mixture of fibers with melted and solidified portions and fibers without melted and solidified portions, or is composed entirely of fibers with melted and solidified portions. The first sheet 11 and the second sheet 12 of the inner weld portion jin are melted and solidified in a state weaker than that of the outer weld portion jout, and are thicker than that of the outer weld portion jout.

[0184] More specifically, in the manufacturing method of this embodiment, a stretchable sheet 10 having the following characteristics is formed: when the elastic member 14 is a thinner elastic member 14, it is in the form of a mixture of fibers having a melted and solidified portion between the elastic member 14 and the outer weld portion jout (i.e., in the inner weld portion jin) and fibers not having a melted and solidified portion; and when the elastic member 14 is a thicker elastic member 14, it only has a melted and solidified portion between the elastic member 14 and the outer weld portion jout (i.e., in the inner weld portion jin).

[0185] The cross-sectional state of the welded portion pair jp of the stretch sheet 10 in its natural state can be confirmed by photographing a measurement sample using a scanning electron microscope (FlexSEM1000 manufactured by Hitachi, Ltd.) (see Figure 14C 、 Figure 14D ), the measurement sample is obtained by cutting the stretchable sheet 10 in its natural state and solidifying it in liquid nitrogen. Figure 14C The inner welded portion jin shown on the lower side and Figure 14D The inner welded portion jin shown on the upper side indicates a state where fibers having melted solidified portions and fibers not having melted solidified portions are mixed. Figure 14C The inner welded portion jin shown on the upper side and Figure 14D The welded portion jin shown below represents a state where all fibers are composed of fibers having melted and solidified portions. Figure 14C and Figure 14DThe outer weld portions jout shown are all in a state where the fibers are gathered and integrated with each other, and the outer weld portion jout portion appears to be a single block.

[0186] Thus, the weld portion j has the inner weld portion jin, which mitigates excessive hardness of the weld portion j. Furthermore, even if a force is applied to the inner weld portion jin, thereby weakening the positional restriction of the elastic member 14, the outer weld portion jout can suppress the elastic member 14 from being separated from between the first sheet 11 and the second sheet 12. Here, although both weld portions j, j in the weld portion pair jp have the inner weld portion jin and the outer weld portion jout, it is sufficient that at least one of the weld portion pair jp has both.

[0187] As mentioned above, the average thickness of the inner weld jin is thicker than the average thickness of the outer weld jout. Here, the "average thickness" is, for example, the average value of the results of measurements taken at multiple locations (e.g., 10) on each of the inner weld jin and the outer weld jout using a thickness gauge (the aforementioned electron microscope). If the inner weld jin, which holds the elastic member 14, is thin, the portion of the inner weld jin closest to the elastic member 14 (the inner end of the inner weld jin in the vertical direction) could break during contraction, making it more likely for the weld to peel. If the thickness of the inner weld jin can cushion the force, the outer weld jout can be prevented from breaking or peeling. Furthermore, even if the thick inner weld jin peels, the outer weld jout maintains the welded state, thus preventing the elastic member 14 from suddenly passing between the pair of welds jP (so-called debonding).

[0188] In addition, if Figure 14B As shown in FIG, the inner welded portion jin may be formed to have a portion that overlaps with the elastic member 14 in the vertical direction depending on the thickness of the elastic member 14. Figure 14B In the welded portion j shown, the inner welded portion jin and Figure 14A Compared to the inner weld jin shown in FIG. , the inner weld jin is formed further inward in the vertical direction. Thus, even when the inner weld jin is formed so as to overlap the elastic member 14, the weld is weaker than the outer weld jout, thereby preventing the elastic member 14 from being cut. Furthermore, by supporting both sides of the elastic member 14 in the vertical direction with the thick portion (inner weld jin), force can be buffered.

[0189] In addition, if Figure 14AAs shown, the stretchable sheet 10 has a portion in which a gap S1 is formed in at least one of the vertical cross-section between the elastic member 14 and the first sheet 11 and between the elastic member 14 and the second sheet 12. The stretchable sheet 10 manufactured by the manufacturing method of this embodiment joins the first sheet 11 and the second sheet 12 in a state where the elastic member 14 is stably arranged without being exposed from the groove 232. Therefore, when the elastic member 14 contracts and its position in the left-right direction is restricted, the elastic member 14 does not excessively contact the first sheet 11 and the second sheet 12 and remain there, thereby forming the gap S1. Thus, by arranging the elastic member 14 while forming the gap S1, the elastic member 14, which is sandwiched between the welded portion pair, is prevented from becoming too rigid when the stretchable sheet 10 contracts.

[0190] Figure 15 14 is a diagram illustrating the structure of the elastic member 14. As described above, examples of the elastic member 14 used in this embodiment include polyurethane rubber, ester rubber, latex (natural rubber), etc. Figure 15 As shown, a thread-like elastic member 141 made of a plurality of elastic fibers 141, such as polyurethane or polyester, is preferably used. In this case, the elastic member 14 has a concave-convex shape, which increases the surface area in contact with the fibers of the first and second sheets 11, 12, and enhances the frictional force with the sheets. This makes it easier to prevent the elastic member 14 from falling out between the welded portions.

[0191] In addition, in the cross section along the vertical direction between the welded portion pair jp that holds the elastic member 14 in a state of being contracted in the left-right direction, the elastic member 14 held therebetween is thinner than the portion not held therebetween by the welded portion pair jp, but a gap S2 ( Figure 15 Thus, even if external pressure is applied to the elastic member 14, the gap S2 can be compressed to generate a release margin, so that the elastic member 14 is difficult to be cut.

[0192] In addition, if Figure 14A As shown, in a cross-section of the stretchable sheet 10 in its natural state where the weld pair jp is formed, the ratio of the area of ​​one side of the elastic member 14 in the thickness direction to the area of ​​the other side relative to the line Le connecting the two vertical sides of the elastic member 14 is preferably in the range of 20:80 to 80:20. In other words, the elastic member 14, whose horizontal position is restricted by the weld pair jp, is less deviated from the center (less eccentricity), making it easier to grip the elastic member 14 when it is cut. Furthermore, even when a force is applied to the stretchable sheet 10 to expand or contract during use, the elastic member 14 is less likely to separate from the weld pair jp.

[0193] Furthermore, it is preferable to use spandex as the elastic member 14. In this case, the number of monofilaments constituting the elastic member 14 is, for example, 50 or more, and the titanium oxide content of the spandex is preferably 3.0% by weight or less. By using such spandex as the elastic member 14, the elastic member 14 is less likely to break.

[0194] other

[0195] The above embodiments are for facilitating understanding of the present invention, and are not intended to limit the interpretation of the present invention. The present invention can be modified and improved without departing from the spirit thereof, and the present invention naturally includes equivalents thereof.

[0196] Figure 16A This is a modified example of the anvil roller 23. Figure 16B It is an explanation Figure 16A FIG. 2 is a diagram of the groove portion 232 of the anvil roller 23. Figure 17 This is a modified example of the stretchable sheet 10, and is a diagram showing a state where the stretchable sheet 10 is stretched without wrinkles. In the above embodiment, the convex portions 231 provided on the anvil roller 23 used in the bonding process are provided with each convex portion 231 having a predetermined number of grooves 232 spaced apart in the cross direction (the convex portions 231 forming the welded portion group jG of the stretchable sheet 10), but the present invention is not limited to this. Figure 16A and Figure 16B As shown, the convex portions 231 of the anvil roller 23 may also be provided continuously in the cross direction. Furthermore, a plurality of rows of convex portions 231 provided continuously in the cross direction may be provided at predetermined intervals L7 in the rotation direction (transportation direction). Figure 16B As shown, the grooves 232 may be continuously arranged at intervals in the cross direction. In addition, the rows of the convex portions 231 extend along the cross direction (CD direction) while meandering in the rotation direction, but are not limited to this. They may also extend linearly along the cross direction (CD direction) without meandering in the rotation direction.

[0197] Figure 17 The stretchable sheet 10 shown is made using Figure 16A and Figure 16B An example of a stretchable sheet 10 formed when the anvil roller 23 shown in FIG. performs the above-mentioned joining process. In the stretchable sheet 10 of this modified example, the plurality of welded portions j have welded portion rows R arranged at predetermined intervals in the vertical direction and the horizontal direction. In addition, the plurality of welded portion rows R are arranged at intervals in the horizontal direction. Figure 17As shown, the weld line R in this modified example meanders in the left-right direction while extending in the up-down direction, that is, the left-right positions of the welds j adjacent to each other in the up-down direction are offset. However, the weld line R can also be formed to extend in the up-down direction instead of meandering in the left-right direction.

[0198] Description of Reference Signs

[0199] 1. Pants-type disposable diapers (absorbent articles)

[0200] 2 Absorbent body

[0201] 3. A pair of waist parts

[0202] 3B back waist

[0203] 3F ventral waist area

[0204] 5 Elastic components

[0205] 5a First elastic member

[0206] 5b Second elastic member

[0207] 10 stretchable sheet

[0208] 10' stacked body

[0209] 11 First Sheet

[0210] 12 Second sheet

[0211] 14 Elastic member

[0212] 14a first elastic member

[0213] 14b second elastic member

[0214] 20 Manufacturing Equipment

[0215] 21Conveying roller group (supply department)

[0216] 22 Ultrasonic welding device (weld forming unit)

[0217] 23 anvil roller

[0218] 23s outer surface

[0219] 24 horn

[0220] 24hs vibration surface

[0221] 24s supporting structure

[0222] 25 discharge roller

[0223] 26 cutting roller (cutting part)

[0224] 27 Support roller (cutting part)

[0225] 31 clamping roller

[0226] 32 clamping rollers

[0227] 141 elastic fiber

[0228] 211 first conveying roller

[0229] 212 second conveying roller

[0230] 213 third conveying roller

[0231] 231 convex part

[0232] 232 slot

[0233] 232b bottom

[0234] 232id second side wall portion

[0235] 232iu first side wall

[0236] 232s starting edge

[0237] 261 cutting edge

[0238] 271 support blade

Claims

1. A method for producing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with an elastic member interposed therebetween, wherein: The method for producing the stretchable sheet comprises: The step of supplying the first sheet, the second sheet, and the elastic member to an anvil roller rotating in the conveying direction with the elastic member being arranged between the first sheet and the second sheet in an extended state in the conveying direction; a joining step of forming a pair of welded portions on both sides of the elastic member in a direction intersecting the conveying direction orthogonal to the conveying direction to join the first sheet and the second sheet; as well as The step of cutting the elastic member, After the cutting step, the shrunken elastic member is held by the pair of welded parts, and the position of the elastic member in the conveying direction is restricted. A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. The convex portion has a groove portion along the rotation direction of the anvil roller, In the cross section of the groove portion along the intersecting direction, The groove portion includes: a pair of first side walls extending from a starting edge of the groove portion to a predetermined position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, In the cross-section, when the intersection points of a line connecting the starting edges of the pair of first side wall portions along the intersection direction and a line extending the pair of second side wall portions respectively toward the starting edge side are set as the first intersection point and the second intersection point, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

2. A method for producing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with an elastic member interposed therebetween, wherein: The method for producing the stretchable sheet comprises: The step of supplying the first sheet, the second sheet, and the elastic member to an anvil roller rotating in the conveying direction with the elastic member being arranged between the first sheet and the second sheet in an extended state in the conveying direction; a joining step of forming a pair of welded portions on both sides of the elastic member in a direction intersecting the conveying direction orthogonal to the conveying direction to join the first sheet and the second sheet; as well as The step of cutting the elastic member, After the cutting step, the shrunken elastic member is held by the pair of welded parts, and the position of the elastic member in the conveying direction is restricted. A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. The convex portion has a groove portion along the rotation direction of the anvil roller, In the cross section of the groove portion along the intersecting direction, The depth of the groove is greater than the height of the convex portion from the outer peripheral surface. The length of the groove portion in the intersecting direction decreases from a starting edge of the groove portion toward a rear side.

3. The method for producing a stretchable sheet according to claim 1 or 2, wherein: The convex portion includes the plurality of grooves provided at intervals along the intersecting direction with respect to the elastic member.

4. The method for producing a stretchable sheet according to claim 3, wherein: In the cross section, The depth of the groove portion is greater than or equal to the distance between the groove portions in the intersecting direction.

5. The method for producing a stretchable sheet according to claim 1, wherein: In the cross section, The length of the groove portion in the intersecting direction decreases from the starting edge toward the back side.

6. The method for producing a stretchable sheet according to claim 1, wherein: In the cross section, an angle formed by the pair of first side wall portions is at least twice an angle formed by the pair of second side wall portions.

7. The method for producing a stretchable sheet according to claim 1, wherein: In the depth direction of the groove portion in the cross section, a length of a portion of the groove portion formed by the pair of second side wall portions is longer than a length of a portion of the groove portion formed by the pair of first side wall portions.

8. The method for producing a stretchable sheet according to claim 1 or 2, wherein: The depth of the groove portion in the cross section is longer than the outer diameter of the elastic member when the elastic member is stretched to a maximum stretchable length in the conveyance direction.

9. The method for producing a stretchable sheet according to claim 8, wherein: The depth of the groove portion in the cross section is longer than the maximum outer diameter of the elastic member that is shrunk after the cutting step.

10. The method for producing a stretchable sheet according to claim 1, wherein In the cross section, a portion of the groove portion corresponding to the pair of first side walls in a depth direction of the groove portion has an area ratio greater than an area ratio of a portion corresponding to the pair of second side walls.

11. The method for producing a stretchable sheet according to claim 2, wherein: The groove portion includes: a pair of first side walls extending from a starting edge of the groove portion to a predetermined position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, In the cross-section, when the intersection points of a line connecting the starting edges of the pair of first side wall portions along the intersection direction and a line extending the pair of second side wall portions respectively toward the starting edge side are set as the first intersection point and the second intersection point, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

12. A method for producing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with a plurality of elastic members interposed therebetween, wherein: The method for producing the stretchable sheet comprises: The step of supplying the first sheet, the second sheet, and the plurality of elastic members to an anvil roller rotating in the conveying direction, with the plurality of elastic members being extended in the conveying direction and spaced apart between the first sheet and the second sheet in a direction perpendicular to the conveying direction; a joining step of forming a pair of welded portions on both sides of each of the elastic members in a direction intersecting the conveying direction orthogonal to the conveying direction to join the first sheet and the second sheet; as well as The step of cutting the elastic member, In the supplying step, the plurality of elastic members supplied to the anvil roller include a first elastic member and a second elastic member having different thicknesses. In the joining step, the pair of welded portions are formed on each of the first elastic member and the second elastic member so as not to form a damaged portion where a portion of the surface is damaged, and In the joining step, the welded portion pairs are formed so that the first elastic member and the second elastic member contracted after the cutting step are sandwiched by the welded portion pairs to restrict the positions of the first elastic member and the second elastic member in the conveying direction.

13. The method for producing a stretchable sheet according to claim 12, wherein: A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. Each of the plurality of convex portions has a groove portion along the rotation direction of the anvil roller. In the joining step, the pair of welded portions is formed in a state in which the first elastic member and the second elastic member are not exposed from the groove portions in which the first elastic member and the second elastic member are respectively arranged.

14. The method for producing a stretchable sheet according to claim 13, wherein: The convex portion includes a plurality of the grooves provided at intervals along the intersecting direction with respect to one elastic member.

15. The method for producing a stretchable sheet according to claim 14, wherein: In the cross section of the groove portion along the intersecting direction, The depth of the groove portion is greater than or equal to the distance between the groove portions in the intersecting direction.

16. The method for producing a stretchable sheet according to claim 13 or 14, wherein: In the cross section of the groove portion along the intersecting direction, The depth of the groove is longer than the outer diameter of each of the first elastic member and the second elastic member when the first elastic member and the second elastic member are stretched to their maximum stretchable lengths in the conveying direction.

17. The method for producing a stretchable sheet according to claim 16, wherein: The depth of the groove portion in the cross section is longer than the maximum outer diameter of each of the first elastic member and the second elastic member that are shrunk after the cutting step.

18. The method for producing a stretchable sheet according to claim 12, wherein: A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. The convex portion has a groove portion along the rotation direction of the anvil roller, In the cross section of the groove portion along the intersecting direction, The groove portion includes: a pair of first side walls extending from a starting edge of the groove portion to a predetermined position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, In the cross section, a portion of the groove portion corresponding to the pair of first side walls in a depth direction of the groove portion has an area ratio greater than an area ratio of a portion corresponding to the pair of second side walls.

19. A stretchable sheet, The stretchable sheet has an up-down direction and a left-right direction that intersect each other. The stretchable sheet has: first sheet; a second sheet material joined to the first sheet material by a plurality of welded portions; as well as The elastic member is provided between the first sheet and the second sheet and can be stretched and retracted in the left-right direction. It is characterized by: The plurality of welded portions include a plurality of welded portion pairs, the plurality of welded portion pairs being located on both sides of the elastic member in the up-down direction, clamping the elastic member in the state of contraction in the left-right direction, and limiting the position of the elastic member in the left-right direction relative to the first sheet and the second sheet. In a cross section of the stretchable sheet along the vertical direction at the position where the welded portion is formed, the pair of welded portions are provided on both sides of the elastic member in the vertical direction, and at least one of the pair of welded portions has: an inner fusion bonded portion including fibers having melted and solidified portions in which constituent fibers constituting the first sheet and the second sheet are in a melted and solidified state; and The outer weld portion is located outside the inner weld portion in the vertical direction and includes only fibers having the melted and solidified portion. The average thickness of the inner weld portion is greater than the average thickness of the outer weld portion.

20. The stretchable sheet according to claim 19, wherein In a cross section of the stretchable sheet along the vertical direction, The pair of welded portions includes both the inner welded portion and the outer welded portion.

21. The stretchable sheet according to claim 19 or 20, wherein In a cross section of the stretchable sheet along the vertical direction, A portion having a gap is formed in at least one of between the elastic member and the first sheet and between the elastic member and the second sheet.

22. The stretchable sheet according to claim 19 or 20, wherein The elastic member is a thread-like elastic member formed by gathering a plurality of elastic fibers, and in a cross section along the vertical direction between the pair of welded portions sandwiching the elastic member in a state of being contracted in the horizontal direction, spaces are present between the elastic fibers.

23. An absorbent article, The absorbent article has an up-down direction and a left-right direction that intersect each other, The absorbent article comprises an absorbent body and a pair of waist portions. It is characterized by: The absorbent article has: first sheet; a second sheet material joined to the first sheet material by a plurality of welded portions; as well as The elastic member is capable of stretching and contracting along the left-right direction. A plurality of elastic members are arranged between the first sheet and the second sheet at intervals in the vertical direction. The plurality of welded portions include a plurality of welded portion pairs, the plurality of welded portion pairs being located on both sides of the elastic member in the up-down direction, clamping the elastic member in the state of contraction in the left-right direction, and limiting the position of the elastic member in the left-right direction relative to the first sheet and the second sheet. The plurality of elastic members include a first elastic member and a second elastic member having different thicknesses when the absorbent article is maximally stretched in the left-right direction. In each of the first elastic member and the second elastic member, no damaged portion, in which a portion of the surface of the first elastic member or the second elastic member is damaged, is provided between the pair of welded portions adjacent to each other in the left-right direction.

24. A device for producing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with an elastic member interposed therebetween, wherein: The stretchable sheet manufacturing device includes: a supply unit that supplies the first sheet material, the second sheet material, and the elastic member to an anvil roller rotating in the conveying direction, with the elastic member being arranged between the first sheet material and the second sheet material and being stretched in the conveying direction; a weld forming unit for forming a plurality of welds, wherein the plurality of welds form a weld pair on both sides of the elastic member in a direction perpendicular to the conveying direction to join the first sheet and the second sheet; as well as a cutting portion for cutting the elastic member, After the elastic member is cut by the cutting portion, the contracted elastic member is clamped by the pair of welding portions, and the position of the elastic member in the conveying direction is restricted. A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. The convex portion has a groove portion along the rotation direction of the anvil roller, In the cross section of the groove portion along the intersecting direction, The groove portion includes: a pair of first side walls extending from a starting edge of the groove portion to a predetermined position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, In the cross-section, when the intersection points of a line connecting the starting edges of the pair of first side wall portions along the intersection direction and a line extending the pair of second side wall portions respectively toward the starting edge side are set as the first intersection point and the second intersection point, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

25. A device for producing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with an elastic member interposed therebetween, wherein: The stretchable sheet manufacturing device includes: a supply unit that supplies the first sheet material, the second sheet material, and the elastic member to an anvil roller rotating in the conveying direction, with the elastic member being arranged between the first sheet material and the second sheet material and being stretched in the conveying direction; a weld forming unit for forming a plurality of welds, wherein the plurality of welds form a weld pair on both sides of the elastic member in a direction perpendicular to the conveying direction to join the first sheet and the second sheet; as well as a cutting portion for cutting the elastic member, After the elastic member is cut by the cutting portion, the contracted elastic member is clamped by the pair of welding portions, and the position of the elastic member in the conveying direction is restricted. A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. The convex portion has a groove portion along the rotation direction of the anvil roller, In the cross section of the groove portion along the intersecting direction, The depth of the groove is greater than the height of the convex portion from the outer peripheral surface. The length of the groove portion in the intersecting direction decreases from a starting edge of the groove portion toward a rear side.

26. A device for manufacturing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with a plurality of elastic members interposed therebetween, wherein: The stretchable sheet manufacturing device includes: a supply unit for supplying the first sheet, the second sheet, and the plurality of elastic members to an anvil roller rotating in the conveying direction, with the plurality of elastic members being arranged in an extended state in the conveying direction at intervals between the first sheet and the second sheet in a direction perpendicular to the conveying direction; a weld forming unit for forming a plurality of welds, wherein the plurality of welds form a weld pair on both sides of each elastic member in a direction perpendicular to the conveying direction, thereby joining the first sheet and the second sheet; as well as a cutting portion for cutting the elastic member, In the supply portion, the plurality of elastic members supplied to the anvil roller include a first elastic member and a second elastic member having different thicknesses. In the weld forming portion, the weld pair is formed on each of the first elastic member and the second elastic member so as not to form a damaged portion where a portion of the surface is damaged, and The weld forming portion forms the weld pairs so that the first elastic member and the second elastic member, which have shrunk after being cut by the cutting portion, are sandwiched by the weld pairs to restrict the positions of the first elastic member and the second elastic member in the conveying direction.

27. An anvil roller used in a device for manufacturing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with an elastic member interposed therebetween, characterized in that: A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. The convex portion has a groove portion along the rotation direction of the anvil roller, A direction perpendicular to the rotation direction is defined as a cross direction. In a cross section of the groove portion along the cross direction, The groove portion includes: a pair of first side walls extending from a starting edge of the groove portion to a predetermined position located on the inner side; and a pair of second side wall portions extending from the prescribed position to the bottom of the groove portion, In the cross-section, when the intersection points of a line connecting the starting edges of the pair of first side wall portions along the intersection direction and a line extending the pair of second side wall portions respectively toward the starting edge side are set as the first intersection point and the second intersection point, the separation distance between the starting edges of the pair of first side wall portions is longer than the distance between the first intersection point and the second intersection point.

28. An anvil roller used in a device for manufacturing a stretchable sheet, wherein the stretchable sheet is formed by laminating a first sheet and a second sheet with an elastic member interposed therebetween, characterized in that: A plurality of convex portions protruding outward in the radial direction of the anvil roller are provided on the outer peripheral surface of the anvil roller. The convex portion has a groove portion along the rotation direction of the anvil roller, A direction perpendicular to the rotation direction is defined as a cross direction. In a cross section of the groove portion along the cross direction, The depth of the groove is greater than the height of the convex portion from the outer peripheral surface. The length of the groove portion in the intersecting direction decreases from a starting edge of the groove portion toward a rear side.

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