Method and device for producing stretchable composite sheet

Abstract

The manufacturing method of the present invention is a manufacturing method for a stretchable composite sheet (1) which is bonded with a stretchable first sheet (2) and a non-stretchable second sheet (3) which is wider than the first sheet. The manufacturing method includes a joining step, wherein the first sheet (2) is overlapped with a part of the second sheet (3) in a state of being stretched in one direction, and the laminated sheet (10) includes a first area (A1) having the first sheet and the second sheet and a second area (A2) having only the second sheet, and the first sheet and the second sheet are intermittently joined in the sheet conveying direction (MD) along the above-mentioned one direction. In the joining step, in addition to forming a joining portion (5) in the first area (A1), a joining portion (5) is also formed at a boundary portion (4) between the first area and the second area.

Description

Technical Field

[0001] The present invention relates to a method and apparatus for producing a stretchable composite sheet. Background Art

[0002] Patent document 1 proposes a technology in which a stretchable first sheet and a non-stretchable second sheet are conveyed in an overlapping state in a sheet conveying direction, and are clamped by a roller having a joining pattern and a pressing component arranged opposite to the roller to form a sealing portion along the conveying direction, thereby bonding the first sheet and the second sheet.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-112226 Summary of the invention

[0006] The present invention relates to a method for manufacturing a stretchable composite sheet, in which a stretchable first sheet and a non-stretchable second sheet wider than the first sheet are bonded. The manufacturing method of the present invention includes a bonding step, wherein the first sheet is overlapped with a part of the second sheet in a state of being stretched in one direction, and the laminated sheet includes a first region having the first sheet and the second sheet and a second region having only the second sheet, and the first sheet and the second sheet are intermittently bonded in a sheet conveying direction along the one direction. In the bonding step, in addition to forming a bonding portion in the first region, a bonding portion is also formed at a boundary portion between the first region and the second region.

[0007] The present invention relates to a manufacturing device for a stretchable composite sheet, in which a stretchable first sheet and a non-stretchable second sheet wider than the first sheet are bonded. The manufacturing device of the present invention includes a bonding mechanism for bonding the first sheet and the second sheet at intervals in a sheet conveying direction along the one direction, in which the first sheet overlaps a part of the second sheet in a state of being stretched in one direction, and includes a first region having the first sheet and the second sheet and a second region having only the second sheet. The bonding mechanism forms a bonding portion at a boundary between the first region and the second region in addition to forming a bonding portion in the first region. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 This is a schematic diagram showing a preferred method and apparatus for producing the stretchable composite sheet of the present invention.

[0009] Figure 2 It is a perspective view of a tooth groove stretching device included in the manufacturing device.

[0010] Figure 3This is a perspective view showing a process for producing a precursor of a stretchable sheet in a preferred method for producing the stretchable composite sheet of the present invention.

[0011] Figure 4 The drawings illustrate a bonding mechanism according to a first embodiment of the present invention and a bonding pattern of a bonding portion formed by the bonding mechanism, wherein (a) is an enlarged view showing the structure of the bonding mechanism and a boundary portion, and (b) is an enlarged view showing the bonding pattern.

[0012] Figure 5 The drawings illustrate a joining mechanism according to a second embodiment of the present invention and a joining pattern of a joining portion formed by the joining mechanism, wherein (a) is an enlarged view showing the structure of the joining mechanism and a boundary portion, and (b) is an enlarged view showing the joining pattern.

[0013] Figure 6 The drawings illustrate a joining mechanism according to a third embodiment of the present invention and a joining pattern of a joining portion formed by the joining mechanism, wherein (a) is an enlarged view showing the structure of the joining mechanism and a boundary portion, and (b) is an enlarged view showing the joining pattern.

[0014] Figure 7 The drawings illustrate a joining mechanism of a modified example of the present invention and a joining pattern of a joining portion formed by the joining mechanism, wherein (a) is an enlarged view showing the structure of the joining mechanism and a boundary portion, and (b) is an enlarged view showing the joining pattern.

[0015] Figure 8 The drawings illustrate a joining mechanism of a modified example of the present invention and a joining pattern of a joining portion formed by the joining mechanism, wherein (a) is an enlarged view showing the structure of the joining mechanism and a boundary portion, and (b) is an enlarged view showing the joining pattern.

[0016] Fig. 9 It is a diagram for explaining the relationship between the width of the second region and the width of the bonding pattern.

[0017] Fig.10 This is a diagram showing one form of a product of a stretchable composite sheet manufactured by the manufacturing method and manufacturing apparatus of the present invention. DETAILED DESCRIPTION

[0018] In Patent Document 1, a sealed portion is formed using a bonding pattern. However, since the sealed portion formed by the bonding pattern does not reach the boundary between the first sheet and the second sheet, there is a possibility that the boundary portion, which becomes a non-bonded portion, may curl up.

[0019] The present invention provides a method and an apparatus for producing a stretchable composite sheet that can solve the above-mentioned disadvantages of the prior art.

[0020] Hereinafter, the present invention will be described based on preferred embodiments thereof with reference to the drawings.

[0021] (First Embodiment)

[0022] Figure 1 This is a diagram schematically showing a preferred method and apparatus 100 for producing a stretchable composite sheet 1 as one embodiment of the method and apparatus for producing a stretchable composite sheet of the present invention.

[0023] Figure 1 The manufacturing method of the stretchable composite sheet 1 shown includes: a precursor manufacturing step of manufacturing a composite member 2A, which is a precursor of the stretchable composite sheet 1; a stretching treatment step of performing a stretching process on the composite member 2A to obtain a stretchable sheet 2; and a sheet sealing step of fitting a plurality of sheets of different properties together, and the stretchable composite sheet 1 is manufactured by these steps. The plurality of sheets mentioned here are the stretchable sheet 2 as the first sheet and the non-stretchable sheet 3 as the second sheet.

[0024] In the precursor manufacturing process, such as Figure 3 As shown, a plurality of elastic threads 21 are bonded to the sheets 20, 20 in a manner extending in one direction and in a substantially non-stretched state, thereby obtaining a composite material 2A as a precursor of a stretchable sheet. More specifically, a large number of elastic threads 21 in a molten state spun from a spinning nozzle 16 are received at a predetermined speed and stretched, and before the elastic threads 21 are solidified, the elastic threads 21 are fused to two sheets 20, 20 made of a fiber material, preferably a nonwoven fabric, in a manner that the elastic threads 21 are arranged in one direction without crossing each other. Thus, a composite material 2A as a precursor of a stretchable sheet is manufactured, in which a plurality of elastic threads 21 are bonded to the sheets 20, 20 in a substantially non-stretched state over their entire lengths.

[0025] Figure 3 The spinning nozzle 16 shown is provided in a spinning head 17, and the spinning head 17 is connected to the extruder. The resin can also be supplied to the spinning head 17 via a gear pump. The elastic resin melt-kneaded by the extruder is supplied to the spinning head 17. In the spinning head 17, a plurality of spinning nozzles 16 are arranged in a row in a straight line. The spinning nozzles 16 are arranged along the width direction of the two sheets 20, 20. The spun molten elastic filament 21 merges with the two sheets 20, 20 respectively fed from the billet at the same speed, is sandwiched between the two sheets 20, 20, and is received at a predetermined speed.

[0026] The elastic thread 21 merges with the two sheets 20, 20 before solidification, that is, in a fusible state. As a result, the elastic thread 21 is fused to the sheets 20, 20 while being sandwiched between the two sheets 20, 20. That is, the elastic thread 21 is fused to the two sheets 20, 20 only by the melting heat brought by the fusible elastic thread 21. As a result, the obtained stretch sheet 2 is less likely to have the hardness that would be generated if an adhesive is applied to the entire area of ​​the boundary surface of the sheets 20, 20, and has excellent softness as a sheet.

[0027] When the elastic thread 21 is merged with the two sheets 20, 20, the elastic threads 21 are arranged in one direction without crossing each other. The elastic thread 21 is merged with the two sheets 20, 20 and the elastic thread 21 is sandwiched between the sheets 20, 20, and the three are sandwiched by a pair of sandwich rollers 18, 18. Thus, a composite material 2A in which the elastic thread 21 is sandwiched between the two sheets 20, 20 is obtained.

[0028] When sheets that do not originally have stretchability are used as the two sheets 20, 20, a stretchability development treatment step is performed to make the sheets 20 stretchable. In the stretchability development treatment step of this embodiment, the sheets 20, 20 are subjected to a stretching treatment using a tooth groove stretching device 25. The stretching treatment is a treatment that extends the composite material 2A along the extension direction of the elastic thread 21 to impart stretchability to the sheets 20, 20. The imparting of stretchability mentioned here also includes the case where the stretchability of a sheet that has a little stretchability is greatly improved.

[0029] The main part of the tooth groove extension device 25 is Figure 2 Shown in. Figure 2 The tooth groove stretching device 25 shown includes a pair of tooth groove rollers 26 and 27 meshing with each other, and the teeth are alternately provided in the circumferential direction with teeth as protrusions extending in the axial direction, and grooves extending in the axial direction formed between the teeth. In the stretchability development process using the tooth groove stretching device 25, the composite material 2A obtained in the precursor production process is supplied between the pair of tooth groove rollers 26 and 27, and the composite material 2A is stretched to obtain the stretchable sheet 2 of the sheet materials 20 and 20 contained in the composite material 2A. As the tooth profile of the tooth groove rollers 26 and 27, a common involute tooth profile or cycloid tooth profile is used, and a tooth profile with a small tooth width is particularly preferred.

[0030] By partially stretching the composite material 2A using a pair of toothed rollers 26, 27, etc., the stretchable sheet 2 is obtained. Figure 1 , the composite material 2A is wound into a tube to form a tube 2R, and then the composite material 2A fed from the tube 2R is subjected to a stretching process. The manufactured composite material 2A may be introduced into a toothed stretching device using toothed rollers 26 and 27 without being wound into a tube.

[0031] The obtained stretchable sheet 2 is stretched in one direction, i.e., the sheet conveying direction MD, and in this stretched state, it is joined with the non-stretchable sheet 3 and laminated to form a laminated sheet 10. In the sheet sealing step, the stretchable sheet 2 and the non-stretchable sheet 3 are bonded and attached to each other by an ultrasonic sealing device 40 serving as a bonding mechanism to form a stretchable composite sheet 1.

[0032] The manufacturing method of this embodiment is as follows Figure 4 As shown in (a), before the sheet sealing step, a region forming step of overlapping the stretch sheet 2 and the non-stretch sheet 3 is performed. In the region forming step, a first region A1 having the stretch sheet 2 and the non-stretch sheet 3 and a second region A2 having only the non-stretch sheet 3 are formed. In addition, in the present manufacturing method, the sheet sealing step is a joining step of forming a joining portion 5 composed of a joining pattern 6 at the boundary portion 4 between the first region A1 and the second region A2 in addition to the first region A1.

[0033] Next, the region forming step and the sheet sealing step will be described.

[0034] like Figure 4 As shown in (a), the width X2 of the non-stretchable sheet 3 in the width direction CD orthogonal to the sheet conveying direction MD is formed to be wider than the width X1 of the stretchable sheet 2 in the width direction CD. The ends 2a and 2b of the stretchable sheet 2 located in the width direction CD are formed into straight lines extending in the sheet conveying direction MD and parallel to each other. Similarly, the ends 3a and 3b of the non-stretchable sheet 3 located in the width direction CD are formed into straight lines extending in the sheet conveying direction MD and parallel to each other.

[0035] In the region forming process, when forming a laminated sheet 10 on which the stretched sheet 2 and the non-stretch sheet 3 are overlapped, the stretch sheet 2 is located at the center of the width direction CD of the non-stretch sheet 3, and the ends are stacked in parallel. Therefore, in the region forming process, in the laminated sheet 10, a first region A1 and a second region A2 are formed in the width direction CD. As a result, the stretchable composite sheet 1 includes the first region A1 and the second region A2. That is, in the region forming process, the stretch sheet 2 overlaps with a part of the non-stretch sheet 3 in a state stretched in one direction to form a laminated sheet 10, and the laminated sheet 10 includes a first region A1 having the stretch sheet 2 and the non-stretch sheet 3, and a second region A2 having only the non-stretch sheet 3. In the present embodiment, one direction refers to the same direction as the sheet conveying direction MD.

[0036] The laminated sheet 10 including the first area A1 and the second area A2 is subjected to a sealing process in the sheet sealing process, in which each boundary portion 4 formed on both sides of the stretch sheet 2 and the non-stretch sheet 3 is bonded to the first area A1 by a bonding mechanism. The boundary portions 4 are formed so as to extend linearly in the sheet conveying direction MD. The second area A2 having only the non-stretch sheet 3 is embossed by a bonding mechanism. Figure 4 In (a), one boundary portion 4 and the joining portion 5 are shown in an enlarged manner. That is, in the sheet sealing step, the stretchable sheet 2 and the non-stretchable sheet 3 are intermittently joined in the sheet conveying direction MD.

[0037] As a bonding mechanism for the sealing process, any device that can bond the stretchable sheet 2 and the non-stretchable sheet 3 can be used, for example, a heat sealing device, an ultrasonic sealing device, a high-frequency sealing device, etc. In this embodiment, an ultrasonic sealing device 40 is used.

[0038] Ultrasonic sealing device 40 such as Figure 1 As shown, it includes: a support roller 41 having a bonding pattern 6 formed with bonding convex portions 9 at intervals in the sheet conveying direction MD; and an ultrasonic horn 42 as a pressing member, which is arranged opposite to the outer peripheral surface 41a of the support roller 41, and sandwiches the stretchable sheet 2 and the non-stretchable sheet 3 [laminated sheet 10] conveyed in the sheet conveying direction MD between the support roller 41 and the outer peripheral surface 41a of the support roller 41, thereby forming a bonding portion 5 (refer to Figure 4 ).

[0039] The joining pattern 6 is a layout pattern of joining portions between the stretchable sheet 2 and the non-stretchable sheet 3 . The joining pattern 6 formed on the support roller 41 is a layout pattern of joining projections 9 corresponding to the layout pattern of joining portions between the stretchable sheet 2 and the non-stretchable sheet 3 .

[0040] The support roller 41 is a support roller that supports the surface of the laminated sheet 10 on the opposite side of the ultrasonic wave application surface facing the ultrasonic horn 42. A bonding pattern 6 for forming a bonding portion 5 is formed on the front end surface of the ultrasonic horn 42 or the outer peripheral surface 41a of the support roller 41. In this embodiment, as shown in FIG. Figure 4 As shown in (a) and (b), on the outer peripheral surface 41a of the support roller 41, a plurality of joining protrusions 9 forming a joining pattern 6 are protrudingly arranged from the outer peripheral surface 41a. A plurality of joining protrusions 9 are arranged on the outer peripheral surface 41a of the support roller 41 to obtain a desired joining pattern 6. In the present embodiment, the joining protrusions 9 are formed as cylindrical protrusions. The desired joining pattern 6 refers to a pattern in which at least the boundary portion 4 is located within the pattern forming area.

[0041] Figure 4(b) shows a partial enlarged view of the bonding pattern 6. The bonding pattern 6 is arranged in a manner that the bonding protrusion 9 is located at least on the boundary portion 4, and the bonding portion 5 is formed across the boundary portion 4. In the present embodiment, the bonding pattern 6 is formed in a manner that the bonding portion 5 is also formed at the boundary portion 4 between the first area A1 and the second area A2 in addition to the first area A1. In the embodiment, the bonding protrusion 9 is formed as a cylindrical protrusion.

[0042] In the pattern forming region, a plurality of bonding protrusions 9 are arranged at predetermined intervals in the sheet conveying direction MD and the width direction CD. Figure 4 As shown in (b), the prescribed interval in the width direction CD refers to the center pitch L between adjacent joining protrusions 9 and joining protrusions 9 in the width direction CD. The prescribed interval in the sheet conveying direction MD refers to the center pitch X between adjacent joining protrusions 9 and joining protrusions 9 in the sheet conveying direction MD (circumferential direction).

[0043] The joining pattern 6 is formed in a manner that a plurality of joining protrusions 9 arranged at a center-to-center pitch L and a center-to-center pitch X are arranged linearly in a circumferential direction of the support roller 41. The joining pattern 6 is a joining pattern in which the joining protrusions 9 are formed at a predetermined interval in the width direction CD. That is, the support roller 41 has a joining pattern 6 in which the joining protrusions 9 are formed at a predetermined interval in the sheet conveying direction MD and the circumferential direction. In the present embodiment, the circumferential direction refers to the same direction as the sheet conveying direction MD.

[0044] In the sheet sealing step, the joining protrusions 9 of a part of the joining pattern 6 are brought into contact with the sheet so as to straddle the boundary 4 in the width direction CD, thereby forming the joining portion 5 .

[0045] In the present embodiment, the joining pattern 6 is configured with the joining protrusions 9 in such a manner as to form a row of joining portions 5 in the sheet conveying direction MD, so that a joining portion arranged at a prescribed interval in the sheet conveying direction MD is formed in the boundary portion 4. That is, the joining portion 5 is a structure formed by gathering the joining portions formed by one joining protrusion 9. In the present embodiment, a row of joining portions 5 spaced apart in the sheet conveying direction MD is formed by using the joining protrusions 9 arranged linearly at intervals in the sheet conveying direction MD. In addition, by arranging a plurality of rows of joining protrusions 9 arranged in a row in the circumferential direction in the width direction CD, a plurality of joining portions can be formed in the sheet conveying direction MD and the width direction CD. The boundary portion 4 is located in the joining area formed by the joining pattern 6, and at least one row of joining portions 5 is formed in such a manner as to straddle the boundary portion 4. In the present embodiment, a joining pattern 6 of an area extending in the sheet conveying direction MD and the width direction CD is formed at one time, and a plurality of joining portions 5 are formed by the joining pattern 6. That is, in the first embodiment, a line segment O connecting the graphic centers of the joining portions 5 in one row, which are patterns adjacent to each other in the sheet conveying direction MD and which constitute the joining pattern 6, is parallel to the sheet conveying direction MD.

[0046] When the laminated sheet 10 is Figure 1 , Figure 4 When the laminated sheet 10 is sandwiched between the supporting roller 41 and the ultrasonic horn 42 as shown in (a), ultrasonic waves are applied to the laminated sheet 10 by the ultrasonic horn 42, thereby melting or softening the sheet material constituting the non-stretchable sheet 3 in the laminated sheet 10, forming a joint portion 5 in which the stretchable sheet 2 and the non-stretchable sheet 3 are partially joined by the joining pattern 6.

[0047] The ultrasonic application surface of the laminated sheet 10 facing the ultrasonic horn 42 side can be formed by the stretchable sheet 2 or the non-stretchable sheet 3, but from the perspective of damage to the stretchable sheet 2 caused by the friction resistance of the ultrasonic horn 42 and the stretchability when the composite sheet is formed, it is preferably formed by the non-stretchable sheet 3. Figure 1 In the figure, reference numerals 28 and 29 are clamping rollers, and reference numeral 3R is a cylindrical object formed by winding the non-stretchable sheet 3. The support roller 41 is a roller driven to rotate, but it can also be a driven roller driven by the sheet being transported. In addition, a non-rotating support member can be used instead of the support roller 41.

[0048] In the manufacturing method and manufacturing device 100 of the present embodiment, in the sheet sealing step, the bonding portion 5 is formed across the boundary portion 4 between the first area A1 and the second area A2 in addition to the first area A1. Therefore, the boundary portion 4 that is not bonded in the prior art can be bonded, so that the manufacturing method and manufacturing device 100 of the stretchable composite sheet 1 in which the boundary portion 4 does not roll up can be provided.

[0049] In the present embodiment, the joining convex portions 9 are formed as convex portions (joining convex portions 9) formed at intervals in the width direction CD. Therefore, when the direction in which the elastic yarns 21 of the stretchable composite sheet 1 extend is the sheet conveying direction MD, the joining portions 5 are also formed at intervals in the width direction CD orthogonal to the sheet conveying direction MD, which can improve the stretchability and softness of the sheet as the stretchable composite sheet 1, and is therefore preferred.

[0050] In addition, in the present embodiment, the bonding pattern 6 is formed on the outer peripheral surface 41a of the support roller 41, but the bonding pattern can also be formed by arranging the bonding convex parts 9 on the surface of the ultrasonic horn 42 in contact with the laminated sheet 10. At this time, the direction in which the elastic thread 21 extends is the sheet conveying direction MD of the laminated sheet 10, and ultrasonic vibration is applied to the ultrasonic horn 42 to form the bonding part 5 in the sheet conveying direction MD of the laminated sheet 10, thereby obtaining the laminated sheet 10 in which the bonding part 5 is formed in the direction in which the elastic thread 21 extends. The bonding part 5 is a sealing part formed at intervals in the direction orthogonal to the direction in which the elastic thread 21 extends, and the bonding part 5 is formed in the direction orthogonal to the direction in which the elastic thread 21 extends, as in the stretchable composite sheet 1, so it is preferred from the viewpoint of improving the softness of the sheet. The bonding pattern formed on the ultrasonic horn 42 refers to the arrangement pattern of the bonding convex parts 9 arranged in a manner corresponding to the arrangement pattern of the bonding part of the stretchable sheet 2 and the non-stretchable sheet 3.

[0051] (Second Embodiment)

[0052] use Figure 5 , a second embodiment of the present invention is described.

[0053] In the first embodiment, the line segment О connecting the centers of the patterns of a row of bonding portions 5 adjacent to each other in the sheet conveying direction MD of the bonding pattern 6 is parallel to the sheet conveying direction MD. Figure 5 As shown in (a) and (b), the joining pattern 6A is formed in such a manner that the joining portion 5A is formed obliquely with respect to the sheet conveying direction MD. That is, the line segment О connecting the graphic centers of the joining portions 5 of a row adjacent to each other in the sheet conveying direction MD of the joining pattern 6A is inclined with respect to the sheet conveying direction MD. In the present embodiment, the joining protrusions 9 arranged in series on the outer peripheral surface 41a of the support roller 41 are arranged obliquely with respect to the outer peripheral surface 41a of the support roller 41. Therefore, in the present embodiment, the joining portion 5A corresponding to the joining portion 5 described in the first embodiment is formed obliquely with respect to the sheet conveying direction MD, and therefore the joining portion 5A is formed in such a manner as to obliquely cross the boundary portion 4.

[0054] According to the structure of the second embodiment, even if the laminated sheet 10 moves in the width direction CD and the boundary portion 4 moves in the sheet conveying direction MD, a certain joining protrusion 9 constituting the joining portion 5A can be formed so as to straddle the boundary portion 4. Therefore, even when the sheet is bent, the boundary portion 4 can be reliably joined by the joining portion 5A, and a manufacturing method and manufacturing device 100 of a stretchable composite sheet 1 in which the boundary portion 4 is less likely to roll up can be provided.

[0055] (Third Embodiment)

[0056] use Figure 6 , a third embodiment of the present invention is described.

[0057] In this embodiment, if Figure 6 As shown in (a) and (b), a joining pattern 6B is formed in which the angle θ of the line segment О described in the second embodiment is alternately switched relative to the sheet conveying direction MD. That is, the angle θ of the inclination of the line segment О is formed in a manner that changes periodically and symmetrically relative to the sheet conveying direction MD. The joining portion 5B, which is equivalent to the joining portion 5 described in the first embodiment, is formed in such a manner that the joining protrusions 9 arranged in series on the outer peripheral surface 41a of the support roller 41 are symmetrically inclined relative to the sheet conveying direction MD, and are formed so that their positions are alternately staggered and inclined relative to the circumference of the support roller 41 (in a serrated shape).

[0058] Therefore, in this embodiment, the joining portion 5B is formed in a zigzag shape with respect to the sheet conveying direction MD, so that Figure 6 As shown, the joints 5B are formed obliquely and alternately across the boundary 4. Therefore, the boundary 4 can be joined even when the sheet is bent, and a method and apparatus 100 for manufacturing a stretchable composite sheet 1 that is less likely to curl up at the boundary 4 can be provided. In addition, the appearance of the article manufactured from the stretchable composite sheet 1 can be improved.

[0059] Although preferred embodiments of the present invention have been described above, the present invention is not limited to the specific embodiments, and various modifications and changes can be made within the scope of the concept of the present invention unless otherwise specified in the above description.

[0060] For example, the joining pattern 6B having the joining portion 5B in which the inclination angle θ of the line segment О changes periodically and symmetrically with respect to the sheet conveying direction MD may not be Figure 6 The structure of the bonding portion is not a linear sawtooth shape as shown, but a curved bonding portion that changes periodically and symmetrically with respect to the sheet conveying direction MD.

[0061] At this time, the joining protrusion 9 constituting the joining pattern for forming the curved joining portion may be arranged in a curved shape whose direction changes alternately with respect to the circumference of the support roller 41 in a manner that changes periodically and symmetrically with respect to the sheet conveying direction MD. When such a curved joining portion that changes periodically and symmetrically with respect to the sheet conveying direction MD is formed, the same effect as the second embodiment can be achieved, so it is preferred.

[0062] The angle θ is preferably greater than or equal to 0.01°, more preferably greater than or equal to 0.3°, more preferably greater than or equal to 0.5°, preferably less than or equal to 45°, more preferably less than or equal to 5°, more preferably less than or equal to 1°, and is preferably greater than or equal to 0.01° and less than or equal to 45°, more preferably greater than or equal to 0.3° and less than or equal to 5°, more preferably greater than or equal to 0.5° and less than or equal to 1°.

[0063] In the above embodiment, the bonding patterns 6 to 6B are formed as a dot pattern in which a plurality of cylindrical bonding protrusions 9 are arranged at intervals in the sheet conveying direction MD and the width direction CD, but the bonding patterns 6 to 6B are not limited to dot patterns. Figure 7 As shown in (a) and (b), the linear joining pattern 6C may be formed at intervals in the sheet conveying direction MD by the rectangular joining portion 5C which is continuous in the width direction CD and crosses the boundary portion 4. In this case, the joining convex portions 9B protruding from the outer peripheral surface 41a and extending in the roller axis direction are formed at intervals in the circumferential direction on the outer peripheral surface 41a of the support roller 41, thereby forming the linear joining pattern 6C.

[0064] When the boundary portion 4 and a portion of the first area A1 and the second area A2 are joined using such a linear joining pattern 6C, a joining portion 5C that is separated in the sheet conveying direction MD and continuous in the width direction CD can be formed across the boundary portion 4, which can achieve the same effect as the first embodiment and is therefore preferred.

[0065] exist Figure 5 In the second embodiment shown in FIG. 1 , all the joint portions 5A formed by the dot-shaped joint patterns 6A are formed to be inclined in one direction relative to the sheet conveying direction MD. Figure 8 As shown in (a) and (b) of FIG. 1 , a bonding pattern 6D having different patterns capable of forming a bonding portion 5D divided into an inclined region V1 and a non-inclined region V2 may be formed.

[0066] In this case, the outer peripheral surface 41a of the support roller 41 is divided into a region Y1 where the joining convex portion 9 is arranged linearly along the sheet conveying direction MD, and a region Y2 where the joining convex portion 9 is arranged on a straight line at an angle relative to the sheet conveying direction MD, and the joining convex portion 9 is arranged in such a manner that these two regions are adjacent to each other on the outer peripheral surface 41a. At least one of the joining convex portions 9 located in any region is arranged so as to be located on the boundary portion 4.

[0067] When the boundary portion 4 is bonded using such a bonding pattern 6D having different patterns, the bonding portion 5D can be formed by the bonding protrusion 9 in any region so as to straddle the boundary portion 4. Figure 8 In the structure shown, considering the bending of the sheet in the width direction CD, the joining protrusion 9 formed in the inclined area Y1 is made opposite to the boundary 4, and the joining portion 5D is formed in a manner straddling the boundary 4. This can achieve the same effect as the second embodiment, so it is preferred.

[0068] use Fig. 9 , the relationship between the width A of the second area A2 in the width direction CD and the width B (joining width) of the joining pattern 6 formed in the second area A2 by the ultrasonic sealing device 40 is described. Fig. 9 In the example shown, the width B of the joining pattern 6 formed in the second area A2 by the ultrasonic sealing device 40 is set to be 5% or more with respect to the width A of the second area A2 in the width direction CD.

[0069] When the widths of both are specified in this way, the joining pattern 6 is also formed in the second area A2 where only the non-stretchable sheet 3 exists, so that the hardness can be obtained by partially increasing the rigidity of the non-stretchable sheet 3 in the second area A2. Therefore, the curling of the stretchable composite sheet 1 at the boundary portion 4 can be prevented, and the rigidity of the stretchable composite sheet 1 can be increased, so that the conveyability of the stretchable composite sheet 1 is improved.

[0070] The width B of the bonding pattern 6 relative to the width A of the second area A2 in the width direction CD is preferably greater than 5%, more preferably greater than 20%, more preferably greater than 50%, preferably less than 100%, more preferably less than 95%, more preferably less than 90%, and further preferably greater than 5% and less than 100%, further preferably greater than 20% and less than 95%, more preferably greater than 50% and less than 90%.

[0071] Fig.10The diaper 200 as an example of a panty-shaped ready-to-wear article manufactured by using a stretchable composite sheet 1 manufactured by a manufacturing method using a manufacturing device 100 of the present invention is shown. In this diaper 200, a rectangular absorbent body 201 is attached to the stretchable composite sheet 1 transported in the sheet transport direction MD with the longitudinal direction as the width direction, and leg openings 202 are formed upstream and downstream in the sheet transport direction across the absorbent body 201. When such a diaper 200 is manufactured by a conventional manufacturing method, the sheet rolls up at the boundary 4 between the stretchable sheet 2 and the non-stretchable sheet 3. Therefore, when the boundary 4 is formed on the inner side of the diaper facing the skin, the rolled-up portion contacts the skin, so the feel of use is insufficient, and when the boundary 4 is located on the outer side of the diaper, the appearance is impaired.

[0072] However, in the above embodiment, the joining portion is formed to at least straddle the boundary 4 to prevent the sheet from rolling up, so even if the boundary 4 or the joining portion is located on the inner or outer side of the diaper, the feel and appearance of the diaper are not impaired. Fig.10 The diaper 200 shown is manufactured using the stretchable composite sheet 1 manufactured by the manufacturing method described in the third embodiment. In the diaper 200, the junction 5B of the boundary 4 between the stretchable sheet 2 and the non-stretchable sheet 3 is formed in a zigzag shape at the boundary 4. Therefore, when the junction 5B is located on the inner side of the diaper that contacts the skin, the boundary 4 can be prevented from rolling up, so that the skin touch is good. In addition, when the junction is located on the outer side of the diaper that does not contact the skin, the beauty of the appearance is not impaired because the boundary 4 does not roll up.

[0073] The forming material of the stretchable composite sheet 1 is explained. As the sheets 20, 20 constituting the stretchable sheet 2, nonwoven fabrics such as hot air nonwoven fabrics, hot roll nonwoven fabrics, spunbond nonwoven fabrics, spunlace nonwoven fabrics, meltblown nonwoven fabrics, etc. can be used respectively. These nonwoven fabrics can be nonwoven fabrics of continuous filaments or short fibers. The sheets 20, 20 can be of the same type or of different types. The "same type of sheet" mentioned here refers to a sheet having the same manufacturing process of the sheet, the type of the constituent fibers of the sheet, the fiber diameter and length of the constituent fibers, the thickness and gram weight of the sheet, etc. When at least one of them is different, it is a "different type of sheet".

[0074] As the non-stretch sheet 3, the same sheet as the sheets 20, 20 exemplified as the sheets 20 constituting the stretch sheet 2 can be used. The non-stretch sheet 3 may be of the same kind as one or both of the sheets 20 constituting the stretch sheet 2, or may be of a different kind.

[0075] The thickness of the non-stretchable sheet 3 in a single state is preferably 0.1 mm or more, more preferably 0.12 mm or more, more preferably 0.15 mm or more, and still more preferably 0.18 mm or more, preferably 1 mm or less, more preferably 0.8 mm or less, more preferably 0.7 mm or less, and still more preferably 0.5 mm or less, and further preferably 0.1 mm or more and 1 mm or less, more preferably 0.12 mm or more and 0.8 mm or less, more preferably 0.15 mm or more and 0.7 mm or less, and still more preferably 0.18 mm or more and 0.5 mm or less. The thickness is measured by 0.5 cN / cm 2 The load is clamped between the flat plates and the distance between the flat plates is measured.

[0076] As the constituent fibers of the sheets 20, 20 and the non-stretchable sheet 3, for example, substantially inelastic inelastic fibers can be used, in which case the sheets 20, 20 can become stretchable fiber layers with the inelastic fibers as the main body. As substantially inelastic inelastic fibers, for example, fibers formed of polyesters such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamides, etc. can be cited. The constituent fibers can be short fibers or long fibers, and can be hydrophilic or hydrophobic. In addition, core-sheath type or parallel type composite fibers, split fibers, special-shaped cross-section fibers, crimped fibers, heat-shrinkable fibers, etc. can also be used. These fibers can be used alone or in combination of two or more.

[0077] As a preferred example of the fiber constituting the sheets 20, 20 and the non-stretchable sheet 3, there can be cited fibers consisting of two or more components of a low melting point component and a high melting point component. As a composite fiber consisting of two or more components of a low melting point component and a high melting point component, a core-sheath type composite fiber is preferred, wherein the core is preferably high melting point PET, PP, and the sheath is preferably low melting point PET, PP, PE.

[0078] The elastic yarn 21 is made of elastic resins such as thermoplastic elastomers and rubber. In particular, when a thermoplastic elastomer is used as a raw material, melt spinning using an extruder can be performed in the same manner as a conventional thermoplastic resin, and the elastic yarn obtained in this way is easy to be heat-welded, so it is suitable for the stretch sheet 2. As thermoplastic elastomers, for example, styrene elastomers such as SBS (styrene-butadiene-styrene), SIS (styrene-isoprene-styrene), SEBS (styrene-ethylene-butadiene-styrene), SEPS (styrene-ethylene-propylene-styrene), olefin elastomers (ethylene-based α-olefin elastomers, propylene elastomers obtained by copolymerizing ethylene, butene, octene, etc.), polyester elastomers, polyurethane elastomers, etc., can be cited, and one of them can be used alone or two or more of them can be used in combination.

[0079] Regarding the above-mentioned embodiment, the present invention further discloses the following method for producing a stretchable composite sheet and apparatus for producing a stretchable composite sheet.

[0080] <1>

[0081] A method for producing a stretchable composite sheet, wherein a stretchable first sheet and a non-stretchable second sheet having a width wider than the first sheet are laminated together.

[0082] The method for manufacturing a stretchable composite sheet includes a joining step of intermittently joining the first sheet and the second sheet in a sheet conveying direction along the one direction, wherein the first sheet overlaps a portion of the second sheet in a state of being stretched in one direction, and the first sheet and the second sheet are joined together.

[0083] In the bonding step, in addition to forming the bonding portion in the first region, a bonding portion is also formed at a boundary between the first region and the second region.

[0084] <2>

[0085] In the method for manufacturing a stretchable composite sheet described in <1> above, the joining step utilizes a roller having a joining pattern on which joining protrusions are formed at prescribed intervals in the circumferential direction and a pressing component arranged opposite to the outer circumferential surface of the roller, so that the joining protrusions that are a part of the joining pattern abut against the boundary portion in a width direction orthogonal to the sheet conveying direction in a manner spanning the boundary portion, thereby forming the joining portion.

[0086] <3>

[0087] In the method for producing a stretchable composite sheet according to <2>, the joining pattern is a joining pattern in which the joining projections are formed at intervals in the width direction.

[0088] <4>

[0089] In the method for producing a stretchable composite sheet according to <3>, a line segment connecting the graphic centers of the patterns adjacent to each other in the sheet conveying direction of the joining pattern is inclined with respect to the sheet conveying direction.

[0090] <5>

[0091] In the method for producing a stretchable composite sheet according to <4>, the inclination angle of the line segment changes periodically and symmetrically with respect to the sheet conveyance direction.

[0092] <6>

[0093] In the method for producing a stretchable composite sheet according to any one of <2> to <5>, a width B of the joining pattern formed in the second region in the width direction is 5% or more and 100% or less relative to a width A of the second region.

[0094] <7>

[0095] In the method for producing a stretchable composite sheet according to any one of <1> to <6>, the first sheet is a stretchable sheet.

[0096] <8>

[0097] In the method for producing a stretchable composite sheet according to any one of <1> to <7>, the second sheet is a non-stretchable sheet.

[0098] <9>

[0099] In the method for producing a stretchable composite sheet according to any one of <1> to <8>, the width X2 of the second sheet in the width direction orthogonal to the sheet conveying direction is formed to be wider than the width X1 of the first sheet in the width direction.

[0100] <10>

[0101] In the method for manufacturing a stretchable composite sheet described in any one of the above <2> to <5>, the width B of the bonding pattern in the width direction is preferably 5% or more, more preferably 20% or more, more preferably 50% or more, preferably 100% or less, more preferably 95% or less, more preferably 90% or less, and preferably 5% or more and 100% or less, more preferably 20% or more and 95% or less, more preferably 50% or more and 90% or less.

[0102] <11>

[0103] A device for manufacturing a stretchable composite sheet, wherein a stretchable first sheet and a non-stretchable second sheet having a width wider than the first sheet are laminated together.

[0104] The manufacturing device of the stretchable composite sheet is characterized in that:

[0105] A bonding mechanism is provided for bonding the first sheet and the second sheet at intervals in a sheet conveying direction along the one direction, wherein the first sheet overlaps a part of the second sheet in a state where the first sheet is stretched in one direction, and the laminated sheet includes a first region having the first sheet and the second sheet and a second region having only the second sheet.

[0106] The joining mechanism forms a joining portion not only in the first region but also in the boundary between the first region and the second region.

[0107] <12>

[0108] In the manufacturing device of the stretchable composite sheet described in <11>, the bonding mechanism includes a roller having a bonding pattern with bonding protrusions formed at predetermined intervals in the circumferential direction, and a pressing member arranged opposite to the outer circumferential surface of the roller,

[0109] The joining portion is formed by causing a part of the joining pattern to come into contact with the boundary portion so as to straddle the boundary portion in a width direction perpendicular to the sheet conveying direction.

[0110] <13>

[0111] In the manufacturing apparatus of the stretchable composite sheet described in the above <12>, the joining pattern is formed on the roller as a joining pattern in which the joining projections are formed at intervals in the width direction.

[0112] <14>

[0113] In the manufacturing apparatus of the stretchable composite sheet according to the above <13>, the line segment connecting the graphic centers of the patterns adjacent to each other in the sheet conveying direction of the joining pattern is formed to be inclined with respect to the sheet conveying direction.

[0114] <15>

[0115] In the manufacturing apparatus of the stretchable composite sheet described in the above <14>, the joining pattern is formed so that the inclination angle of the line segment changes periodically and symmetrically with respect to the sheet conveying direction.

[0116] <16>

[0117] In the manufacturing device of the stretch composite sheet described in any one of <12> to <15>, the width B in the width direction of the joining pattern formed by the joining mechanism in the second region is 5% or more and 100% or less relative to the width A in the width direction of the second region.

[0118] Industrial Applicability

[0119] According to the method and apparatus for producing a stretchable composite sheet of the present invention, the joining portion is formed at the boundary between the first sheet and the second sheet in addition to the first region, so that the boundary does not curl up.

Claims

1. A method for producing a stretchable composite sheet, wherein a first stretchable sheet and a second non-stretchable sheet having a width wider than the first sheet are laminated together, The method for producing the stretchable composite sheet is characterized in that: The method comprises a step of joining the first sheet and the second sheet at intervals in a sheet conveying direction along the one direction, wherein the first sheet overlaps a part of the second sheet in a state of being stretched in one direction, and the laminated sheet includes a first region having the first sheet and the second sheet and a second region having only the second sheet. In the bonding step, in addition to forming a bonding portion in the first region, a bonding portion is also formed at a boundary between the first region and the second region. In the joining process, the laminated sheet is introduced between a roller having a joining pattern with joining protrusions formed at predetermined intervals in the circumferential direction and a pressing member arranged opposite to the outer circumferential surface of the roller, so that the joining protrusions of a part of the joining pattern abut against the boundary portion in a width direction orthogonal to the sheet conveying direction so as to straddle the boundary portion, thereby forming the joining portion in the first region and the boundary portion. The joining pattern is a joining pattern in which the joining projections are formed at intervals in both the sheet conveying direction and the width direction, and A line segment connecting the graphic centers of the patterns of the joining pattern adjacent to each other in the sheet conveying direction is inclined with respect to the sheet conveying direction.

2. The method for producing a stretchable composite sheet according to claim 1, wherein: The inclination angle of the line segment changes periodically and symmetrically with respect to the sheet conveying direction.

3. The method for producing a stretchable composite sheet according to claim 1 or 2, wherein: A width B of the bonding pattern formed in the second region in the width direction is 5% or more and 100% or less relative to a width A of the second region.

4. The method for producing a stretchable composite sheet according to claim 1 or 2, wherein: The first sheet is a stretch sheet.

5. The method for producing a stretchable composite sheet according to claim 1 or 2, wherein: The second sheet is a non-stretchable sheet.

6. The method for producing a stretchable composite sheet according to claim 1 or 2, wherein: The width X2 of the second sheet in the width direction orthogonal to the sheet conveying direction is formed to be wider than the width X1 of the first sheet in the width direction.

7. The method for producing a stretchable composite sheet according to claim 1 or 2, wherein: The width B of the bonding pattern in the width direction is 20% or more and 95% or less of the width A of the second region.

8. The method for producing a stretchable composite sheet according to claim 1, wherein: The joining portion is formed by using a supporting roller having a joining protrusion formed in the circumferential direction, and is formed by arranging the joining protrusions arranged in series along the outer circumferential surface of the supporting roller in a manner that is symmetrically inclined relative to the sheet conveying direction and whose positions are alternately staggered and inclined relative to the circumferential direction of the supporting roller.

9. The method for producing a stretchable composite sheet according to claim 1, wherein: As the joining portion, a curved joining portion that periodically changes symmetrically with respect to the sheet conveying direction is formed.

10. The method for producing a stretchable composite sheet according to claim 2, wherein: The angle θ of the inclination of the line segment is greater than or equal to 0.01° and less than or equal to 45°.

11. The method for producing a stretchable composite sheet according to claim 1, wherein: The bonding pattern is formed as a dot pattern in which a plurality of cylindrical bonding projections are arranged at intervals in the sheet conveyance direction and the width direction.

12. The method for producing a stretchable composite sheet according to claim 1, wherein: The joining pattern is a linear joining pattern in which rectangular joining portions are continuously formed in a width direction orthogonal to the sheet conveying direction and cross a boundary portion and are formed at intervals in the sheet conveying direction.

13. The method for producing a stretchable composite sheet according to claim 1, wherein: The bonding pattern has a plurality of different patterns capable of forming a bonding portion divided into a region inclined with respect to the sheet conveying direction and a region not inclined.

Images