TWI637838B - Composite sheet and method of manufacturing same - Google Patents

Abstract

The method for producing a composite sheet according to the present invention includes a embossing forming step of biting the first sheet (2') into the nip portion of the first roll (11) and the second roll (21) and imparting thereto Concave-convex; intermediate manufacturing step of superposing the second sheet (3') with the first sheet (2') and joining the second sheet (3') to the first sheet (2) a plurality of first joint portions (4) corresponding to portions of the convex portions (14) of the first roll (11) to obtain a composite sheet intermediate (1'); and a joining step of using The third roll (31) having a concavo-convex shape different from the concavo-convex shape of the first roll (11) on the circumferential surface forms a second joint portion (5) in the composite sheet intermediate (1'). The second joint portion (5) is formed by a pattern in which one first joint portion (4) and another first joint portion (4) adjacent thereto are connected.

Description

Composite sheet and method of manufacturing same

The present invention relates to a method of manufacturing a composite sheet comprising two sheets and having a plurality of convex portions formed in one sheet.

It is known that a spunbonded nonwoven fabric is spot-bonded to at least one surface of an elastic material to form a composite nonwoven fabric, and after the composite nonwoven fabric is stretched in a specific direction to apply a load, the load is removed, thereby producing a spunbonded nonwoven fabric. A composite nonwoven fabric which is loose and becomes bulky (refer to Patent Document 1). This composite nonwoven fabric is used as a side belt of a pants-type diaper. As a method of obtaining a composite sheet having a plurality of convex portions, in addition to the method described in Patent Document 1, the methods described in Patent Documents 2 and 3 are also known.

However, the non-woven fabric described in Patent Document 1 is slack due to plastic deformation by the spunbonded nonwoven fabric, so that it is not easy to always produce slack with good reproducibility at a constant size. In view of the shortcomings of such a conventional composite sheet, the applicant has previously proposed a method of manufacturing a composite sheet which can eliminate the disadvantage (refer to Patent Document 4). The method for producing a composite sheet according to Patent Document 4 has a step of using a first roll including a peripheral surface having an uneven shape, and a second surface having a concave-convex shape in which a concave-convex shape of the first roll and a concave shape of the first roll are engaged. In the apparatus for manufacturing a composite sheet of rolls, the nip portion between the two rolls is bitten into the first sheet, and the first sheet is provided with irregularities, and the suction is formed by the suction path formed in the first roll. The first sheet is held on the peripheral surface of the first roll in a state of being unevenly shaped, and the second sheet is overlapped with the second sheet, and the second sheet is placed on the first roll. The first sheet on the convex portion is joined.

Prior technical literature Patent literature

Patent Document 1: Japanese Patent Laid-Open No. Hei 5-59655

Patent Document 2: Japanese Patent Laid-Open No. Hei 10-245757

Patent Document 3: Japanese Patent Laid-Open No. Hei 2-18036

Patent Document 4: Japanese Patent No. 4627077

The present invention relates to an improvement of a method for producing a composite sheet according to Patent Document 4, and more particularly to a method for producing a composite sheet which can provide a composite sheet excellent in appearance and strength.

The inventors of the present invention conducted various studies for the purpose of further improving the method for producing a composite sheet described in Patent Document 4, and as a result, found that in the composite sheet having irregularities obtained by the execution of the production method, The joint portion is additionally formed by using another joint pattern different from the joint pattern of the first sheet and the second sheet in the composite sheet, thereby improving the appearance and joint strength of the composite sheet.

The present invention has been completed based on the above findings, and the first and second sheets are partially joined to form a joint portion, and the first sheet is protruded from a portion other than the joint portion, and the inside is formed. A method of producing a composite sheet that is a plurality of convex portions of a cavity. The method for producing a composite sheet according to the present invention includes a step of forming a concavity and convexity, and using a first roll having a concave-convex shape on the circumferential surface, and a second surface having a concave-convex shape in which the uneven shape of the first roll is a bite shape on the circumferential surface The roller causes the nip between the two rolls to bite into the first sheet to impart unevenness to the first sheet; and the intermediate manufacturing step, the first sheet is always deformed by the uneven shape Holding the second sheet on the circumferential surface of the first roll, the second sheet is overlapped with the first sheet, and the second sheet is joined to the first sheet to correspond to the first sheet. a plurality of first joint portions are formed in a portion of the convex portion of the roll to obtain a composite sheet intermediate; and a joining step of using a circumferential surface having a difference from the uneven shape of the first roll In the third roll of the uneven shape, the two sheets constituting the intermediate of the composite sheet are placed in a state in which the peripheral surface of the third roll is held on the first sheet side of the composite sheet intermediate A portion corresponding to the convex portion of the third roller is joined to form a second joint portion in the composite sheet intermediate. The second joint portion is formed by a pattern in which one of the first joint portions and another one of the first joint portions adjacent thereto are connected.

Further, according to the present invention, the first and second sheets are partially joined to form a joint portion, and the first sheet is protruded from a portion other than the joint portion, and a plurality of cavities are formed inside. A composite sheet of convex portions. The composite sheet of the present invention includes a plurality of first joining portions formed as a scatter pattern by the regular pattern as the joint portion, and a second joining portion connecting the plurality of the first joining portions adjacent to each other.

1‧‧‧Composite sheet

1'‧‧‧Intermediate

1a‧‧‧ upper surface

1A~1D‧‧‧Composite sheet

1b‧‧‧ lower surface

2‧‧‧Upper

2'‧‧‧1st sheet

3‧‧‧Under

3'‧‧‧2nd sheet

4‧‧‧1st joint

5‧‧‧2nd joint

6‧‧‧ convex

10‧‧‧ Manufacturing equipment

11‧‧‧1st roll

11a‧‧‧ gear

11b‧‧‧ spacer

12‧‧‧Rotary axis

13‧‧‧ Gear Group

13'‧‧‧

13A‧‧‧ convex formation area

13A'‧‧‧

13B‧‧‧non-formed areas

13B'‧‧‧

14‧‧‧ convex

16‧‧‧Voids

17‧‧‧ openings

18‧‧‧Attracting the way

21‧‧‧second roller

22‧‧‧ Anvil Roll

31‧‧‧3rd roller

32‧‧‧Rotary axis

33‧‧‧ rotating body

34‧‧‧ recess

35‧‧‧ convex

40‧‧‧Connecting device

41‧‧‧4th roller

51(5)‧‧‧Linear

52(5)‧‧‧Linear

53(5)‧‧‧Continuous line

53a‧‧‧Linear

53b‧‧‧Linear

54(5)‧‧‧Continuous line

54a‧‧‧Linear

54b‧‧‧Linear

54c‧‧‧Linear

P‧‧‧ area

Q‧‧‧Area

X‧‧‧ direction

Y‧‧‧ direction

Fig. 1 is a perspective view showing an enlarged example of a composite sheet of the present invention produced by the production method of the present invention.

Fig. 2 is a schematic plan view showing a first sheet (upper layer) side of the composite sheet shown in Fig. 1 (an explanatory view of a pattern of the first joining portion and the second joining portion).

Fig. 3 is a schematic view showing an essential part of an embodiment of a manufacturing apparatus for a composite sheet used for carrying out the production method of the present invention.

Fig. 4 is a perspective view showing a main part of a first roller in the manufacturing apparatus shown in Fig. 3;

Fig. 5 is an exploded perspective view showing a portion of a first roller in the manufacturing apparatus shown in Fig. 3.

Fig. 6 is a perspective view showing a main part of a third roller in the manufacturing apparatus shown in Fig. 3.

7(a) to 7(d) are respectively a view corresponding to Fig. 2 of a variation of the composite sheet of the present invention produced by the production method of the present invention.

Hereinafter, the present invention will be described with reference to the drawings based on preferred embodiments of the present invention. First, an example of a composite sheet of the present invention produced by the method for producing a composite sheet of the present invention will be described with reference to Figs. 1 and 2 . In this embodiment In the composite sheet 1, as shown in FIGS. 1 and 2, the first and second sheets (the upper layer 2 and the lower layer 3) are partially joined to each other to form the joint portions 4 and 5 (the first joint portion 4). And the second joint portion 5). The first sheet (upper layer 2) protrudes beyond the joint portions 4 and 5 to form a plurality of convex portions 6 which become hollows inside. The upper layer 2 and the lower layer 3 are partially joined to the joint portions 4, 5, and the convex portion 6 is not joined. Further, the X direction of FIGS. 1 and 2 coincides with the direction (CD, Cross Machine Direction) orthogonal to the sheet conveying direction (MD, Machine Direction) at the time of manufacture of the composite sheet 1, and the Y direction and the sheet The material transport direction (MD) is the same.

When the composite sheet 1 is further described, the composite sheet 1 is configured to include the upper layer 2 as the first sheet and the lower layer 3 as the second sheet, and the upper layer 2 forms the upper surface 1a of the composite sheet 1. The lower layer 3 forms the lower surface 1b of the composite sheet 1. Moreover, when the composite sheet 1 is used as a front sheet for an absorbent article, the upper surface 1a (first sheet-like object) becomes the surface of the wearer's skin side when the absorbent article is worn ( The skin facing surface), the lower surface 1b (the second sheet) is a surface that faces the side of the wearer's skin when worn (non-skin contrast surface).

Typically, the upper layer 2 and the lower layer 3 are formed of various nonwoven fabrics or films, respectively. Examples of the nonwoven fabric include a non-woven fabric, a spunbonded nonwoven fabric, a melt-blown nonwoven fabric, a water needle nonwoven fabric, and a needle-punched nonwoven fabric produced by a carding method. When a film is used as the upper layer 2 and the lower layer 3, in particular, when the composite sheet 1 is used as a front sheet for an absorbent article, it is preferable to perforate the film as the upper layer 2 and the lower layer 3 and A plurality of openings are provided to allow liquid to pass through.

In the composite sheet 1, two kinds of joint portions 4 and 5 having different patterns are formed. In the joint portions 4 and 5, the upper layer 2 (first sheet) and the lower layer 3 (second sheet) are welded and integrated. In the present embodiment, the plurality of first joint portions 4 having a quadrangular shape in a plan view are formed in a scatter pattern by a regular pattern, and the second joint portion 5 is connected to the first joint portion 4 and The pattern of the other first joining portion 4 adjacent thereto is formed by patterning a plurality of first joining portions 4 and 4 adjacent to each other.

In the regular pattern of the first joint portion 4 in the present embodiment, a plurality of imaginary polygons are arranged on one surface of the composite sheet 1 without a gap, and the first joint portion 4 having a specific shape is disposed in a plurality of the plurality of A pattern of all the tops of the corners. More specifically, as shown in FIG. 2, the pattern is configured such that a plurality of imaginary hexagons (substantially hexagonal shapes) are arranged in a honeycomb shape on one surface of the composite sheet 1, and a first joint of a quadrangular shape in plan view. The portion 4 is arranged in a pattern of a plurality of six tops of the hexagons. In the pattern, a plurality of imaginary hexagonal shapes of the same shape (a hexagon formed by the six first joint portions 4) are connected in the Y direction (MD) without a gap to form a hexagonal line, and A plurality of lines of the hexagon are arranged in the direction (CD) without leaving a gap. The plurality of hexagonal lines are arranged such that the hexagonal shapes of the two adjacent rows in the X direction are staggered. In this embodiment, the hexagons of the two rows adjacent in the X direction are staggered in the Y direction by half. One pitch (one and a half the length of an imaginary hexagonal MD). There are three imaginary hexagons around each of the plurality of first joint portions 4, and one first joint portion 4 has a top portion of three imaginary hexagons existing around it. As shown in FIG. 2, a plurality of first joint portions 4 formed by such a regular pattern form a joint portion row including a plurality of first joint portions 4 arranged in a zigzag shape in the Y direction, and are spaced apart in the X direction. A plurality of rows of the joint row are arranged at a specific interval.

The second joint portion 5 is formed in a continuous linear shape, and is continuous with all of the plurality of first joint portions 4 which are formed in a regular pattern by a regular pattern, and is continuous by the second joint portion 5 The enclosed area is formed in a hexagonal shape in plan view. In this manner, the second joint portion 5 is configured to include a linear portion extending in a direction intersecting both the X direction and the Y direction. The width of the second joint portion 5 (the length in the direction orthogonal to the direction in which the linear portions extend) is kept constant without change.

As shown in FIG. 1 and FIG. 2, a plurality of convex portions 6 (that is, non-joining portions of the upper layer 2 and the lower layer 3) are respectively formed into six hexagonal first joint portions 4 in a plan view to connect the six portions 6 to each other. The first joining portion 4 is continuously surrounded by the second joining portion 5 having a hexagonal shape in plan view. Each of the plurality of convex portions 6 is formed in a substantially hexagonal shape in plan view, and as a whole Formed as a flat hexagonal column with a radiant arc of curvature. That is, on the upper surface 1a of the composite sheet 1, a plurality of convex portions 6 having a substantially hexagonal shape in plan view are parallel to each other with the opposite sides of the adjacent convex portions 6, 6 spaced apart from each other. The arrangement is such that the arrangement is substantially honeycomb-shaped, and the interval becomes the second joint portion 5.

As shown in FIGS. 1 and 2, the plurality of convex portions 6 are arranged in a zigzag shape. Here, the zigzag pattern refers to a row in which a plurality of convex portions 6 are arranged at equal intervals in one direction, and is arranged in a direction orthogonal to the one direction as a plurality of rows, and is orthogonal to the one direction. The two adjacent rows are offset from each other with a convex portion 6 (preferably shifted by a half pitch). As will be described in more detail, when a plurality of rows in which a plurality of convex portions 6 are arranged at equal intervals in one direction are projected in a direction orthogonal to the one direction, adjacent to the specific row When the projection images of the convex portions 6 of one row are arranged between the projection images of the convex portions 6 of a particular row (preferably in the middle), it is considered that the plurality of convex portions 6 are arranged in a zigzag shape. Further, the "arranged in the zigzag shape" mentioned in the present invention includes not only the configuration in which a plurality of convex portions 6 are perfectly arranged as described above, but also the occurrence of manufacturing inevitable deviations, etc. The form of the deviation of the unintended minor configuration. When the plurality of convex portions 6 are arranged in a zigzag shape, for example, when the composite sheet 1 is used as a front sheet for an absorbent article, the pressure of contact with the wearer's skin of the absorbent article is It is uniformly dispersed to achieve good cushioning properties, and the absorption of the liquid is maintained uniformly in the entire composite sheet 1 as a whole.

Since the composite sheet 1 of the present embodiment has the joint portions 4 and 5 as described above, the convex portion 6 has high visibility and the shape of the convex portion 6 is outstanding, and the appearance is excellent. Further, since the two sheets (the upper layer 2 and the lower layer 3) are joined to the joint portion 5 in addition to the joint portion 4, the strength is excellent, and the convex portion 6 is maintained well. Further, since the upper surface 1a has the uneven shape including the joint portions 4 and 5 and the convex portion 6, the composite sheet 1 is used as a front sheet for an absorbent article such as a disposable diaper or a menstrual napkin. In the case of use, the surface of the absorbent article is worn by setting the surface 1a having the uneven shape to the opposite side of the skin. The contact area between the skin of the person and the front sheet (composite sheet 1) is reduced, and the air permeability is improved, thereby effectively preventing discomfort such as sultry heat and rash. Further, in the joint portions 4 and 5, the constituent fibers constituting the upper layer 2 and the lower layer 3 of the composite sheet 1 are melted and formed into a film shape, thereby forming a liquid which is hard to permeate the liquid in the thickness direction of the composite sheet 1. unit. Therefore, for example, when the composite sheet 1 is used as a front sheet for an absorbent article, even if excretion liquid such as urine enters the joint portions 4 and 5, the excretion liquid in the joint portions 4 and 5 does not. The composite sheet 1 is transmitted in the thickness direction, but flows along the joint portions 4, 5, particularly along the continuous linear second joint portion 5, to the upper surface 1a (the skin facing surface). As described above, the joint portions 4 and 5 can function as a liquid guide path that controls the flow in the liquid surface direction and promotes the diffusion of the liquid surface. Further, since the convex portion 6 has a cavity inside, the concealing effect is also absorbed in the absorbent article by the absorbent body disposed on the non-skin opposing side of the front sheet (composite sheet 1). The color of the excrement becomes shallow as viewed from the side of the front sheet.

From the viewpoint of exerting the above-described effects more reliably, it is preferable that the size and the like of each portion in the composite sheet 1 are set as follows.

A plurality of first joining area 4 each is preferably 0.6mm ² or more, and further preferably 0.8mm ² or more, and preferably 1.4mm ² or less, and further preferably 1.2mm ² or less, more specifically Preferably, it is 0.6 to 1.4 mm ² , and further preferably 0.8 to 1.2 mm ² .

The viewpoint of improving the visibility of the joint portion 5 and ensuring the joint strength of the joint portion 5 and securing the durability of the rolls (the first and second rolls described below) used for forming the joint portion 5 In view of the above, the width of the second joining portion 5 (the length in the direction orthogonal to the extending direction of the linear portion) is preferably 0.2 mm or more, and more preferably 0.5 mm or more. Moreover, it is preferable that the width of the second joining portion 5 is a width that does not protrude from the first joining portion 4 when the first joining portion 4 is overlapped, that is, is narrower than the width of the first joining portion 4.

The apparent thickness of the composite sheet 1 under the pressure of 0.36 kPa (the thickness of the composite sheet 1 in the formation region of the convex portion 6) is preferably 0.5 mm or more, more preferably 1.0 mm or more, and further preferably It is 5.0 mm or less, more preferably 4.0 mm or less, and more specifically, preferably. It is 0.5 to 5.0 mm, and more preferably 1.0 to 4.0 mm.

Next, a method of manufacturing the composite sheet 1 will be described with reference to the manufacturing apparatus of the composite sheet shown in FIGS. 3 to 7 as a method of manufacturing the composite sheet of the present invention. As shown in Fig. 3, the manufacturing apparatus 10 of the present embodiment includes a first roller 11 having a concave-convex shape on its circumferential surface, and a second roller 21 having a concave-convex shape on the circumferential surface of the second roller 11 in a shape of a snap. The uneven shape; the anvil roll 22 (the joining means for forming the first joining portion 4) is disposed so as to face the first roll 11 with the circumferential surface thereof; and the third roll 31 has the surface of the first roll 11 and the first roll 11 a concavo-convex shape having a different concavo-convex shape; a bonding device 40 that forms a second bonding portion 5 on the workpiece (composite sheet intermediate 1') together with the third roller 31; and a fourth roller 41, Each of the first roller 11 and the third roller 31 is disposed such that the circumferential surfaces thereof face each other.

The first roller 11 and the second roller 21 are disposed such that the uneven portions of the respective roller circumferential surfaces are engaged with each other. In addition, the first roller 11 and the anvil roller 22 are disposed such that the top of the convex portion 14 on the circumferential surface of the first roller 11 abuts against the circumferential surface of the anvil roller 22.

Fig. 4 is a perspective view showing a principal part of the first roller 11, and Fig. 5 is an exploded perspective view showing a part thereof. The first roller 11 is formed by combining a plurality of gears 11a and spacers 11b including spur gears of the same modulus, and the members 11a and 11b are attached to the rotating shaft 12 in a concentric shape and formed into a roll shape. The thickness of the spacer 11b is preferably 0.5 to 2.0 times the thickness of the gear 11a, and more preferably 0.8 to 1.2 times. In the present embodiment, the gear 11a and the spacer 11b have the same width. The center opening of the gear 11a and the spacer 11b has a rotating shaft 12 inserted into the opening. A notch portion (not shown) is formed in each of the gear 11a, the spacer 11b, and the rotating shaft 12, and a wedge (not shown) is inserted into the notch portion. Thereby, the idling of each of the gears 11a and the spacers 11b is prevented.

As shown in Fig. 5, the gear 11a and the spacer 11b are different in diameter from the tip end, and the diameter of the tip end of the spacer 11b is substantially the same as the diameter of the disc-shaped portion of the gear 11a from which the teeth are removed, and the gear 11a is larger than the spacer 11b. The tip circle has a larger diameter.

In the first roller 11, one piece of gear is disposed on each of the two spacers 11b on both sides thereof 11a, and the complex array is arranged with the gear group 13 of the three pieces. In each gear group 13, as shown in Fig. 4, the two gears 11a, 11a are arranged such that the teeth of the two gears 11a, 11a are juxtaposed in the direction of the rotation axis of the roller 11, i.e., the teeth of the two gears 11a, 11a are separated. The specific interval (corresponding to the interval between the thicknesses of the one spacers 11b) is arranged so as to face the direction of the rotation axis of the roller 11. Here, the "rotational axis direction of the roller 11" is an extending direction of the rotating shaft 12, and corresponds to the X direction of FIGS. 1 and 2.

By assembling the two kinds of gears 11a and 11a and the one spacer 11b in this manner, the pair of processed sheets (the first sheet 2' are formed on the circumferential surface of the first roller 11 (each gear group 13). The convex portion (the convex portion 14) used for the unevenness is provided, and the convex portion forming region 13A and the convex portion non-forming region 13B where the convex portion is not formed are alternately formed in the rotation axis direction of the roller 11. The convex portion forming region 13A includes a circumferential surface of the gear 11a, and the convex portion 14 includes teeth of the gear 11a. The plan view shape of the tip end surface of the convex portion 14 (the teeth of the gear 11a) corresponds to the plan view shape of the first joint portion 4 of the composite sheet 1, and is a quadrangular shape in the present embodiment. On the other hand, the convex non-formation region 13B includes the circumferential surface of the spacer 11b. The spacer 11b has teeth on the circumferential surface, but as described above, since the diameter of the tip circle is substantially the same as the diameter of the disk-shaped portion of the gear 11a from which the teeth are removed (refer to FIG. 5), the teeth of the spacer 11b. When the unevenness is applied to the to-be-processed sheet (1st sheet 2'), it is not utilized.

The gear group 13 is used in two or more groups. Each of the gear trains 13 is disposed such that the pitch of the uneven portions in the adjacent gear groups 13 and 13 is shifted. In the present embodiment, the positions of the concavo-convex portions of the adjacent gear groups 13, 13 are shifted by a half pitch in the rotational direction of the roller 11.

As shown in FIG. 5, in each gear group 13, as shown in FIG. 5, a plurality of gap portions are formed at regular intervals in the rotation direction of the roller 11 between the two gears 11a and 11a (the convex portion non-formation region 13B). 16. Each of the gap portions 16 is formed by two kinds of gears 11a and 11a and a spacer 11b located between the two. More specifically, each of the gap portions 16 is defined by the opposing side faces of the two gears 11a and 11a and the two adjacent teeth of the spacer 11b. Therefore, the gap portion 16 is formed in the same number as the number of teeth of the spacer 11b. The void portion 16 is not formed in the convex portion The area 13B opens to the outside.

In the gear 11a, a plurality of openings 17 are formed so as to surround the opening through which the center of the rotary shaft 12 is inserted. Each of the openings 17 has the same diameter and is formed at a position equidistant from the center of the gear. The angles formed by the adjacent opening portions 17, 17 and the center of the gear are equal. The number of the openings 17 in each of the gears 11a is the same as the number of teeth of the spacer 11b. Further, when the gear groups 13 are assembled, the gears 11a and the spacers 11b are disposed such that the respective opening portions 17 are located between adjacent teeth of the spacer 11b. In the state in which the gear groups 13 are assembled in this manner, and the gear groups 13 are arranged such that the distance between the uneven portions is different from each other, the opening portions 17 of the respective gears 11a are connected in the direction of the rotation axis of the roller 11 so as to be inside the roller 11 A plurality of suction paths 18 extending in the direction of the rotation axis are formed. Further, each suction path 18 communicates with the gap portion 16 described above.

At least one end of the suction path 18 communicates with a suction source (not shown) such as a blower or a vacuum pump. Therefore, when the suction source is operated and the suction operation is performed, the air is sucked from the gap portion 16 in the convex portion non-formation region 13B via the suction path 18. Since the first roller 11 has such a suction mechanism for the air from the gap portion 16, the sheet can be held on the circumferential surface by suction from the inside of the roller.

The second roller 21 has the same configuration as the first roller 11 except that the diameter (the tip circle diameter) is shorter than that of the first roller 11, and has a concave surface on the circumferential surface of the first roller 11 The shape is a concave-convex shape of a bite shape. However, the second roller 21 does not have the suction mechanism of the air provided in the first roller 11, and the sheet cannot be held on the circumferential surface by suction from the inside of the roller.

The anvil roll 22 includes a cylindrical rotating body that is rotatably supported by the rotation of the rotating shaft, and is disposed such that the circumferential surface of the rotating body faces the circumference of the first roller 11 . The circumferential surface of the anvil roll 22 does not have a concavo-convex shape, and is substantially (macroscopically) smooth. A heating device (not shown) is attached to the anvil roll 22, and heat is transferred to the circumferential surface of the processed sheet (the second sheet 3') by heat conduction from the heating device. Furthermore, in order to improve the first piece The shape of the uneven shape of the shape and the formability of the first joint portion may be the same as that of the first roller 11.

As shown in FIG. 6 , the third roller 31 includes a cylindrical rotating body 33 that is rotatably supported by the rotation of the rotating shaft 32 , and has a circumferential surface of the first roller 11 on the circumferential surface of the rotating body 33 . Concave and convex shapes with different concave and convex shapes. The uneven shape of the circumferential surface of the rotating body 33 corresponds to the uneven shape on the layer 2 side of the composite sheet 1, and the plurality of concave portions 34 having a hexagonal shape in plan view are opposite to the adjacent concave portions 34, 34. The surfaces are arranged in parallel with each other at intervals (that is, arranged in a substantially honeycomb shape), and the convex portions 35 are formed in the spaces. Here, the term "planar view" refers to a case where the concave-convex shape of the circumferential surface of the roller 31 is observed from the outer side in the normal direction of the circumferential surface (the direction orthogonal to the rotation axis direction of the roller 31).

As described below, the uneven shape of the circumferential surface of the third roller 31 (rotating body 33) is pressed by the uneven shape (the plurality of convex portions 14) of the circumferential surface of the first roller 11 The shaped sheet to be processed (the side of the first sheet 2' in the composite sheet intermediate 1') has a bite shape. In short, the uneven shape of the circumferential surface of the third roll 31 is a shape that can receive the unevenness of the first sheet 2' in the composite sheet intermediate 1' on the circumferential surface thereof. In the present embodiment, the circumferential surface of each of the first roller 11 and the third roller 31 is assumed to be planar and overlapped in order to realize the engagement shape of the roller and the sheet to be processed. The division of the circumferential surface of the first roller 11 is formed by a plurality of convex portions of the processed sheet by extrusion by the uneven shape of the roller 11 (in the present embodiment, it is finally The center of the area surrounded by the convex portion 14 (the teeth of the gear 11a) and the periphery of the third roller 31 are a plurality of each of the convex portions 6 of the composite sheet 1 (in the present embodiment) The centers of the recesses 34 on the face are identical. Therefore, the uneven shape of the circumferential surface of the third roller 31 is different from the uneven shape of the circumferential surface of the first roller 11, but the uneven shape of the circumferential surface of the third roller 31 becomes an acceptable composite sheet intermediate 1 In the state in which the first sheet 2' of the composite sheet intermediate 1' is embossed, the first sheet 2' of the composite sheet intermediate 1' is engaged with the uneven shape of the circumferential surface of the third roll 31. Keep it on the circumference.

A plurality of fine portions are formed on the formation region of each concave portion 34 on the circumferential surface of the third roller 31. a vent hole (not shown), and a suction path (not shown) that communicates with the vent hole, a suction source (not shown) such as a blower or a vacuum pump, and the suction hole (not shown) are formed inside the third roller 31. When the source operation is performed and the suction operation is performed, air is sucked from the vent hole through the suction path. Since the third roller 31 has such an air suction mechanism from the vent hole of the circumferential surface, the sheet can be held on the circumferential surface by suction from the inside of the roller.

The joining device 40 is disposed opposite to the circumferential surface of the third roller 31, and forms a joint portion in the processed sheet (composite sheet intermediate 1') between the two 31 and 32 together with the third roller 31 ( Second joint portion 5). In the present embodiment, a known ultrasonic sealing device is used as the bonding device 40.

The fourth roller 41 has the same basic configuration as the anvil roller 22, and includes a cylindrical rotating body rotatably supported by the rotation of the rotating shaft. The circumferential surface of the rotating body does not have a concave-convex shape, and substantially (macroscopically) It is smoother. Further, a plurality of fine vent holes (not shown) are formed on the circumferential surface of the fourth roller 41, and a suction source such as the vent hole, the blower, and the vacuum pump is formed inside the fourth roller 41 (not shown). In the suction passage (not shown) that is connected, when the suction source is operated to perform the suction operation, the air is sucked from the vent hole through the suction passage. Since the fourth roller 41 has such an air suction mechanism from the vent hole of the circumferential surface, the sheet can be held on the circumferential surface by suction from the inside of the roller.

As described above, in the manufacturing apparatus 10, since the first roller 11, the third roller 31, and the fourth roller 41 are each configured to hold the sheet on the circumferential surface thereof by suction from the inner side of the roller, In the method for producing the composite sheet 1 described above, between the step of forming the first joining portion 4 (the intermediate production step) and the step of forming the second joining portion 5 (joining step), the processed sheet (composite) may not be used. The phase of the uneven pattern in the sheet intermediate 1') is shifted to convey the processed sheet, whereby the specific portion of the composite sheet intermediate 1' in which the first joining portion 4 is formed can be further The second joint portion 5 is formed with high precision.

Further, in the method for producing the composite sheet 1 described below, the step of forming the first joining portion 4 (the intermediate manufacturing step) and the step of forming the second joining portion 5 (joining step) In view of the fact that the phase of the uneven pattern in the processed sheet (composite sheet intermediate 1') is not shifted, the manufacturing apparatus 10 preferably has the following configuration A or B.

. In the configuration A, each of the rollers 11, 21, 22, 31, and 41 in the manufacturing apparatus 10 is synchronously rotated by transmitting a driving force from the same driving source by using a known gear or a belt-shaped rolling element attached thereto. Set by the way.

. Configuration B: The manufacturing apparatus 10 includes the same number of servo motors as the number of the rollers 11, 21, 22, 31, and 41, and each roller is connected to each servo motor in a one-to-one manner, and the servo connected to the roller can be utilized. The motor controls the rotation of each roller.

A method of manufacturing the composite sheet 1 using the manufacturing apparatus 10 having the above configuration will be described. First, a strip-shaped first sheet 2' as a material for forming the upper layer 2 is successively sent out from a roll-shaped original sheet (not shown), and is sent out from another original sheet of a roll shape (not shown). A strip-shaped second sheet 3' as a material for forming the lower layer 3. Then, as shown in FIG. 3, the nip portion of the first roller 11 and the second roller 21 is bitten into the first sheet 2' to be fed, and the first sheet 2' is provided with irregularities (concave-convex forming step).

By the uneven shape of the first sheet 2', the first sheet 2' is formed by a regular pattern with the first joint portion 4 of the composite sheet 1, that is, with the sheet. One of the plurality of imaginary hexagons is arranged in a honeycomb shape, and the first joint portion 4 having a specific shape (a quadrangular shape in plan view) is disposed on the top of each of the plurality of hexagons. The pattern forms a plurality of concave portions (extruded portions) formed by pressing by a plurality of convex portions 14 of the rolls 11 when the two rolls 11, 21 are engaged, and is composed of six concave portions ( Each of the plurality of regions surrounded by the extruded portion and having a hexagonal shape in a plan view forms a convex portion. Then, in the first sheet 2' which is formed by the unevenness, the bottom of the plurality of recesses (the pressed portion), that is, the contact portion with the tip end portion of the convex portion 14 of the first roller 11 is the next In the step (the intermediate production step), the portion of the first joining portion 4 in the composite sheet 1 is formed, and the convex portion formed in the hexagonal shape in plan view is finally formed into the composite sheet 1. The portion of the convex portion 6.

In the above-described uneven shape forming step, the first roll 11 is sucked as described above. The suction is applied from the nip portion of the first roller 11 and the second roller 21 to the merging portion of the first sheet 2' and the second sheet 3' to the most of the first roller 11 and the fourth roller 41. The approach portion (the transfer portion of the composite sheet intermediate 1') is controlled to be carried out. Therefore, the first sheet 2' which is formed by the unevenness of the first roll 11 and the second roll 21 is applied to the void portion formed in the convex portion non-formation region 13B formed in the first roll 11. The attraction of 16 is in close contact with the circumferential surface of the roller 11 and maintains its state of being convex and concave. When the suction is not performed, the first sheet 2' is floated from the circumferential surface of the first roll 11, and as a result, a sheet having a desired uneven shape cannot be obtained.

Next, as shown in FIG. 3, the first sheet 2' is held in a state in which the first sheet 2' is held in a concave-convex shape on the circumferential surface of the first roll 11, and the second sheet 3' and the first sheet are fed one after another. The sheet 2' is overlapped, and the second sheet 3' is joined to a portion of the first sheet 2' corresponding to the convex portion 14 of the first roller 11 (the recessed portion (the pressed portion) At the bottom portion, a plurality of first joint portions 4 (see FIG. 2) are formed, thereby obtaining a composite sheet intermediate 1' (intermediate production step).

In the present embodiment, in the intermediate manufacturing step, as a method of joining the second sheet 3' to the first sheet 2', as shown in FIG. 3, the first roll 11 and the anvil are used. A method of nip between the rolls 22 to overlap the first sheet 3' and the first sheet 2'. Both the first roller 11 and the anvil roller 22 or only the anvil roller 22 are previously heated to a specific temperature, and by the nip between the rollers 11, 22, the convex portion forming region in the first roller 11 is formed. The first sheet 2' and the second sheet 3' on the convex portion 14 of the 13A (see Fig. 4) (i.e., on the teeth of the respective gears 11a) are joined by thermal fusion, and the hot melt portion becomes the first 1 joint portion 4.

In addition, in FIG. 2, the correspondence relationship of the some 1st junction part 4 of the composite sheet 1 and each part of the 1st roll 11 (gear group 13) is shown. As shown in FIG. 2, the composite sheet 1 has a portion in which a row 13' extending in the Y direction (MD) is connected in three rows in the X direction (CD), and the row 13' of the composite sheet 1 is respectively described above. In the uneven forming step and the intermediate manufacturing step, a region formed by one of the first gears 11 is formed. Also, each row 13' of the composite sheet 1 Rows 13A' and 13B' extending in the Y direction are formed in a row in the X direction, and the row 13A' is formed in the uneven portion forming step and the intermediate manufacturing step, and the convex portion forming region 13A of the first roller 11 is used. In the formed region, the row 13B' is a region formed by the convex portion non-formation region 13B of the first roller 11 in the above-described uneven shape forming step and the intermediate material producing step. In the row 13A' of the composite sheet 1, the convex portion 14 (the teeth of the gear 11a) of the convex portion forming region 13A is spaced apart by a specific interval in the Y direction (corresponding to two adjacent to each other in the rotation direction of the roller 11). A plurality of first joint portions 4 are formed at intervals of the intervals between the convex portions 14 and 14. On the other hand, as described above, since the convex portion 14 is not formed in the convex portion non-formation region 13B, the first bonding portion 4 is not formed in the row 13B' of the composite sheet 1. Further, the plurality of convex portions 6 of the composite sheet 1 are respectively formed by the one gear group 13 of the first roller 11 and the gear group 13 in the uneven shape forming step and the intermediate manufacturing step. The other two sets of gear groups 13 adjacent to each other in the rotation axis direction of the roller 11 are defined close to the convex portion forming region 13A of the set of gear groups 13.

In the present embodiment, the fourth roller 41 disposed so that the circumferential surfaces of the first roller 11 and the third roller 31 are opposed to each other, as shown in FIG. 3, is obtained in the intermediate manufacturing step. The composite sheet intermediate 1' is directly transferred from the circumferential surface of the first roll 11 to the circumferential surface of the fourth roll 41 and held on the circumferential surface of the fourth roll 41, and further from the circumferential surface of the fourth roll 41. Directly transferred to the circumferential surface of the third roller 31.

In other words, first, the strip-shaped composite sheet intermediate 1' is sucked and held by the first sheet 2' side on the circumferential surface of the first roll 11, and is rotated by the rotation of the first roll 11 The conveyance is carried to the closest portion to the fourth roller 41, and is transferred to the circumferential surface of the fourth roller 41 at the closest portion. In this manner, the strip-shaped composite sheet intermediate 1' transferred to the circumferential surface of the fourth roll 41 is always sucked and held by the circumferential surface of the fourth roll 41 on the second sheet 3' side. By the rotation of the fourth roller 41, it is conveyed to the closest portion to the third roller 31, and is transferred to the circumferential surface of the third roller 31 at the closest portion. The transfer from the fourth roller 41 to the third roller 31 is performed such that the first sheet-like object 2' having the unevenness of the composite sheet intermediate 1' is on the circumferential surface side of the third roller 31.

The uneven shape of the circumferential surface of the third roll 31 (rotating body 33) and the first sheet 2' side of the composite sheet intermediate 1' which is formed by the unevenness in the uneven forming step are formed into a bite shape. Therefore, as shown in FIG. 3, the strip-shaped composite sheet intermediate 1' transferred to the circumferential surface of the third roll 31 is sucked and held by the first sheet 2' side of the uneven shape. The state of the circumferential surface of the third roller 31. In the state in which the composite sheet intermediate 1' is held, a plurality of the convex portions in the first sheet 2' of the composite sheet intermediate 1' are formed by the six first joint portions 4 The plurality of convex portions surrounded by a plurality of regions having a hexagonal shape in a plan view are respectively a plurality of convex portions that are inserted into the circumferential surface of the third roller 31 and surrounded by the convex portions 35 and have a hexagonal shape in plan view. The state inside the recess 34. The depth of the concave portion 34 is preferably the height of the convex portion from the viewpoint of not being crushed when the convex portion of the composite sheet intermediate 1' is inserted into the concave portion 34 of the third roller 31. That is, the height of the convex portion 14 (the teeth of the gear 11a) of the first roller 11 is the same or larger than the height.

Next, in a state where the peripheral surface of the third roll 31 is held on the side of the first sheet 2' of the composite sheet intermediate 1', the two sheets 2' constituting the composite sheet intermediate 1' are 3' is joined to a portion corresponding to the convex portion 35 of the third roller 31, whereby the second joining portion 5 (see FIG. 2) is formed in the composite sheet intermediate 1' (joining step). In the joining step, the composite sheet intermediate 1' is in a state in which the first sheet-like object 2'1 side of the uneven shape and the peripheral surface of the third roll 31 (rotating body 33) are engaged with each other. It is kept on the circumference.

In the present embodiment, the second sheet 3' side of the composite sheet intermediate 1' is held in the third position by the joining device 40 as the ultrasonic sealing device disposed on the circumferential surface. The composite sheet intermediate 1' in the state of the circumferential surface of the roller 31 is ultrasonically sealed, whereby the portions of the two sheets 2', 3' corresponding to the convex portions 35 of the third roller 31 are welded. The joining is performed to form the second joining portion 5 that is continuous with all of the plurality of first joining portions 4 that are formed in advance. In short, all of the first joint portions 4 overlap the second joint portion 5. In addition, there is a case where the first joint portion 4 and the second joint portion 5 are disposed, and the first joint portion 4 that is not overlapped with the second joint portion 5 is present at the side portion or the end portion of the sheet. But in addition to this When the first joining portion 4 is inevitably overlapped with the second joining portion 5, it is considered that "all the first joining portions 4 overlap the second joining portion 5".

By the above method, the composite sheet 1 shown in Figs. 1 and 3 is obtained. As described above, the method for producing a composite sheet according to the present embodiment relates to an improvement of the method for producing a composite sheet according to Patent Document 4 of the applicant's prior application, by the embodiment of the production method of the present embodiment. The obtained composite sheet 1 is particularly improved in appearance and strength. In other words, in the manufacturing method of the present embodiment, a plurality of ones formed by a regular pattern in a scatter pattern are formed on one surface side (the first sheet 2' side) obtained in the intermediate production step. The one side of the composite sheet intermediate 1' of the first joining portion 4 is additionally formed to have another pattern different from the pattern of the first joining portion 4 in the joining step which is one step below the intermediate manufacturing step. The second joining portion 5 of the pattern (the pattern of the one first joining portion 4 and the other one of the first joining portions 4 adjacent thereto) is formed, and thus the composite sheet 1 finally obtained and the composite sheet as the intermediate material thereof The appearance (appearance) of the intermediate 1' (composite sheet obtained by the execution of the production method described in Patent Document 4) is changed and improved, and the joint area is increased and the first joint is applied. The overlapping portion of the portion 4 and the second joining portion 5 is divided into two joining processes (sealing processing), and the strength is also improved.

Further, the composite sheet 1 can be preferably used for absorbent articles such as disposable diapers, menstrual sanitary napkins, and incontinence pads. The absorbent article is generally composed of a liquid-permeable front sheet, a liquid-impermeable back sheet, and a liquid-retaining absorber interposed between the sheets. The composite sheet 1 is preferably used as a constituent member of an absorbent article such as a front sheet, a back sheet, a disposable diaper having a fastening tape (so-called unfolded disposable diaper) The substrate sheet, the sheet for fastening the buckle, the substrate sheet of the side flap having the flank of the menstrual sanitary napkin, and, in addition, preferably used as a mechanical fastening A sheet for a ring member for a firmware, a sheet for cleaning, and a wiping sheet.

Further, the manufacturing apparatus 10 according to the present embodiment differs from the technique described in Patent Document 1 in that it is possible to form a convex portion with a desired distance and a good reproducibility at a constant size. The advantage of the convex portion of the composite sheet of 6. Further, since the gap portion 16 is provided between the gears 11a, the shape of the peripheral surface of the uneven roller to be used is not damaged. Therefore, there is an advantage that a plurality of small convex portions can be reliably formed at a small pitch. Further, the distance between the convex portions or the size can be freely changed by a simple operation of changing only the combination or width of the gears. The advantage of being able to form a plurality of smaller convex portions with smaller pitches is advantageous in terms of obtaining a good-looking sheet with a good touch, a high cushioning feeling, and a better visual impression.

In Fig. 7, a variation of the composite sheet obtained by the practice of the production method of the present invention is shown. The components that are different from the composite sheet 1 described above are mainly described as the same, and the same components are denoted by the same reference numerals, and the description thereof is omitted. The components that are not particularly described are appropriately applied to the description of the composite sheet 1. The composite sheets 1A to 1D shown in Fig. 7 are formed by the pattern in which the second joining portion 5 is formed by connecting one first joining portion 4 and another one of the first joining portions 4 adjacent thereto. Sheet 1 is common. The composite sheets 1A to 1D and the composite sheet 1 have the same configuration except for the pattern of the second joint portion 5. Further, the second joining portion 5 of the composite sheets 1A to 1D shown in Fig. 7 is configured to be included in a linear portion extending in a direction intersecting both the X direction (CD) and the Y direction (MD). Common. Further, the second joining portion 5 of the composite sheet 1 is continuous so as to overlap all of the plurality of first joining portions 4, but the second joining portions 5 of the composite sheets 1A to 1D shown in Fig. 7 are not uniform. In this manner, in the composite sheets 1A to 1D, a plurality of second joining portions 5 which are only partially overlapped with one of the plurality of first joining portions 4 are formed. The composite sheets 1A to 1D shown in Fig. 7 also exhibit the same effects as those of the composite sheet 1 described above.

In the composite sheet 1A shown in FIG. 7( a ), the second joining portion 5 is configured to include a plurality of strips adjacent to each other in the direction intersecting the X direction and the Y direction, and extending over the two first joining portions 4 . A linear portion 51 formed between the four. Each of the plurality of linear portions 51 extends in the same direction and has the same length. Further, only one linear portion 51 extends from one first joint portion 4, and two or more linear portions 51 are not extended.

In the composite sheet 1B shown in FIG. 7(b), the second joint portion 5 is configured to include a plurality of strips In addition to the linear portion 51, a plurality of linear portions 52 formed between the two first joint portions 4 and 4 are further included. The two first joint portions 4 and 4 that overlap the linear portion 52 are adjacent to each other in a direction intersecting the three directions in the X direction and the Y direction and the extending direction of the linear portion 51. Further, in the composite sheet 1B, a region P in which a plurality of linear portions 51 are formed at a predetermined interval in the Y direction is alternately formed in the X direction, and a plurality of straight lines are formed at a predetermined interval in the Y direction. Region Q of the portion 52. The linear portion 51 adjacent to the X direction and the linear portion 52 have a line symmetry relationship with respect to a virtual straight line (not shown) parallel to the Y direction.

In the composite sheet 1C shown in FIG. 7(c), the second joint portion 5 is configured to include a plurality of joints in a plurality of joint portions including a plurality of first joint portions 4 arranged in a zigzag shape in the Y direction. A plurality of continuous linear portions 53 extending in the Y direction by the plurality of first joint portions 4. Each of the continuous linear portions 53 is formed by connecting the two linear portions 53a and 53b extending in the direction intersecting the X direction and the Y direction in the Y direction without being spaced apart from each other in the Y direction, and is formed in a zigzag shape in plan view. . The two continuous linear portions 53 and 53 adjacent in the X direction are interposed by one imaginary straight line (not shown) extending in the Y direction via the center between the two continuous linear portions 53 and 53. The relationship of line symmetry.

In the composite sheet 1D shown in FIG. 7(d), the second joining portion 5 is configured to include a plurality of continuous linear portions 54 extending in the X direction via the plurality of first joining portions 4. Each of the continuous linear portions 54 is connected to the two linear portions 54a and 54b extending in the direction intersecting the X direction and the Y direction, and the linear portions 54c extending in the X direction are not spaced apart in the X direction. form.

The present invention is not limited to the above embodiment. For example, the configuration of the first roller 11 (the configuration of the gear group, the uneven shape of the circumferential surface, and the like) is not limited to the above-described embodiment, and can be appropriately changed depending on the uneven shape in the composite sheet which is a target of manufacture. Further, the second roller 21 may have a shape in which it is engaged with the first roller 11, and does not have the same configuration as the first roller 11. In the present invention, the technology related to the manufacturing apparatus described in Patent Document 4 can be suitably applied.

Further, in the above embodiment, the bonding device 40 is an ultrasonic sealing device, but the bonding device of the present invention is not limited thereto, and may be a roller (heat roller) having the same configuration as the anvil roller 22. Further, instead of the anvil roll 22, an ultrasonic sealing device having the same configuration as that of the bonding device 40 may be used.

Regarding the above-described embodiments of the present invention, the following supplementary notes (manufacturing method of composite sheet and composite sheet) are further disclosed.

<1> A method of producing a composite sheet, wherein the first sheet and the second sheet are partially joined to each other to form a joint portion, and the first sheet is protruded from a portion other than the joint portion. Further, the manufacturing method includes a plurality of convex portions having a cavity as a cavity, and the manufacturing method includes a step of forming a concavity and convexity, and using a first roll having a concave-convex shape on the circumferential surface, and having a concave surface on the circumferential surface and the first roll The second roll having a shape in which the shape is formed into a concave shape, the nip portion between the two rolls is bitten into the first sheet, and the first sheet is provided with irregularities; and the intermediate manufacturing step is performed on the first side. The sheet-like object is held on the peripheral surface of the first roll in a state of being unevenly shaped, and the second sheet is superposed on the first sheet, and the second sheet is joined to the first sheet. a plurality of first joint portions are formed in a portion of the one sheet corresponding to the convex portion of the first roll to obtain a composite sheet intermediate; and a joining step of using the first roll on the circumferential surface a third roller having a concavo-convex shape having different concavo-convex shapes, and holding the composite sheet on a circumferential surface of the third roller In the state of the first sheet side of the intermediate material, the two sheets constituting the intermediate material of the composite sheet are joined at a portion corresponding to the convex portion of the third roll, thereby interposing the composite sheet intermediate The second joint portion is formed in the middle portion, and the second joint portion is formed by a pattern in which one of the first joint portions and the other one of the first joint portions adjacent thereto are connected.

<2> The method for producing a composite sheet according to the above <1>, wherein the fourth roller disposed so that the circumferential surfaces of the first roller and the third roller are opposed to each other is used, and the intermediate portion is used The composite sheet intermediate obtained in the object production step is directly transferred from the circumferential surface of the first roll to the circumferential surface of the fourth roll and held on the circumferential surface of the fourth roll, and further The circumferential surface of the four rolls is directly transferred to the circumferential surface of the third roll.

<3> The method for producing a composite sheet according to the above <2>, wherein the first, third, and fourth rolls are each configured to hold the sheet on the circumferential surface thereof by suction from the inside of the roll.

The method for producing a composite sheet according to any one of the above aspects, wherein the uneven shape of the circumferential surface of the third roller is such that the peripheral surface thereof is acceptable in the intermediate sheet of the composite sheet. In the shape of the concavities and convexities of the first sheet, in the joining step, the composite sheet intermediate has a concave-convex shape of the first sheet-like side and the circumferential surface of the third roll formed by the unevenness It is held on the circumferential surface for the state of the occlusion.

<5> The method for producing a composite sheet according to the above <4>, wherein the first roller and the third roller are each planarly expanded and superposed on each other, the first roller The circumferential surface is defined by the center of the region surrounded by the plurality of convex portions of each of the plurality of convex portions of the processed sheet by the pressing of the uneven shape of the first roller. The centers of the concave portions on the circumferential surface of the third roller are identical.

The method of manufacturing a composite sheet according to any one of the above-mentioned, wherein the first roller system respectively combines a plurality of gears including a spur gear of the same modulus and a spacer, and the The gears and the spacers are mounted concentrically on the rotating shaft of the roller and formed into a roll shape.

The method for producing a composite sheet according to any one of the above-mentioned items, wherein the first roll is disposed so as to face each other on the circumferential surface of the first roll, and the first roll is used. And the anvil roll is heated to a specific temperature in advance, and in the intermediate manufacturing step, the second sheet and the first sheet are made between the first roll and the anvil roll When the sheets are overlapped, they are pinched.

The method for producing a composite sheet according to any one of the above-mentioned, wherein the second sheet-side pair of the composite sheet intermediate is held in the above-mentioned joining step The composite sheet intermediate in the state of the circumferential surface of the third roll is ultrasonically sealed.

<9> A composite sheet in which the first and second sheets are partially joined to form a joint portion, and the first sheet is protruded from a portion other than the joint portion, and the inside is formed to be empty. a plurality of convex portions of the cavity, and the bonding portion includes a plurality of first bonding portions formed in a regular pattern and having a scatter shape, and a second plurality of the first bonding portions adjacent to each other Joint.

<10> The composite sheet according to the above <9>, wherein the plurality of the convex portions are arranged in a zigzag shape.

<11> The composite sheet according to the above <9> or <10>, wherein the regular pattern of the first joint portion is a plurality of imaginary polygons arranged on one side of the composite sheet without a gap and having a specific shape The first joint portion is disposed on a pattern of a plurality of the tops of the plurality of polygons.

<12> The composite sheet according to the above <11>, wherein all of the first joining portions overlap the second joining portion.

The composite sheet according to the above <11> or <12>, wherein the second joining portion is configured to be included in a conveying direction of the sheet and a direction orthogonal to the conveying direction at the time of production of the composite sheet. The linear portion extending in the direction in which the two directions intersect.

The composite sheet according to any one of the above-mentioned <11>, wherein the pattern is a honeycomb element on a surface of the composite sheet, and a plurality of imaginary hexagons (substantially hexagonal) are arranged The first joint portion having a quadrangular shape in plan view is disposed on a pattern of six of the plurality of hexagonal shapes.

The composite sheet according to any one of the above <11> to <14> wherein The region surrounded by the second joint portion is formed in a hexagonal shape in plan view.

The composite sheet according to any one of the above-mentioned items, wherein the convex portion is formed by six hexagonal hexagonal joints in a plan view and connected to the six The first joint portion is continuous with the second joint portion which is hexagonal in plan view, and is formed into a substantially hexagonal column having a substantially hexagonal shape in plan view.

<17> The composite sheet according to the above <13>, wherein the plurality of linear portions constituting the second joining portion extend in the same direction and have the same length, and only one of the first joining portions extends One of the linear portions is not extended by two or more of the linear portions.

<18> The composite sheet according to the above <13>, wherein a plurality of regions P of the linear portions are formed at a predetermined interval in the MD (the direction in which the sheet is conveyed at the time of production of the composite sheet) A region Q in which a plurality of other linear portions extending in a direction different from the linear portion in the region P is formed at a predetermined interval, and the MD is alternately formed in a CD (direction orthogonal to the MD). The linear portion adjacent to the CD and the other linear portion have a line symmetry relationship based on an imaginary straight line parallel to the MD.

<19> The composite sheet according to the above <13>, wherein the second joining portion is configured to include a plurality of the plurality of joining portions included in the plurality of first joining portions arranged in a zigzag shape in the MD The first joint portion is a continuous linear portion extending in the MD.

<20> The composite sheet according to the above <19>, wherein the continuous linear portion is formed in a zigzag shape in a plan view.

The composite sheet according to the above <13>, wherein the second joining portion is configured to include a plurality of continuous linear portions extending from the plurality of first joining portions via the plurality of first joining portions.

The composite sheet according to any one of the above-mentioned <9>, wherein the composite sheet is used as a front sheet for an absorbent article.

The composite sheet according to any one of the above-mentioned <9>, wherein the first joint portion is formed as the two types of joint portions having different patterns in the composite sheet. And the second joint portion.

The composite sheet according to any one of the above-mentioned <1>, wherein the first and second sheets are formed by the respective first and second sheets. It is melted to form a film.

Industrial availability

According to the method for producing a composite sheet of the present invention, a composite sheet excellent in appearance and strength is obtained. Further, the composite sheet of the present invention can be produced by the method for producing a composite sheet of the present invention, and is preferably used as a constituent member (front sheet, etc.) of an absorbent article such as a disposable diaper or a menstrual napkin. . In particular, when the composite sheet of the present invention is used as a top sheet for an absorbent article, the front sheet is excellent in liquid diffusibility, and the liquid to be absorbed is excellent in concealability.

Claims (7)

A method for producing a composite sheet, wherein the first sheet and the second sheet are partially joined to form a joint portion, and the first sheet is protruded from a portion other than the joint portion, and is formed with The inside is a plurality of convex portions of the cavity, and the manufacturing method includes a embossing forming step of using a first roll having a concave-convex shape on the circumferential surface, and having a concave-convex shape on the circumferential surface of the first roll The second roll having a concave-convex shape, the first sheet is bitten into the nip between the rolls, and the first sheet is provided with irregularities; and the intermediate manufacturing step is performed on the first sheet. The object is held on the circumferential surface of the first roller in a state of being embossed, and the second sheet is overlapped with the first sheet, and the second sheet is joined to the first sheet. a plurality of first joint portions are formed corresponding to portions of the convex portions of the first roll to obtain a composite sheet intermediate; and a joining step of using a circumferential surface having a difference from the first roll The third roll of the uneven shape is held in the composite sheet by the circumferential surface of the third roll In the state of the first sheet side of the object, the two sheets constituting the intermediate material of the composite sheet are joined to a portion corresponding to the convex portion of the third roll, thereby being in the composite sheet intermediate The second joint portion is formed; and the second joint portion is formed by a pattern in which one of the first joint portions and the other one of the first joint portions adjacent thereto are connected. The method for producing a composite sheet according to claim 1, wherein the fourth roll disposed so that the circumferential surface of each of the first roll and the third roll is opposed to each other is used in the intermediate production step. The composite sheet intermediate material is directly transferred to the circumferential surface of the fourth roll from the circumferential surface of the first roll and held on the circumferential surface of the fourth roll, and further directly from the circumferential surface of the fourth roll The peripheral surface of the third roller is transferred. The method of producing a composite sheet according to claim 2, wherein the first, third, and fourth rolls are each configured to hold the sheet around the circumference by suction from the inner side of the roll. surface. The method for producing a composite sheet according to any one of claims 1 to 3, wherein the uneven shape of the circumferential surface of the third roll is such that the circumferential surface thereof is acceptable for the first sheet in the intermediate sheet of the composite sheet. In the above-described joining step, the composite sheet intermediate is held in a state in which the first sheet-like side formed by the uneven shape and the peripheral surface of the third roll are engaged with each other. On the circumference. The method of producing a composite sheet according to claim 4, wherein the circumferential surface of the first roll is unfolded when the circumferential surface of each of the first roll and the third roll is unfolded in a planar shape The center of the region surrounded by the plurality of convex portions formed in each of the plurality of convex portions of the processed sheet by the pressing of the uneven shape of the first roller and the third roller The center of the recess on the circumference is the same. The method of manufacturing a composite sheet according to any one of claims 1 to 3, wherein the first roller system respectively combines a plurality of gears and spacers including spur gears of the same modulus, and the gears and spacers are The rotating shaft of the roller is mounted concentrically and formed into a roll shape. The method for producing a composite sheet according to any one of claims 1 to 3, wherein in the joining step, the second sheet side of the composite sheet intermediate is held by the third roll The above composite sheet intermediate in the state of the surface is subjected to ultrasonic sealing.