WO2011025032A1

WO2011025032A1 - Method for producing absorbent article and stretching device

Info

Publication number: WO2011025032A1
Application number: PCT/JP2010/064812
Authority: WO
Inventors: 友美奥; 則昭伊藤; 坂口　智; 吉一小笠原
Original assignee: ユニ・チャーム株式会社
Priority date: 2009-08-31
Filing date: 2010-08-31
Publication date: 2011-03-03
Also published as: JP2011050493A; AR078006A1; CN101803974A; JP5623042B2; TW201124118A; TWI499406B

Abstract

Disclosed is a method for producing an absorbent article, which comprises a sheet heating step (S20) in which a composite sheet (120) is heated with a heating roll (510), and a sheet stretching step (S30) in which the composite sheet (120) is stretched in the cross direction (CD) with a pair of embossing roll mechanisms (520). In the sheet heating step (S20), the composite sheet (120) is heated to a temperature that is higher than the softening point of an adhesive material but lower than the lowest softening temperature among the softening temperatures of the plurality of sheets. In the sheet stretching step (S30), a plurality of projections constituting the embossing roll mechanisms (520) are heated to a temperature higher than 40°C but lower than the softening point of the adhesive material.

Description

Absorbent article manufacturing method and stretching apparatus

The present invention relates to a method for manufacturing an absorbent article comprising at least a composite sheet in which a plurality of sheets are bonded together with an adhesive, and an absorbent body attached to the composite sheet, and a stretching apparatus used in the method for manufacturing the absorbent article. About.

Absorbent articles such as sanitary napkins and diapers include a liquid-permeable top sheet that allows liquid to pass through, a liquid-impermeable back sheet that does not pass liquid, and an absorber provided between the top sheet and the back sheet. With. The back sheet is composed of a back film and a back nonwoven fabric provided outside the back film.

The back sheet is an inelastic material, and when used as it is, the texture is not good. Therefore, the back sheet is subjected to a treatment for improving flexibility and texture. For example, a gear stretching method is disclosed (see Patent Document 1).

The gear stretching method is a method in which a back sheet is passed between a pair of rolls having gear teeth meshing with each other to form unevenness in the thickness direction on the back sheet. Thereby, the back sheet is deformed into a shape along the gear teeth. Therefore, the back sheet is stretched in the width direction. Moreover, since the back sheet is thinned in the thickness direction as a result of being stretched in the width direction, the rigidity of the back sheet can be reduced.

However, since the back film and the back nonwoven fabric are bonded together with an adhesive, the degree of stretching is greatly different between a portion where the adhesive is applied and a portion where the adhesive is not applied. On the other hand, a method is known in which the back sheet is heated when the back sheet is bitten by the gear teeth by heating the gear teeth. According to this method, the adhesive material is softened, and it becomes easy to adapt to the unevenness of the gear teeth, so that the difference between the degree of stretching of the part where the adhesive is applied and the degree of stretching of the part where the adhesive is not applied can be reduced.

However, the conventional gear stretching method described above has the following problems. That is, the adhesive must be softened for a short period of time when the back sheet passes between a pair of rolls having gear teeth, and the temperature of the gear teeth must be increased as much as possible or the conveying speed must be delayed.

In the gear stretching method, the back nonwoven fabric is reduced in weight by the gear teeth pushing the back sheet, so if the heat transfer is insufficient, the back sheet will have uneven weight, and there will be holes (pinholes). It tends to occur. Moreover, when the temperature of the gear teeth is too high, there is a problem that the fibers of the back nonwoven fabric are thermally fused and hardened, and the texture is deteriorated.

JP 2002-316359 A (page 5)

The manufacturing method according to the first feature includes a composite sheet (back sheet 20) in which a plurality of sheets (for example, the back film 20A and the back nonwoven fabric 20B) are bonded together with an adhesive, and an absorbent body that is bonded to the composite sheet ( An absorbent article comprising at least an absorber 30). The manufacturing method of an absorbent article is a process A in which the composite sheet conveyed along the conveyance direction is heated by a heating roll (heating roll 510) rotating along the conveyance direction (machine direction MD) of the composite sheet. (Sheet heating step S20) and a plurality of convex portions (convex portions 532 and convex portions 542) are formed on the outer periphery, and the other convex portion is fitted between one convex portion with the composite sheet interposed therebetween. A step B (sheet stretching step S30) of stretching the composite sheet in a crossing direction (crossing direction CD) orthogonal to the transport direction by a pair of stamping roll mechanisms (embossing roll mechanism 520); In A, the composite sheet is heated to a temperature higher than the softening point of the adhesive and lower than the lowest softening temperature among the softening temperatures of the plurality of sheets. In the step B, Protrusion of the number is higher than 40 degrees, and is heated to a temperature lower than the softening point of the adhesive.

FIG. 1 is a plan view showing an absorbent article 1 according to this embodiment. FIG. 2 is a cross-sectional view (AA cross-sectional view of FIG. 1) showing the absorbent article 1 according to the present embodiment. FIG. 3 is a cross-sectional view (BB cross-sectional view of FIG. 1) showing the absorbent article 1 according to the present embodiment. Fig.4 (a) is a top view which shows the back surface sheet 20 which concerns on this embodiment (the 1). FIG. 4B is an enlarged cross-sectional view (AA cross-sectional view of FIG. 4A) showing the back sheet 20 according to the present embodiment. FIG. 5 is a plan view showing the back sheet 20 according to the present embodiment (No. 2). FIG. 6 is a diagram for explaining a method for manufacturing an absorbent article according to the present embodiment. FIG. 7A is an enlarged perspective view showing a part of the stretching apparatus 500 according to the present embodiment. FIG. 7B is an axial sectional view of the embossing roll mechanism 520 according to the present embodiment. FIG. 8 is a perspective view showing the widening roll mechanism 600 according to the present embodiment.

Hereinafter, a method for manufacturing an absorbent article and a stretching apparatus according to the present embodiment will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. However, it should be noted that the drawings are schematic and ratios of dimensions and the like are different from actual ones.

Therefore, specific dimensions should be determined in consideration of the following explanation. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings.

First, the structure of the absorbent article 1 manufactured by the method for manufacturing an absorbent article according to the present embodiment will be described with reference to the drawings. FIG. 1 is a plan view showing an absorbent article 1 according to this embodiment. FIG. 2 is a cross-sectional view (AA cross-sectional view of FIG. 1) showing the absorbent article 1 according to the present embodiment. FIG. 3 is a cross-sectional view (BB cross-sectional view of FIG. 1) showing the absorbent article 1 according to the present embodiment. In the present embodiment, the absorbent article 1 is an open diaper.

As shown in FIGS. 1 to 3, the absorbent article 1 has a vertically long shape in a direction (hereinafter, referred to as a longitudinal direction L) from the wearer's front waistline (belly side) to the back waistline (back side).

In the longitudinal direction L, the absorbent article 1 corresponds to the front waistline region S1 corresponding to the wearer's front waistline, the rear waistline region S2 corresponding to the wearer's back waistline, the wearer's inseam, and the front waistline region. There is a crotch region S3 located between S1 and the rear waistline region S2.

In addition, the absorbent article 1 has a center region C1 including an absorber 30 described later in the width direction W orthogonal to the longitudinal direction L, and a pair of side regions located outside the center region C1 with respect to the width direction W. C2.

Such an absorbent article 1 includes a top sheet 10, a back sheet 20, and an absorber 30. Further, the absorbent article 1 is provided with a waist flap portion 40 and a side flap portion 50.

The top sheet 10 is provided on the side in contact with the wearer's skin. The top sheet 10 is disposed so as to wrap the absorber 30. The top sheet 10 is formed of a liquid-permeable sheet such as a hydrophilic nonwoven fabric or woven fabric, an apertured plastic film, or an apertured hydrophobic nonwoven fabric.

The back sheet 20 is provided outside the absorbent article 1 when worn. The back sheet 20 is formed of a liquid-impermeable (eg, polyethylene) sheet-like back film 20A that does not transmit liquid, and a sheet-like back nonwoven fabric 20B provided outside the back film. The back sheet 20 constitutes a composite sheet in which a plurality of sheets are bonded together with an adhesive. Details of the back sheet 20 will be described later.

The absorber 30 is provided between the top sheet 10 and the back sheet 20. The absorber 30 absorbs the body fluid of the wearer. The absorber 30 is formed of a mixed powder 30A such as pulverized pulp or a superabsorbent polymer, and a covering material 30B such as a tissue that covers the mixed powder 30A.

The waist flap portion 40 is provided in the front waistline region S1 and the back waistline region S2 with respect to the longitudinal direction L. The waist flap portion 40 has a pair of front flap portions 40A located in the front waistline region S1 and a pair of rear flap portions 40B located in the rear waistline region S2.

40 A of front side flap parts are formed when the side sheet | seat 60 affixed on the back surface sheet 20 extends toward the width direction W outer side. In addition, 40 A of front side flap parts may be formed when the back nonwoven fabric 20B extends instead of the side sheet 60. FIG.

The rear side flap part 40B is formed by extending the side seat 60 toward the outer side in the width direction W similarly to the front side flap part 40A. In addition, the back side flap part 40B may be formed by extending the back nonwoven fabric 20B instead of the side sheet 60 similarly to the front side flap part 40A. A locking portion 41 that locks to the front waistline region S1 is provided on the surface of the rear flap portion 40B on the side where the absorber 30 is provided.

The locking portion 41 is formed by, for example, a hook-and-loop fastener. In this case, the locking portion 41 is a male member, and a female member is provided as a locked portion in a region where the locking portion 41 of the front waistline region S1 is locked. In addition, as long as front waistline area | region S1 is comprised with the nonwoven fabric, front waistline area | region S1 itself may fulfill | perform the role of a to-be-latched part.

The side flap part 50 is provided along the longitudinal direction L outside the absorbent body 30 in the width direction W outside. The side flap portion 50 is provided with a string-like body 51 made of rubber (for example, polyurethane) having elasticity in the longitudinal direction L. The string-like body 51 is joined to the back sheet 20 in a state of being stretched in the longitudinal direction L. The string-like body 51 includes a first string-like body 51A, a second string-like body 51B, a third string-like body 51C, and a fourth string-like body 51D from the inner side to the outer side in the width direction W.

Next, the configuration of the back sheet 20 described above will be described with reference to the drawings. Fig.4 (a) is a top view which shows the back surface sheet 20 which concerns on this embodiment. FIG. 4B is an enlarged cross-sectional view (AA cross-sectional view of FIG. 4A) showing the back sheet 20 according to the present embodiment.

As shown in FIG. 4A, the back sheet 20 has a stretched portion 21 and an unstretched portion 22. The extending portion 21 is formed by pressing the back sheet 20 in the thickness direction T of the back sheet 20. That is, the stretched portion 21 is a region having a smaller basis weight (mass per unit area) than that of the unstretched portion 22 by being subjected to stretching.

As shown in FIG. 4B, the stretched portion 21 is formed by alternately arranging a rough portion 21L having a large stretch amount and a dense portion 21T having an expansion amount smaller than the coarse portion 21L. The coarse portion 21L and the dense portion 21T are arranged in a state of being continuous in the longitudinal direction L and being arranged in the width direction W.

The extending portion 21 has a central extending portion 21A located in the central region C1 and an end extending portion 21B located in a part of the side region C2. In the present embodiment, the part of the side region C2 indicates the crotch region S3 excluding the edge region C3 including the edge portion 20E located on the outer side in the width direction W.

Here, the end extension portion 21B is not necessarily provided in a part of the side region C2, and may be provided in the entire side region C2, and is provided in the crotch region S3 as shown in FIG. It does not have to be done. Further, the central extension portion 21A does not necessarily have to be provided in the entire region of the central region C1, and may be provided in at least a part of the central region C1, for example, on the outer side in the longitudinal direction L as shown in FIG. You may provide in the center area | region C1 except the edge part area | region C4 containing the edge part 20E located.

Such a stretched portion 21 is preferably expanded by 3.0 times or less with respect to the back sheet 20 before the back sheet 20 is stretched. Moreover, the extending | stretching part 21 is joined to the absorber 30 in the state expanded and flattened in the width direction W (refer FIG. 6).

In the unstretched portion 22, the back sheet 20 is not pressed in the thickness direction T. That is, the unstretched portion 22 is a region excluding the stretched portion 21 in the back sheet 20. The unstretched portion 22 is provided in the pair of side regions C2.

Next, a method for manufacturing an absorbent article for manufacturing the above-described absorbent article 1 will be described with reference to the drawings. FIG. 6 is a diagram for explaining a method for manufacturing an absorbent article according to the present embodiment.

As shown in FIG. 6, the manufacturing method of an absorbent article manufactures the absorbent article 1 provided with the back sheet 20 and the absorber 30 at least. The manufacturing method of the absorbent article includes a sheet bonding step S10, a sheet heating step S20, a sheet stretching step S30, a sheet widening step S40, an absorbent body joining step S50, a string-like body arranging step S60, and a side flap. It includes a forming step S70, a waist flap arranging step S80, and a product cutting step S90.

In the sheet bonding step S10, an adhesive (for example, hot melt) is used to convey the back sheet 120A in which the back film 20A is continuous and the nonwoven sheet 120B in which the back nonwoven fabric 20B is continuous (hereinafter, machine direction MD). The composite sheet 120 is formed by bonding together while being conveyed.

In the sheet heating step S20, the composite sheet 120 is heated by a heating roll 510 described later. At this time, the composite sheet 120 is heated to a temperature higher than the softening point of the adhesive and lower than the lowest softening temperature (for example, the back film 20A) among the softening temperatures of the plurality of sheets. In particular, the composite sheet 120 is heated to a temperature of at least 20 degrees below the lowest softening temperature of the plurality of sheets.

In the sheet stretching step S30, the heated composite sheet 120 is pressed in the thickness direction T of the composite sheet 120 by a stamping roll mechanism 520 described later. Thereby, the composite sheet 120 is stretched in the width direction W of the composite sheet 120 (that is, the cross direction CD orthogonal to the machine direction MD), and the stretched portion 21 and the unstretched portion 22 are formed in the composite sheet 120. At this time, the convex part (the convex part 532 and the convex part 542) of the embossing roll mechanism 520 described later is heated to a temperature higher than 40 degrees and lower than the softening point of the adhesive.

In the sheet widening step S40, the stretched composite sheet 120 is widened (expanded) by the widening roll mechanism 600 described later until the composite sheet 120 becomes flat toward the outside in the width direction W of the composite sheet 120.

In the absorber bonding step S50, the absorber 30 to which the top sheet 10 is bonded is bonded (placed) on the widened composite sheet 120.

In the string-like body arranging step S60, the string-like body 51 is placed on the composite sheet 120 corresponding to the outer side in the width direction W of the absorbent body 30 with the string-like body 51 extended with respect to the machine direction MD of the composite sheet 120. To place.

In the side flap forming step S70, the nonwoven fabric sheet 120B extending in the width direction W with respect to the back sheet 120A is folded back inward in the width direction W, thereby wrapping the string-like body 51 with the nonwoven fabric sheet 120B and forming the side flap portion 50. To do.

In the waist flap arrangement step S80, the front flap portion 40A formed in advance and the rear flap portion 40B to which the locking portion 41 is attached are joined to the composite sheet 120.

In product cutting process S90, the composite sheet 120 provided with the absorber 30, the side flap part 50, and the waist flap part 40 is cut | disconnected to the magnitude | size of one product along the width direction W, and the absorbent article 1 is manufactured.

Next, the configuration of the stretching apparatus 500 used in the above-described sheet heating step S20 and sheet stretching step S30 will be described with reference to the drawings. FIG. 7A is an enlarged perspective view showing a part of the stretching apparatus 500 according to the present embodiment. FIG. 7B is an axial sectional view of the embossing roll mechanism 520 according to the present embodiment.

As shown in FIG. 7A, the stretching device 500 stretches the composite sheet 120 in which the back sheet 120A and the nonwoven fabric sheet 120B are bonded together in the cross direction CD while being conveyed along the machine direction MD. In the present embodiment, the composite sheet 120 is joined by an adhesive applied in a spiral pattern. The stretching apparatus 500 includes a heating roll 510 and an embossing roll mechanism 520.

The heating roll 510 is provided on the upstream side in the machine direction MD from the embossing roll mechanism 520. The heating roll 510 heats the composite sheet 120 before passing through the embossing roll mechanism 520 while rotating along the machine direction MD.

The heating roll 510 is set to a predetermined temperature. Specifically, the heating roll 510 has the composite sheet 120 higher than the softening point of the adhesive and lower than the lowest softening temperature (for example, the back film 20A) among the softening temperatures (so-called melting points) of the plurality of sheets. It has the 1st heating part (not shown) heated to low temperature.

The embossing roll mechanism 520 heats the composite sheet 120 that has passed through the heating roll 510 and presses the composite sheet 120 in the thickness direction T of the composite sheet 120. The embossing roll mechanism 520 is set to a predetermined temperature. Specifically, the embossing roll mechanism 520 is a second heating that heats a plurality of convex portions (the convex portions 532 and the convex portions 542) described later to a temperature higher than 40 degrees and lower than the softening point of the adhesive. Part (not shown).

As shown in FIG. 7B, such an embossing roll mechanism 520 has a plurality of convex portions (so-called stretched blades) formed on the outer periphery, and sandwiches the composite sheet 120 between one convex portion 532. The other convex part 542 is comprised by a pair of roll mechanism which fits.

The shapes of the convex portion 532 and the convex portion 542 are tapered from the outer periphery to the outer side of the roll mechanism in the cross section in the axial direction of the roll mechanism. In this embodiment, the shape of the convex part 532 and the convex part 542 is a substantially triangular shape in the cross section in the axial direction of a roll mechanism.

Ferritic stainless steel (SUS430 2B) is used for the convex portions 532 and the convex portions 542. For example, the thickness t1 of the convex portion 532 and the thickness t2 of the convex portion 542 are 0.7 to 1.0 mm, respectively. Moreover, it is preferable that the outer surface of the convex part 532 and the convex part 542 is polished.

In such a stretching apparatus 500, for example, the temperature of the heating roll 510 is 100 degrees. The temperature of the embossing roll mechanism 520 is 60 degrees. The length (L) along the direction orthogonal to the axial direction of the roll mechanism when the convex portion 532 and the convex portion 542 are fitted is 1.6 mm. The interval (p1) between the plurality of projections 532 and the interval (p2) between the plurality of projections 542 are 2.5 mm. Under these conditions, the stretching apparatus 500 can perform a 1.3-fold stretching process on the composite sheet 120 before the composite sheet 120 is stretched.

In the stretching apparatus 500, the magnification (stretching ratio) at which the composite sheet 120 is stretched in the width direction W can be changed by appropriately changing the above-described various conditions. Moreover, the height of the convex part 532 and the convex part 542 corresponding to the center area | region C1 and the side part area | region C2 of the composite sheet 120 may differ. Thereby, the draw ratio in the center area | region C1 and the draw ratio in the side part area | region C2 can be changed.

Next, the configuration of the widening roll mechanism 600 used in the above-described sheet widening step S40 will be described with reference to the drawings. FIG. 8 is a perspective view showing the widening roll mechanism 600 according to the present embodiment.

As shown in FIG. 8, the widening roll mechanism 600 widens the composite sheet 120 stretched by the embossing roll mechanism 520 toward the outside in the cross direction CD of the composite sheet 120 until it becomes flat. As a result, the extending portion 21 (the rough portion 21L and the dense portion 21T) provided in the composite sheet 120 becomes flat, and the extending portion 21 widens. The widening roll mechanism 600 includes a first expansion roll mechanism 610 and a second expansion roll mechanism 620.

The first expansion roll mechanism 610 sandwiches one side portion 120E1 of the composite sheet 120. The first expansion roll mechanism 610 includes a first upper pressing roll 611 and a first lower pressing roll 612.

The first upper pressing roll 611 is disposed on one surface side (upper surface side) of the composite sheet 120. The first upper pressing roll 611 rotates along the feeding direction of feeding the composite sheet 120 around the axis while being in contact with the upper surface of the composite sheet 120.

The first lower pressing roll 612 is disposed on the opposite side (lower surface side) of the first upper pressing roll 611 with the composite sheet 120 interposed therebetween. The first lower pressing roll 612 sandwiches the composite sheet 120 with the first upper pressing roll 611. The first lower pressing roll 612 rotates in the delivery direction for feeding the composite sheet 120 around the axis while being in contact with the lower surface of the composite sheet 120.

In the first upper pressing roll 611 and the first lower pressing roll 612, the center line CL side of the composite sheet 120 is positioned closer to the machine direction MD. That is, the first upper pressing roll 611 and the first lower pressing roll 612 are inclined with respect to the intersecting direction CD in the plan view of the composite sheet 120. Accordingly, the first upper pressing roll 611 and the first lower pressing roll 612 can widen the composite sheet 120 until it becomes flat.

The second expansion roll mechanism 620 sandwiches the other side portion 120E2 of the composite sheet 120. The second expansion roll mechanism 620 includes a second upper pressing roll 621 and a second lower pressing roll 622. The configuration of the second expansion roll mechanism 620 is the same as that of the first expansion roll mechanism 610. Therefore, the description of the second expansion roll mechanism 620 is omitted.

In such a widening roll mechanism 600, the angle of inclination of the first upper pressing roll 611 and the first lower pressing roll 612 with respect to the intersecting direction CD, or the intersecting direction CD of the second upper pressing roll 621 and the second lower pressing roll 622. The degree of widening of the composite sheet 120 can be changed by appropriately changing the inclination angle with respect to.

(Comparison evaluation)
Next, in order to further clarify the effects of the present invention, a comparative evaluation performed using a stretching apparatus according to the following comparative examples and examples will be described. In addition, this invention is not limited at all by these examples.

Tables 1 to 3 show data on the conditions of each sheet, adhesive, and stretching device used in the comparative evaluation. Moreover, the adhesive material used by comparative evaluation was manufactured with the following method.

First, a part of a stabilizer such as a plasticizer and an adhesion-imparting agent (for example, tackifier) is put into a container having an internal temperature of 140 to 160 degrees. Next, a base polymer (thermoplastic polymer) such as SBSS (Styrene-Butadiene-Styrene) is put into the container and mixed by stirring under reduced pressure.

Next, the remaining stabilizer such as a plasticizer and a tackifier is put into the container and mixed by stirring under reduced pressure. Next, the mixed adhesive is taken out and packed. The composition of the adhesive thus manufactured is as shown in Table 1.

As a result of stretching the composite sheet 120 using the stretching apparatuses according to Comparative Examples 1 to 10 and Examples 1 to 8, the composite sheet 120 stretched by each stretching apparatus has a probability of occurrence of holes (pin holes) (perforated holes). Rate) was measured respectively.

As a result, as shown in Tables 2 and 3, it was found that the stretching apparatuses according to Examples 1 to 8 had a lower perforation rate than the stretching apparatuses according to Comparative Examples 1 to 10. That is, the stretching apparatus according to Examples 1 to 8 heats the composite sheet 120 at a temperature higher than the softening point (about 82 ° C.) of the adhesive and lower than the softening temperature of the composite sheet 120 (about 120 ° C.). ing. In the stretching apparatuses according to Examples 1 to 8, the plurality of convex portions are heated to a temperature higher than 40 degrees and lower than the softening point of the adhesive (about 82 ° C.). Therefore, it can be seen that the stretching apparatuses according to Examples 1 to 8 have a low perforation rate.

In the present embodiment described above, the composite sheet 120 is heated before being pressed. At this time, the composite sheet 120 is heated to a temperature higher than the softening point of the adhesive and lower than the lowest softening temperature (for example, the back film 20A) among the softening temperatures of the plurality of sheets. According to this, before the composite sheet 120 is pressed by the embossing roll mechanism 520, the adhesive between the plurality of sheets can be softened.

In addition, when the composite sheet 120 is heated at a temperature lower than the softening point of the adhesive, the adhesive between the plurality of sheets cannot be softened. Further, when the composite sheet 120 is heated at a temperature higher than the lowest softening temperature (for example, the back film 20A) among the softening temperatures of the plurality of sheets (the back film 20A and the back nonwoven fabric 20B), the back film 20A is heat-melted. It may be worn and hardened, the texture may deteriorate, and a plurality of sheets may be torn.

The heated composite sheet 120 is stretched in the width direction W by being pressed in the thickness direction T. At this time, the convex part 532 and the convex part 542 are heated to a temperature higher than 40 degrees and lower than the softening point of the adhesive. According to this, the composite sheet 120 is pressed in a state where the adhesive between the plurality of sheets is soft and the composite sheet 120 is warmed. For this reason, the adhesive between a plurality of sheets becomes easy to become familiar with the convex portions 532 and the convex portions 542. Therefore, heat transfer to the composite sheet 120 is sufficient, and the occurrence of perforations (pinholes) can be reliably suppressed without causing unevenness in the weight of the composite sheet 120.

In addition, when the convex part is heated at a temperature lower than 40 degrees, the adhesive material between the composite sheets 120 that has become soft oozes out between the plurality of sheets when passing through the embossing roll mechanism 520, and the convex part Easy to adhere to the surface. Adhesive material adhering to the surface of the convex portion may adhere to the composite sheet 120, and manufacturing defects such as perforations due to the adhesive material adhering to the composite sheet 120 may occur.

Further, when the convex portion is heated at a temperature higher than the softening point of the adhesive, only the fitting portion between the convex portion 532 and the convex portion 542 is extended, and the damage applied to the fitting portion is increased. Further, the unevenness of the weight per unit area is generated in the composite sheet 120, and perforation (pinhole) is likely to occur.

Thus, according to the manufacturing method of the absorbent article and the stretching apparatus 500 according to the present embodiment, a plurality of sheets are stretched uniformly in the width direction W without damaging the composite sheet 120 bonded with the adhesive. it can.

In the present embodiment, the composite sheet 120 is heated to a temperature of at least 20 degrees or less than the lowest softening temperature among the softening temperatures of the plurality of sheets. When the composite sheet 120 is heated at a temperature higher than at least 20 degrees lower than the lowest softening temperature among the softening temperatures of the plurality of sheets, a part of the composite sheet 120 is heat-sealed and becomes too hard. May end up.

In this embodiment, the composite sheet 120 is joined by an adhesive applied in a spiral pattern. According to this, in the spiral pattern, the adhesive material is sprayed onto the composite sheet 120 in a mist form, and is applied with a thin linear shape and a high density. For this reason, when the composite sheet 120 is stretched, the composite sheet 120 is less likely to be unevenly stretched, and perforations (pinholes) are further less likely to occur.

(Other embodiments)
Although the contents of the present invention have been disclosed through the embodiments of the present invention as described above, it should not be understood that the descriptions and drawings constituting a part of this disclosure limit the present invention. From this disclosure, various alternative embodiments, examples, and operational techniques will be apparent to those skilled in the art.

For example, the embodiment of the present invention can be modified as follows. Specifically, the composite sheet 120 has been described as being used for the back sheet 20, but is not limited thereto, and may be a member (for example, a front sheet) configured by a plurality of sheets. Moreover, you may be used for the member of various absorbent articles, such as a disposable diaper and a sanitary napkin.

Moreover, although the shape of the convex part (the convex part 532 and the convex part 542) has been described as having a tapered shape (substantially triangular shape) in the cross section in the axial direction, the shape is not limited to this, It may be trapezoidal or arcuate.

Moreover, in sheet | seat bonding process S10, although demonstrated as what bonds back sheet | seat 120A in which back film 20A continued, and nonwoven fabric sheet | seat 120B in which back nonwoven fabric 20B continued, it is not limited to this, Back film 20A may be intermittently bonded to the nonwoven fabric sheet 120B.

The manufacturing method of the absorbent article has been described as having the sheet bonding step S10 to the product cutting step S90, but is not limited to this, and at least the sheet heating step S20, the sheet stretching step S30, Needless to say, the absorber bonding step S50 can be set as appropriate according to the purpose.

Thus, it goes without saying that the present invention includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

Note that the entire contents of Japanese Patent Application No. 2009-200709 (filed on August 31, 2009) are incorporated herein by reference.

According to the characteristics of the present invention, a method for manufacturing an absorbent article that can be uniformly stretched in the width direction without damaging a composite sheet in which a plurality of sheets are bonded together with an adhesive, and a method for manufacturing the absorbent article. The drawing apparatus used can be provided.

Claims

A method of manufacturing an absorbent article comprising at least a composite sheet in which a plurality of sheets are bonded together with an adhesive, and an absorber attached to the composite sheet,
Step A of heating the composite sheet transported along the transport direction by a heating roll rotating along the transport direction of the composite sheet;
A plurality of convex portions are formed on the outer periphery, and the composite sheet is orthogonal to the transport direction by a pair of embossing roll mechanisms in which the other convex portion is fitted between the one convex portion with the composite sheet interposed therebetween. Step B extending in the crossing direction
In step A,
The composite sheet is heated to a temperature higher than the softening point of the adhesive and lower than the lowest softening temperature among the softening temperatures of the plurality of sheets,
In step B,
The method for producing an absorbent article, wherein the plurality of convex portions are heated to a temperature higher than 40 degrees and lower than a softening point of the adhesive.
In step A,
The said composite sheet is a manufacturing method of the absorbent article of Claim 1 heated to the temperature of at least 20 degrees or less from the lowest softening temperature among the softening temperature of these sheets.
The method for manufacturing an absorbent article according to claim 1, wherein the composite sheet is joined by the adhesive applied in a spiral pattern.
Step of widening the composite sheet until it becomes flat toward the outside in the width direction of the composite sheet by a widening roll mechanism provided after at least one of the side portions in the width direction of the composite sheet. The manufacturing method of the absorbent article as described in any one of Claims 1 thru | or 3 which has these.
A stretching device that stretches a composite sheet in which a plurality of sheets are bonded together with an adhesive, in a crossing direction orthogonal to the transport direction while transporting along the transport direction of the composite sheet,
A heating roll that rotates along the conveying direction of the composite sheet and heats the composite sheet;
A plurality of convex portions are formed on the outer periphery, and a pair of embossing roll mechanisms with which the other convex portion is fitted between the one convex portion across the composite sheet,
The heating roll has a first heating unit that heats the composite sheet to a temperature higher than the softening point of the adhesive and lower than the lowest softening temperature among the softening temperatures of the plurality of sheets,
The embossing roll mechanism includes a second heating unit that heats the plurality of convex portions to a temperature higher than 40 degrees and lower than the softening point of the adhesive.