JP2011115308A - Method for manufacturing absorbent article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing an absorbent article which is capable of stably and continuously manufacturing the absorbent article, and simple in constitution as compared with a conventional article and excellent in flexibility and stretchability, with high finish precision. <P>SOLUTION: The method for manufacturing the absorbent article, which has an absorbent body 10 including an absorbent core 4 and an exterior member 12 to which the absorbent body 10 is fixed, includes a stretching step for arranging the absorbent body 10 on one side of a base material sheet 120 being the raw material of the exterior member 12 to obtain a laminate 110 and making the laminate 110 undergo stretching processing to apply stretchability to the base material sheet 120. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an absorbent article such as a disposable diaper having a liquid-retaining absorbent core.

  Disposable diapers, which are a type of absorbent article, may loosen or slip off from the wearer's body due to the wearer's exercise, etc. Elastic stretchability is given to the peripheral part of the part. Moreover, in addition to these peripheral parts, the underpants type disposable diaper by which elastic elasticity was provided also to the waist part located below the peripheral part of a waist part is known. When giving elastic stretchability to a disposable diaper, a stretched thread-like or belt-like elastic member is fixed between two substantially non-stretchable sheets via an adhesive, and the elastic member is contracted. A method of forming a gather is generally used.

  Moreover, the elastic sheet obtained by the method which does not form the said gathers is known as a material used for an absorbent article. For example, in Patent Documents 1 to 3, a processing apparatus including a pair of rolls having tooth grooves engaged with each other on the peripheral surface portion is used, and the roll is rotated to supply a sheet of nonwoven fabric or the like to the meshed portion, It describes that the sheet is stretched. After the stretching process, the sheet exhibits elasticity, and the sheet becomes an elastic sheet.

  However, when manufacturing an absorbent article using such a stretchable sheet (a sheet that develops stretchability by stretching), there is a problem that the finished dimensions are not stable due to tension fluctuations during sheet conveyance. Therefore, in Patent Document 4, a stretchable stretchable sheet and a non-stretchable sheet are joined and transported to prevent the influence of fluctuations in tension during sheet transport, and a disposable diaper with high finishing accuracy is obtained. We have proposed a manufacturing method that enables stable and continuous production.

JP 2007-177384 A JP 2008-156785 A JP 2008-253679 A JP 2007-105453 A

  When manufacturing an absorbent article using a stretchable sheet, as described in Patent Document 4, by joining and transporting a stretchable sheet and a non-stretchable sheet, finished dimensional accuracy and overall Although the strength is improved to some extent, the present situation is that there is a demand for even higher accuracy with respect to the arrangement position and finished dimensions of other members such as the absorbent main body with respect to the stretchable sheet. In addition, the absorbent article described in Patent Document 4 has a configuration in which the waist elastic member and the leg elastic member are sandwiched and fixed by two sheets, but has a simpler configuration and relatively less material and manufacturing. There is a demand for an absorbent article that can reduce the manufacturing cost in the process.

  Accordingly, an object of the present invention is to provide an absorbent article that has a simple structure as compared with conventional products and that can stably and continuously produce an absorbent article excellent in flexibility and stretchability with high finishing accuracy. It is in providing the manufacturing method of.

  The present invention relates to a method of manufacturing an absorbent article having an absorbent main body including an absorbent core and an exterior body to which the absorbent main body is fixed, and is a base sheet that is a raw material of the exterior body The absorbent main body is disposed on one surface to obtain a laminate, the laminate is stretched, and a method for producing an absorbent article comprising a stretching step for imparting stretchability to the base sheet is provided. This solves the problem.

  According to the method of manufacturing an absorbent article of the present invention, it is possible to stably and continuously manufacture an absorbent article having excellent flexibility and stretchability with a simple configuration as compared with conventional products. it can.

Drawing 1 is a perspective view showing one embodiment of a pants type disposable diaper as an example of an absorptive article manufactured by a manufacturing method of the present invention. FIG. 2 is a plan view on the skin contact surface side (surface sheet side) showing a developed state in which the diaper shown in FIG. FIG. 3 is an exploded perspective view of the diaper shown in FIG. 4 is a cross-sectional view schematically showing a cross section taken along line II-II in FIG. FIG. 5 is a schematic perspective view showing an outline of a manufacturing process of the diaper shown in FIG. FIG. 6 is a schematic diagram illustrating a state in which the composite sheet is stretched by the tooth gap roll in the stretching step illustrated in FIG. 5. FIG. 7 is a perspective view showing a pants-type disposable diaper as another example of the absorbent article manufactured by the manufacturing method of the present invention. FIG. 8 is a plan view on the skin contact surface side (surface sheet side) showing a developed state in which the diaper shown in FIG. FIG. 9 is a schematic perspective view showing an outline of a manufacturing process of the diaper shown in FIG.

  Hereinafter, a method for manufacturing an absorbent article according to the present invention (hereinafter, also simply referred to as a manufacturing method) will be described based on the preferred embodiments with reference to the drawings. First, the absorbent article manufactured by the manufacturing method of the first embodiment of the present invention will be described. In the first embodiment, a pants-type disposable diaper 1 shown in FIGS. 1 to 4 is manufactured as an absorbent article.

  The diaper 1 has the absorptive main body 10 containing the absorptive core 4 and the exterior body 12 to which the absorptive main body 10 is fixed, as shown in FIG.2 and FIG.3. More specifically, the diaper 1 includes a liquid-permeable top sheet 2, a liquid-impervious or liquid-impervious (water repellency, etc.) back sheet 3, and a liquid disposed between both sheets 2 and 3. An absorptive main body 10 having a retentive absorptive core 4 and an exterior body 12 disposed on the non-skin contact surface side (the back sheet 3 side) of the absorptive main body 10 and to which the absorptive main body 10 is fixed. ing. The exterior body 12 is composed of one base sheet 120 (see FIG. 5). As shown in FIG. 2, the absorbent main body 10 has a shape (rectangular shape) that is long in one direction in plan view.

  As shown in FIG. 2, the diaper 1 includes an abdominal side A disposed on the abdomen side of the wearer when worn, a back side B disposed on the back side, and an abdominal side A and a back side B. Crotch part C located between the two. The exterior body 12 defines the outline of the diaper, and in an unfolded state, the both side edges along the longitudinal direction have an hourglass shape that is inwardly bound in the central portion in the longitudinal direction. In the exterior body 12, both side edges A1 and A2 on the ventral side A and both side edges B1 and B2 on the back side B are joined to each other. As shown in FIG. A pair of side seal portions S, S, a waist opening 5 and a pair of leg openings 6, 6 are formed.

  In addition, in this specification, a skin contact surface is a surface turned to a wearer's skin side at the time of wear in an absorbent article and its structural member, and a non-skin contact surface in an absorbent article and its structural member It is a surface that is directed to the side opposite to the wearer's skin when worn. The longitudinal direction is a direction along the long side of the absorbent article or the constituent member of the absorbent article, and the width direction is a direction orthogonal to the longitudinal direction. In the case of a pant-type absorbent article such as diaper 1, when the pant-type absorbent article is developed as shown in FIG. 2, the direction along the long side (vertical direction in FIG. 2) is the pant-type absorbent article. The longitudinal direction of the article, and the left-right direction in FIG. 2 is the width direction of the pant-type absorbent article.

  The absorbent main body 10 is formed by integrating the top sheet 2, the back sheet 3, and the absorbent core 4. As the top sheet 2, the back sheet 3, and the absorbent core 4, various types conventionally used for this type of article can be used without particular limitation. For example, various nonwoven fabrics or apertured films can be used as the top sheet, and a resin film, a laminate of a resin film and a nonwoven fabric, or the like can be used as the back sheet. The resin film used for the back sheet preferably has air permeability. As the absorbent core 4, a fiber material such as pulp is preferably provided with particles of a superabsorbent polymer, and these constituent materials are covered with a sheet (not shown) such as tissue paper or nonwoven fabric. Can be used.

  As shown in FIG. 2, side cuffs 8 and 8 made of a liquid-resistant or water-repellent and breathable material are formed on the left and right sides of the absorbent main body 10 in the longitudinal direction. One or a plurality of side cuff elastic members 81 are arranged in an extended state near the free end of each side cuff 8. The side cuff 8 stands up when the diaper is worn to prevent the liquid from flowing out. In FIG. 3, a sheet material for forming the side cuffs 8 and 8 is indicated by reference numeral 82. The portions 82 </ b> S that extend outward from both side edges of the absorbent core 4 in the sheet material 82 are fixed between the absorbent core 4 and the back sheet 3 or between the back sheet 3 and the exterior body 12. Yes.

  As shown in FIGS. 3 and 4, the exterior body 12 includes a heat seal, a high frequency seal, or an ultrasonic seal at the side seal portions A 1, A 2, B 1, and B 2 in each of the ventral portion A and the back portion B. Are joined together.

  In the diaper 1, as shown in FIG. 3, the exterior body 12 sandwiches a portion that forms an opening peripheral edge of the waist opening 5 in each of the ventral side A and the back side B (a waist elastic member 51 described later is sandwiched). It has a length that extends further outward in the longitudinal direction of the diaper than the portion to be fixed), and its extended portions 12a and 12b are folded back toward the absorbent main body 10 side. As for the absorptive main body 10, the skin contact surface side in the longitudinal direction both ends is covered with the folded-back parts (extension part) 12a, 12b of the exterior body 12, and the covered part is the exterior body 12. Are bonded to the folded portions 12a and 12b via an adhesive. Thereby, the both ends of the longitudinal direction of the absorptive main body 10 are coat | covered with the exterior body 12, and are being fixed reliably.

  As for the absorptive main body 10, only the center part of the width direction is joined via the exterior body 12 and the adhesive agent 15 in the part except the both ends of the longitudinal direction, as shown in FIG. By joining the absorptive main body 10 and the exterior body 12 in this manner, the expansion and contraction of the exterior body 12 is less likely to be hindered by the joining of the absorptive main body 10, so that a good fit can be obtained at the waistline portion. The width W1 (see FIG. 4) of the region where the absorbent main body 10 and the exterior body 12 are bonded is 20 to 80% of the width W of the absorbent main body 10 in each of the ventral side A and the back side B. It is preferable that there is more preferably 30 to 70%.

  One or a plurality of waist elastic members 51 are disposed on the peripheral edge 50 of the waist opening 5 in each of the ventral side A and the back side B along the peripheral edge of the opening of the waist opening 5. ing. The waist elastic member 51 is fixed in an expanded state between the exterior bodies 12 that are folded and overlapped with each other via an adhesive 52. As the waist elastic member 51, a material in which a stretchable material such as natural rubber, polyurethane resin, urethane foam resin, hot melt stretchable member or the like is formed into a thread shape (thread rubber) or a belt shape (flat rubber) is preferably used. .

  In this type of conventional diaper, the leg opening 6 is provided on the peripheral edge 60 of each of the pair of leg openings 6, 6 existing over the abdomen A, crotch C and dorsal B. Although one or a plurality of leg elastic members are arranged along the peripheral edge of the opening, such a leg elastic member is not arranged in the diaper 1. As described above, the diaper 1 has a simple structure as compared with the conventional product, in which the exterior body 12 that fixes the absorbent main body 10 is configured by a single sheet and does not include the leg elastic member. .

  As will be described later, the diaper 1 is partially stretched on the exterior body 12, and as shown in FIG. 2, the stretched part (the part with hatched lines in FIG. 2). , Also referred to as a stretched portion). The stretched part P1 passes through both side edges 10s, 10s along the longitudinal direction of the absorbent main body 10 and extends in the longitudinal direction of the diaper 1 in the width direction outside the two virtual straight lines (not shown). It is formed in the direction and is not formed in the arrangement region of the absorbent main body 10 and the region located in the longitudinal direction of the diaper 1 across the arrangement region. The stretched portion P1 is preferably formed at least on the ventral side A and the dorsal side B. In the stretching step in the manufacturing method of the present invention described later, the bases of the ventral side A and the dorsal side B are used. It is preferable to stretch the material sheet 120 (the raw material of the exterior body 12, see FIG. 5).

  In the stretched portion P1, stretchability in the width direction of the diaper 1 (left-right direction in FIG. 2) is imparted to the exterior body 12 itself by stretch processing described later. Here, “stretchability” means that the film can be extended in a predetermined direction and contracts when the extension is released. The exterior body 12 in the stretched part P1 is stretched or partially broken or stretched by the stretching process, such as fibers forming the sheet, and thus is destroyed to such an extent that it cannot be broken. Therefore, it is easy to stretch in a predetermined direction (width direction of the diaper 1) and the amount of elongation is increased as compared with a portion of the same sheet that has not been stretched (a portion that has not undergone plastic deformation). . That is, the sheet 12 itself in the stretched portion P1 is easily stretched in the width direction of the diaper 1 even with low stress. For this reason, the stretched portion P1 has a large amount of elongation when pulled in the width direction of the diaper 1 as compared to an exterior body in a conventional diaper that has not been stretched, and is easily stretched with a small force. It has sex. Moreover, in addition to such high extensibility, the exterior body 12 has a property of contracting when the extension is released, and has the elasticity. The raw fabric (base material sheet 120) of the outer package 12 is a latent elastic sheet that exhibits elasticity by stretching as described later.

  Next, the 1st embodiment of the manufacturing method of this invention which is the method of manufacturing continuously the underpants type disposable diaper 1 is demonstrated with reference to FIG. In the manufacturing method of the first embodiment, the absorbent main body 10 is disposed on one surface of the base sheet 120 to obtain a laminate 110, the laminate 110 is stretched, and the base sheet 120 is stretched. It includes a stretching step, and further includes a leg portion forming step for forming the leg portion 6 on the base sheet 120 before the stretching step. In the first embodiment, in the stretching step, the laminate 110 is stretched in the longitudinal direction [conveying direction, machine direction (MD)] to impart MD stretchability to the laminate 110.

  In the manufacturing method of the first embodiment, a strip-shaped base sheet 120 is used as the raw material of the exterior body 12. The base sheet 120 does not substantially extend in the longitudinal direction [conveyance direction, machine direction (MD)] before the stretching process is performed, but after the stretching process is performed, The stretched portion can be expanded and contracted to MD. That is, the base material sheet 120 potentially has MD stretchability (extension) before being subjected to the stretching process, and such characteristics are not manifested, and the stretching process is performed. Thus, the stretchability (extension) of the MD of the part subjected to the stretching process is expressed, and it is a sheet to be called a latent stretchable sheet. Here, “substantially does not extend in a predetermined direction (MD in the first embodiment)” means that even if the tension during conveyance is applied in the predetermined direction (MD), it does not extend or is slightly extended. This means that the amount of elongation is less likely to fluctuate due to fluctuations in conveyance tension.

  In the manufacturing method of the first embodiment, as shown in FIG. 5, first, the absorbent main body 10 is placed on one surface of the base sheet 120 while applying tension to the base sheet 120 and transporting it in the longitudinal direction. It arrange | positions and the laminated body 110 is obtained. In the first embodiment, a large number of absorbent main bodies 10 obtained by cutting a continuous body (not shown) of separately manufactured absorbent main bodies 10 into unit lengths are intermittently bonded onto the base sheet 120. It is fixed. Arrangement of the absorbent main body 10 on the base material sheet 120 is performed while maintaining the stretched state of the base material sheet 120. In the first embodiment, in addition to the absorbent main body 10, the waist elastic member 51 is introduced in an expanded state on one surface of the base sheet 120. The adhesive 15 (see FIG. 3) that fixes the absorbent main body 10 to the base sheet 120 can be applied to either one or both of the absorbent main body 10 and the base sheet 120. Moreover, the adhesive agent 52 (refer FIG. 3) which fixes the waist part elastic member 51 to the base material sheet 120 can be applied to any one or both of the waist part elastic member 51 and the base material sheet 120. .

  Next, in the leg portion forming step, as shown in FIG. 5, leg holes 112 are formed in the laminate 110 by removing the trim 111 for forming the leg openings from the laminate 110. The peripheral part of the leg hole 112 is a part which finally becomes a leg part (peripheral part 60 of the leg opening 6). The trim 111 can be removed using a known cutting means such as a rotary cutter or a laser cutter. The trim 111 for forming the leg openings can be removed before the absorbent main body 10 is disposed on one surface of the base sheet 120.

  Next, both side portions 12a and 12b of the base sheet 120 are folded back so as to cover both end portions of the absorbent main body 10 and the waist elastic member 51, and in that state, the laminate 110 is placed between a pair of unillustrated rolls. Narrow pressure. Thereby, the base material sheet 120, the absorptive main body 10, and the waist elastic member 51 are substantially integrated through the adhesives 15 and 52.

  Thus, the laminated body 110 in which the leg holes 112 are formed through the leg portion forming step is continuously conveyed in the longitudinal direction, and the laminated body 110 being conveyed is stretched in the stretching process, and Stretchability is imparted to the laminate 110 by expressing potential stretchability. The elastic member 51 is fixed in an expanded state on the base material sheet 120 in the laminate 110 before the stretching step, and the stretching process is also performed on the elastic member 51 fixed to the base material sheet 120. Does not affect the elastic member 51. By such stretching, the stretchability (extension) of the MD of the portion of the base sheet 120 that has been stretched is expressed, and thereby the stretchability of the MD is imparted to the base sheet 120.

  As one of the main features of the production method of the first embodiment, a latent stretchable sheet [a sheet that exhibits stretchability (stretchability) of the stretched portion by being stretched] Before the stretching process is performed, that is, before the stretchability of the latent stretchable sheet is expressed, the necessary process (placement of absorbent main body, formation of leg portions) is performed on the latent stretchable sheet. . In general, the stretchable sheet obtained by subjecting the latent stretchable sheet to stretching is easy to stretch due to the tension during its transport and has poor transport stability. Therefore, the stretchable sheet is transported while transporting the stretchable sheet alone. When various processing (cutting, bending, joining with other members, etc.) is performed, the variation in the tension causes a shift in the position for performing various processing such as the cutting position, the bending position, the joining position, There is a risk that the accuracy of processing such as cutting, bending, and joining may be reduced.

  Therefore, in the manufacturing method of the first embodiment, as described above, before the base sheet 120 that is a latent elastic sheet is stretched, that is, the base sheet 120 in a state that does not substantially extend in the MD. As necessary processing, arrangement of the absorbent main body 10 and formation processing of the leg portion (removal of the trim 111 from the base sheet 120) are performed. This makes it possible to place the absorbent body 10 with high accuracy, facilitates the cutting and removal of the trim 111, stabilizes the cut shape of the leg hole 112, and extends the diaper manufacturing process in all steps. The order of the steps is lower, and the transport distance of the base sheet 120 that exhibits MD stretchability obtained through the stretching step is shortened, so the influence of tension during transport of the base sheet 120 is reduced. Can do.

  In the stretching step in the manufacturing method of the first embodiment, as a method of stretching the laminate 110 (base sheet 120), a pair of sandwiching bodies having tooth grooves that mesh with each other is used, and a sheet is sandwiched between the sandwiching bodies. The gear extension method is used. The sandwiching body may have a pair of tooth groove rolls in which the tooth grooves are meshed with each other in a gear shape, or a flat plate shape. Alternatively, two sets of nip rolls may be used, and the sheet may be stretched in the transport direction between the rolls depending on the transport speed difference.

  The stretching process in the stretching process of the first embodiment is an in-line process with a pair of tooth gap rolls 71 as shown in FIG. The pair of tooth groove rolls 71 has tooth grooves extending in the roll axial direction (CD) and meshing with each other on the peripheral surface portions. More specifically, tooth gaps are formed on the peripheral surface portions of the pair of tooth groove rolls 71, and high extension portions 72 extending in the axial direction of the rolls are separated in the roll circumferential direction to form two pairs. The tooth gap is not formed between the adjacent high extension parts 72 and 72 in each roll, and a substantially flat low or non-extension part 73 is formed. Each highly elongated portion 72 has a substantially rectangular shape, and is formed over substantially the entire length in the axial direction with the longitudinal direction thereof coinciding with the axial direction of each roll. The two pairs of high extending portions 72 in the pair of tooth gap rolls 71 are formed so as to periodically mesh with the rotation of the rolls. In the high extension portion 72, a large number of teeth 80 (see FIG. 6) are formed at predetermined intervals in the circumferential direction of the roll, and a groove is formed between adjacent teeth 80. Between the mutually facing high stretched portions 72, the base material sheet 120 of the laminate 110, which is a stretched product, is subjected to stretching processing on the MD and extends to the MD. In the first embodiment, a stretching process is performed on a part of the base material sheet 120 (a part that becomes the stretched part P1 in the diaper shown in FIG. 2). The stretching process for the base material sheet 120 is performed while maintaining the state in which the base material sheet 120 is tensioned and conveyed in the longitudinal direction.

  FIG. 6 schematically shows a state in which the base sheet 120 is stretched by the pair of tooth space rolls 71 in the stretching step. As shown in FIG. 6, teeth 80 having a predetermined height H are formed in the high extension portion 72, and when the high extension portions 72 of the pair of tooth gap rolls 71 are engaged with each other, The tooth gaps of both rolls are engaged with each other at a predetermined engagement depth D. Therefore, the portion of the base sheet 120 that is bitten between the opposing highly stretched portions 72 is broken to such an extent that part or all of the constituent fibers of the portion are stretched or broken, and cannot be broken as a whole. Thus, plastic deformation occurs, and thereby, the film extends in the MD (longitudinal direction of the base sheet 120) to become a high elongation region. The stretched portion develops or improves stretchability. On the other hand, the portion of the base sheet 120 that passes between the opposing low or non-stretched portions 73 is a low or non-stretchable region that does not substantially cause plastic deformation and does not substantially exhibit stretchability.

  In the manufacturing method of a 1st embodiment, after implementing a leg part formation process and an extending process as mentioned above, the process similar to the manufacturing method of the conventional underpants type disposable diaper can be implemented. That is, the laminated body 110 is folded in two in a direction perpendicular to the conveying direction, and then the side seal portion S is formed by heat sealing, ultrasonic sealing, high frequency sealing, or the like to obtain a diaper continuous body 1 '. Thereafter, the pants-type disposable diaper 1 can be obtained by cutting the diaper continuous body 1 ′ into individual diapers. In addition, in the process after an extending process, since the elasticity is provided to the base material sheet 120, it is a sheet | seat (laminated body) from a viewpoint which implements the folding of the laminated body mentioned above and formation of a side seal part accurately. In this conveyance, in order to suppress conveyance deviation as much as possible, it is preferable to use a sheet conveyance unit that conveys the sheet while holding the sheet, such as a suction conveyor.

  According to the manufacturing method of the first embodiment, the diaper 1 including the stretched portion P1 (see FIG. 2) having high stretchability (extensibility) in the diaper width direction is thus efficiently continuous. Can be manufactured. In particular, in the manufacturing method of the first embodiment, as described above, the absorbent body 10 is arranged on one surface of the base material sheet 120 that is a latent elastic sheet to obtain the laminate 110, and the base of the laminate 110 is obtained. After removing the trim 111 from the material sheet 120 to form the leg holes 112 (leg portions), the base sheet 120 is subjected to a stretching process to develop the stretchability of the MD. MD is not substantially extended, and the conveyance stability of the base material sheet 120 is high (it is difficult to extend due to tension during conveyance). Since the arranging step and the leg portion forming step are performed, the absorbent main body 10 can be arranged at a predetermined position with high accuracy, and the trim 111 can be removed with high accuracy. Therefore, the shape of the leg hole 112 is uniform, the processing accuracy including the stretching process is high, and a pant-type absorbent article with high finishing accuracy can be manufactured stably and continuously.

  Moreover, since the diaper 1 obtained by the manufacturing method of the first embodiment has the stretched portion P1 in the exterior body 12, the exterior body 12 is excellent in the diaper width direction (left-right direction in FIG. 2). It stretches and is excellent in preventing slippage, and is excellent in flexibility and stretchability, and has a wide size application range. That is, the diaper 1 has a simple structure as compared with the conventional product, in which the outer package 12 to which the absorbent main body 10 is fixed is composed of one base sheet 120 that has been subjected to stretching, It is flexible and has a wide range of sizes, and can handle various physical characteristics and body shapes of the wearer. Moreover, since the exterior body 12 touches a wearer's skin gently, the diaper 1 has few tightenings, and there is a space | gap, it is hard to leave a mark on the skin, and it is excellent in a feeling of wear. Further, such a feature of the diaper 1 can be obtained by simply extending a member originally provided without changing the size of the diaper pattern (exterior body) or adding a new member. Therefore, although the diaper 1 has high performance, the material cost is reduced and the manufacturing cost is reduced, and it is environmentally friendly.

  Below, the latent elastic sheet (base material sheet 120) used by this invention is demonstrated. As described above, the latent stretchable sheet is a sheet that does not substantially stretch before being subjected to the stretching process, but after the stretching process, the processed portion exhibits stretchability in a predetermined direction. The latent elastic sheet becomes an elastic sheet after being stretched. Hereinafter, when referring to the latent stretchable sheet in a state where stretchability after being stretched is expressed, it is referred to as a stretchable sheet.

  The latent elastic sheet does not substantially extend in a predetermined direction before being stretched. Specifically, the latent elastic sheet preferably has a maximum elongation of MD of 10% or less (the length only extends up to 1.1 times) before being stretched, and is in the same direction. More preferably, the maximum elongation of is 8% or less. The latent elastic sheet preferably has a maximum elongation of 10% or less (particularly 8% or less) in both the longitudinal direction and the width direction perpendicular thereto before being stretched. The elongation recovery rate and the maximum elongation are each measured by the following methods.

  When the latent stretchable sheet becomes a stretchable sheet, the maximum elongation in the longitudinal direction (MD) is 100% or more, and the elongation when stretched to 100% in that direction is then contracted. The recovery rate (elongation recovery rate at 100% elongation) is preferably 70% or more. Here, “elongation 100%” refers to a state in which a sheet having a length of 50 mm is extended to 100 mm, for example. Moreover, when a latent elastic sheet becomes an elastic sheet, it is preferable that the longitudinal direction (MD) is a sheet | seat which can expand | extend more largely than the width direction (CD). As an example of a preferred latent elastic sheet, when it becomes an elastic sheet, it stretches greatly in the longitudinal direction and contracts after expansion (maximum elongation of 100% or more and elongation recovery rate at 100% elongation of 70% or more However, in the width direction, there is a sheet that extends only slightly (for example, a maximum elongation of 50% or less). The elongation recovery rate and the maximum elongation are each measured as follows.

[Method for measuring elongation recovery rate]
A sample piece having a length of 50 mm and a width of 25 mm is prepared. Using a Tensilon device, the sample piece is fixed at the chuck interval L0, and the length L2 at the time of 100% elongation at a speed of 300 mm / min (L2 = L0 × 2) Then, the length of the sample piece when the tensile load becomes 0 after starting to return at the same speed as the tensile speed is defined as the length L1 after the elongation recovery. The elongation recovery rate at 100% elongation is calculated from the following equation.
Elongation recovery rate at 100% elongation (%) = [(L2-L1) / (L2-L0)] × 100

[Measurement method of maximum elongation]
A sample piece having the same size as that of the sample piece used in the method for measuring the elongation recovery rate is elongated under the same conditions, and the elongation at the time of breaking is defined as the maximum elongation. The point of time of rupture is a point where the tensile load shows the maximum value in the relationship curve between the elongation rate and the load.

  As the latent stretchable sheet used in the present invention, various sheets that exhibit stretchability in a predetermined direction by stretching can be used, and a single layer structure or a multilayer structure in which a plurality of layers are laminated may be used. For example, (1) a sheet in which an extensible fiber layer is integrated on both sides or one side of an elastic fiber layer, and (2) an extensible fiber layer is integrated on both sides or one side of a net-like elastic sheet. (3) a sheet in which stretchable fiber layers are integrated on both sides or one side of an elastic sheet made of an elastic film, (4) a large number of sheets arranged to extend in one direction without crossing each other An elastic sheet or the like in which the elastic filament is bonded to a stretchable nonwoven fabric over the entire length thereof in a substantially non-stretched state can be preferably used. In addition, as an integration method of the elastic fiber layer and the extensible fiber layer, these are laminated and hydroentangled, or the fibers are entangled by air-through, etc., heat embossing, adhesive, ultrasonic wave The method of joining by etc. is mentioned. As the sheet (1), for example, a fiber sheet used as a material for the stretchable nonwoven fabric disclosed in Japanese Unexamined Patent Application Publication No. 2007-138374 and Japanese Unexamined Patent Application Publication No. 2008-179128 can be used.

  Next, another embodiment of the production method of the present invention will be described with reference to FIGS. About the embodiment of the following manufacturing methods, a different component from the manufacturing method of the 1st embodiment mentioned above is explained mainly, the same component is attached with the same numerals and explanation is omitted. The description of the manufacturing method of the first embodiment is appropriately applied to components that are not particularly described.

  7 and 8 show a pants-type disposable diaper 20 manufactured according to the second embodiment of the manufacturing method of the present invention. As shown in FIG. 2, the exterior body 22 in the diaper 20 has an abdominal side exterior body 22A disposed on the abdominal side portion A and a back side exterior body 22B disposed on the back side portion B. Both exterior bodies 22A and 22B are arranged at a predetermined interval L5 in a direction orthogonal to the waistline direction (longitudinal direction of the diaper 20, up and down direction in FIG. 8). Between the absorptive main body 10 and both exterior body 22A, 22B, it has joined with the adhesive agent. The crotch part C positioned between the two exterior bodies 22A and 22B is not provided with an exterior body to which the absorbent main body 10 is fixed, and the outer surface (non-skin contact surface) of the diaper 20 in the crotch part C. Is formed by the back sheet 3 that forms the non-skin contact surface of the absorbent main body 10. Both side edges A1, A2 of the ventral side exterior body 22A and both side edges B1, B2 of the back side exterior body 22B are joined to each other, and the diaper 20 is joined to the pair of side seal parts S, S, A waist opening 5 and a pair of leg openings 6 and 6 are formed.

  In the diaper 20, the ventral-side exterior body 22 </ b> A is, as shown in FIG. 8, a part of the ventral-side part A that forms the opening peripheral edge of the waist opening 5 (a part that clamps and fixes the waist elastic member 51). Furthermore, it has the length extended to the outward of a diaper longitudinal direction, The extension part 22a is return | folded by the absorptive main body 10 side. Further, the back side exterior body 22B has a length that extends further outward in the diaper longitudinal direction than the portion of the back side B that forms the opening peripheral edge of the waist opening 5, and the extension part 22b is folded back to the absorbent main body 10 side. As for the absorptive main body 10, the skin contact surface side in the longitudinal direction both ends is covered with these extension parts 22a and 22b, and the covered part applies an adhesive agent to the extension parts 22a and 22b. Is glued through.

  The ratio (L6 / L7) of the total length L6 in the direction (longitudinal direction of the diaper 1) perpendicular to the waistline direction of each of the exterior bodies 22A and 22B and the total length L7 in the direction of the diaper is preferably 0.1-0. 4, More preferably, it is 0.2-0.3. Further, the length (the shortest distance between the abdominal exterior body 22A and the back exterior body 22B) in the direction perpendicular to the waistline direction of the portion (crotch portion C) where the exterior body to which the absorbent main body 10 is fixed is not disposed. The ratio (L5 / L7) between the separation distance L5 and the total length L7 of the diaper is preferably 0.1 to 0.4, more preferably 0.2 to 0.3.

  As in the diaper 1 described above, the diaper 20 does not have a leg elastic member, and the two exterior bodies 22A and 22B that fix the absorbent main body 10 are each composed of one sheet. Compared to conventional products, this is a simple configuration.

  The diaper 20 is partially stretched on the exterior body 22 and has a stretched portion P2 as shown in FIG. The stretched portion P2 is formed outward in the width direction from two imaginary straight lines (not shown) that extend through the entire length in the longitudinal direction of the diaper 1 through the side edges 10s and 10s of the absorbent main body 10, respectively. It is not formed in the arrangement area of the absorbent main body 10 and the area located in the longitudinal direction of the diaper 1 across the arrangement area. The stretched portion P2 is formed on the ventral side A and the back side B. The stretched part P2 is formed in the same manner as the stretched part P1 in the diaper 1 described above, and the stretched part P2 itself is provided with stretchability in the width direction of the diaper 20 (left and right direction in FIG. 8). ing.

  Next, a second embodiment of the manufacturing method of the present invention, which is a method for continuously manufacturing the above-described pants-type disposable diaper 20, will be described with reference to FIG. In the manufacturing method of the second embodiment, two belt-like base sheets 220A and 220B are used as the base sheet that is the raw material of the outer package 22, and both sheets 220A and 220B are predetermined in the width direction thereof. They are separated by a distance (a distance corresponding to L5) and transported parallel to each other in the longitudinal direction. Base sheet 220A, 220B is a latent elastic sheet, and is the same sheet as base sheet 120 described above.

  In the manufacturing method of the second embodiment, as shown in FIG. 9, first, the two base sheets 220A and 220B are separated from each other in the width direction and are transported in parallel with each other. On each one side, the absorptive main body 10 is arrange | positioned so that this absorptive main body 10 may cross between both base material sheet 220A, 220B, and the laminated body 210 is obtained.

  Next, both side portions 22a and 22b of both base sheet 220A and 220B are folded back so as to cover both end portions of the absorbent main body 10 and the waist elastic member 51, and in that state, the laminate 210 is a pair or more (not shown). Narrow pressure between rolls. Then, the laminate 210 is continuously conveyed in the longitudinal direction, and the base material sheets 220A and 220B are stretched by the pair of tooth gap rolls 71 in the stretching process. By such a stretching process, the stretchability (extension) of the MD of each of the base material sheets 220A and 220B, which has been subjected to the stretching process, is expressed, whereby each of the base material sheets 220A and 220B has an MD. Elasticity.

  In the manufacturing method of the second embodiment, after carrying out the stretching step as described above, the laminate 210 is folded in two in a direction orthogonal to the conveying direction, and then the side seal portion S is heat sealed, A diaper continuum 20 ′ is obtained by ultrasonic sealing, high-frequency sealing, or the like. Thereafter, the pants-type disposable diaper 20 can be obtained by cutting the diaper continuous body 201 ′ into individual diapers. Also by the manufacturing method of the second embodiment, the same effects as those of the first embodiment described above can be obtained.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the embodiment mentioned above, It can change suitably. For example, in the embodiment described above, the both side portions 12a and 12b of the base sheet 120 are folded inward before the base sheet 120 is stretched, but the base sheet 120 is stretched. Later, the side portions 12a and 12b may be folded inward. Moreover, regarding the absorbent article manufactured by the present invention, the waist elastic member may be omitted.

  The scope of application of the present invention is not limited to the above-described pants-type disposable diapers, and is suitable for, for example, unfolded disposable diapers (diapers having fastened fastening tapes), sanitary napkins, and the like.

1,20 Pants-type disposable diapers (absorbent articles)
2 Top sheet 3 Back sheet 4 Absorbent core 5 Waist opening 51 Waist elastic member 6 Leg opening 10 Absorbent body 12, 22 Exterior body 22A Abdominal side exterior body 22B Back side exterior body 71 Tooth groove roll 72 High extension part 73 Low or non-stretched portion 80 Teeth 110, 210 Laminate 111 Trim for forming leg opening 112 Leg hole 120, 220A, 220B Base sheet A Abdominal side B Back side C Crotch lower part P1, P2 Stretched part

Claims (5)

A method of manufacturing an absorbent article having an absorbent main body including an absorbent core and an exterior body to which the absorbent main body is fixed,
An extending step of providing the laminate by arranging the absorbent main body on one surface of the base sheet that is the raw material of the exterior body, subjecting the laminate to stretching, and imparting stretchability to the base sheet The manufacturing method of the provided absorbent article.   In the stretching step, the laminated body is engaged between a pair of sandwiching bodies in the base sheet of the laminated body by interposing the laminated body between a pair of sandwiching bodies having tooth grooves engaged with each other. The method for producing an absorbent article according to claim 1, wherein the product is made stretchable. The absorbent article comprises an abdominal side portion disposed on the abdomen side of the wearer when worn, a back side portion disposed on the back side, and a crotch portion positioned between the abdominal side portion and the back side portion. Have
The manufacturing method of the absorbent article of Claim 1 or 2 which performs an extending | stretching process on the said base material sheet of the said belly side part and the said back side part in the said extending process. The absorbent article has a leg portion located around the wearer's leg when worn,
The manufacturing method of the absorbent article in any one of Claims 1-3 provided with the leg part formation process which forms the said leg part in the said base material sheet before the said extending process.   As the base sheet, two belt-shaped base sheets are used, and the two base sheets are separated by a predetermined distance in the width direction and conveyed in parallel with each other in the longitudinal direction. The said absorptive main body is arrange | positioned so that this absorptive main body may cross | intersect between these two base material sheets on one surface of each of the base material sheet of 1 sheet, The said laminated body is obtained. The manufacturing method of the absorbent article in any one of.

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