JP2010119743A - Absorbent article and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent article which has a groove formed on the skin contact side by compressing a sheet such as a surface sheet and an absorber and is excellent to form the groove because the surface sheet and the like in the groove is suppressed from floating up; and a method for producing the same. <P>SOLUTION: The absorber 4 includes a plurality of bulges 41 and 42 bulged on the skin contact side at the center in the width direction. The plurality of the bulges 41 and 42 are disposed to have a determined interval between them in the longitudinal direction of the absorbent article 1, and the surface sheet 2 and the absorber 4 are compressed to form an intermediate groove 8b which extends in the width direction orthogonally crossing the longitudinal direction, between the bulges 41 and 42 adjoining to each other in the longitudinal direction. A part 11c of a core wrap sheet 11 which is positioned between the bulges 41 and 42 adjoining to each other in the longitudinal direction, is loaded with a lowered tensile strength in the longitudinal direction, compared with the other parts of the core wrap sheet 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an absorbent article such as a sanitary napkin, a panty liner (corimono sheet), an incontinence pad, and a method for producing the same.

  Absorbent articles such as sanitary napkins include a substantially longitudinal product having a top sheet, a back sheet, and an absorbent body interposed between both sheets. The absorbent body is configured to include an absorbent core that includes wood pulp, a highly water-absorbent resin, and the like, and a core wrap sheet such as tissue paper or nonwoven fabric that covers the outer surface of the absorbent core. . The core wrap sheet serves as a sheet for receiving an absorber-forming material such as wood pulp or a highly water-absorbent resin during production of the absorbent body, and plays a role of wrapping and shaping the absorbent core after production.

  As a technique using a core wrap sheet, for example, in Patent Document 1, two surfaces of an absorbent core are covered with hydrophilic paper (core wrap sheet), the paper provided on the two surfaces and the absorbent There is described an absorbent body in which a core is compressed and integrated by a number of dot-like embossed portions. The embossed portion is uniformly formed over the entire surface of the absorbent core. According to the absorber described in Patent Document 1, it is said that due to the formation of the embossed portion, separation between the core wrap sheet and the absorbent core hardly occurs, and a strong bonded state is formed between the two. .

  Conventionally, in absorbent articles such as sanitary napkins, in order to improve adhesion to the body and leakage prevention properties, it is known that the absorbent body protrudes in a convex shape from the central part or from the central part to the buttocks. Yes. Also, in absorbent articles such as sanitary napkins, in order to improve leakage prevention and wearability, it is also known to form a groove formed by compacting the topsheet and the absorbent on the skin contact surface side. ing. For example, in Patent Document 2, a medium-high part that is narrower than the absorbent body and protrudes in a convex shape is formed on the skin contact surface side of the absorbent body, and the middle-high part serves as a front part and a rear part of the absorbent article. The absorbent article which consists of the front middle-high part and back middle-high part which are provided in the part separately is described. The front middle high part and the rear middle high part are each surrounded by the groove.

  However, the absorbent article as described in Patent Document 2, that is, the front middle high part and the rear middle high part are arranged at a predetermined interval in the longitudinal direction of the absorbent article, and the top sheet and the absorbent body are between both middle high parts. In the absorbent article in which the groove formed by consolidation is formed, especially in the groove located between the middle and high parts, the surface to be joined and integrated with the absorber that supports the middle and high parts from below The sheet or the core wrap sheet may be lifted from the surface of the absorber, and as a result, the moldability of the groove may be lowered.

  Various countermeasures have been proposed for floating the top sheet in the groove. For example, Patent Document 3 describes a method in which a step is formed on a pressure surface of a pressure roll used for forming a groove to provide a high pressure portion and a low pressure portion, and the groove is formed using the pressure roll. Yes. Further, Patent Document 4 describes a method for defining a difference in size between the existence area of the widthwise embossing groove extending in the width direction of the absorbent article and the existence area of the longitudinal embossing groove extending in the longitudinal direction within a specific range. ing. However, the methods described in Patent Documents 3 and 4 are effective in floating the surface sheet and the core wrap sheet in a groove located between two middle and high portions arranged at a predetermined interval in the longitudinal direction of the absorbent article. Cannot be prevented.

JP 2003-284743 A JP 2006-239162 A JP 2000-14701 A JP 2003-265519 A

  Accordingly, an object of the present invention is to have a groove formed by compacting a sheet such as a surface sheet and an absorber on the skin contact surface side, and the float of the surface sheet or the like in the groove is suppressed, so that the groove is formed. It is providing the absorbent article excellent in property, and its manufacturing method.

  The present invention comprises a top sheet for forming a skin contact surface, a back sheet for forming a non-skin contact surface, and an absorbent body interposed between the two sheets, the absorbent body comprising the absorbent core and the absorbent core. The absorbent article is configured to include a core wrap sheet that covers the skin contact surface side of the skin, and the absorbent body has a mid-high portion that protrudes toward the skin contact surface side in the center region in the width direction. The middle-high portion is composed of a front middle-high portion and a rear middle-high portion that are separately provided, and the top sheet and the absorber are consolidated between the front middle-high portion and the rear middle-high portion. The intermediate groove to be formed is formed to extend in the width direction of the absorbent article, and the portion of the core wrap sheet located between the front middle high portion and the rear middle high portion is the core wrap sheet. Reduces the longitudinal tension of the absorbent article compared to other parts By providing an absorbent article that is obtained by achieving the above object.

  The present invention also provides a method for manufacturing the absorbent article, wherein a plurality of absorbent cores arranged at a predetermined interval in one direction are wrapped with a core wrap sheet while maintaining the arrangement form. To obtain a covering including an absorbent layer integrated with the core wrap sheet, and the core wrap sheet positioned between the absorbent cores adjacent to the one direction in the covering. A step of performing a tension reduction process for reducing the tension in the one direction of the core wrap sheet; and supplying the one surface sheet of the covering subjected to the tension reduction process, and then adsorbing the absorption adjacent to the one direction. A method for producing an absorbent article, comprising: a step of pressing a predetermined portion of the covering including between the functional cores from the top sheet side with a pressing means to form a groove in the predetermined portion. To achieve the purpose One in which the.

  ADVANTAGE OF THE INVENTION According to this invention, the float of the surface sheet etc. in a groove | channel is suppressed, The absorbent article excellent in the moldability of a groove | channel and excellent in an external appearance, leak prevention property, and mounting property can be provided.

  Hereinafter, the present invention will be described based on preferred embodiments with reference to the drawings. FIG. 1 is a plan view schematically showing a skin contact surface side (surface sheet side) of a sanitary napkin (hereinafter also referred to as a napkin) according to a first embodiment of the present invention, and FIG. FIG. 3 is a cross-sectional view schematically showing a cross section taken along line II, and FIG. 3 is a schematic view of a state before the formation of a cutting line of an absorbent body (absorbent core covered with a core wrap sheet) in the sanitary napkin shown in FIG. FIG.

  The napkin 1 according to the first embodiment includes a liquid-permeable top sheet 2 that forms a skin contact surface, a liquid-impermeable or water-repellent back sheet 3 that forms a non-skin contact surface, and both the sheets 2, The liquid-retaining absorbent 4 interposed between the three is provided, and has a substantially vertically long shape. The napkin 1 has, in the longitudinal direction, a front part A that is disposed opposite to the excretion site of the wearer when worn, and a rear part B that is arranged on the back side (rear) with respect to the front part A when worn. Yes. The boundary between the front part A and the rear part B in the first embodiment exists at the approximate center in the longitudinal direction of the napkin 1.

  The top sheet 2 and the back sheet 3 have dimensions larger than those of the absorbent body 4, extend from both ends in the longitudinal direction of the absorbent body 4, and are joined to each other by heat sealing or the like at the end portions of the extended sections. Forming part. The top sheet 2 covers the entire area of the absorbent body 4 on the skin contact surface side, further covers both side portions along the longitudinal direction of the absorbent body 4, and the left and right sides of the absorbent body 4 on the non-skin contact surface side. It reaches to both sides. The back sheet 3 extends outward from both side edges along the longitudinal direction of the absorbent body 4 to form a flap portion 5. The flap portion 5 further extends outward in the width direction of the napkin 1 at the front portion A, and forms a pair of wing portions 6 and 6. When the napkin 1 is attached, the wing portion 6 is used with its non-skin contact surface side folded back to the outer surface side of the crotch portion of the underwear, and an adhesive portion 7 is provided on the non-skin contact surface side. Moreover, the adhesion part which is not shown in figure which fixes the napkin 1 to clothes, such as underwear, is also provided in the predetermined location located under the absorber 4 in the non-skin contact surface side of the back surface sheet 3. These adhesive portions are provided by applying a hot melt adhesive to a predetermined location, and are covered with a release sheet (not shown) made of a film, a nonwoven fabric, paper, or the like before the napkin 1 is used.

  In the present specification, the skin contact surface is a surface directed toward the skin side of the wearer when the absorbent article is mounted, and the non-skin contact surface is the side opposite to the skin side when the absorbent article is mounted. It is the surface that is directed to. The longitudinal direction is a direction along the longitudinal direction of the absorbent article or its constituent members, and the width direction is a direction orthogonal to the longitudinal direction.

  As shown in FIGS. 1 and 3, the absorbent body 4 has a front middle-high portion 41 and a rear middle-high portion 42 that protrude on the skin contact surface side at the center in the width direction. These two middle and high portions 41 and 42 are arranged at predetermined intervals in the longitudinal direction of the napkin 1. The absorbent body 4 includes a liquid-retaining absorbent core and a liquid-permeable core wrap sheet that covers the skin contact surface side of the absorbent core, and is a part of the absorbent body 4. The front middle-high part 41 and the rear middle-high part 42 are also comprised by the absorptive core and the core wrap sheet | seat which covers it. More specifically, in the absorbent body 4, a vertically long absorbent core extending from the vicinity of the front end 1 a of the front part A of the napkin 1 to the vicinity of the rear end 1 b of the rear part B is integrated with one core wrap sheet 12. A lower absorbent layer 40 and an upper absorbent layer disposed on the skin contact surface of the lower absorbent layer 40, the upper absorbent layer being a core wrap sheet having two absorbent cores. 11 and the two absorbent cores are spaced apart from each other in the longitudinal direction of the napkin 1 to form the middle and high portions 41 and 42 separately. With such a configuration of the upper absorbent layer, the central portion in the width direction on the skin contact surface side of the napkin 1 becomes a bulky middle-high portion compared to other portions. The interval between the middle and high portions 41 and 42 is usually about 5 to 30 mm.

  As shown in FIG. 1, the middle and high portions 41, 42 (upper layer absorbent layer) are vertically long and narrower than the lower layer absorbent layer 40, and the longitudinal direction thereof coincides with the longitudinal direction of the napkin 1. It is arranged on the skin contact surface. The front middle high portion 41 has a rectangular shape with rounded corners in plan view, and the rear middle high portion 42 has a rear end from its front end (end closer to the longitudinal front end 1a of the napkin 1) in plan view. It has a tapered shape in which the width gradually decreases toward the end of the napkin 1 close to the longitudinal rear end 1b. The non-skin contact surface side of each of the middle and high portions 41 and 42 and the skin contact surface side of the lower layer absorbent layer 40 may be joined by a joining means such as an adhesive.

  As shown in FIGS. 2 and 3, the absorbent core constituting the absorbent body 4 is composed of two liquid-permeable core wrap sheets 11 and 12, and absorbs the middle and high portions 41 and 42 (upper absorbent layers). The core and the absorbent core of the lower absorbent layer 40 are individually covered. That is, the core wrap sheet 11 integrally covers the entire skin contact surface side of the absorbent core of each of the middle and high portions 41 and 42, and further, both side portions along the longitudinal direction of each of the absorbent cores. It coat | covers integrally and reaches the non-skin contact surface side of each of this absorptive core, and coat | covers the whole surface integrally. The core wrap sheet 12 covers the entire surface of the lower absorbent layer 40 on the skin contact surface side of the absorbent core, and further covers both side portions along the longitudinal direction of the absorbent core. It reaches the non-skin contact surface side of the core and covers the entire surface. The core wrap sheets 11 and 12 and the absorbent core of each absorbent layer are joined to each other by a joining means such as a hot melt adhesive at a predetermined site. As described above, the absorbent body 4 is configured by covering the absorbent core with the core wrap sheets 11 and 12 because the shape stability of the absorbent body 4 is improved, and the absorbent core has a particulate high water absorption capacity. When a functional resin is included, it is effective for maintaining the supported state.

  The core wrap sheet 11 exists between the middle and high portions 41 and 42 adjacent to each other in the longitudinal direction of the napkin 1, and as shown in FIG. 1, the top sheet 2 and the absorbent body 4 (core wrap sheets 11, 12). And an intermediate groove 8b formed by consolidating the absorbent core of the lower absorbent layer 40 extends in the width direction perpendicular to the longitudinal direction. More specifically, the skin contact surface of the napkin 1 (the upper surface of the topsheet 2) is formed with a closed annular groove 8 that surrounds the front middle-high portion 41, and the intermediate groove 8b It has become a part. The intermediate groove 8 b is formed in a substantially U shape that protrudes toward the rear middle high portion 42 adjacent to the intermediate groove 8 b, and the U-shaped top portion is located at the center in the width direction of the napkin 1.

  The groove 8 includes, in addition to the intermediate groove 8b, a groove 8a formed symmetrically with the intermediate groove 8b across the front of the front middle high portion 41, and a pair of grooves 8c and 8c extending in the longitudinal direction of the napkin 1. These grooves 8 a, 8 b, 8 c, 8 c are connected to each other at an end portion to form an annular shape surrounding the front middle high portion 41. In the groove 8, the absorbent core of the top sheet 2, the core wrap sheets 11, 12 and the lower absorbent layer 40 is joined and integrated.

  In addition to the groove 8, a groove 9 surrounding the rear middle high part 42 and a groove 10 surrounded by the groove 9 and surrounding the rear end side of the rear middle high part 42 are formed on the skin contact surface of the napkin 1. ing. The grooves 9 and 10 are formed in a substantially U shape that is narrower than the intermediate groove 8b. Although the intermediate groove 8b and the groove 9 are not connected, the rear middle high portion 42 is substantially surrounded by both the grooves 8b and 9. As described above, the grooves 8, 9, and 10 in which the top sheet 2 and the absorbent body 4 are consolidated and integrated are formed on the skin contact surface side of the napkin 1. Diffusion of the liquid in the planar direction is effectively suppressed, and twisting can be prevented. In particular, the presence of the grooves 8b, 9, 10 increases the upward flexibility of the rear portion B of the napkin 1, thereby further improving the fit of the napkin 1 to the wearer's body. The grooves 8, 9, 10 can be formed in accordance with a conventional method, for example, by heat embossing. The grooves 8, 9, and 10 are linearly formed by continuously forming a large number of rectangular seal portions by heat embossing or the like, and are formed by pressing the topsheet 2 into the lower absorbent layer 40 in a concave shape. ing. The widths of the grooves 8, 9, and 10 are preferably 1 to 8 mm, and more preferably 1 to 4 mm, from the viewpoint of reliably achieving the above-described effects by these grooves.

  One of the main features of the napkin 1 according to the first embodiment is that the core wrap sheet 11 integrally covers the absorbent cores of the front middle high portion 41 and the rear middle high portion 42 adjacent to each other in the longitudinal direction of the napkin 1. A portion (hereinafter also referred to as an intermediate portion) 11c located between the middle and high portions 41, 42 is reduced in tension in the longitudinal direction as compared with other portions of the core wrap sheet 11. is there. More specifically, as shown in FIGS. 1 and 3, the intermediate portion 11 c of the core wrap sheet 11 has two cutting lines for cutting the core wrap sheet 11 (intermediate portion 11 c) in the longitudinal direction of the napkin 1. 15 and 16 are formed extending in the width direction of the napkin 1. FIG. 3 is a schematic diagram of the absorbent body 4 before the cutting lines 15 and 16 are formed. The cutting lines 15 and 16 have a substantially U shape that is convex toward the rear middle-high part 42 in plan view. The curvatures of the substantially U-shaped cutting lines 15 and 16 are substantially the same as the curvature of the substantially U-shaped intermediate groove 8b. Thus, since the intermediate part 11c is cut | disconnected over the full length of the width direction of the napkin 1 with the cutting lines 15 and 16, the tension | tensile_strength of the longitudinal direction of the napkin 1 of this intermediate part 11c is zero. Here, the intermediate part 11 c of the core wrap sheet 11 is a part located between the rear end 41 b of the front middle high part 41 and the front end 42 a of the rear middle high part 42 in the core wrap sheet 11.

  The cutting lines 15 and 16 and the intermediate groove 8b do not overlap. That is, in the first embodiment, the cutting lines 15 and 16 are formed respectively in the longitudinal direction of the napkin 1 across the intermediate groove 8b. Each of the cutting lines 15 and 16 is preferably formed in a region within 1 to 15 mm starting from the central portion in the width direction of the intermediate groove 8b (central portion in the napkin longitudinal direction). The portion sandwiched between the cutting lines 15 and 16 in the core wrap sheet 11 exists between the two cutting lines 15 and 16, and the top sheet 2, the core wrap sheet 12 and the lower layer absorption in the intermediate groove 8b. Integrated with layer 40.

  Thus, in the napkin 1 of the first embodiment, the tension in the longitudinal direction of the napkin of the intermediate portion 11c of the core wrap sheet 11 is such that the cutting lines 15 and 16 of the core wrap sheet 11 formed before and after the intermediate groove 8b. Is reduced as compared with other parts of the core wrap sheet 11, so that the core wrap sheet 11 in the intermediate groove 8 b and the lower layer of the surface sheet 2 disposed on the skin contact surface side of the sheet 11 Lifting from the surface of the absorption layer 40 is prevented, and the formability of the intermediate groove 8b is improved. If the tension of the intermediate portion 11c of the core wrap sheet 11 is not reduced, the tension is started downward by the tensions starting from the intermediate grooves 8b of the top sheet 2 and the core wrap sheet 11 and both the sheets 2, 11. Due to the upward restoring force of the absorbent cores of the middle and high portions 41 and 42, the joined state of the sheets in the intermediate groove 8b is destroyed, and as a result, the sheets 2 and 11 may be lifted from the surface of the lower absorbent layer 40. is there. That is, the reduction in the tension of the intermediate portion 11c of the core wrap sheet 11 suppresses the transmission of the tension and the restoring force to the formation position of the intermediate groove 8b, thereby improving the formability of the intermediate groove 8b.

  The material for forming each part of the napkin 1 will be described. As the top sheet 2, the back sheet 3, and the core wrap sheets 11 and 12, various kinds of materials conventionally used in the technical field can be used without particular limitation. As the surface sheet 2, for example, a liquid-permeable sheet such as a nonwoven fabric or an apertured film can be used. The back sheet 3 may be liquid-impermeable or liquid-permeable. For example, a resin film that does not have moisture permeability, a resin film that has micropores and has moisture permeability, a nonwoven fabric such as a water-repellent nonwoven fabric, these and other A laminate with a sheet can be used.

  As the absorptive core constituting the absorber 4 [upper layer absorbing layers (middle and upper portions 41, 42), lower layer absorbing layer 40], various types of cores conventionally used in the technical field can be used without particular limitation. For example, a fiber aggregate made of hydrophilic fibers such as wood pulp or synthetic fiber, or a fiber aggregate in which particulate superabsorbent resin is held can be used. As the core wrap sheets 11 and 12 covering the absorbent core, for example, paper such as tissue paper, various nonwoven fabrics, apertured films, and the like can be used. The compositions of the absorbent cores of the lower absorbent layer 40 and the middle and high portions 41 and 42 may all be the same, or any of them may be different.

The basis weight of the lower absorbent layer 40, from the viewpoint of absorption performance, preferably 100 to 500 g / m ^2, more preferably a 150 to 350 g / m ^2. From the same point of view, the basis weight of the front middle high portion 41 is preferably 100 to 700 g / m ² , more preferably 150 to 600 g / m ² , and the lower absorbent layer 40 under no load of the front middle high portion 41. The height of the protrusion from the surface on the skin contact surface side is preferably 1 to 30 mm, more preferably 2 to 15 mm. From the same point of view, the basis weight of the rear middle high portion 42 is preferably 100 to 700 g / m ² , more preferably 150 to 600 g / m ² , and the lower absorbent layer 40 under no load of the rear middle high portion 42. The raised height from the surface on the skin contact surface side is preferably 1 to 20 mm, and more preferably 2 to 10 mm. In addition, the basic weight of the absorption layer said here means the basic weight (basis weight of a fiber assembly) which does not contain a core wrap sheet and super absorbent polymer.

  Next, other embodiment of the absorbent article of this invention is described with reference to drawings. As for other embodiments of the absorbent article to be described later, components that are different from the napkin 1 of the first embodiment described above will be mainly described, and similar components will be denoted by the same reference numerals and description thereof will be omitted. The description about the napkin 1 of 1st Embodiment is applied suitably to the component which is not demonstrated especially. 4 to 6, the lower absorption layer 40 is not shown. 4 and 5, the cutting lines 17 and 18 are drawn with a predetermined width for easy explanation.

  FIG. 4 shows a part of the absorbent body of the sanitary napkin which is the second embodiment of the absorbent article of the present invention [before the upper layer absorbent layer (middle and high portions 41, 42)] groove formation (after the cutting line is formed). It is a perspective view which shows this state typically. The cutting lines 15 and 16 in the first embodiment are formed over the entire width in the napkin width direction of the intermediate portion 11c of the core wrap sheet 11 (see FIG. 3), whereas the cutting lines 17 in the second embodiment are formed. Is formed only at the central portion of the intermediate portion 11c in the napkin width direction, and is not formed over the entire width of the intermediate portion 11c in the napkin width direction. One cutting line 17 exists in the part which forms the skin contact surface side (upper surface side) of the absorbent body 4 in the core wrap sheet 11 covering the absorbent cores of the middle and high portions 41 and 42. ing. Although the tension | tensile_strength of the longitudinal direction of the napkin is not zero by the cutting line 17, the intermediate part 11c of the core wrap sheet | seat 11 is reduced compared with the other site | part of this core wrap sheet | seat 11. FIG.

  The length L1 of the cutting line 17 (that is, the cutting line whose length in the napkin width direction is less than the entire width of the intermediate part 11c of the core wrap sheet 11) and the core wrap sheet 11 before the cutting line 17 is formed. The ratio (L1 / L) to the total width of the intermediate part 11c in the napkin width direction (maximum width when the width of the intermediate part 11c is not constant) L is preferably 0.2 to 0.95, more preferably 0.4. ~ 0.8. Further, the width of the cutting line 17 (the length in the direction orthogonal to the length direction of the cutting line) is equal to or less than the length P2 (see FIG. 6) along the napkin longitudinal direction of the intermediate part 11c.

  In the second embodiment, the cutting line 17 and the intermediate groove 8b (not shown in FIG. 4) may or may not overlap. The part (non-overlapping part) that does not overlap with the cutting line 17 in the intermediate groove 8b is compared with the part (overlapping part) that overlaps with the cutting line 17 in the intermediate groove 8b. Since the number of sheets is large, each sheet is bonded with a stronger bonding force. Therefore, forming part or all of the intermediate groove 8b so as not to overlap the cutting line 17 is effective for preventing the sheet from being lifted. The same effect as the napkin of 1st Embodiment is show | played also by the napkin of 2nd Embodiment.

  FIG. 5 shows a part of the absorbent body of the sanitary napkin according to the third embodiment of the absorbent article of the present invention [before the upper absorbent layer (middle and high portions 41, 42)] groove formation (after the cutting line is formed). It is a perspective view which shows this state typically. In the napkin of the third embodiment, a plurality of cutting lines 18a and 18b are arranged in the intermediate portion 11c of the core wrap sheet 11 so as to form a line at predetermined intervals in the width direction of the napkin 1, respectively. The rows of the cutting lines 18a and 18b (three rows in FIG. 5) are arranged at predetermined intervals in the longitudinal direction of the napkin 1, respectively. There are five cutting lines 18a at the site forming the skin contact surface side (upper surface side) of the absorbent body 4 in the core wrap sheet 11 covering the middle and high portions 41, 42. Five 18b exist in the site | part facing this site | part in this core wrap sheet | seat 11, and each cutting line 18a and each cutting line 18b mutually oppose in the up-down direction. The sizes of the cutting lines 18a and 18b are substantially the same. The widths of the cutting lines 18a and 18b can be made the same as the cutting line 17 (see FIG. 4) in the second embodiment.

  In the third embodiment, the cutting lines 18a and 18b and the intermediate groove 8b (not shown in FIG. 5) may or may not overlap. The napkin of the third embodiment can achieve the same effects as the napkin of the first embodiment.

  FIG. 6 is a schematic view showing a state in which a tension reducing process is performed on a part of the absorbent body [upper absorbent layer (middle and high portions 41, 42)] in the sanitary napkin according to the fourth embodiment of the absorbent article of the present invention. FIG. In the napkin of 4th Embodiment, the high expansion | extension part 19 with the high expansion | extension rate of a napkin longitudinal direction is formed in the intermediate part 11c of the core wrap sheet | seat 11 compared with the other site | part of this core wrap sheet | seat 11. As shown in FIG. In FIG. 6, it is described that the unevenness (ridge) is formed in the high extension portion 19, but such a clear unevenness is not necessarily formed in the actual high extension portion. Absent. Moreover, in FIG. 6, it describes so that the high expansion | extension part 19 in the side part pinched | interposed into the skin contact surface side and the non-skin contact surface side of the core wrap sheet | seat 11 may stand upright in the perpendicular direction. However, the high extension portion 19 in the actual side portion is not necessarily in an upright state, and is along the napkin longitudinal direction on the skin contact surface side and the non-skin contact surface side. In some cases, it extends from the side edge so as to relax. Due to the high extension part 19, the intermediate part 11c of the core wrap sheet 11 has higher extensibility than other parts (low or non-extension part) of the sheet 11 and is more easily extended with a small force. Therefore, in the intermediate part 11 c where the high extension part 19 is formed, the tension in the longitudinal direction of the napkin is reduced as compared with other parts of the core wrap sheet 11.

  The high extension portion 19 is formed at a substantially central portion of the intermediate portion 11c in the longitudinal direction of the napkin and extends over the entire width of the portion. The ratio (P1 / P2) of the length P1 along the napkin longitudinal direction of the high extension portion 19 to the length P2 along the napkin longitudinal direction of the intermediate portion 11c is preferably 0.2 to 1.0, and further Preferably it is 0.5-1.0.

  The high elongation portion 19 is obtained by performing a stretching process on the intermediate portion 11 c of the core wrap sheet 11. For example, as will be described later, the core wrap sheet can be stretched by a gear stretching method in which a pair of gears having gear teeth that mesh with each other are used and the sheet is meshed with the gears. The shape of the gear may be a pair of gear rolls (wave rolls) in which the tooth gaps are engaged in a gear shape, or may be a flat plate shape.

  The core wrap sheet 11 according to the fourth embodiment is 1) a sheet that does not have stretchability or stretchability before stretching, and that exhibits stretchability or stretchability by stretching, or 2) some before stretching. It is preferable that the sheet has extensibility or stretchability and the stretchability or stretchability is improved by stretching. In addition, extensibility is a property that can be extended in one direction when pulled in one direction with a predetermined tensile load, and when the tensile load is removed, does it return to the original length before pulling? It doesn't matter whether or not. Stretchability is a property that when stretched in one direction with a predetermined tensile load, it stretches in one direction, and when the tensile load is removed, it can return to its original length before pulling. Say. Examples of the sheet satisfying 1) and 2) include a nonwoven fabric containing elastic fibers (a thermoplastic elastomer fiber such as a styrene-based elastomer, a polyolefin-based elastomer, a polyester-based elastomer, and a polyurethane-based elastomer).

  The elongation ratio of the high elongation portion 19 varies depending on the material of the core wrap sheet 11, but when the core wrap sheet 11 is, for example, a nonwoven fabric containing elastic fibers, it is preferably 10% or more, more preferably 15% or more. It is. Moreover, in that case, the low or non-extension part (parts other than the intermediate part 11c) in the core wrap sheet 11 that has not been stretched is hardly extended or slightly extended even if it is extended by hand. The elongation ratio of the low or non-stretched portion is less than 10%. The elongation rate of the core wrap sheet can be adjusted, for example, by appropriately adjusting the gear shape (tooth height, tooth pitch, etc.) used in the gear stretching method. The elongation rate is measured as follows.

<Measurement method of elongation rate>
The sample is pulled using a tensile tester such as Tensilon to measure the elongation. A sample of a predetermined size (for example, a width of 25 mm and a length of 50 mm) is prepared from the measurement object (sheet). The sample length (when the sample size is 25 mm and the length is 50 mm, the tensile load is 1 N / 25 mm width) is pulled in the length direction of the sample, and the sample length when the sample stops stretching ( A) is measured, and the elongation percentage (%) is calculated by the following formula. Elongation rate (%) = [(A-50) / 50] × 100. That is, [(sample length after stretching at a tensile load of 1.0 N−sample length before stretching) / (sample length before stretching)] × 100. For example, when the sample size is 25 mm wide and 50 mm long, the elongation rate is 100% when the sample length after elongation is 100 mm, and the elongation rate is 200% when the sample length after elongation is 150 mm. .

  In the fourth embodiment, the high extension portion 19 and the intermediate groove 8b (not shown in FIG. 6) may or may not overlap. The overlapping of the high extension portion and the intermediate groove means that part or all of the intermediate groove is formed in the high extension portion of the core wrap sheet. When the high extension part 19 and the intermediate groove 8b are overlapped, the flexibility of the intermediate groove 8b is increased, which leads to an improvement in wearing feeling and texture. Moreover, when the high extension part 19 and the intermediate groove 8b do not overlap, since the intermediate groove 8b is a low or non-extension part, the deflection | deviation of the absorber 4 at the time of napkin mounting | wearing is prevented effectively. The effect similar to that of the napkin of the first embodiment is also obtained by the napkin of the fourth embodiment.

  Next, a preferred embodiment of the method for producing an absorbent article of the present invention will be described with reference to the drawings, taking the method for producing the sanitary napkin of the first embodiment as an example. FIG. 7 is a diagram schematically showing a groove forming step in manufacturing a sanitary napkin.

  In the manufacturing method of the present embodiment, first, a plurality of (two) absorbent cores arranged at a predetermined interval in one direction are wrapped with the core wrap sheet 11 while maintaining the arrangement form, whereby the plurality of the absorbent cores are wrapped. Upper absorbent layer (middle and high portions 41, 42) in which the absorbent core is integrated with the core wrap sheet 11 and the lower layer absorption formed by wrapping one absorbent core long in one direction with the core wrap sheet 12 A continuous body of the covering 50 (see FIG. 7) including the layer 40 is manufactured. The covering 50 corresponds to the absorbent body 4 in the napkin 1 of the first embodiment, and the continuous body of the covering 50 is separated into individual coverings 50 as described later. The one direction (the direction in which the plurality of absorbent cores form a line) coincides with the longitudinal direction of the finished napkin. The strip-shaped core wrap sheet 11 integrally covers the absorbent cores of the pair of middle and high portions 41 and 42, and the strip-shaped core wrap sheet 12 covers a continuous body of absorbent cores of the lower absorbent layer 40. ing. The upper absorbent layer (middle and high portions 41, 42) and the lower absorbent layer 40 can be manufactured according to a conventional method using a known apparatus. Between the absorbent core and the core wrap sheet 11 in the upper absorbent layer, between the absorbent core and the core wrap sheet 12 in the lower absorbent layer 40, and between the upper absorbent layer and the lower absorbent layer 40 (core wrap). The sheets 11 and 12) are bonded to each other by an adhesive or a known sealing method as necessary.

  Next, with respect to the continuous body of the covering 50 including the upper absorbent layer and the lower absorbent layer 40 in which the absorbent core is wrapped with the strip-shaped core wrap sheets 11 and 12, the unidirectional direction in the continuous body The core wrap sheet 11 positioned between the middle and high portions 41 and 42 adjacent to each other (in the conveying direction of the covering body 50) is subjected to a tension reduction process for reducing the unidirectional tension of the core wrap sheet 11. More specifically, the intermediate portion 11c of the strip-shaped core wrap sheet 11 (the portion located between the pair of middle and high portions 41, 42 adjacent to the one direction in the strip-shaped core wrap sheet 11) is cut, Cut lines 15 and 16 (see FIG. 3) for cutting the sheet 11 in the one direction are formed. Thereby, the tension | tensile_strength of this one direction of the strip | belt-shaped core wrap sheet | seat 11 is made into zero. The cutting of the sheet 11 can be performed using a known cutter or the like. In addition, when the middle and high portions 41 and 42 (upper layer absorbent layers) integrally wrapped with the core wrap sheet 11 are cut along the cutting lines 15 and 16 as described above, the cut middle and high portions 41 and 42 are moved downward. From the viewpoint of production, it is preferable that there is a support to be supported from above. In this embodiment, the continuum of the lower absorbent layer 40 plays a role as the support.

  The continuous body of the covering body 50 that has been subjected to the tension reducing process, that is, the cutting lines 15 and 16 are formed on the belt-like core wrap sheet 11 that covers the upper absorbent layer, is separated into individual covering bodies 50. After that, grooves 8, 9, and 10 (see FIG. 1) are formed at predetermined portions by the groove forming step. In the groove forming step, as shown in FIG. 7, after supplying the strip-shaped topsheet 2 ′ to the surfaces of the middle and high portions 41, 42 in the covering 50 that has been subjected to the tension reduction treatment, 50, the predetermined portion of the covering 50 including the middle and high portions 41, 42 adjacent to each other in the conveying direction) is squeezed from the top sheet 2 ′ side by the pressing roll 61, and the grooves 8, 9, 10 is formed. That is, the grooves 8, 9, and 10 receive the pressure and the pressure roll 61 heated to a predetermined temperature in a state where the middle and high portions 41 and 42 of the covering body 50 are in contact with the top sheet 2 ′ and both are laminated. By passing between the anvil roll 62, it is formed by pressing by the embossed groove protrusion 61a formed on the peripheral surface portion of the pressing roll 61 from the top sheet 2 ′ side. In this embodiment, as shown in FIG. 7, the belt-like topsheet 2 ′ is placed on the conveying device for the covering 50, and the covering 50 separated individually is turned upside down. Thus, pressing is performed by the embossed groove protrusion 61a of the pressing roll 61 positioned below the covering body 50 in a state where the surface sheet 2 ′ side of the covering body 50 is directed downward. Moreover, although not shown in figure, the protrusion 61a for embossing grooves is formed in the pattern corresponding to the groove | channels 8, 9, and 10, and this pressing roll is in the state where a fixed pressing force was applied to the pressing roll 61. As the 61 rotates, the tips of the embossed groove protrusions 61a sequentially come into contact with the cover 50 from the 2 'side, thereby forming the grooves 8, 9, and 10 as shown in FIG.

  After completion of the groove forming step, a belt-like back sheet (not shown) is supplied, and the covering 50 is sandwiched between the back sheet and the top sheet 2 ′, and then the extending portion from the covering 50 in both sheets is The sanitary napkin according to the first embodiment is obtained by forming the end seal portion by joining at a predetermined site by a sealing method such as heat sealing and then separating the napkin into individual napkins.

  In the above embodiment, a plurality of absorbent cores are covered with the core wrap sheet 11 on the lower absorbent layer 40 formed by covering the absorbent core with the core wrap sheet 12, and the two are integrated. The core wrap sheet 11 was subjected to a tension reducing process in a state where the upper absorbent layers (middle and high portions 41 and 42) were overlaid, but before the two layers were overlaid, the core constituting the upper absorbent layer The lap sheet 11 may be subjected to a tension reducing process, and then both layers may be overlapped.

  Moreover, the napkin of 2nd Embodiment shown in FIG. 4 and the napkin of 3rd Embodiment shown in FIG. 5 can each be manufactured according to the manufacturing method mentioned above. In the second and third embodiments, the length in the napkin width direction of the cutting lines 17 and 18 formed in the intermediate portion 11c of the core wrap sheet 11 in the tension reducing process is less than the full width of the intermediate portion 11c in the napkin width direction. Since the intermediate portion 11c is not separated by the cutting line, the cutting line formation (tension reduction processing) in the second and third embodiments is easily performed regardless of the presence or absence of the lower absorbent layer 40. Can do.

  Moreover, when manufacturing the napkin of 4th Embodiment shown in FIG. 6, ie, the napkin in which the high expansion | extension part 19 is formed in the intermediate part 11c of the core wrap sheet | seat 11, as said tension reduction process, it mentioned above. Instead of cutting the intermediate portion 11c of the belt-shaped core wrap sheet 11, a stretching process using a gear stretching method is performed. That is, as shown in FIG. 8, the intermediate portion 11c of the belt-shaped core wrap sheet 11 is engaged between a pair of sandwiching bodies 71, 72 having tooth grooves engaged with each other, and the one direction (the conveying direction of the covering body 50). ) To form a highly elongated portion 19 as shown in FIG. When the core wrap sheet 11 constituting the upper absorbent layer in the laminate composed of the upper absorbent layer (the middle and high portions 41 and 42) and the lower absorbent layer 40 is thus stretched, the lower absorbent layer 40 If there is, the stretching process becomes difficult. Therefore, the stretching process is preferably performed without the lower absorbent layer 40 as shown in FIG.

  Teeth 71a and 72a having a predetermined height are formed on the surfaces of the pair of sandwiching bodies 71 and 72 facing the workpiece, and the tooth grooves of the sandwiching bodies 71 and 72 are meshed with each other. Sometimes, the tooth gaps of both sandwiching bodies are engaged with each other at a predetermined engagement depth. Therefore, the part (high extension part 19) of the workpiece to be stretched (intermediate portion 11c of the core wrap sheet 11) bitten between the tooth spaces facing each other is stretched in the conveying direction of the stretched workpiece, It becomes a high elongation region that expresses excellent extensibility.

  As mentioned above, although this invention was demonstrated based on the preferable embodiment, this invention is not restrict | limited to the said embodiment. For example, in the above embodiment, a sanitary napkin is given as one example of application of the absorbent article of the present invention. Further, in addition to the intermediate portion 11c of the core wrap sheet 11 (between the front middle high portion 41 and the rear middle high portion 42), a groove located in the core wrap sheet 11 near the front end of the front middle high portion 41 in the napkin longitudinal direction. The tension reducing process may be performed at the same position or the vicinity thereof as 8a and / or at the same position or the vicinity thereof as the groove 10 located in the vicinity of the rear end of the rear middle high portion 42 in the napkin longitudinal direction.

  Moreover, although the napkin of the said embodiment had two middle-high parts in the longitudinal direction, you may have three or more in the longitudinal direction. When three or more middle-high portions are arranged at predetermined intervals in the longitudinal direction, there are two or more spaces between the middle-high portions adjacent to each other in the longitudinal direction. An intermediate groove extending in the direction can be formed. When there are a plurality of intermediate grooves in this way, the tension of the core wrap sheet described above can be reduced corresponding to each intermediate groove. Moreover, the middle-high part may be formed integrally with the lower layer absorption layer.

  Moreover, in the said embodiment, the absorptive core of each middle-high part 41 and 42 (upper layer absorption layer) and the absorptive core of the lower layer absorption layer 40 were each coat | covered with the two core wrap sheets 11 and 12, respectively. However, the laminated body of the absorbent core of the upper absorbent layer and the absorbent core of the lower absorbent layer 40 may be integrally covered with a single core wrap sheet. Moreover, the core wrap sheet should just coat | cover the skin contact surface side of an absorptive core, and does not need to coat | cover the non-skin contact surface side.

  The intermediate groove 8b is curved in a substantially U shape in plan view, but may be bent in a substantially V shape or may be a straight shape extending in the width direction of the napkin 1. Further, although the groove 8a and the intermediate groove 8b are formed symmetrically with the front middle high portion 41 interposed therebetween, both the grooves 8a and 8b may not be symmetrical. Further, the intermediate groove 8b and the groove 9 may be connected.

  Further, in the present invention, in addition to the above-described reduction in the tension of the core wrap sheet, in addition to the above-described reduction in the tension of the core wrap sheet, from the viewpoint of more effectively suppressing the floating of the surface sheet or the like in the groove and further improving the moldability of the groove, Moisture may be applied (sprayed with water) to the groove and its vicinity in the formed member (surface sheet, core wrap sheet, absorbent core). Such an effect of improving the moldability of the groove due to moisture application is particularly effective when the member includes a hydrophilic fiber such as pulp fiber. The bonding force between the members is further increased, and effectively acts to prevent the surface sheet and the like from being lifted.

FIG. 1 is a plan view schematically showing a skin contact surface side (surface sheet side) of a sanitary napkin that is a first embodiment of the absorbent article of the present invention. FIG. 2 is a cross-sectional view schematically showing a cross section taken along line II of FIG. FIG. 3 is a perspective view schematically showing a state of the sanitary napkin shown in FIG. 1 before the formation of the cutting line of the absorbent body. FIG. 4 is a perspective view schematically showing a state before forming a groove in a part of the absorbent body (upper absorbent layer) in a sanitary napkin that is the second embodiment of the absorbent article of the present invention. FIG. 5 is a perspective view schematically showing a state before forming a groove in a part of the absorbent body (upper absorbent layer) in a sanitary napkin that is the third embodiment of the absorbent article of the present invention. FIG. 6 schematically shows a state where a tension reducing process (stretching process) is performed on a part of the absorbent body (upper absorbent layer) in the sanitary napkin according to the fourth embodiment of the absorbent article of the present invention. It is a perspective view. FIG. 7 is a view schematically showing a groove forming step in manufacturing the sanitary napkin shown in FIG. FIG. 8 is a side view schematically showing an outline of an example of the tension reduction processing of the core wrap sheet.

Explanation of symbols

1 Sanitary napkin (absorbent article)
2 Top sheet 3 Back sheet 4 Absorber 8, 9, 10 Groove 8 b Intermediate groove 11, 12 Core wrap sheet 15, 16, 17, 18 a, 18 b Cutting line 19 High extension part 40 Lower layer absorption layer 41 Front middle high part 42 Rear middle high Part 61 Squeeze roll 61a Embossed groove projections 71, 72 A pair of sandwiching bodies 71a, 72a having tooth grooves Teeth A Front part B Rear part

Claims (10)

A surface sheet that forms a skin contact surface, a back sheet that forms a non-skin contact surface, and an absorbent body interposed between the two sheets, the absorbent body comprising an absorbent core and the skin contact of the absorbent core An absorbent article configured to include a core wrap sheet covering the surface side,
The absorbent body has a mid-high portion that protrudes toward the skin contact surface side in the center region in the width direction, and the mid-high portion includes a front mid-high portion and a rear mid-high portion that are separately provided, and the front mid-height An intermediate groove formed by consolidating the topsheet and the absorbent body is formed extending in the width direction of the absorbent article between the portion and the rear middle high portion,
In the core wrap sheet, the portion located between the front middle high portion and the rear middle high portion has a reduced tension in the longitudinal direction of the absorbent article as compared to other portions of the core wrap sheet. Absorbent article.   The absorbent article according to claim 1, wherein a cutting line is formed extending in the width direction at a portion of the core wrap sheet positioned between the front middle high portion and the rear middle high portion.   The absorbent article according to claim 2, wherein the cutting line and the intermediate groove do not overlap.   The absorbent article according to claim 2, wherein a plurality of the cutting lines are present in a portion of the core wrap sheet that forms the skin contact surface side of the absorbent body.   In the core wrap sheet, a high extension portion having a higher extension ratio in the longitudinal direction than the other portions of the core wrap sheet is formed at a portion located between the front middle high portion and the rear middle high portion. The absorbent article according to claim 1.   The absorptive article according to claim 5 in which said high extension part and said middle slot have overlapped.   The absorptive article according to claim 5 in which said high extension part and said middle slot do not overlap. It is a manufacturing method of the absorptive article according to claim 1,
An absorbent layer in which the plurality of absorbent cores are integrated with the core wrap sheet by wrapping the plurality of absorbent cores arranged at a predetermined interval in one direction with a core wrap sheet while maintaining the arrangement form. A tension reduction treatment for reducing the tension in the one direction of the core wrap sheet on the core wrap sheet positioned between the absorbent cores adjacent to the one direction in the cover A process of applying
After supplying the one surface sheet of the covering subjected to the tension reduction treatment, a predetermined portion of the covering including between the absorbent cores adjacent in the one direction is pressed from the surface sheet side. A method for producing an absorbent article, comprising: a step of squeezing with a means to form a groove in the predetermined part.   The method for manufacturing an absorbent article according to claim 8, wherein the tension reduction process is a process of cutting the core wrap sheet positioned between the absorbent cores adjacent in the one direction.   The tension reduction process is a process of increasing the elongation rate in one direction of the core wrap sheet by subjecting the core wrap sheet positioned between the absorbent core materials adjacent in the one direction to stretching. The manufacturing method of the absorbent article of Claim 8.

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