JP2010104547A - Absorbent article and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an absorbent article providing a soft sense of wearing, having a high sense of dryness on the front surface side and a high liquid absorbency into a lower layer side, and preventing local liquid backflow. <P>SOLUTION: The absorbent article includes a front surface sheet, a rear surface sheet, and an absorber disposed between the sheets. The absorber has a multi-layered structure including an upper layer and a lower layer of both sides of the absorber folded and layered on each other along the longitudinal direction of the absorber. The folded edge of both sides in the lateral direction of the folded absorber and the lower layer have compressed areas with higher density of projections/recesses than that of the center in the lateral direction of the upper layer. The upper layer of the absorber and the front surface sheet are integrated by recess grooves formed from the front surface sheet to the upper layer in a part corresponding to an excretion part on both sides in the longitudinal direction of the absorbent article. The bottom of each recess groove is located in the upper layer side from the front surface of the lower layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an absorbent article that is attached to a human body and absorbs human body excretory fluid and the like, and a method of manufacturing the absorbent article.

  For example, in absorbent articles such as sanitary napkins and panty liners for women, diapers for the elderly and infants, various improvements have been added to improve functionality and wearing feeling. Yes. Specifically, the development of materials that enhance the functions required of each component, such as the top sheet that contacts the skin, the back sheet that contacts the clothes, and the absorbent body sandwiched between both sheets, Improvements in structure, or combinations thereof have been studied and attempted.

As shown in Patent Document 1, a panel made of absorbent core is divided into three sections on the center and both sides, and the side panels on both sides are folded to one side of the middle panel to form an absorbent core. There is a product made by absorbing this with a liquid-permeable cover.
Further, in Patent Document 2, a large number of compressed portions that are depressed from the back sheet side and / or the top sheet side are formed apart from each other, and the thickness of the compressed portion increases by liquid absorption compared to before the liquid absorption. An absorbent article made in such a manner is disclosed. Specifically, this article is a sanitary napkin in which an absorbent material is embossed so that one side of the absorbent body is depressed, and a smooth surface that is not depressed is directed toward the skin surface side. According to this sanitary napkin, it is said that it is excellent in the drawability of the liquid from a surface sheet, and the liquid retainability in the site | part corresponding to the excretion part of the human body when it mounts | wears, ie, the absorption point vicinity.

  Furthermore, Patent Document 3 is a sheet material obtained by laminating nonwoven fabrics, and has a layer state change region whose layer state changes along a predetermined direction, and the layer state change region is folded in a predetermined direction. It is described that the layer state of each layer of the nonwoven fabric laminate is made different in the thickness direction of the nonwoven fabric laminate. Specifically, the layer state is made different by changing the number and size of embossments in each layer. This nonwoven fabric laminated sheet is said to be suitably used as a diffusion layer interposed between a top sheet or an absorber and a top sheet.

By the way, it is assumed that the absorber and other members are integrated, and the absorber and the elastic material constitute an absorption portion, and the absorber is covered with the elastic material, or conversely, the elastic material is covered with the absorber. A sanitary napkin having a configuration in which both are integrated (first integration means), and in addition, the two are bonded or bonded by a crimp groove (second integration means). (See Patent Document 4). In the napkin specifically disclosed here, the top sheet, the absorbent body, the elastic member, and the back sheet are all integrated by the crimp groove.
JP-A-7-163619 JP 2006-55352 A JP 2007-168219 A JP-A-10-216172

  In this type of absorbent article, in order to increase liquid absorbency, the pulp fiber layer may be compressed to improve the liquid drawing. In order to increase the density of the fiber layer by compression, a method of embossing the absorbent body is employed. When the liquid spreading area and the remaining liquid amount of the absorbent body as the pulp fiber body are tested with respect to the drop of horse blood, the spreading area is embossed more than the case without embossing, and the embossing rate (described later) It has been confirmed that the liquid spreading increases when the surface area is increased, and the amount of liquid remaining on the surface is greatly reduced in the absorbent body having an increased embossing ratio than in the case without embossing.

  However, if embossing is simply performed on the entire absorbent body, (b) the entire absorbent body becomes hard and uncomfortable for the user, and (b) an “absorber thickness” that provides a sense of security and fit is ensured. It is difficult to ensure a balance between thickness and absorbency, and (c) the diffusion area on the surface is widened, so that the liquid is likely to spread to the surroundings, causing liquid leakage.

  The present invention realizes a soft wearing feeling of an absorbent article, has a high dry feeling on the surface side of the article and a high liquid drawing property to the lower layer side, and further suppresses local liquid return and a method for producing the same The purpose is to provide.

  The present invention is an absorbent article having a top sheet, a back sheet, and an absorbent body disposed between the two sheets, wherein the absorbent body is disposed on both sides of the absorbent body along the longitudinal direction of the absorbent body. Has a multilayer structure of an upper layer portion and a lower layer portion that are folded and stacked, and the folded edges on both sides in the width direction of the folded absorbent body and the lower layer portion are more than the center portion in the width direction of the upper layer portion. There is an unevenly densified compressed region, and the upper layer of the absorbent body and the top sheet are applied from the top sheet to the top layer at both side portions in the longitudinal direction of the absorbent article and corresponding to the excretory part The object is achieved by an absorbent article which is integrated by a concave groove and the bottom of the concave groove is located on the upper layer side of the lower surface.

  Further, the present invention provides the flat plate-shaped absorbent body after embossing is performed on both sides in the longitudinal direction of the vertically long plate-shaped absorbent body comprising the central portion and both side portions thereof, and the topsheet is disposed on one side of the flat plate-shaped absorbent body. By squeezing from the surface sheet side at a position corresponding to both sides of the central portion of the absorbent body to provide a concave groove, the flat plate absorbent body and the top sheet are integrated, and then both side portions of the flat plate absorbent body The manufacturing method of the absorbent article which folds back to the back side with the said surface sheet is provided.

  The absorbent article of the present invention realizes a soft wearing feeling, and also has a dry feeling on the article surface side and a high liquid drawing property to the lower layer side, and the inner absorbent body is difficult to twist and is locally stable while being morphologically stable. It has an excellent effect of suppressing liquid return. Moreover, according to the manufacturing method of this invention, said absorbent article can be efficiently produced in large quantities, maintaining the quality.

Prior to describing the embodiments of the present invention, definitions of some terms used in the present invention are described below.
First, in the present invention, the “excretion part corresponding part (q)” in the upper layer or the lower layer includes a part facing the position of the excretion part of the human body when the absorbent article is attached to the human body, and the excretion liquid thereof. It refers to an area that can be sufficiently received, and in particular, the excretory part facing part (preferably approximately the central part of the excretory part corresponding part) (q ₃ ) may be referred to as an absorption point of the absorber.
Next, “higher density by embossing” or “higher density of unevenness” refers to forming a region in which the fiber density is partially increased by forming unevenness on a structural member composed of fibers. For example, it is possible to form irregularities by point embossing or linear embossing by embossing or a combination of this and a flat roll, and flat pressing only does not include compressing the whole or a whole area of the member only by the flat roll.

The size of the emboss is not particularly limited, but if it is point emboss, the area of one point is preferably 0.7 to ²⁰ mm ² , and if it is linear emboss, the line width is preferably 1 to 10 mm. . In the linear embossing, a high compression portion and a low compression portion may be provided in one line, and the length of each is not particularly limited, but is preferably 3 to 8 mm, for example. In the present invention, “fiber density” means the mass of fiber per unit volume in a predetermined region of the fiber member.

  In the present invention, “stacking” or “stacking” includes not only stacking while two members are in contact with each other but also including interposing another sheet member or an adhesive between the two members. And in the absorbent article of this invention, when the upper layer and the lower layer are overlaid, it is preferable that both layers are laminated | stacked by the substantially same width. In this case, it is possible to form the above laminated structure by folding both side portions of one flat absorbent body so as to be in contact with the lower surface of the central portion.

  In the absorbent article of this invention, it is preferable that there exists an area | region densified by the embossing etc. in the excretion part corresponding | compatible part at least of the lower layer of an absorber. However, in consideration of the difference in the wearing state of the user and the shift at the time of wearing, it may be an area corresponding to the portion corresponding to the excretion part, and this is the same for the concave groove described later.

  In the present invention, the “concavo-convex densification rate” or “embossing rate” refers to the “concavo-convex densified portion” or “emboss” included in the area A in the embossed region of the target member. This is the ratio (Σa / A) of the sum of area a. Here, unless otherwise indicated, the area A is a range in which 50 to 100 embossed or high-pressure parts can be measured. In the absorbent article of the present invention, the “concavo-convex densification rate” or “embossing rate” in the excretory part corresponding position of the lower layer part of the absorber is not particularly limited, but is 10 to 70% in the embossed region. Preferably there is.

  The present invention will be described below based on embodiments, but the present invention is not construed as being limited thereto.

  FIG. 1 is a perspective view schematically showing a sanitary napkin as a preferred embodiment (Embodiment 1) of the absorbent article of the present invention with a part thereof broken, and FIG. 2 is taken along the line II-II in FIG. FIG. The sanitary napkin 10 according to the first embodiment includes an absorbent body 1 as a main part of the present invention, a top sheet 2 provided on the surface of the absorbent body 1, and a back sheet 3 attached to the back surface of the absorbent body 1. have. Then, both end portions in the longitudinal direction of the article are joined by side seals 4. Note that the lower surface of the back sheet 3 is slightly tacky, so that it is lightly adhered to the back surface of the underwear during use.

  The absorbent body 1 is composed of a pulp fiber body and a thin mount 5 that wraps the pulp fiber body, and both side portions in the longitudinal direction are folded to the back side of the central portion, thereby forming a two-layer structure of an upper layer 6 and a lower layer 7. Here, both side portions of the flat absorbent body before being folded are folded so as to face each other, and the end portions are brought into contact with each other on the back side of the upper layer 6 to constitute the lower layer 7. Moreover, the surface sheet 2 mentioned later is arrange | positioned on the upper surface of a flat absorber in the flat state of the absorber 1, and both sides are folded by the center part lower surface of the absorber 1 with the absorber 1. FIG. Side sheets 8 are stretched on both sides of the absorbent body 1 in a folded state.

In the lower layer part of the absorbent body 1, the excretory part corresponding part q and the vicinity thereof are densified by embossing. In FIG. 1, the longitudinal region of the excretory part corresponding portion is indicated as q ₁ and the width direction is indicated as q ₂ . Rectangular region disposing the excretion point _{q 3} in the center surrounded by these auxiliary lines _{q 1} and _{q 2} are shown as excretory part corresponding portion q (see FIG. 1, 2, 5, 6). Further, the upper layer 6 of the absorbent body 1, from the upper surface of the topsheet 2 so as to surround the central portion q ₃ of the excretory part corresponding portion, the groove 11 is formed at its peripheral position. Although the concave groove 11 is formed by pressing, the surface sheet 2 and the upper layer 6 of the absorbent body 1 are integrated by the formation of the concave groove 11, so that the surface sheet 2 is laterally displaced from the absorbent upper layer 6. It is designed not to wake up. The depth of the concave groove 11 and the peripheral shape will be described later.

  As shown in FIG. 1, side embossed portions 12 that similarly extend in the longitudinal direction from the upper side of the topsheet 2 are formed on both side portions on the upper layer surface of the absorber 1, whereby the topsheet 2, the absorber 1, Are joined so as to be more stably integrated.

In the sanitary napkin according to the first embodiment, the concave groove 11 of the excretory part corresponding portion q of the upper layer 6 is formed continuously in an oval shape defined by a corrugated peripheral edge (see FIGS. 1 and 5). The top sheet 2 and the upper layer 6 of the absorber 1 are integrated by the concave groove 11. In the present invention, the term “integrated” means that the integrated members are joined so as not to be broken or peeled off by a force applied when wearing a normal absorbent article.
The oval shape extends in the lateral width direction at the longitudinal central portion C (see FIG. 5), and the lateral width direction is slightly narrowed at both side portions S connected to the central portion C, and further connected thereto. The portions T at both ends in the longitudinal direction are again expanded in the lateral width direction. The oval shape is formed symmetrically with respect to the longitudinal center line of the absorber 1. Such an elliptical peripheral shape is referred to as a corrugated peripheral shape in the present invention. By surrounding the excretory part corresponding part q in an oval shape with such a waveform periphery, the fit feeling when worn is improved.

  3 is an enlarged cross-sectional view of part A in FIG. 2, and FIG. 4 is an enlarged cross-sectional view of part B in FIG. The excretion part corresponding | compatible part q of the lower layer 7 densified by the embossed part 15 formed in the lower layer 7 has improved liquid drawing-in property. And the embossing convex part 15a of the lower layer 7 and the back surface 6b of the upper layer 6 contact, and the liquid from the upper layer 6 is drawn in to the lower layer side through this contact part. Along with this, the liquid drawn into the lower layer moves to the embossed portion 15b having a higher density. On the other hand, a slight gap p is generated between the embossed concave portion 15b of the lower layer 7 and the upper layer back surface 6b, so that the liquid can be prevented from returning directly from the lower embossed concave portion 15b where the liquid or the like is concentrated to the upper layer side. In this way, the shape and ratio of the embossed convex portions 15a and the concave portions 15b of the lower layer 7 can be adjusted to obtain an absorber structure in which the liquid drawing property and the liquid return preventing property are controlled. In addition, in this embodiment, the embossed part 15 is made into the connection structure of the embossing convex part 15a and the recessed part 15b.

  The depth of the concave groove 11 provided on the surface (upper surface) 6 a of the upper layer is a depth that does not communicate with the lower layer 7 and stays inside the upper layer 6. In the present invention, each member “communicating” means not only the state in which one member has penetrated the hole, but also the state in which one member has penetrated deeply into the other member even though it has not penetrated. Specifically, it is preferable that the liquid or the like is not easily exchanged even if the members are in contact with each other, and it is more preferable that the members are separated. In the present embodiment, the concave groove 11 has a bottom portion 11a, and the bottom portion 11a is positioned above (on the front surface side) the upper layer-lower layer interface position line r (see FIG. 4). Further, a concave groove (depression) 13 is formed on the back surface (lower surface) 6 b of the upper layer 6 at a position corresponding to the concave groove 11.

  The concave groove 11 of the upper layer 6 can prevent the liquid brought to the excretory part corresponding part q by the groove part compressing part 11b, and can exhibit an action in which the liquid does not spread laterally from this part. Accordingly, the concave groove 11 functions as a leak-proof groove depending on circumstances. Moreover, since the concave groove 11 is not open to the lower layer side, and the upper layer and the lower layer are not connected and integrated in the concave groove 11, liquid bleeding in the concave groove 11 is prevented. Further, as described above, by forming the concave groove 13 by pressing on the lower side of the concave groove 11, the groove compression portion 11b between the concave groove 11 and the concave groove 13 is densified, and the upper layer, the lower layer, Since the groove 13 is ensured to have a large separation distance, the liquid return prevention property at this portion is further promoted by deformation during wearing. Further, since the groove 13 is separated from the lower layer 7, the liquid shielding effect is also enhanced.

  The embossed portion 15 formed in the excretory portion corresponding portion q of the lower layer 7 may be either point embossed or line embossed, but in the present embodiment, in the case of line embossed, it is formed to extend in the longitudinal direction of the lower layer 7. The The line embossing is formed in a form in which a plurality of deep recesses and shallow recesses are alternately arranged in the longitudinal direction. In both cases of point embossing and line embossing, liquid diffusion in the lateral width direction of the absorbent body 1 is prevented, and the pulling power of liquid due to higher density is improved. In this case, particularly, in the case of line embossing, the liquid drawn from the upper layer 6 is introduced in the longitudinal direction, better lateral diffusion prevention is achieved, and the liquid drawing force is also improved. Since densification by embossing is formed only in the excretory part-corresponding portion, leakage prevention is improved together with flexibility as an absorbent body.

  FIG. 6 is a plan view schematically showing a sanitary napkin 20 as another preferred embodiment (embodiment 2) of the absorbent article of the present invention (corresponding to the plan view of embodiment 1 shown in FIG. 5). .) In this embodiment, the shape of the concave groove 11 formed in the upper layer 6 is different from that of the first embodiment, and other configurations are the same in both embodiments. In the second embodiment, the concave grooves 11 are formed in the form of linear concave grooves 11 formed in a certain number of lines on both sides thereof in the longitudinal direction, and these linear concave grooves 11 are formed. Are arranged intermittently in the longitudinal direction. In Embodiment 2, three bodies are formed side by side on both sides of the absorbent body 1 so as to sandwich the excretory part corresponding portion from the lateral width direction.

  These linear grooves 11 are also formed by pressing from the upper surface of the top sheet 2 to the upper layer 6, whereby the top sheet 2 and the upper layer 6 are integrated. The depth of the linear concave groove 11 remains in the upper layer 6 as in the first embodiment, and is not communicated with the lower layer 7. A groove (dent) may be formed on the upper layer back surface corresponding to the position of the linear groove 11. Such a linear groove 11 also prevents the topsheet 6 from being displaced or “twisted” with respect to the upper layer 6 of the absorbent body 1 and stabilizes the structure of the absorbent article 10. Liquid leakage in the lateral width direction from the excretory part-corresponding portion is prevented by the linear concave groove 11, and the fit is not impaired.

Next, the preferable embodiment of the manufacturing method of the absorbent article which concerns on this invention is demonstrated.
The sanitary napkin of each of the above embodiments can be usually produced by a production process of this kind of article. For example, it is broadly divided into a board supply roll, defibrating machine, pulp stacking machine, embossing press machine, folding device, cutter, and sheeting device. Absorbent articles can be manufactured automatically and continuously on a series of transport lines until removal. When the absorbent body material is folded into an absorbent body, for example, a folding device having a crease roller and a baffle plate for folding is used, the side of the absorbent body material is folded back to the back side, and the central portion of the absorbent body material It can be folded so that it overlaps the back side of. As the folding device, for example, those disclosed in FIGS. 4 to 7 of JP-A-11-137604 can be referred to.

A part of the manufacturing process of the sanitary napkin of the first embodiment shown in FIGS. 1 to 5 will be described in more detail with reference to FIG. First, as shown in FIG. 2A, the embossed portions 15 are formed on both sides of the rectangular pulp fiber body held on the mount to prepare the flat plate absorbent body 16. At this time, if the production is performed on the continuous production line as described above, the flat absorbent body 16 is sent as an absorbent sheet opposite (continuous flat absorbent body) continuous in the illustrated MD direction. In Fig.7 (a), the flat absorber 16 is shown as a rectangular sheet for simplification, and the embossing row | line | column is shown as two rows. The same applies to FIGS. 7B and 7C. The flat absorbent body 16 preferably has a constant basis weight as a whole, and the range thereof is preferably 50 to 300 g / m2.
Next, a surface sheet in which the side sheet 8 is stuck to the both sides W in the longitudinal direction on the back surface of the surface sheet 2 is produced, and this is overlaid on the upper surface of the plate-like absorber 16 as shown in FIG. Match. Then, the concave grooves 11 connected in an oval shape having a corrugated periphery from the top sheet to the flat absorbent body 16 are squeezed, for example, by hot embossing or the like. By this concave groove 11, the top sheet and the flat absorbent body 16 are integrated.

  Thereafter, both sides of the integrated surface sheet and the absorbent body 1 are moved to the back side of the flat absorbent body 16 at the position (b) D of the side nonwoven fabric 8, that is, in the vicinity of both side parts W of the central portion V. Folding is performed, whereby the absorbent body 1 having a two-layer structure of an upper layer 6 and a lower layer 7 is obtained. Finally, it is possible to obtain an absorbent article assembled by attaching the back sheet 3 to the back surface of the absorbent body and further disposing a predetermined member. 7A to 7C are schematically shown as a whole for the purpose of general understanding of the manufacturing procedure and member arrangement, and the dimensions, shapes, and positions of the respective parts are mutually or differently implemented. It is not aligned with the form.

  In the absorbent article of the present invention, the top sheet is preferably made of a material that is liquid-permeable and soft against the skin. For example, a non-woven fabric made of natural fibers such as cotton or a non-woven fabric made of various synthetic fibers subjected to hydrophilic treatment can be used. The back sheet is preferably made of a liquid-impermeable sheet material. The back sheet may be water vapor permeable as required. Specifically, in order to obtain sufficient water vapor permeability, a film made of synthetic resin such as polyethylene in which fine powder made of a filler such as calcium carbonate is dispersed is stretched and a porous film having fine holes is used. preferable. Examples of the side sheet include a nonwoven fabric, a film sheet, and paper. From the viewpoint of leakage prevention, it is preferable that the side sheet is formed of a liquid non-permeable or hardly permeable hydrophobic nonwoven fabric, a leak-proof film sheet, or the like. One sheet may be used, or two or more sheets may be combined with a functional sheet. As the material for forming the absorber, those usually used for absorbent articles can be used. Specifically, for example, a fiber aggregate or a combination of this and a polymer water-absorbing polymer can be used. As the fibers constituting the fiber assembly, hydrophilic natural fibers such as pulp fibers, synthetic fibers (preferably subjected to hydrophilic treatment), and the like can be used.

  In each said embodiment, although the sanitary napkin was demonstrated in detail about the absorbent article of this invention as an example, this invention is not limited to this, There exists an effect in various absorbent articles. Examples of the absorbent article of the present invention include a sanitary napkin, a panty liner, an incontinence pad and the like as preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view schematically showing a sanitary napkin as a preferred embodiment (Embodiment 1) of an absorbent article according to the present invention, partially broken away. It is an expanded sectional view along the II-II line of FIG. It is an expanded sectional view of the A section of FIG. It is an expanded sectional view of the B section of FIG. It is a top view of the sanitary napkin of this Embodiment 1. It is the top view which showed typically the sanitary napkin as another preferable embodiment (Embodiment 2) of the absorbent article of this invention. It is a fragmentary perspective view for demonstrating the one part process of the preferable embodiment in the manufacturing method of the absorbent article of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Absorber 2 Top sheet 3 Back sheet 4 Seal part 5 Mount 6 Upper layer 7 Lower layer 8 Side sheet 10, 20 Sanitary napkin 11, 13 Groove 12 Side embossed part 15 Embossed part (unevenness densification part)
q Excretion part corresponding part

Claims (5)

An absorbent article having a top sheet, a back sheet, and an absorbent body disposed between the two sheets,
The absorber has a multilayer structure of an upper layer portion and a lower layer portion that are laminated by folding both sides of the absorber along the longitudinal direction of the absorber, and folding edges on both sides in the width direction of the folded absorber Part and the lower layer part has a compressed region densified and densified than the central part in the width direction of the upper layer part,
The upper layer of the absorbent body and the top sheet are integrated by concave grooves formed on both sides of the absorbent article in the longitudinal direction and from the top sheet to the upper layer at the excretory part corresponding portion, The bottom is an absorbent article located on the upper layer side of the lower layer surface.   The absorptive article according to claim 1 which has a ditch on an upper layer back side corresponding to a portion which has a ditch of the upper layer.   The absorbent article according to claim 1 or 2, wherein the concave grooves are arranged so as to be continuous.   The flat absorbent body having a constant basis weight is folded along the longitudinal direction so that both sides thereof face each other at the center of the article, and has the upper layer and the folded lower layer. Absorbent article according to item.   Embossing is performed on both sides in the longitudinal direction of the vertically long plate-shaped absorbent body composed of the central portion and both side portions thereof, and after placing the topsheet on one side of the plate-shaped absorbent body, the central portion of the plate-shaped absorbent body By squeezing from the top sheet side at a position corresponding to both sides, the flat absorbent body and the top sheet are integrated, and then the both sides of the flat absorbent body are back together with the top sheet. The manufacturing method of the absorbent article folded in the side.

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