Individually packaged absorbent article and method for manufacturing an individually packaged absorbent article

Abstract

To provide an individually packaged absorbent article minimizing sound generated when opening the individually packaged absorbent article.SOLUTION: An individually packaged absorbent article includes an absorbent article and a packaging sheet for individually packaging the absorbent article. The packaging sheet is folded in half or more in a first direction, the two or more packaging sheets are overlapped at edges in a second direction orthogonal to the first direction, and the edges are respectively sealed to form seal parts. Each seal part has a plurality of through-holes having peripheral walls projecting in a thickness direction of the packaging sheets, where the packaging sheets constituting the peripheral wall are not fused each other.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an individually packaged absorbent article and a method for manufacturing an individually packaged absorbent article. [Background technology]

[0002] Absorbent articles such as sanitary napkins, panty liners, and incontinence pads are generally provided in an individually packaged state. A known packaging form for such individually packaged absorbent articles (individually packaged absorbent articles) is one in which a packaging sheet is folded in half or more in one direction to encase the absorbent article and both edges are sealed.

[0003] For example, Patent Document 1 discloses an individual package for an absorbent article in which the absorbent article is folded together with a packaging material in their longitudinal direction, and the folded and overlapped packaging materials are joined to each other at a pair of edges of the individual package, and the packaging materials at each of the pair of edges are joined to each other at a plurality of joints.

[0004] Patent Document 1 describes that the joints are formed by heat sealing, and further describes that by forming the joints in a specified shape and arrangement, the peeling noise when opening (the noise generated when peeling off the packaging material when opening) is reduced. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2007-268015 A Summary of the Invention [Problem to be solved by the invention]

[0006] In Patent Document 1, an attempt is made to reduce the noise generated when opening by devising the shape and arrangement of the joint. However, the joint is formed by heat sealing, and the packaging materials (packaging sheets) are fused together at the joint. Because such fusion bonding is strong, a loud noise is inevitably generated when the bond is released or broken. Therefore, there is a limit to how much the sound generated when opening can be reduced.

[0007] Most users dislike the sound that is generated when opening the package. For example, if the sound is loud when opening the package, people outside the cubicle may know that the user is using an absorbent article in the workplace or in a public restroom, and many users find this embarrassing. Therefore, it is desirable to make the sound generated when opening the package as small as possible.

[0008] In view of the above, an object of one aspect of the present invention is to provide an individually packaged absorbent article that reduces the noise generated when the individually packaged absorbent article is opened. [Means for solving the problem]

[0009] A first aspect of the present invention is an individually packaged absorbent article comprising an absorbent article and a packaging sheet for individually packaging the absorbent article, wherein the packaging sheet is folded in half or more in a first direction, two or more of the packaging sheets are overlapped at their edges in a second direction perpendicular to the first direction, and the edges are each sealed to form a sealed portion, the sealed portion having a plurality of through holes with peripheral walls protruding in the thickness direction of the packaging sheet, and the packaging sheets constituting the peripheral walls are not fused to each other.

[0010] According to the first aspect, the sealed portion has a plurality of through holes with peripheral walls protruding in the thickness direction of the packaging sheet, and the packaging sheets constituting the peripheral walls are not fused to each other, so that when the packaging sheets are peeled off at the time of opening, no loud noise that may be generated at the joint formed by fusion is generated. Therefore, even a user who has hesitated to open an individually packaged absorbent article because he or she felt embarrassed that the sound of opening would be heard by those around him or her can open the individually packaged absorbent article without any concerns.

[0011] Furthermore, the peripheral wall protruding in the thickness direction exhibits a relatively large resistance, particularly in the surface direction (the direction along the surface of the individually packaged absorbent article or the packaging sheet), and therefore can prevent unintentional opening before use. Also, since the peripheral wall protruding in the thickness direction exhibits a relatively small resistance in the thickness direction, an excessively large force is not required when pulling in the thickness direction to peel off the packaging sheet when opening, and opening is easy. Thus, according to the first aspect, the sound when opening can be reduced, and the sealed portion has sufficient sealing and opening properties.

[0012] In a second aspect of the present invention, the free edge of the peripheral wall has a curved portion.

[0013] According to the second aspect, since the free edge of the peripheral wall has a warped portion, the resistance in the thickness direction can be appropriately increased, and the packaging sheets can be configured to be less likely to peel off from each other. Therefore, the sealing property of the seal part can be improved by providing a warped portion depending on the type of material, the size of the through hole, the protruding height of the peripheral wall, etc.

[0014] In a third aspect of the present invention, the packaging sheet is folded in three or more folds.

[0015] According to the third aspect of the present invention, it is possible to reliably package absorbent articles with a simple structure. Also, according to the present invention, although an area where three or more packaging sheets are overlapped is formed, it is possible to provide a packaging structure with excellent sealing properties and openability even in such an area where three or more packaging sheets are overlapped.

[0016] In a fourth aspect of the present invention, the packaging sheet is made of a resin film.

[0017] According to the fourth aspect, since the packaging sheet is easily stretched when the through holes are formed, the peripheral edge protruding in the thickness direction can be easily formed, and therefore the seal portion can be easily formed.

[0018] A fifth aspect of the present invention is a method for manufacturing an individually packaged absorbent article including an absorbent article and a packaging sheet for individually packaging the absorbent article, comprising: placing the absorbent article on the packaging sheet; folding the packaging sheet in two or more folds in a first direction; overlapping two or more of the packaging sheets at edges in a second direction perpendicular to the first direction; and forming, without heating, a plurality of through holes having peripheral walls protruding in the thickness direction of the packaging sheet, thereby forming seal portions on each of the edges.

[0019] According to the fifth aspect, it is possible to provide a method for manufacturing an individually packaged absorbent article, which can provide the same effects as those of the first aspect.

[0020] In a sixth aspect of the present invention, the plurality of through holes are formed using a roll equipped with a plurality of needles.

[0021] According to the sixth aspect, in the fifth aspect, the through holes can be easily formed. Effect of the Invention

[0022] According to one aspect of the present invention, an individually packaged absorbent article can be provided that reduces the noise generated when the individually packaged absorbent article is opened. [Brief description of the drawings]

[0023] [Figure 1] 1 is a plan view of an individually packaged absorbent article according to one embodiment of the present invention. [Diagram 2] 2 is a cross-sectional view taken along line II in FIG. 1. [Diagram 3] FIG. 2 is an enlarged view of a portion II in FIG. [Figure 4] 3, and is an enlarged cross-sectional view of a through hole. FIG. [Diagram 5] FIG. 11 is an enlarged cross-sectional view of another example of a through hole. [Figure 6] 11A and 11B are diagrams illustrating changes in the through holes when the packaging sheets are peeled away from each other when opening the package. [Figure 7] 1 is a schematic diagram of an apparatus for manufacturing individually packaged absorbent articles according to one embodiment of the present invention. [Figure 8] FIG. 8 is an enlarged cross-sectional view of a protruding portion of the roll shown in FIG. [Figure 9] 11A and 11B are diagrams for explaining the formation of a through hole by a needle. [Figure 10] FIG. [Figure 11] 1 is an enlarged photograph of the seal portion formed in Example 1. [Figure 12] 1 is an enlarged photograph of a through hole formed in Example 1. [Figure 13] 1 is an enlarged photograph of a through hole formed in Example 2. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, unless otherwise specified, the same or corresponding components may be denoted by the same reference numerals and the description thereof may be omitted. In addition, the drawings are schematic to facilitate understanding of the invention.

[0025] Fig. 1 shows a plan view of an individually packaged absorbent article 100 according to one embodiment of the present invention. Fig. 2 shows a cross-sectional view taken along line II in Fig. 1. As shown in Figs. 1 and 2, the individually packaged absorbent article 100 has an absorbent article 1 and a packaging sheet 10 that individually packages the absorbent article 1.

[0026] (Absorbent articles) The absorbent article 1 in this embodiment is preferably substantially flat (having a shape in which the length and width are greater than the thickness) and has an elongated shape in a plan view. More specifically, it may be a sanitary napkin, a panty liner (discharge sheet), a light incontinence pad, etc. The absorbent article 1 may be generally configured to include a liquid-impermeable back sheet, a liquid-permeable top sheet, and a main body (absorbent article main body) having an absorbent body provided between these two sheets.

[0027] As the back sheet of the absorbent article 1, a sheet material having at least water impermeability, such as an olefin resin sheet of polyethylene or polypropylene, can be used. Also, a laminated nonwoven fabric in which a nonwoven fabric is laminated on a polyethylene sheet or the like, or a laminated sheet of nonwoven fabric in which a waterproof film is interposed to ensure substantial liquid impermeability, can be used. Moreover, from the viewpoint of preventing stuffiness, it is more preferable to use a material having moisture permeability.

[0028] The top sheet is a liquid-permeable sheet that allows bodily fluids such as menstrual blood, vaginal discharge, and urine to quickly pass through. As the top sheet, a nonwoven fabric with or without holes, a porous plastic sheet, or the like is preferably used. As the material fiber constituting the nonwoven fabric, for example, olefins such as polyethylene and polypropylene, synthetic fibers such as polyester and polyamide, regenerated fibers such as rayon and cupra, and blended fibers thereof, and natural fibers such as cotton can be used alone or in combination of two or more kinds. In addition, composite fibers combining synthetic fibers with different melting points can also be used.

[0029] The absorbent interposed between the back sheet and the top sheet is not limited as long as it is a material capable of absorbing and retaining body fluids, but preferably contains cotton-like pulp and a water-absorbing polymer. As the water-absorbing polymer, superabsorbent polymer granular powder (superabsorbent polymer (SAP)), superabsorbent fiber (SAF)), and combinations thereof can be used. As the pulp, chemical pulp obtained from wood, cellulose fibers such as dissolving pulp, and artificial cellulose fibers such as rayon and acetate can be used. As the raw material for chemical pulp, broadleaf wood and softleaf wood are used, but softleaf wood is preferably used because of its long fiber length. Synthetic fibers may be mixed into the absorbent.

[0030] The thickness of the absorbent article 1 may be preferably 1 to 20 mm, and more preferably 2 to 10 mm. The thickness does not have to be uniform over the entire surface of the absorbent article 1, and the absorbent article may have a bulging structure in a portion facing the wearer's bodily fluid excretion opening when worn, or in a portion facing the buttocks crease, etc.

[0031] (Packaging structure for individually packaged absorbent articles) As shown in Fig. 1 and Fig. 2, an individually packaged absorbent article 100 is formed by folding an absorbent article 1, which is flat and elongated in a plan view, together with a packaging sheet 10, which is also elongated. In the example shown in Fig. 1 and Fig. 2, the absorbent article 1 is placed on the inner surface of the packaging sheet 10 so that the longitudinal direction (first direction) D1 of the elongated packaging sheet 10 and the longitudinal direction of the absorbent article 1 are aligned, and the packaging sheet 10 and the absorbent article 1 are folded together in thirds in the first direction D1 to package the absorbent article 1. More specifically, the third fold is performed by folding back a first region R1 including one end 11 of the packaging sheet 10 in the first direction D1 toward the inner surface of the packaging sheet 10 (the surface on which the absorbent article 1 is arranged) at a first fold line FL1, and then folding back a second region R2 including the other end 12 of the packaging sheet 10 in the second direction D2 toward the inner surface of the packaging sheet 10 at a second fold line FL2 in the same manner as the first region R1. At this time, the second region R2 is at least partially overlapped with the first region R1, more specifically, the second region R2 is overlapped with the outer surface of the second region R1. This results in the absorbent article 1 being housed in the packaging sheet 10. In this embodiment, the region between the first region R1 and the second region R2 is the third region R3 (FIG. 2). In addition, both the first fold line FL1 and the second fold line FL2 are fold lines extending along the second direction D2 (the short-side direction or width direction of the packaging sheet 10) perpendicular to the first direction D1. Such a packaging method of overlapping two regions at the end of the longitudinal direction D1 of the packaging sheet 10 is preferable because it is simple and can reliably enclose and protect the absorbent article without being exposed to the external environment.

[0032] The packaging sheet 10 may be folded in half. In this case, the packaging sheet 10 may be folded together with the absorbent article 1 along a single fold line extending along the second direction D2, or the absorbent article 1 may be folded to wrap the absorbent article 1 without folding the absorbent article 1, and then sealed portions may be formed on both edge portions in the second direction D2. In this case, it is preferable to also form a sealed portion at the end portion of the packaging sheet 10 in the first direction D1 (the end portion opposite to the fold line side).

[0033] The packaging sheet 10 may also be folded in four or more. This allows a relatively long absorbent article to be packaged. In this case, the length of the first region R1, which is folded first, is made longer than the length of the third region R3, and when folding the first region R1, the first region R1 is first folded to the inner side or outer side at a third fold line extending along the second direction D2 located between the first fold line FL1 and the one end 11, and then the entire first region R1 is folded at the first fold line FL1, and then the second region R2 is folded at the second fold line FL2 as described above, so that the entire first region R1 is folded in four. Furthermore, depending on the number of folds in the second region R2, the second region R2 may be folded in five or more.

[0034] After the first region R1 and the second region R2 are folded in order, a sealing tape 30 can be provided in the center in the second direction D2 so as to straddle the other end 12 of the packaging sheet 10, i.e., from the second region R2 to the first region R1. The sealing tape 30 separates the end of the second region R2 (the other end 12 and its vicinity) from the underlying first region R1, preventing dust and the like from entering the inside of the individually packaged absorbent article 100. In addition, a user can start opening the individually packaged absorbent article 100 by lifting and pulling the sealing tape 30, making the opening operation easier.

[0035] The dimensions of the packaging sheet 10 are selected depending on the size and shape of the absorbent article 1 to be packaged, but for example, when the packaging sheet 10 is unfolded, the length in the first direction D1 can be 120 to 500 mm, and the length in the second direction D2 (sometimes simply referred to as width) can be 75 to 180 mm. When the packaging sheet 10 is folded (FIG. 1), the length in the first direction D1 can be 50 to 160 mm.

[0036] The material of the packaging sheet 10 is preferably a resin film from the viewpoint of being able to form an appropriate through hole (described later) in the seal portion. By making the packaging sheet 10 from a resin film, the ink color develops well when printing is performed on the packaging sheet 10, and the pattern can be printed sharply, so that the design can be improved. Specific examples of the resin constituting the resin film include polyolefin-based films such as polypropylene and polyethylene, polyester, polyvinyl alcohol, etc.

[0037] (Sealing part) As described above, after the packaging sheet 10 is folded, sealed portions 20, 20 as shown in Fig. 1 are formed on both edges of the packaging sheet 10 in the second direction D2. The sealed portions 20, 20 close both edges of the individually packaged absorbent article 100, preventing the absorbent article 1 from being exposed to the outside, which is hygienic. The sealed portions 20, 20 are also formed to be openable. Here, "openable" or "openable" refers to a seal that is strong enough to be opened by hand without using tools.

[0038] In this embodiment, the edge of the individually packaged absorbent article 100 refers to a region where the absorbent article 1 does not exist in a plan view. Thus, at the edge, the packaging sheets 10 are overlapped in contact with each other in the thickness direction of the individually packaged absorbent article 100 (direction perpendicular to the first direction D1 and perpendicular to the second direction). When the individually packaged absorbent article 100 is formed, two or more packaging sheets 10 are overlapped at the edge. When the individually packaged absorbent article 100 is formed by folding in three as in the example shown in Figs. 1 and 2, a zone where two packaging sheets are overlapped and a zone where three packaging sheets are overlapped may be formed. Note that the edge of the individually packaged absorbent article 100 is preferably a region from the edge in the second direction D2 to a position 10 to 40 mm inward.

[0039] As shown in FIG. 1, the seal portions 20, 20 are made up of a number of small through holes 25, 25, ... (described in detail later), and can be visually confirmed to extend in a continuous strip shape in the first direction D1. The width (length in the second direction D2) of the strip-shaped seal portion 20 may be constant or may vary depending on the location. In addition, the seal portion 20 may not extend to the edge of the second direction D2, and may not be present in an area up to a predetermined distance from the edge of the second direction D2. Furthermore, depending on the arrangement of the through holes 25, 25, ..., the inner edge of the seal portions 20, 20 (edge ​​in the second direction D2) may be linear as shown in FIG. 1, or may be wavy.

[0040] When opening the individually packaged absorbent article 100, it is necessary to unfold the folded packaging sheet 10. In this case, the packaging sheet 10 can be unfolded in the reverse order to the folding procedure described above. That is, in the case of the individually packaged absorbent article 100 that is folded in three (FIGS. 1 and 2), the user peels the second region R2 from the first region R1, or from the first region R1 and the third region R3, and then peels the first region R1 from the third region R3. When peeling the packaging sheet 10, it is necessary to break the seal portions 20, 20 formed on both edges in the second direction D2 in sequence in the first direction D1.

[0041] (Through hole) FIG. 3 shows an enlarged view of part II in FIG. 2. FIG. 4 shows a cross-sectional view taken along line III-III in FIG. 3, that is, a cross-sectional view of the through hole. Part II in FIG. 2 is a part in which the third region R3, the first region R1, and the second region R2 are stacked in this order, and the through hole 25 is formed by penetrating the three stacked packaging sheets. Furthermore, as shown in FIG. 4, the through hole 25 is not a hole formed by simply removing a part of the three packaging sheets, but a hole having a peripheral wall 21 protruding to one side of the packaging sheet 10 (one side of the individually packaged absorbent article 100). In the example shown in FIG. 3 and FIG. 4, the peripheral wall 21 of the through hole 25 is formed from the side where the second region R2 is provided toward the side where the third region R3 is provided (from top to bottom in FIG. 4), but may be formed from the side where the third region R3 is provided toward the side where the second region R2 is provided (from bottom to top in FIG. 4).

[0042] In this embodiment, the packaging sheets are not fused to each other at the peripheral wall 21 of the through hole 25. In the conventional embodiment in which the packaging sheets are fused to each other to form the joint, the material of the packaging sheets is denatured when the joint is formed, so that, for example, the packaging sheets are at least partially fused to each other to be integrated, and the interface between the packaging sheets is at least partially or not observed at all. However, in this embodiment, the packaging sheets are not denatured by heat, so that they are in close contact with each other on the surface but exist independently. In this way, since the packaging sheets are provided with the through hole 25 formed without being fused to each other, it is not necessary to break the fused part formed by integrating the packaging sheets when peeling the packaging sheets off. A loud noise is likely to be generated when breaking the fused part, but such a loud noise is not generated according to this embodiment. Therefore, the user can open the individually packaged absorbent article 100 without hesitation even in the toilet of the workplace or a public toilet, without worrying about the generated noise. Furthermore, according to this embodiment, the force required to break the sealed part is smaller than that required for a sealed part consisting of a joint formed by fusion. Therefore, the opening operation can be performed smoothly.

[0043] Furthermore, the peripheral wall 21 of the through hole 25 in this embodiment protrudes in the thickness direction of the packaging sheet 10, and the overlapped packaging sheets 10 are bent (to extend in the thickness direction) approximately perpendicular to the surface direction (the direction along the surface of the individually packaged absorbent article or the packaging sheet). Therefore, the peripheral wall 21 of the through hole 25 exhibits a relatively large resistance in the surface direction. In other words, the peripheral wall 21 of the through hole 25 can function as a locking portion having a locking effect. Therefore, for example, even if a force is applied that shifts one sheet (one layer) of the overlapped packaging sheets as a whole in the surface direction, it is difficult to shift. Therefore, the seal portion 20 can maintain its sealing function (excellent sealability), and the possibility that the individually packaged absorbent article 100 is unintentionally opened before use can be reduced.

[0044] On the other hand, the peripheral wall 21 of the through-hole 25 exhibits a relatively small resistance in the thickness direction. Therefore, when the packaging sheets are separated in the thickness direction, opening can be performed without requiring a large force (excellent opening property).

[0045] In this manner, in this embodiment, the sound generated when opening the package can be reduced, and the function of the sealing portion (sealing property and opening property) can be sufficiently ensured. Furthermore, since the sealing portion in this embodiment is not formed by fusion, but by physically deforming the packaging sheet 10, even if the surface of the packaging sheet 10 has been subjected to a peeling treatment or the like, a desired sealing portion can be formed regardless of the type or degree of the treatment.

[0046] The diameter d1 of through hole 25 may be set depending on the material of the packaging sheet, the size of the absorbent article to be packaged, the width of the sealed portion, etc., but is preferably 0.1 to 3 mm. The diameter d1 of through hole 25 is the diameter at the center position of through hole 25 in the thickness direction.

[0047] In part II of Fig. 2, three packaging sheets are overlapped, but for example, two packaging sheets are overlapped in the zone close to fold line FL1 and the zone close to fold line FL2. Depending on how the packaging sheet 10 is folded, when folded in four or more, the number of overlapping packaging sheets 10 at the edge of the individually packaged absorbent article 100 may be four or more, or even five or more. In any case, the through-hole 25 is formed penetrating all of the multiple packaging sheets.

[0048] FIG. 5 shows a modified example of the through hole 25. The configuration of the through hole 25 shown in FIG. 5 is basically the same as that shown in FIG. 4, but is different from the through hole 25 shown in FIG. 4 in that the free edge of the peripheral wall 21 of the through hole 25 has a warped portion 22. The warped portion 22 refers to a portion where the free end (tip) of the peripheral wall 21 extending in the thickness direction is further curved in a direction away from the center of the through hole 25. When the warped portion 22 is formed, the layer of the packaging sheet 10 arranged on the second side may be exposed on the first side, assuming that the side where the peripheral wall 21 protrudes is the first side and the opposite side to the protruding side is the second side. In the example shown in FIG. 5, when viewed from the third region R3 side, the second region R2 is not visible if there is no through hole, but the formation of the through hole 25 and the warped portion 22 at least partially exposes the second region R2 on the third region R3 side. At the warped portion 22 (at the tip of the peripheral wall 21), the overlapping packaging sheets may be in close contact with each other or may be separated from each other as shown in FIG.

[0049] By forming the warped portion 22, the overlapped packaging sheets can have a C-shape in cross section cut in the thickness direction. Therefore, it is possible to appropriately increase not only the resistance in the surface direction but also the resistance in the thickness direction. In other words, the locking action of the peripheral wall 21 is enhanced. It is possible to configure the packaging sheets so that they are less likely to peel off from each other. Therefore, the form shown in FIG. 5 is preferable when it is desired to further improve the sealing performance by the through holes 25, for example, when it is desired to reduce the number of through holes 25 included in the seal portion 20, when the packaging sheets are easily slippery in the surface direction, or the like.

[0050] The change in state of through hole 25 when the packaging sheet is peeled off at the time of opening will be further described below with reference to Fig. 6. Fig. 6 shows an example of through hole 25 having warped portion 22 (Fig. 5). Fig. 6(a) shows Fig. 5 again.

[0051] In this example, the through hole 25 is configured by stacking the third region R3, the first region R1, and the second region R2 in order as described above. When opening, the second region R2 arranged on the outermost side is lifted and peeled off as shown in FIG. 1. In this embodiment, the through hole 25 is not formed by fusion, so the surfaces of the stacked packaging sheets can be relatively easily separated from each other. Therefore, the second region R2 can be lifted from the first region R1 with a relatively small force. FIG. 6(b) shows the state in which the second region R2 is lifted. Since the packaging sheets are not fused to each other at the peripheral wall 21 of the through hole 25, the second region R2 can be relatively easily pulled up in the thickness direction as shown in FIG. 6(b). At this time, the fused portion is not broken, and the closely attached packaging sheets are simply separated from each other, so no loud noise is generated.

[0052] Thereafter, a step of peeling the first region R1 from the third region R3 may be performed, and in this case as well, the packaging sheets can be peeled away from each other without producing a loud noise.

[0053] The arrangement of the through holes 25, 25, ... in the seal portion 20 in a plan view is not particularly limited. The through holes 25, 25, ... may be arranged in a lattice pattern as shown in FIG. 3, may be arranged in a staggered pattern, or may be arranged randomly. The number of through holes 25, 25, ... arranged in the second direction D2 is also not particularly limited, but is preferably three or more in consideration of sealability. In addition, it is preferable that the number is eight or less in consideration of maintaining the strength of both edges and opening properties. The pitch between the through holes 25, 25 along the first direction D1 or the second direction D2 (the distance from the center of one through hole to the center of the adjacent through hole) may be 1 to 6 mm.

[0054] In addition, the multiple through holes 25, 25, ... may all have the same diameter as shown in FIG. 3, or may have different diameters. For example, the diameters of the through holes 25, 25, ... may be gradually smaller from the inside to the outside in the second direction D2. In this way, it is preferable from the viewpoint of improving the sealing property of the sealed portion if the diameter of the through hole 25 on the inside of the second direction D2 is larger than the diameter of the through hole 25 on the outside of the second direction D2. When the individually packaged absorbent article 100 is opened, the second region R2 is first peeled off, and at that time, the user holds the center of the second region R2 in the second direction D2 and pulls it, so the through hole 25 to which the force is applied first is the through hole 25 on the innermost side in the second direction D2. Therefore, by making the diameter of the through hole 25 on the inside of the second direction D2 larger, the locking action of the through hole 25 is enhanced.

[0055] 3, the planar shape of through-hole 25 is approximately circular, but may be elliptical, triangular, quadrangular (including square, rectangular, trapezoid, etc.), or any other polygonal shape other than a quadrangle. The planar shape of through-hole 25 can be adjusted by changing the cross-sectional shape of needles provided in a roll used in a manufacturing method described later.

[0056] (Method of manufacturing individually packaged absorbent articles) FIG. 7 is a schematic diagram of a manufacturing device 50 for an individually packaged absorbent article 100 according to this embodiment. As shown in FIG. 7, the individually packaged absorbent article 100 can be manufactured by using a pair of opposing rolls 51, 52 (a first roll 51 and a second roll). More specifically, a plurality of absorbent articles 1 are arranged at a distance from each other on the inner surface of a long original packaging sheet 10a conveyed in a conveying direction (machine direction) Dm, and the original packaging sheet 10a is folded together with the absorbent articles 1 in a direction Dv perpendicular to the conveying direction Dm (a direction corresponding to the first direction D1 of the individually packaged absorbent article 100 finally obtained). At this time, the original packaging sheet 10a can be folded in half or more. Next, the uncut continuous body of the individually packaged absorbent article is passed between the first roll 51 and the second roll 52, and both edges are sealed to form a sealed portion 20. The formation of the sealed portion 20 can be performed on the edges of two adjacent uncut individually packaged absorbent articles almost simultaneously. Simultaneously with the formation of the sealed portion 20, cutting may be performed to separate the individually packaged absorbent articles.

[0057] The first roll 51 may be provided with protrusions 51a, 51a, ... at intervals in the circumferential direction, and the second roll 52 may be provided with protrusions 52a, 52a, ... at intervals in the circumferential direction. The protrusions 51a, 51a, ... and the protrusions 52a, 52a, ... are configured to face each other. In other words, the original packaging sheet 10a is sandwiched between the protrusions 51a and 52a and passes between the rolls.

[0058] 8 shows a schematic enlarged view of the protruding portion 51a of the first roll 51 and the protruding portion 52a of the second roll 52. As shown in FIG. 8, needles N, N, ... may be provided protruding from the surface of the protruding portion 51a of the first roll 51. On the other hand, the protruding portion 52a of the second roll 52 facing the protruding portion 51a of the first roll 51 is not provided with the needles N, and may have a shape without irregularities, for example. However, depending on the configuration of the seal portion 20 to be obtained, unlike the example of FIG. 8, multiple needles may be formed alternately on both the protruding portion 51a of the first roll 51 and the protruding portion 52a of the second roll 52.

[0059] FIG. 9 shows a schematic diagram of the formation of the through-hole 25 by one of the needles N, N, ... formed on the protruding portion 51a of the first roll 51. As shown in FIG. 9, the needles N formed on the protruding portion 51a of the first roll 51 are pressed against the protruding portion 52a of the second roll 52, so that the needles N penetrate the overlapped packaging sheets. At this time, a part of the packaging sheet is deformed (stretched) and rises in the direction in which the needles N are pressed, so that the peripheral wall 21 protruding on the side opposite to the side of the protruding portion 51a having the needles N (the side of the protruding portion 52a) can be formed. Here, when the packaging sheet is made of a material that is more easily stretched, the peripheral wall 21 is easily formed and the warped portion 22 is also easily formed. For this reason, it is preferable that the packaging sheet 10 is formed from a resin film that is easily stretched.

[0060] It is preferable that the protruding portion 52a of the second roll 52 on the side where the needles N are not provided is made of a material capable of receiving the needles N, for example, an elastic body such as rubber, or is covered with such a material. This allows the tips of the needles N to bite into the surface of the protruding portion 52a as shown in Fig. 9, so that the needles N are less likely to wear or break.

[0061] In this embodiment, the process of piercing the needles N through the stacked packaging sheets is performed without heating. In this specification, performing without heating means performing without providing a heating means, and does not exclude the case where the temperature of the product is increased. For example, even in a non-heating process, the temperature of the components of the manufacturing device and the product may increase due to frictional heat in the manufacturing device, heat from electrical elements, etc. According to this embodiment, the non-heating process can form the through holes 25 without fusing the packaging sheets together. Since the packaging sheets are not fused together, the sound generated when opening the individually packaged absorbent article can be reduced as described above. In addition, the process without heating does not require complicated temperature adjustment of the roll, and does not require a heating device, so costs can be reduced.

[0062] FIG. 10 shows a cross-sectional view of one needle N having a circular cross section. The shape and dimensions of the needle N used to form the through-hole 25 are not particularly limited as long as it can form a through-hole having a peripheral wall protruding in the thickness direction. As shown in FIG. 10, the needle has an end Ns that tapers sharply from the main body, and it is preferable that the tip (the very tip) of the end Ns is flat and forms a surface. This can prevent the state of the needle N from changing due to wear of the end.

[0063] The diameter d2 of the needle N can be about 0.5 to 2.5 mm. The diameter d2 of the needle N may be the same overall except for the end, but as shown in FIG. 10, it is preferable that the diameter d2 becomes smaller toward the tip, since this can prevent the needle N from breaking. When the diameter varies depending on the location, the diameter d2 of the needle can be the diameter at the base position of the end that tapers sharply from the main body. The length of the end Ns of the needle N may be 0.2 to 4 mm. The diameter b of the flat surface at the tip of the needle N is preferably 0.1 to 1 mm. The taper angle α of the end Ns of the needle N is preferably 30 to 60°.

[0064] One embodiment of the present invention may be an individually packaged absorbent article obtained by the above-mentioned manufacturing method, i.e., an individually packaged absorbent article obtained by placing an absorbent article on a packaging sheet, folding the packaging sheet in two or more folds in a first direction, overlapping two or more of the packaging sheets at the edges in a second direction perpendicular to the first direction, and forming a plurality of through holes having peripheral walls protruding in the thickness direction of the packaging sheet without heating, thereby forming seal portions on each of the edges. EXAMPLES

[0065] (Example 1) A pair of rolls similar to the first roll 51 and second roll 52 of the individually packaged absorbent article manufacturing apparatus 50 described with reference to Figures 7 to 10, i.e., a roll having a protruding portion with multiple needles on one side and an opposing roll without needles, was used to form a seal portion consisting of multiple through holes without heating in a laminate consisting of three overlapping packaging sheets made of polyethylene resin film.

[0066] A photograph of a part of the sealed portion is shown in Fig. 11. An enlarged photograph of one through hole is shown in Fig. 12. As shown in Fig. 12, the obtained through hole protruded from the surface of the packaging sheet, and a warped portion was formed at least partially.

[0067] (Example 2) Using a heat sealing device, a sealed portion consisting of a plurality of fused portions was formed on the same three-ply packaging sheet as used in Example 1. The fused portion formed in Example 2 was formed using a pair of a heat sealing roll having a protrusion having a diameter equivalent to that of the needle used in Example 1 and an opposing roll.

[0068] An enlarged photograph of the fused portion formed is shown in Fig. 13. As can be seen from Fig. 13, although the fused portion protruded from the surface of the packaging sheet, the packaging sheets were joined together and integrated. In addition, at the end of the peripheral wall, the resin forming the packaging sheet was denatured and discolored, and air bubbles were formed.

[0069] In addition, in each of Example 1 and Example 2 in which a sealed portion was formed, the sound generated when one of the stacked packaging sheets was peeled off was confirmed. The sound generated from the sealed portion formed in Example 1 was slight. In contrast, in Example 2, when the packaging sheet was peeled off, a sound similar to the sound generated when the packaging sheet is torn was generated, and the volume of the sound was also smaller than the sound generated in Example 1. [Explanation of symbols]

[0070] 1. Absorbent articles 10 Packaging Sheet 10a Original packaging sheet 11 One end of the first direction 12 The other end of the first direction 20 Seal part 21 Peripheral wall of through hole 22 Curved part 25 Through hole 30 Sealing tape 50 Manufacturing equipment for individually packaged absorbent articles 51 Roll 1 51a 1st protrusion 52 Roll 2 52a Second protrusion 100 individually packaged absorbent articles D1 First direction (longitudinal direction of packaging sheet) D2 Second direction (width direction of packaging sheet) Dm Transport direction FL1 First fold line FL2 Second fold line N Needle Ns Needle end R1 1st area R2 2nd area R3 3rd area

Claims

1. An individually packaged absorbent article comprising an absorbent article and a packaging sheet for individually packaging the absorbent article, the packaging sheet is folded in two or more in a first direction, two or more of the packaging sheets are overlapped at edges in a second direction perpendicular to the first direction, and the edges are sealed to form a seal portion; the sealed portion has a plurality of through holes each having a peripheral wall protruding in a thickness direction of the packaging sheet, and the packaging sheets constituting the peripheral wall are not fused to each other, An individually packaged absorbent article, wherein a plurality of the through holes are arranged in the second direction, and the diameter of the through holes gradually decreases from the inside to the outside in the second direction.

2. The individually packaged absorbent article according to claim 1 , wherein a free edge portion of the peripheral wall has a curved portion.

3. The individually packaged absorbent article according to claim 1 or 2, wherein the packaging sheet is folded in three or more folds.

4. The individually packaged absorbent article according to claim 1 , wherein the packaging sheet is made of a resin film.

5. A method for producing an individually packaged absorbent article, comprising: an absorbent article; and a packaging sheet for individually packaging the absorbent article, the method comprising: Placing an absorbent article on the packaging sheet; The packaging sheet is folded in half or more in a first direction, and two or more of the packaging sheets are overlapped with each other at edges in a second direction perpendicular to the first direction; forming a plurality of through holes having peripheral walls protruding in a thickness direction of the packaging sheet without heating, thereby forming a seal portion on each of the edges; A method for manufacturing an individually packaged absorbent article, wherein a plurality of the through holes are arranged in the second direction, and the diameter of the through holes gradually decreases from the inside to the outside in the second direction.

6. The method for producing an individually packaged absorbent article according to claim 5 , wherein the plurality of through holes are formed using a roll having a plurality of needles.

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