Individually packaged absorbent article

Abstract

An individually packaged absorbent article in which an absorbent article is individually packaged by a packaging sheet made of a refractory material, the packaging sheet being folded up to the inner surface side in a first direction of the packaging sheet, and both edge portions in a second direction perpendicular to the first direction being sealed to form a sealing portion, the sealing part comprises a plurality of pressing parts which are pressed together in the thickness direction of the packaging sheet and are separated from each other, the inner surface of the packaging sheet is coated with a heat-sealing agent in a specified pattern at least on the region corresponding to the sealing part, and the heat-sealing agent in the region of the packaging sheet to which the heat-sealing agent is coated is less than the heat-sealing agent in the region of the packaging sheet to which the heat-sealing agent is coated. And the heat sealing agent is overlapped with the pressing part.

Description

Technical Field

[0001] The present invention relates to individually packaged absorbent articles. Background Art

[0002] Many absorbent articles such as sanitary napkins, panty liners, and incontinence pads are individually packaged with packaging sheets for reasons of hygiene during storage and convenience during carrying, and are provided as individually packaged absorbent articles (individual packages) in a sealed state. The packaging structure of individually packaged absorbent articles is generally, for example, in the following form: the absorbent article is placed on the inner surface of the packaging sheet, the packaging sheet is folded to the inner surface side together with the absorbent article, and the two edges are sealed.

[0003] As the material of the packaging sheet, resin films, nonwoven fabrics, etc. are still the mainstream, but packaging sheets made of refractory materials such as paper are also known, as described in Patent Document 1. When refractory materials are used for packaging sheets, bonding by thermal fusion cannot be performed or cannot be performed sufficiently, so it is considered to seal the packaging sheet by physically deforming it (forming unevenness, etc.).

[0004] [Prior art literature]

[0005] [Patent Literature]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2022-24624 Summary of the invention

[0007] [Problems to be solved by the invention]

[0008] However, sometimes it is not possible to obtain a seal with sufficient sealing strength by simply relying on the physical deformation of the packaging sheet, and it is not possible to obtain sufficient sealing of the individually packaged absorbent article. In this regard, for example, sealing based on adhesives, tapes, etc. along the two edges is considered, but the sealing strength of the sealed portion is too high, and it is difficult to peel off the seal when the individually packaged absorbent article is opened, and the packaging sheet may be broken when peeling.

[0009] In view of the above, an object of one embodiment of the present invention is to provide a structure in which a seal portion having an appropriate seal strength is provided in an individually packaged absorbent article formed of a packaging sheet made of a refractory material.

[0010]

Methods to solve the problem

[0011] One embodiment of the present invention is an individually packaged absorbent article formed by individually packaging an absorbent article through a packaging sheet made of a refractory material, the packaging sheet being folded to the inner surface side in a first direction of the packaging sheet, and two edge portions in a second direction perpendicular to the first direction are sealed to form a sealed portion, the sealed portion comprising a plurality of pressure portions separated from each other in the direction of the surface into which the packaging sheet is pressed in the thickness direction, a heat sealant is applied in a specified pattern on at least an area of ​​the inner surface of the packaging sheet corresponding to the sealing portion, and the heat sealant applied on the packaging sheet overlaps with the pressure portions.

[0012] [Effects of the invention]

[0013] According to one aspect of the present invention, there is obtained a structure in which an individually packaged absorbent article formed using a packaging sheet made of a refractory material is provided with a seal portion having an appropriate seal strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0014]

Figure 1

[0015]

Figure 2

[0016]

Figure 3

[0017]

Figure 4

[0018]

Figure 5

[0019]

Figure 6

[0020]

Figure 7

[0021]

Figure 8

[0022]

Fig. 9

[0023]

Fig.10

[0024]

Fig.11

[0025] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In addition, in each of the drawings, the same or corresponding structures may be given the same reference numerals and the description thereof may be omitted unless otherwise specified.

[0026] (Basic structure of individually packaged absorbent articles)

[0027] First, the basic structure of the individually packaged absorbent article will be described. Figure 1 A plan view of an individually packaged absorbent article 100 is given in FIG. Figure 2 In the given Figure 1 The plan view of the individually packaged absorbent article in the unfolded state is a view observed from the inner surface of the packaging sheet 10 or from the skin side of the absorbent article 1. Figure 3 Given in Figure 1 The II line cross section, Figure 4 Given Figure 1 The II-II line cross section.

[0028] like Figure 1 to Figure 4 As shown, the individually packaged absorbent article 100 includes a packaging sheet 10 and an absorbent article 1 that is individually packaged by the packaging sheet 10. Figure 2 As shown, the packaging sheet 10 can be in an elongated shape in the unfolded state, having a longitudinal direction (long side direction, first direction) D1 and a transverse direction (short side direction, second direction) D2 perpendicular to the longitudinal direction. The longitudinal direction D1 and transverse direction D2 of the packaging sheet 10 can correspond to the long side direction and short side direction of the absorbent article 1, respectively.

[0029] (Absorbent articles)

[0030] The absorbent article 1 packaged by the packaging sheet 10 may be a flat and elongated article to be worn facing the discharge outlet of body fluids (menstrual blood, vaginal discharge, urine, etc.). Specific examples of the absorbent article 1 may be sanitary napkins, panty liners (vaginal discharge sheets), and panty liners for light incontinence. In this specification, the embodiments are described based on the example that the absorbent article is a sanitary napkin.

[0031] Absorbent article 1 such as Figure 2 As shown, the structure may include a liquid-permeable top sheet 3, a liquid-impermeable back sheet (not shown), and an absorbent body 4 disposed between the top sheet 3 and the back sheet.

[0032] As the back sheet, a sheet having at least water-blocking properties, such as an olefin resin sheet such as polyethylene or polypropylene, can be used. A laminated nonwoven fabric obtained by laminating a nonwoven fabric on a polyethylene sheet or the like, or a laminated sheet obtained by ensuring substantial liquid-impermeability of a nonwoven fabric through a waterproof film, etc. can be used. In addition, a sheet having moisture permeability can be used.

[0033] As the top sheet 3, it is suitable to use a porous or non-porous nonwoven fabric, a porous plastic sheet, etc. 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 cuprammonium yarn and their blended fibers, and natural fibers such as cotton can be used alone or in combination of two or more.

[0034] The absorbent body 4 is not limited as long as it is a material that can absorb and retain body fluids, but preferably contains cotton pulp and absorbent polymers. As absorbent polymers, superabsorbent polymer granular powder (superabsorbent polymer (SAP)), superabsorbent polymer fiber (superabsorbent fiber (SAF)) and combinations thereof can be used. As pulp, cellulose fibers such as chemical pulp and dissolving pulp obtained from wood, artificial cellulose fibers such as rayon and acetate can be cited. As pulp, hardwood pulp obtained from hardwood, softwood pulp obtained from softwood or mixed pulp thereof can be cited. In addition, the pulp can be recycled pulp regenerated from used pulp.

[0035] The thickness of the absorbent body 4 may be 0.5 to 25 mm. The absorbent body 4 may be structured so that the area corresponding to the body fluid discharge outlet (body fluid discharge outlet corresponding area) and the area behind the body fluid discharge outlet corresponding area facing the groove of the buttocks are bulged. The absorbent body 4 has a size and shape that does not exceed the top sheet 3 and the back sheet, and the outer edges of the back sheet and the top sheet 3 are bonded by adhesives such as hot melt adhesives, heat sealing, ultrasonic sealing, etc. at the front and rear edge portions of the absorbent body.

[0036] like Figure 2 As shown, side sheets 7, 7 may be provided on the outer side of the side portion of the absorbent body 4 at both ends in the transverse direction D2 along the longitudinal direction D1. As the side sheet 7, a water-repellent treated nonwoven fabric or a hydrophilic treated nonwoven fabric may be used.

[0037] In addition, if Figure 1 to Figure 4 In the example shown, the absorbent article 1 is a so-called wingless type without wings, but it may be configured as a winged article having wings extending from the sides. The wings can be formed by bonding the side sheets and the back sheet.

[0038] Furthermore, a back sheet side (non-skin side, i.e., side facing the underwear when worn) of the absorbent article 1 may be provided with an anti-drift adhesive portion for preventing the absorbent article 1 from drifting from the underwear when the absorbent article 1 is attached to the underwear. The anti-drift adhesive portion may be formed in a plurality of strips extending in the longitudinal direction D1 or the transverse direction D2.

[0039] The total length of the absorbent article 1 may be 140 to 430 mm, and the width of the absorbent article 1 (the width of the main body excluding the wings when the wings are provided) may be 40 to 130 mm.

[0040] (Packaging Sheet)

[0041] The packaging sheet 10 in this embodiment can be made of a refractory material. In this embodiment, the packaging sheet made of a refractory material includes a packaging sheet made of a refractory material and a packaging sheet having a refractory material layer on the surface. Refractory material refers to a material that the packaging sheets cannot be melted or hardly melted together even if heated (for example, heated to 80°C or above).

[0042] The refractory material can be an aggregate of refractory fibers. As an aggregate of refractory fibers, preferably, paper can be cited. By using a paper packaging sheet 10, it can contribute to plastic reduction and can help achieve sustainable development goals. In addition, paper can be given a unique style, such as the appearance and feel of a soft impression of natural materials, thereby providing a good mood to the user. In addition, in this specification, paper refers to a thin flat plate made by gluing plant fibers and other fibers with an adhesive. In particular, it refers to plant fibers as the main raw material, for example, the plant fibers, especially cellulose fibers, in the fibers contained are more than 50%, preferably more than 80%. Plant fibers as raw materials for paper can include wood pulp, non-wood pulp, old paper pulp, and cotton cellulose, and the pulp can be any of mechanical pulp and chemical pulp. In addition, the above-mentioned plant fibers can be recycled fibers such as rayon, cuprammonium silk, etc., or plant fibers (recycled pulp, etc.) recycled from structural components of absorbent articles and / or packaging sheets for absorbent articles.

[0043] Additives may be added to the paper. Specific examples of paper include various types of paper such as Western paper, Japanese paper, processed paper, and synthetic paper. Furthermore, paper used for other purposes in the past may be, for example, paper called newspaper, printing paper (including high-quality paper), note paper, drawing paper, packaging paper, thin paper, mixed paper, etc. In the case of thin paper, it may be thin imitation paper, Indian paper, rice paper, glassine paper, facial tissue, toilet paper, filter paper, etc.

[0044] In addition, in this specification, the paper packaging sheet refers to a sheet mainly comprising the above-mentioned paper. Among the paper packaging sheets, there are obviously packaging sheets consisting only of paper, and laminated sheets consisting of sheets consisting of paper and materials other than paper may also be included. When the packaging sheet 10 contains a sheet consisting of a material other than paper, the material other than paper may be a resin film, a non-woven fabric, etc. Here, the packaging sheet 10 is not laminated with a sheet of material other than paper, and when it is composed of paper, it is particularly preferred based on the viewpoint of plastic reduction and / or the viewpoint of being able to give the unique natural style of paper to the product. In addition, the paper packaging sheet is relatively easy to break. Based on the coating pattern of the heat sealant given in this embodiment and the relationship between the pressure-applying portion and the coating portion of the heat sealant, a single-packaged absorbent article can be provided, which can appropriately adjust the sealing strength of the sealing portion, has sufficient encapsulation and prevents breaking when unsealed.

[0045] Furthermore, in the sealing portion of the present embodiment, as long as appropriate sealing strength can be ensured, certain processing other than the application of the above-mentioned heat sealant may be performed on the paper packaging sheet 10. The processing may include processing such as pleating, embossing, calendering, slitting, laminating, etc., which impose physical deformation on the packaging sheet 10, or may include processing such as waterproofing, demolding, ink printing, etc., which add substances to the packaging sheet 10. Here, when performing the processing of adding substances, in order to avoid affecting the sealing strength of the sealing portion, it is preferred to perform the processing in an area other than the area corresponding to the sealing portion. Furthermore, the processing of adding substances is preferably performed in an area where an area without a heat sealant is formed on the inner surface of the packaging sheet 10 (for example, refer to Figure 7 , explanation to be given later).

[0046] The antifouling function is improved by the above-mentioned waterproof processing or mold release processing (for example, coating a waterproof agent or mold release agent containing silicone resin, paraffin resin, fluororesin, etc.). When the waterproof processing is performed on the side of the packaging sheet 10 facing the anti-shift adhesive portion on the back of the absorbent article 1 (the inner surface of the packaging sheet), the packaging sheet 10 can be in contact with the anti-shift adhesive portion without peeling the sheet.

[0047] In addition, the outer surface of the packaging sheet 10 in this embodiment can be printed with ink. By implementing ink printing, the design of the individually packaged absorbent article is improved. When ink printing is implemented on the packaging sheet 10, it is preferable to use a material (non-crepe paper, non-embossed paper) as the packaging sheet 10 that is not processed by pleating, embossing, etc. to form unevenness on the surface of the packaging sheet.

[0048] The packaging sheet 10 used in this embodiment preferably has a grammage of 8 to 50 g / m 2 , more preferably 10 to 40 g / m 2By using a packaging sheet 10 having a gram weight within the above range, a single-package absorbent article having a good feel and suppressing rough touch can be obtained, and the generation of noise when carrying or opening the package can also be prevented. In addition, the thickness of the packaging sheet 10 (the thickness after pleating in the case of crepe paper) is preferably 30 to 200 μm, and more preferably 35 to 100 μm.

[0049] The size of the packaging sheet 10 is based on the size and shape of the packaged absorbent article 1. For example, when the packaging sheet 10 is fully unfolded (unfolded), the length of the longitudinal direction D1 (sometimes simply referred to as the length) can be 100 to 450 mm, and the length of the transverse direction D2 (sometimes simply referred to as the width) can be 70 to 250 mm. In the example shown in the figure, the packaging sheet 10 has a rectangular shape in the unfolded state, but it can also have a shape such as an oblong oval.

[0050] (Packaging structure)

[0051] like Figure 1 to Figure 4 As shown in FIG. 1 , the absorbent article 1 is packaged by folding it together with the packaging sheet 10 to form a separately packaged absorbent article 100. When folded, as shown in FIG. Figure 2 As shown, in the following state, the absorbent article 1 is placed on the inner surface of the packaging sheet 10 so that the back sheet side of the absorbent article 1 faces it. Then, the packaging sheet 10 and the absorbent article 1 are folded together in the longitudinal direction D1 based on the first fold line F1 and the second fold line F2 along the transverse direction D2. More specifically, based on the first fold line F1, the first region R1 including one end 11 of the longitudinal direction D1 of the packaging sheet 10 is folded in the longitudinal direction D1, and based on the second fold line F2, the second region R2 including the other end 12 of the longitudinal direction D1 of the packaging sheet 10 is folded. The area between the first region R1 and the second region R2 of the packaging sheet 10 is the third region R3. In the example shown in the figure, the packaging sheet 10 is folded in such a manner that the second region R2 is folded first and the first region R1 is overlapped on the outer surface of the second region R2 ( Figure 1 and Figure 2 ), or the folding order of the first region R1 and the second region R2 may be reversed. In this way, the packaging sheet 10 is folded into three parts together with the absorbent article 1 (inner three-fold), and after wrapping the absorbent article 1, the two edge parts of the transverse direction D2 are sealed along the longitudinal direction D1 to form the sealed parts 15,15.

[0052] Such a packaging form of three or more folds can be formed relatively simply, and the absorbent article 1 can be hygienically wrapped, and it is also easy to take out the absorbent article 1. In addition, the folding form is not limited to three folds, and can be four or more folds, or two folds.

[0053] (Seal part)

[0054] like Figure 1As shown, in the individually packaged absorbent article 100, the positions where the absorbent article 1 does not exist at the two edges in the horizontal direction D2 are sealed to form seals 15, 15. The seals 15, 15 can be formed along the entire length of the longitudinal direction D1 of the packaging sheet 10. This can prevent garbage, dust, or fingers or small objects from accidentally invading from the lateral end edge (obtaining sealing properties), which is preferred from this point of view. The seals 15, 15 are formed by, for example, inserting the two edge portions of the folded packaging sheet 10 (the two edge portions of the lateral direction D2 of the packaging sheet 10) into a pair of rollers, and applying pressure and heat by the two rollers, thereby pressing the packaging sheets 10 together in the thickness direction.

[0055] The range of the transverse direction D2 in which the sealing portion 15 is provided may be a range of 20 mm from the end edge of the transverse direction D2. The sealing portion 15 may be formed in the entire above range, or may be formed in a part of the above range, for example, at a position slightly away from the end edge of the transverse direction D2. The length (width) of the transverse direction D2 of the sealing portion 15 itself is preferably 3 to 15 mm.

[0056] Figure 5 An enlarged view of part III including the sealing portion 15 is given. Figure 5 As shown, the sealing portion 15 may include a plurality of pressure portions 15a, 15a... that are separated from each other when viewed from above. The pressure portions 15a, 15a... are formed by, for example, clamping a roller having a plurality of convex portions on the surface with shapes corresponding to the pressure portions 15a, 15a... and a roller (support roller, etc.) having no concave-convex surfaces facing the roller. Therefore, the pressure portions 15a, 15a... can be said to be portions or indentations where the packaging sheets are pressed together in the thickness direction. The pressure portion 15a may be a portion that is recessed compared to the surroundings (a portion that protrudes compared to the surroundings when viewed from the opposite side). In the example shown in the figure, portions other than the plurality of pressure portions 15a, 15a... are portions where the packaging sheets are not pressed together by the above-mentioned convex portions on the roller surface, or are non-pressure portions. In this way, the pressure-applying portions 15a, 15a...are separated from each other in the plane direction and exist in a dotted form, and there is a non-pressure-applying portion between the pressure-applying portions 15a, 15a..., thereby preventing the packaging sheets from being continuously adhered to each other along the entirety of the sealing portion 15, and preventing the seal strength from being too strong. Therefore, when peeling off the packaging sheet during unsealing, the packaging sheet 10 can be suppressed from being broken, and the seal can be easily released. In addition, by applying pressure to the individually packaged absorbent article 100, the air that has entered the interior is discharged to the outside through the non-pressure-applying portion, thereby preventing the individually packaged absorbent article from being accidentally broken before unsealing. Furthermore, it is also possible to prevent the two edges of the individually packaged absorbent article 100 from being excessively hardened and damaging the hand feel.

[0057] like Figure 5In the example shown, a plurality of rows of pressure applying portions 15a, 15a ... are formed in a straight line along the transverse direction D2, and such a plurality of rows are arranged in parallel in the longitudinal direction D1. Then, the position of the pressure applying portion 15a located on the innermost side of the transverse direction D2 is not aligned in the transverse direction D2, and the inner contour line L of the sealing portion 15 is wavy (refer to Figure 1 ). By forming the inner contour line L of the sealing portion 15 in a wavy shape, the design of the sealing portion 15 is improved, and the aesthetics of the individually packaged absorbent article 100 is also improved. In addition, the inner contour line L of the sealing portion 15 may be a line that smoothly connects the inner end of the pressure portion 15a located at the innermost side in the lateral direction D2 in the longitudinal direction D1.

[0058] In addition, if Figure 5 In the example shown, the shape of each pressure applying portion 15a is circular, and further, the area of ​​the pressure applying portion 15a in a row of a plurality of pressure applying portions 15a arranged in parallel in the transverse direction D2 is different. In the example shown in the figure, the area of ​​the pressure applying portion 15a increases as it approaches the inner side in the transverse direction D2. Thus, the strength of the innermost side in the transverse direction D2, which corresponds to the peeling start position when the sealing portion 15 is released, can be increased, and accidental opening before use can be prevented.

[0059] In this embodiment, the sealing portion 15 is composed of a plurality of separated pressure applying portions 15a, 15a..., and as described later, when overlapping with the heat sealant, the arrangement, size, shape, etc. of the pressure applying portions 15a, 15a... are not particularly limited. Figure 6 As shown in (a), a pressure-applying portion 15a may be a square. Figure 6 As shown in (b), the shape of one pressure-applying portion 15a may be a rhombus. In addition, the arrangement of the pressure-applying portions 15a, 15a... may also be a grid-like arrangement ( Figure 6 (a)), or staggered ( Figure 6 (b)), or may be randomly arranged. In addition, even if it is arranged in a grid or staggered manner, it may be a structure that reduces the number of the pressure-applying portions 15a, 15a ... on the innermost side of the lateral direction D2 ( Figure 6 (a) etc.).

[0060] In addition, the shape of the pressure applying portion 15a is not limited to Figure 5 and Figure 6 The shape shown may be, for example, an ellipse, a square, a quadrilateral other than a rhombus, a polygon other than a quadrilateral, a heart, a star, a teardrop, etc. In addition, in the sealing portion 15, one dimension of the pressure applying portion 15a may be a circle with a diameter of about 0.2 to 1.5 mm or a dimension having an equivalent area thereto.

[0061] The area ratio of the pressing portions 15a, 15a, ... in the sealing portion 15, that is, the ratio of the total area occupied by the pressing portions 15a, 15a, ... to the area of ​​the sealing portion 15, is preferably 5 to 50%, more preferably 10 to 40%.

[0062] (Heat sealant)

[0063] In this embodiment, a heat sealant is used to improve the sealing strength of the sealing portion 15, 15. The heat sealant may contain a thermoplastic resin, preferably a resin that softens or melts at 70 to 170°C, preferably an olefin-based heat sealant. In addition, the heat sealant may be an aqueous dispersion of resin particles. Specific examples of heat sealants include the "CHEMIPEARL (registered trademark)" series manufactured by Mitsui Chemicals, Inc.

[0064] By using a heat sealant, even if the packaging sheet 10 is made of a refractory material, the packaging sheets can be bonded to each other by heat sealing (heat sealing). The heat sealant provided between the packaging sheets melts or softens, adheres to the packaging sheets, and then cools and solidifies the heat sealant, whereby the packaging sheets are strongly fixed to each other, thereby obtaining a high sealing strength compared to a seal utilizing physical deformation of the packaging sheets. In addition, depending on the type of heat sealant, gram weight, material of the packaging sheet, etc., there is a possibility that the sealing strength is too large. In this method, the heat sealant is applied in a specified pattern, so that the sealing strength can be well adjusted.

[0065] For example, Figure 2 to Figure 4 As shown, the heat sealant 20 can be applied on the inner surface of the packaging sheet 10. At this time, the range of the heat sealant 20 coating can be the entire inner surface, or a portion of the inner surface, at least including the sealing portion 15, 15 ( Figure 1 The area corresponding to the sealing portion 15, 15 (the area corresponding to the sealing portion), more specifically, as Figure 7 As shown, the sealing portions 15 , 15 may be formed in predetermined areas (sealing portion formation predetermined areas) 14 , 14 . Figure 7 is with Figure 2 Similarly, in the development view of the individually packaged absorbent article 100, the outline of the absorbent article 1 is indicated by a two-dot chain line. Figure 7 As shown, the heat sealant 20 is applied to at least the edge regions 18, 18 including the above-mentioned seal portion corresponding region (seal portion forming region 14, 14). The edge regions 18, 18 may be regions of a certain width, including the entire seal portion forming region 14, and not overlapping with the absorbent article 1 when the absorbent article 100 is packaged separately.

[0066] The heat sealant 20 is applied to the area 19 outside the edge areas 18, 18 at a gram weight less than the gram weight of the heat sealant 20 in the edge areas 18, 18, or as Figure 7 As shown in the example, it is also possible to have a structure in which the heat sealant 20 is not substantially applied. In this way, the sealing strength of the sealing portion 15 can be ensured, while reducing the cost caused by the heat sealant. On the other hand, depending on the type of the heat sealant 20, it also has the function of reinforcing the packaging sheet 10, so by expanding the area where the heat sealant 20 is applied, the strength of the packaging sheet 10 can be improved. When a breakable material such as paper is used as the packaging sheet 10, it is preferred to apply the heat sealant 20 to the area 19 outside the edge area 18, 18, and it is more preferred to apply the heat sealant 20 to both the edge area 18, 18 and the area 19 outside of the edge area 18, 18 with the same gram weight.

[0067] The predetermined pattern of the heat sealant 20 applied to the packaging sheet 10 is not particularly limited, and may be, for example, a dot-dispersed pattern. Figure 8 Given Figure 2 This is an enlarged view of part IV of the Figure 8 In the example shown, the heat sealant 20 is provided in a dot pattern. By applying the heat sealant in a dot pattern, the heat sealant can be dispersed in a regular pattern, so that the heat sealant can be uniformly dispersed in the application area of ​​the heat sealant, and the sealing strength of the seal portion 15 can be prevented from being uneven. In addition, by applying the heat sealant 20, the rigidity of the packaging sheet 10 changes, and the touch and the like change to some extent, but by making the pattern discontinuous, the change in the touch and the like can be suppressed (for example, the loss of the softness of the packaging sheet 10 can be suppressed).

[0068] like Figure 8 In the example shown, the heat sealant 20 is printed at a dot rate of 70%. In the dot pattern, multiple microscopic, dot-shaped heat sealant portions may be spaced apart from each other and discontinuous, or multiple dot-shaped heat sealant portions may be contacted and continuous.

[0069] In the coating area of ​​the heat sealant 20, the coating area ratio of the heat sealant 20 is not particularly limited as long as the heat-sealed sealing portion 15, 15 can be formed, and is preferably 40% or more, more preferably 50% or more, further preferably 60% or more, and further preferably 70% or more. By setting the coating area ratio to 40% or more, the extension area of ​​the heat sealant 20 on the packaging sheet 10 increases, thereby improving the sealing strength of the sealing portion 15. In addition, according to the type and weight of the heat sealant 20, the material of the packaging sheet 10, the pressure portion 15a ( Figure 5 , Figure 6The conditions such as the pattern and area ratio of the packaging sheet 10 (such as the pattern and area ratio) can be 95% or less, 90% or less, or 80% or less. The above-mentioned coating area ratio of the heat sealant is the above-mentioned dot ratio in the case of the dot pattern. In addition, the coating area ratio of the heat sealant 20 can be more specifically the ratio of the total area where the heat sealant 20 is provided in the edge area 18 (mentioned above) relative to the area of ​​the edge area 18 (mentioned above) of the inner surface of the packaging sheet 10 before folding. The case where the coating area ratio is 100% means that the heat sealant 20 is coated on the entire surface.

[0070] Examples of the coating method of the heat sealant 20 include flexographic printing, offset printing, screen printing, and gravure printing. Among them, flexographic printing is preferred because a stable coating amount and coating pattern can be obtained and inexpensive water-based ink can be used.

[0071] (Relationship between heat sealant pattern and pressure applying portion)

[0072] As described above, the seal portion 15 formed by sealing after folding the packaging sheet 10 includes the pressing portions 15a, 15a, ..., and the pressing portion 15a can be formed at a specified area ratio in the seal portion 15. In addition, the heat sealant 20 is formed in a specified pattern on the packaging sheet 10 before folding, and the heat sealant 20 in the coating area of ​​the heat sealant 20 is also coated at a specified coating area ratio. Here, in order to firmly form the seal portion 15 of the individually packaged absorbent article 100, the following structure is important: when the seal portion 15 is formed, the heat sealant is set at the position of the pressing portion 15a when the transverse D2 edge portion of the folded packaging sheet is heated and pressed by a pair of rollers.

[0073] In this embodiment, when observing the coating area of ​​the heat sealant 20 on the inner surface of a packaging sheet 10, the heat sealant 20 overlaps with the pressure-applying portion 15a. The sealing portion 15 is formed at the transverse D2 edge portion of the packaging sheet 10 after folding, and the portion corresponding to the sealing portion 15 (the portion included in the sealing portion 15) is either at a position facing the inner surface of the packaging sheet 10 or at a position where the inner surface and the outer surface of the packaging sheet 10 face each other (the inner surface of the first region R1 and the outer surface of the second region face each other, Figure 1 and Figure 4 Even in a position where the inner surface and the outer surface of the packaging sheet 10 face each other, at least as in the present embodiment, when the heat sealant 20 applied to the inner surface of the packaging sheet 10 overlaps with the area of ​​the pressing portion 15a, a seal can be firmly formed due to direct heating by the roller and the strong overlap of the heated area and the heat sealant 20.

[0074] Fig. 9 Given in Figure 5 FIG. 1 is an enlarged view of one packaging sheet 10 (first region R1) included in the portion V of FIG. Fig. 9In FIG. 1 , the heat seal portion 20 applied on the inner surface of the first region R1 is indicated by gray (pear pattern) surrounded by a dotted line, and the contours of the pressing portions 15a, 15a, ... are indicated by solid lines. Then, the overlapping portion C where the pressing portion 15a overlaps with the heat sealant 20 is indicated by black. The overlapping portion C can be said to be a common portion of the heat sealant 20 and the pressing portion 15a in one packaging sheet 10.

[0075] Observing from the inner surface of a piece of packaging sheet 10, for example, the ratio Pc (Pc=Sc / Sc×100) of the total area (Sc) of the overlapping portion C relative to the total area (Se) of the pressure-applying portion 15a in the inner surface of the first region R1 is preferably 50% or more, 60% or more, or 70% or more, and may be 95% or less, 90% or less, or 80% or less. By having the ratio Pc be 50% or more, the sealing strength can be ensured, and the individually packaged absorbent articles can be sufficiently encapsulated before unsealing. In addition, by having the ratio Pc be 95% or less, no burden is imposed on the packaging sheet during unsealing, and the package can be opened smoothly, thereby improving the ease of unsealing. It is also possible to prevent the packaging sheet from rupturing, so that a packaging sheet that is relatively easy to rupture, such as paper, can be used, in particular paper with a small grammage. In addition, based on Fig. 9 In the example of the pressure applying portion pattern and the heat sealant pattern shown, the ratio Pc of the total area (Sc) of the overlapping portion C to the total area (Se) of the pressure applying portion 15a is about 61.5%.

[0076] In this way, by making the ratio Pc (also referred to as the area ratio of the overlapping portion C) of the total area (Sc) of the overlapping portion C relative to the total area (Se) of the pressing portions 15a within a specified range, the sealing portions 15, 15 can be formed with an appropriate sealing strength regardless of the pattern (shape, size, interval, spacing, arrangement of each pressing portion) and area ratio of the pressing portions 15a, 15a..., and the pattern (shape, size, continuous or discontinuous of the applied heat sealing agent in plan view) and the applied area ratio of the heat sealing agent 20. In other words, when the ratio Pc is within a specified range, the degree of freedom of the pattern of the heat sealing agent 20 and / or the pattern of the sealing portion 15 is increased.

[0077] In addition, from the viewpoint of improving the sealing strength, such as Fig. 9 As shown, preferably, all the pressure-applying parts 15a, 15a... overlap at least partially with the heat sealant 20, and there may be a pressure-applying part 15a that does not overlap with the heat sealant 20. Here, preferably, two or more pressure-applying parts 15a that do not overlap with the heat sealant 20 (pressure-applying parts 15a that do not include the overlapping part C) are not adjacent, that is, preferably, at least one of any two adjacent pressure-applying parts 15a, 15a overlaps with the heat sealant 20. Thus, it is possible to prevent a decrease in the local sealing strength. That is, it is possible to prevent the sealing strength of the sealing part 15 from deviating.

[0078] like Fig. 9 As shown in FIG. 1 , when the heat sealant 20 is formed in a dot shape, it is preferred that the dot spacing of the heat sealant 20 (the distance between the center of one dot and the center of the dot adjacent to the one dot) is smaller than the distance between the pressure applying parts 15a, 15a (the distance between the center of one pressure applying part 15a and the center of the pressure applying part 15a adjacent to the one pressure applying part 15a). Thus, the number of pressure applying parts 15a without overlapping parts C is reduced.

[0079] In addition, the ratio Pc of the total area (Sc) of the overlapping part C relative to the total area (Se) of the pressure-applying part 15a can be measured by, for example, peeling off the sealing part 15 of the individually packaged absorbent article 100, magnifying the inner surface of a piece of packaging sheet 10 by using a microscope or the like, taking an image and performing image analysis.

[0080] <Modification>

[0081] Fig.10 A modification example of the overlapping portion C is given in FIG. Fig.10 (a), the pattern of the heat sealant 20 is similar to that of Figure 8 In addition, Fig.10 The pressing parts 15a, 15a, ... in (a) have the same size. Fig.10 In the example shown in (a), the ratio Pc of the total area (Sc) of the overlapping portions C to the total area (Se) of the pressing portions 15a is 62.61%.

[0082] In addition, if Fig.10 As shown in (b), even if the pattern of the heat sealant 20 is arranged in a dotted shape, the shape of the dots constituting the pattern can be made square. In this case, the discontinuity of the heat sealant 20 can be maintained while increasing the coating area ratio of the heat sealant 20. When the coating area ratio of the heat sealant 20 is high, even if the pattern of the same pressure-applying part 15a, 15a... is used, it is easy to increase the ratio of the overlapping part C (the above-mentioned Pc) of the heat sealant 20 and the pressure-applying part 15a. On the other hand, by making the heat sealant 20 discontinuous, changes in the touch of the packaging sheet 10 that can be caused by the coating of the heat sealant 20 as described above can be suppressed. Fig.10 In the example shown in (b), the ratio Pc of the total area (Sc) of the overlapping portions C to the total area (Se) of the pressing portions 15a is 68.73%.

[0083] like Fig.10 As shown in (c), the heat sealant 20 may be arranged in a lattice shape. Fig.10The example of (c) may be a pattern in which the heat sealant 20 is a plurality of lines extending in the longitudinal direction D1 and the transverse direction D2 and arranged crosswise. Such a continuous pattern of the heat sealant 20 can improve the strength of the packaging sheet 10 along the entire packaging sheet 10, and is therefore suitable for the following situation where an easily breakable material such as paper or a material with a small grammage is used as the packaging sheet 10. In the example shown in FIG810(c), the ratio Pc of the total area (Sc) of the overlapping portion C to the total area (Se) of the pressure-applying portion 15a is 65.35%.

[0084] Furthermore, the coating pattern of the heat sealant 20 may be in the form of stripes spaced apart from each other. In this case, the stripes may extend in the longitudinal direction D1 or the transverse direction D2, such as Fig.10 As shown in (d), it can also be inclined relative to the longitudinal direction D1 or the lateral direction D2. Fig.10 In the example shown in (d), the ratio Pc of the total area (Sc) of the overlapping portions C to the total area (Se) of the pressing portions 15a is 67.26%.

[0085] <Modification of Application of Heat Sealing Agent>

[0086] As described above, the individually packaged absorbent article 100 according to the present embodiment may have a structure in which the packaging sheet 10 is folded in three or more folds. In this case, different regions of the packaging sheet 10 may be formed with different numbers of overlapping sheets depending on the position. For example, in a packaging structure of three folds, Figure 1 and Figure 4 As shown, the packaging sheet 10 is formed into a thicker region (thick region) Za where three sheets are overlapped, and a thinner region (thin region) Zb where two sheets are overlapped. When the sealing portion 15 is formed by, for example, heating and pressurizing with a pair of rollers, there is a tendency that the sealing strength in the thick region Za is greater than the sealing strength in the thin region Zb.

[0087] In this regard, the area ratio Pc of the overlapping portion C in the packaging sheet 10 contained in the thick region Za is smaller, and the area ratio Pc of the overlapping portion C in the packaging sheet 10 contained in the thin region Zb is larger. As a result, the unevenness of the sealing strength can be suppressed along the longitudinal direction D1 of the sealing portion 15. Therefore, the following situation can be prevented, that is, the sealing strength changes in the middle of peeling off the sealing portion 15 during unsealing, thereby putting a burden on the packaging sheet 10 and the packaging sheet 10 is broken, and the uncomfortable feeling of pulling during unsealing can be suppressed. Therefore, for example, in this example, the coating area ratio of the heat sealant 20 applied to the packaging sheet 10 contained in the thick region Za can be made smaller, and the coating area ratio of the heat sealant 20 applied to the packaging sheet 10 contained in the thin region Zb can be made larger.

[0088] A more specific structure is Fig.11 shown. Fig.11 is with Figure 2Similarly, in the development view of the individually packaged absorbent article 100, the outline of the absorbent article 1 is indicated by a two-dot chain line. Fig.11 As shown in FIG. 1 , the heat sealant 20 is applied to the entire inner surface of the packaging sheet 10, and the coating area ratio of the heat sealant 20 varies depending on the position. The coating area ratio of the heat sealant 20 in the regions Ra1 and Ra2 of the packaging sheet 10 corresponding to the thick region Za can be made smaller than the coating area ratio of the heat sealant 20 in the regions Rb1, Rb2, and Ra3 of the packaging sheet 10 corresponding to the thin region Zb.

[0089] The present invention is described above based on the embodiments, but the present invention is not limited to these embodiments. The above embodiments can be variously changed, modified, replaced, added, deleted and combined within the scope of the patent claims, which also belong to the technical scope of the present invention. In addition, the above structural elements can be combined arbitrarily.

[0090] Furthermore, preferred embodiments of the present invention are described below.

[0091] The first method is an individually packaged absorbent article in which the absorbent article is individually packaged by a packaging sheet made of a refractory material, the packaging sheet being folded to the inner surface side in a first direction of the packaging sheet, and the two edge portions in a second direction perpendicular to the first direction are sealed to form a sealing portion, the sealing portion comprising a plurality of pressure portions spaced apart from each other in a surface direction formed by pressing the packaging sheet together in a thickness direction, a heat sealant being applied in a specified pattern on at least an area of ​​the inner surface of the packaging sheet corresponding to the sealing portion, and the heat sealant applied on the packaging sheet overlapping the pressure portions.

[0092] In the first method described above, a heat sealant is applied to at least the area corresponding to the sealing portion on the inner surface of the packaging sheet, so even if the packaging sheet is made of a refractory material, heat sealing can be used to seal the two edge portions. Therefore, compared with sealing that does not use an adhesive substance and utilizes the physical deformation (forming concave and convex, etc.) of the packaging sheet, a higher sealing strength can be ensured. In addition, depending on the type and gram weight of the heat sealant, the sealing strength may be too large. According to this method, the heat sealant is formed in a specified pattern, so the sealing strength can be adjusted to a suitable level. Furthermore, the heat sealant applied on the inner surface of the packaging sheet overlaps with the pressure portion, so that the sealing portion can be formed more solidly with a more suitable sealing strength, regardless of the pattern of the pressure portion and the coating pattern of the heat sealant.

[0093] In the second aspect, a ratio of a total area of ​​overlapping portions of the heat sealing agent and the pressure applying portion to a total area of ​​the pressure applying portion is 50 to 95%.

[0094] According to the second embodiment, the ratio of the total area of ​​the overlapped portion of the heat sealant and the pressure-applying portion (the common portion of the pressure-applying portion and the heat sealant) to the total area of ​​the pressure-applying portion is within a specified range, thereby improving the above-mentioned effect that a seal portion having a suitable seal strength can be formed regardless of the pattern of the heat sealant and / or the pattern of the pressure-applying portion of the seal portion. That is, the effect that the individually packaged absorbent article has sufficient sealing properties before opening and that a seal portion that can be easily peeled off without breaking the packaging sheet when opening can be improved.

[0095] In a third embodiment, the refractory material is paper.

[0096] According to the third embodiment, paper has a unique natural style (appearance and feel), which can give users a good mood. In addition, by using paper, it is also helpful to achieve sustainable development goals. Paper is generally a material that is easy to break, but according to this embodiment, even if a packaging sheet using such a material is used, a sealing portion with appropriate sealing strength can be formed.

[0097] In a fourth aspect, the predetermined pattern of the heat sealant is a halftone dot pattern.

[0098] According to the fourth aspect, the heat sealant is dispersed microscopically in the heat sealant application area, so that the heat sealant can be more uniformly arranged in the application area, thereby preventing the seal strength from decreasing due to an increase in the pressure-applying portion that does not overlap with the heat sealant.

[0099] In a fifth aspect, the coating area ratio of the heat sealant in the packaging sheet is 40% or more.

[0100] According to the fifth embodiment, the heat sealant is applied at a specified coating area ratio, thereby increasing the sealing strength in the sealing portion. In addition, by reinforcing the packaging sheet itself with the heat sealant, even when using an easily breakable packaging sheet (made of paper, with a small grammage, etc.), the rupture of the packaging sheet during unsealing can be suppressed.

[0101] In the sixth aspect, at least one of any two adjacent pressure applying portions overlaps with the heat sealing agent.

[0102] According to the sixth aspect, regardless of the pattern of the heat sealant and / or the pattern of the pressure applying portion, it is possible to avoid the unheat-sealed portion from becoming larger and prevent the local sealing strength from being reduced.

[0103] In the seventh aspect, the gram weight of the heat sealant in the area other than the area corresponding to the seal portion is smaller than the gram weight of the heat sealant in the area corresponding to the seal portion of the packaging sheet, or the heat sealant is substantially not applied in the area other than the area corresponding to the seal portion.

[0104] According to the seventh aspect, the amount of heat sealant in the packaging sheet other than the area corresponding to the seal portion when the absorbent article is individually packaged is reduced, thereby reducing the cost of the heat sealant while maintaining the effect of the seal portion having an appropriate sealing strength.

[0105] In the eighth embodiment, there is a thin area in which the number of overlapping sheets of the packaging sheet is 2 sheets and a thick area in which the number of overlapping sheets of the packaging sheet is 3 or more sheets, and the coating area ratio of the heat sealing agent in the packaging sheet contained in the thick area is smaller than the coating area ratio of the heat sealing agent in the packaging sheet contained in the thin area.

[0106] In the individually packaged absorbent article, there are regions where the number of overlapping sheets of the packaging sheet is different. The region with a large number of overlapping sheets (thick region) tends to have higher sealing strength than the region with a small number of overlapping sheets (thin region), and the sealing strength along the longitudinal direction of the packaging sheet is prone to be uneven. In this regard, through the eighth embodiment, by changing the gram weight of the heat sealant according to the region, specifically, by reducing the coating area ratio of the heat sealant of the packaging sheet contained in the thick region and increasing the coating area ratio of the heat sealant of the packaging sheet contained in the thin region, it is possible to seek uniform sealing strength.

[0107] This application claims the benefit of priority based on Japanese Patent Application No. 2023-055942 filed on March 30, 2023, the entire contents of which are incorporated herein by reference.

[0108] [Reference Signs]

[0109] 1. Absorbent articles

[0110] 3 Top sheet

[0111] 4 Absorber

[0112] 7 Side sheets

[0113] 10 Packaging Sheet

[0114] 11 The longitudinal end

[0115] 12 The other end of the vertical direction

[0116] 15 Sealing part

[0117] 15a Pressure section

[0118] 18 Marginal area

[0119] 19 Areas other than the marginal area

[0120] 20 Heat sealant

[0121] 30 Fixing strap

[0122] 100 Individually wrapped absorbent articles

[0123] C Overlapping portion (the portion where the pressure-applying portion overlaps the heat-sealing agent 20)

[0124] D1 Longitudinal direction of packaging sheet (long side direction, first direction)

[0125] D2 Transverse direction of packaging sheet (short side direction, second direction)

[0126] F1 1st fold line

[0127] F2 2nd fold line

[0128] R1 Area 1

[0129] R2 Area 2

[0130] R3 Area 3

[0131] Za thick area

[0132] Zb thin area

Claims

1. An individually packaged absorbent article, wherein: The absorbent articles are individually packaged with packaging sheets made of refractory materials. The packaging sheet is folded to the inner surface side in the first direction of the packaging sheet, and two edge portions in the second direction perpendicular to the first direction are sealed to form a sealing portion, and the sealing portion includes a plurality of pressure-applying portions spaced apart from each other in a surface direction, and the surface direction is a surface direction formed by pressing the packaging sheets together in the thickness direction, A heat sealant is applied in a specified pattern on at least the area of ​​the inner surface of the packaging sheet corresponding to the sealing portion. The heat sealant coated on the packaging sheet overlaps with the pressing portion.

2. The individually packaged absorbent article according to claim 1, wherein the ratio of the total area of ​​the overlapping portion of the heat sealant and the pressure applying portion to the total area of ​​the pressure applying portion is 50 to 95%.

3. The individually packaged absorbent article according to claim 1 or 2, wherein the refractory material is paper.

4. The individually packaged absorbent article according to claim 1 or 2, wherein the prescribed pattern of the heat sealant is a dot pattern. 5 . The individually packaged absorbent article according to claim 1 , wherein the coating area ratio of the heat sealant in the packaging sheet is 40% or more. 6 . The individually wrapped absorbent article according to claim 1 , wherein at least one of any two adjacent pressing portions overlaps with the heat sealing agent.

7. The individually packaged absorbent article according to claim 1 or 2, wherein the gram weight of the heat sealant in the region other than the region corresponding to the sealed portion is smaller than the gram weight of the heat sealant in the region of the packaging sheet corresponding to the sealed portion, or The heat sealing agent is not substantially applied to the region other than the region corresponding to the sealed portion.

8. The individually wrapped absorbent article according to claim 1 or 2, comprising a thin region where two wrapping sheets are overlapped and a thick region where three or more wrapping sheets are overlapped, The coating area ratio of the heat-sealing agent in the packaging sheet contained in the thick region is smaller than the coating area ratio of the heat-sealing agent in the packaging sheet contained in the thin region.

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