Individually packaged absorbent articles

Abstract

To provide an individually packaged absorbent article having a seal portion excellent in sealability before use and easiness of opening when being opened.SOLUTION: There is provided an individually packaged absorbent article including a packaging sheet and an absorbent article individually packaged by the packaging sheet. The packaging sheet has a vertical direction and a horizontal direction orthogonal to the vertical direction. The packaging sheet is folded in the vertical direction, and marginal parts in the horizontal direction are sealed respectively, forming a seal portion. The seal portion includes a plurality of bonding parts separated from each other. The seal portion includes an inside region, an intermediate region, and an outside region in this order from the inside to the outside in the horizontal direction. The bonding strength in the inside region is higher than that in the intermediate region, and the bonding strength in the outside region is higher than that in the intermediate region.SELECTED DRAWING: Figure 4

Description

Technical Field

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

Background Art

[0002] Generally, absorbent articles such as sanitary napkins, panty liners, incontinence pads, etc. are provided as individually packaged absorbent articles (individual packages) in a state where they are individually packaged and sealed by a packaging sheet for reasons such as hygiene during storage and convenience during carrying.

[0003] As a form of individually packaged absorbent articles, as described in Patent Document 1, after folding the packaging sheet together with the absorbent article in the longitudinal direction of the packaging sheet, both lateral edges of the packaging sheet are sealed, and a seal portion is formed along the longitudinal direction of the individually packaged absorbent article in many cases. Further, the seal portion is composed of a plurality of joined portions that are separated from each other and where the packaging sheets are joined in the thickness direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Individually packaged absorbent materials need to have the characteristic of not being unintentionally opened before use (sealability), while also needing to be able to be opened easily by smoothly separating the packaging sheets when first used (ease of opening). However, it is difficult to form a seal that possesses both sealability and ease of opening. For example, if ease of opening is prioritized and the joint strength of the seal is reduced, the packaging sheets may easily peel off near the opening of the individually packaged absorbent material (near the edge of the packaging sheet) before first use. On the other hand, if sealability is prioritized and the joint strength of the seal is increased, the seal may not peel off when attempting to open the individually packaged absorbent material for use, and if excessive force is applied to open it, the packaging sheets may be damaged.

[0006] Therefore, one aspect of the present invention aims to provide individually packaged absorbent articles equipped with a seal portion that is excellent in sealing performance before use and ease of opening when opened. [Means for solving the problem]

[0007] A first aspect of the present invention is a individually packaged absorbent article comprising a packaging sheet and an absorbent article individually packaged by the packaging sheet, wherein the packaging sheet has a longitudinal direction and a transverse direction perpendicular to the longitudinal direction, the packaging sheet is folded in the longitudinal direction and the transverse edges are sealed to form a sealed portion, the sealed portion includes a plurality of joints spaced apart from each other, the sealed portion has an inner region, an intermediate region and an outer region in this order from the inside to the outside in the transverse direction, the bonding strength in the inner region is greater than the bonding strength in the intermediate region and the bonding strength in the outer region is greater than the bonding strength in the intermediate region.

[0008] In individually packaged absorbent articles in which the packaging sheet is folded vertically and then the horizontal edges are sealed, the position where the seal is most likely to start peeling is the inner side of the seal in the horizontal direction (closer to the horizontal center). Therefore, in the first embodiment described above, by making the bonding strength of the inner region of the seal greater than that of the intermediate region, the bonding at the position where the seal is likely to start peeling can be strengthened, and unintended opening before use can be prevented without increasing the bonding strength of the entire seal. In other words, the sealing performance can be improved. Furthermore, since the bonding strength in the intermediate region is less than that in the inner region, when the user intentionally opens the package at the start of use, if only the seal in the inner region is peeled off, the seal in the intermediate region that follows the inner region is easy to peel off, and the opening operation is smooth. In other words, ease of opening can be ensured. Moreover, in this embodiment, by making the bonding strength in the outer region greater than that in the intermediate region, unintended opening from the horizontal edge of the individually packaged absorbent article can also be prevented, which also contributes to improved sealing performance.

[0009] In a second aspect of the present invention, in the inner region, the ratio of the total length of the joint to the length of the seal on a straight line passing through the joint in the longitudinal direction is smaller than the ratio of the total length of the joint to the length of the seal on a straight line passing through the joint in the longitudinal direction in the intermediate region, and in the outer region, the ratio of the total length of the joint to the length of the seal on a straight line passing through the joint in the longitudinal direction is smaller than the ratio of the total length of the joint to the length of the seal on a straight line passing through the joint in the longitudinal direction in the intermediate region.

[0010] The seal portions at both edges can be formed, for example, in a manufacturing line, by a pair of rolls arranged so that their axes align with an orthogonal direction (the longitudinal direction of the individually packaged absorbent article) perpendicular to the product transport direction (the transverse direction of the individually packaged absorbent article). The pair of rolls may consist of a roll with a surface pattern of irregularities corresponding to the pattern of the joint, and an opposing roll. Therefore, at positions where the proportion of the total longitudinal length of the joint is large, the roll pressure is dispersed, the linear pressure (the force applied per unit length in the longitudinal direction when forming the seal portion) decreases, and the joint strength of the joint tends to decrease. On the other hand, at positions where the proportion of the total longitudinal length is small, the linear pressure increases, and the joint strength of the joint tends to increase.

[0011] According to the second embodiment described above, the bonding strength of the inner and outer regions is adjusted by adjusting the ratio of the sum of the longitudinal lengths of the joints in the inner and outer regions. This means that the bonding strength can be adjusted by the two-dimensional configuration (size, pitch, etc.) of the joint. Therefore, the bonding strength can be varied in each region within the seal without requiring complex modifications to the apparatus for forming the seal.

[0012] In a third aspect of the present invention, the vertical distance between the joints in the inner region is greater than the vertical distance between the joints in the intermediate region.

[0013] If the joints in the inner region are closely spaced in the vertical direction, when the packaging sheet is pulled during opening, the packaging sheet may tear along the vertically aligned joints at the inner edge of the sealed area. Therefore, by increasing the vertical spacing between the joints in the inner region according to the third embodiment described above, it is possible to prevent the packaging sheet from tearing along the joints as described above.

[0014] In a fourth aspect of the present invention, the area of ​​each joint decreases from the inside to the outside in the lateral direction.

[0015] According to the fourth embodiment described above, the rigidity of the lateral edge can be reduced as it extends outward in the lateral direction. Since the edges of the individually packaged absorbent article are more likely to come into contact with the user's hand as they extend outward in the lateral direction, reducing the rigidity of the part closer to the lateral outer direction effectively provides a softer feel to the user's hand holding the individually packaged absorbent article.

[0016] In a fifth aspect of the present invention, the inner contour of the sealing portion is wave-shaped.

[0017] According to the fifth embodiment described above, the linear pressure along the longitudinal direction (the force applied per unit length in the longitudinal direction when forming the seal portion) can be increased in the inner region. Furthermore, aesthetics and design can be improved.

[0018] In a sixth aspect of the present invention, the packaging sheet includes paper.

[0019] According to the sixth embodiment described above, it is possible to impart a unique, natural texture to the packaging sheet, reduce the amount of plastic material used, and contribute to reducing the burden on the natural environment when discarded. Furthermore, since paper is a material that does not easily increase the bonding strength of the seal portion by conventional methods, there is a possibility that the packaging sheet may break if the bonding strength is forcibly increased. Therefore, by adopting the configuration of the first embodiment described above, excellent sealing performance before use can be obtained even when the packaging sheet contains paper. [Effects of the Invention]

[0020] According to one aspect of the present invention, it is possible to provide individually packaged absorbent articles equipped with a seal portion that is excellent in sealing performance before use and ease of opening when opened. [Brief explanation of the drawing]

[0021] [Figure 1] This is a plan view of an individually packaged absorbent article according to the first embodiment of the present invention. [Figure 2] This is a plan view showing the individual absorbent article in Figure 1 before it is folded, or a plan view showing the individual absorbent article in Figure 1 unfolded. [Figure 3] It is a cross-sectional view taken along line I-I of FIG. 1. [Figure 4] It is a partially enlarged view of the seal portion of FIG. 1. [Figure 5] It is a plan view of the individually packaged absorbent article according to the second embodiment of the present invention. [Figure 6] It is a partially enlarged view of the seal portion of FIG. 5. [Figure 7] It is a view showing a modified example of the seal portion.

Mode for Carrying Out the Invention

[0022] Hereinafter, embodiments of the present invention will be described 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.

[0023] <First Embodiment> (Individually Packaged Absorbent Article) FIG. 1 shows a plan view of the individually packaged absorbent article 100. FIG. 2 shows a plan view of the absorbent article in a deployed state or before folding and the packaging sheet of the absorbent article shown in FIG. 1, and is a view seen from the inner surface of the packaging sheet 10 or from the body side of the absorbent article 1. Further, FIG. 3 shows a cross-sectional view taken along line I-I of FIG. 1.

[0024] As shown in FIGS. 1 to 3, the individually packaged absorbent article 100 according to the present embodiment includes a packaging sheet 10 and an absorbent article 1 individually packaged by the packaging sheet 10. As shown in FIG. 2, the packaging sheet 10 may have an elongated shape and has a longitudinal direction (longitudinal direction) D1 and a lateral direction (lateral direction) D2 orthogonal to the longitudinal direction. Further, the longitudinal direction D1 and the lateral direction D2 of the packaging sheet 10 respectively correspond to the longitudinal direction and the lateral direction of the absorbent article 1.

[0025] (Absorbent Article) In this embodiment, the absorbent article 1 packaged by the packaging sheet 10 may be a flat, elongated article designed to be worn facing the outlet for bodily fluids (menstrual blood, vaginal discharge, urine, etc.). Specific examples of the absorbent article 1 may include sanitary napkins, panty liners (discharge liners), and light incontinence pads. This specification will describe embodiments based on the example of sanitary napkins.

[0026] The absorbent article 1 may have, for example, a liquid-permeable top sheet 3, a liquid-impermeable back sheet (not shown), and an absorbent material 4 placed between the top sheet 3 and the back sheet, as shown in Figure 2.

[0027] As the backsheet, a sheet material having at least water-impermeable properties can be used, such as an olefin resin sheet made of polyethylene or polypropylene. Laminated nonwoven fabrics, such as polyethylene sheets laminated with nonwoven fabric, or laminated nonwoven fabric sheets with a waterproof film interposed to ensure substantially liquid impermeability can be used. Materials with moisture permeability may also be used.

[0028] As the top sheet 3, perforated or non-perforated nonwoven fabrics or porous plastic sheets are preferably used. As material fibers 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 cupro, and blends thereof, as well as natural fibers such as cotton can be used individually or in combination of two or more types.

[0029] The absorbent material 4 is not limited to any material that can absorb and retain bodily fluids, but it is preferable to include cotton-like pulp and a superabsorbent polymer. As the superabsorbent polymer, superabsorbent polymer granules (SAP), superabsorbent polymer fibers (SAF), and combinations thereof can be used. As the pulp, examples include cellulose fibers such as chemical pulp and dissolved pulp obtained from wood, and artificial cellulose fibers such as rayon and acetate.

[0030] The thickness of the absorbent material 4 may be 0.5 to 25 mm. The absorbent material 4 may also have a structure in which the area corresponding to the body fluid drainage port (body fluid drainage port corresponding area) and the area behind the body fluid drainage port corresponding area, facing the groove of the buttocks, are bulged. The absorbent material 4 has dimensions and shape that do not protrude from the top sheet 3 and the back sheet, and at the front and rear edges of the absorbent material, the outer edges of the back sheet and the top sheet 3 are joined by adhesive means such as hot melt adhesive, heat seal, or ultrasonic seal.

[0031] As shown in Figure 2, side sheets 7, 7 may be provided along the longitudinal direction D1 at both ends of the transverse direction D2 on the outer side of the absorbent 4. A water-repellent nonwoven fabric or a hydrophilic nonwoven fabric can be used as the side sheet 7.

[0032] In the examples shown in Figures 1 to 3, the absorbent article 1 is a so-called wingless type without wings, but it may also be configured as a winged article having wings extending to the sides. The wings may be formed by joining the side sheet and the back sheet.

[0033] Furthermore, the back sheet side of the absorbent article 1 (the side that does not come into contact with the skin, i.e., the side that faces the underwear when worn) may be provided with an adhesive portion to prevent the absorbent article 1 from shifting away from the underwear when attached to the underwear. The adhesive portion to prevent shifting may be formed in the shape of multiple strips extending in the vertical direction D1 or the horizontal direction D2.

[0034] The total length of absorbent article 1 can be 140 to 430 mm, and the width of absorbent article 1 (the width of the main body excluding the wings if it has wings) can be 40 to 130 mm.

[0035] (Packaging sheet) The materials that make up the packaging sheet 10 are not particularly limited, and paper, resin film, nonwoven fabric, etc., can be used.

[0036] The packaging sheet 10 containing paper has a low environmental impact when disposed of and is preferable from the standpoint of sustainable development goals. Furthermore, paper can impart a unique texture, such as the gentle appearance and feel of natural materials. In this specification, "paper" can refer to a flat sheet made by binding plant fibers or other fibers together with an adhesive. In particular, it can refer to paper primarily made from plant fibers (pulp), for example, paper in which plant fibers make up 50% or more of the fibers, preferably 80% or more. The type of pulp contained in the paper may include wood pulp, non-wood pulp, or recycled paper pulp, and these may be either mechanical pulp or chemical pulp. The pulp may be recycled pulp from absorbent articles and / or packaging sheets for absorbent articles. Additives may also be added to the paper. Furthermore, specific examples of paper used in the packaging sheet 10 include various types of paper such as Western paper, Japanese paper, processed paper, and synthetic paper. Furthermore, papers conventionally used for other purposes, such as newsprint, printing paper (including fine paper), writing paper, drawing paper, packaging paper, tissue paper, and miscellaneous paper, can be used either unprocessed or processed. When using tissue paper, thin imitation paper, Indian paper, rice paper, glassine paper, tissue paper, toilet paper, filter paper, etc., may also be used.

[0037] When a resin film is used as the material for the packaging sheet, even when printing is applied to the packaging sheet, the outlines of the printed characters and patterns become clearer, and the color development of the colorants is also improved, thus enhancing the design of the packaging sheet. Examples of resins that can be used include polyolefins such as polypropylene and polyethylene, polyester, and polyvinyl alcohol. Stretched resin films are preferred. Furthermore, the resin film may be either a non-permeable film or a permeable film.

[0038] When nonwoven fabric is used as the material for the packaging sheet 10, the texture, flexibility, etc., can be improved. Meltblown nonwoven fabric, spunbond nonwoven fabric, etc., are preferred as the nonwoven fabric used, and a combination of multiple layers of these nonwoven fabrics can also be used. Furthermore, the fibers constituting the nonwoven fabric may be polyolefins such as polypropylene and polyethylene, polyamides such as polyester and nylon, etc.

[0039] The packaging sheet 10 may be a single-layer sheet made of the above-mentioned materials, or it may be a laminated sheet made by laminating multiple layers made of different materials. For example, it may be a sheet made by laminating a resin film and paper.

[0040] The inner and / or outer surfaces of the packaging sheet 10 may be treated with a release agent. The release agent may be a liquid release agent (mold release agent) containing, for example, a silicone resin, paraffin resin, or fluororesin. For example, by treating the inner surface of the packaging sheet 10 with a release agent, the aforementioned adhesive portion for preventing slippage formed on the back of the absorbent article 1 can be brought into direct contact with the inner surface of the packaging sheet 10, thus eliminating the need to provide a separate release sheet between the absorbent article 1 and the packaging sheet 10.

[0041] The dimensions of the packaging sheet 10 depend on the size and shape of the absorbent article 1 to be packaged. For example, when the packaging sheet 10 is fully unfolded (not folded), the length in the vertical direction D1 (sometimes simply called the length) can be 100 to 450 mm, and the length in the horizontal direction D2 (sometimes simply called the width) can be 70 to 250 mm. In the illustrated example, the packaging sheet 10 has a rectangular shape when unfolded, but it may also have a shape such as an elongated ellipse.

[0042] (Packaging structure of individually packaged absorbent articles) In the individually packaged absorbent article 100, the absorbent article 1 is packaged by being folded together with the packaging sheet 10. When folding, as shown in Figure 2, the absorbent article 1 is placed on the inner surface of the packaging sheet 10 with the back sheet side of the absorbent article 1 facing the packaging sheet 10. Then, the packaging sheet 10 and the absorbent article 1 are folded together in the vertical direction D1 along the first fold line F1 and the second fold line F2 along the width direction D2. More specifically, at the first fold line F1, a first region R1 including one end 11 of the packaging sheet 10 in the vertical direction D1 is folded back in the vertical direction D1, and at the second fold line F2, a second region R2 including the other end 12 of the packaging sheet 10 in the vertical direction D1 is folded back. The region between the first region R1 and the second region R2 of the packaging sheet 10 is the third region R3. In the illustrated example, the packaging sheet 10 is folded so that the second region R2 is folded first, and the first region R1 overlaps the outer surface of the second region R2 (Figure 1), however, 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 thirds (inner thirds) together with the absorbent article 1 to wrap the absorbent article 1, and then both edges in the horizontal direction D2 are sealed along the vertical direction D1 (Figure 1).

[0043] Such a tri-fold or more packaging format can be formed relatively easily, allows for hygienic wrapping of the absorbent article 1, and also facilitates the removal of the absorbent article 1. The folding format is not limited to tri-folds; it can also be four-fold or more, or even bi-fold. In the case of a four-fold, the packaging sheet 10 should be folded along a third fold line that runs along the horizontal direction D2, located between the second fold line F2 and the other end 12, before folding the second region R2 along the second fold line F2.

[0044] Furthermore, the individually packaged absorbent article 100 may have a fastening tape 50 in the center of the lateral direction D2 near the edge of the first region R1 (one end 11 of the packaging sheet 10). As shown in Figure 1, the fastening tape 50 may be provided across the first region R1 and the second region R2, straddling one end 11 of the packaging sheet 10. The presence of the fastening tape 50 makes it easier to open the individually packaged absorbent article 100, as the user can lift and pull the first region R1 by holding the fastening tape 50. At that time, the first region R1 is peeled away from the second region R2 located below it.

[0045] (Seal part) As shown in Figure 1, in the individually packaged absorbent article 100, the areas on both edges in the lateral direction D2 where the absorbent article 1 is not present are sealed, forming sealed portions 20, 20. The sealed portions 20, 20 may be formed along the entire length of the individually packaged absorbent article 100 in the vertical direction D1, which is preferable because it prevents dirt, dust, or other small objects or fingers from entering from the lateral edges. However, the sealed portions 20, 20 do not have to be formed to the end of the vertical direction D1, and there may be portions that are interrupted in the middle of the vertical direction D1.

[0046] In the example shown in Figure 1, the width of the seal portion 20 is constant along the vertical direction D1, but it is not necessarily constant and may vary. The inner contour of the seal portion 20 in the horizontal direction D2 may have irregularities (as will be described in detail later), and the width of the seal portion 20 may increase gradually or stepwise towards either end in the vertical direction D1. The width of the seal portion 20 (length in the horizontal direction D2, or the average value if the width varies) may be between 3 and 15 mm.

[0047] Figure 4 shows an enlarged view of part II of the sealing portion 20. As shown in Figure 4, the sealing portion 20 may include a plurality of joints 30, 30, ... that are spaced apart from each other in a plan view. Each joint 30, 30, ... is a portion where the packaging sheets 10 are joined together in the thickness direction. In the illustrated example, the parts other than the plurality of joints 30, 30, ... are non-jointed portions where the packaging sheets 10 are not joined together. In this way, by having the joints 30, 30, ... spaced apart from each other and scattered, it is possible to prevent the packaging sheet from becoming difficult to peel off when opened, which could lead to damage to the packaging sheet, or the edges becoming excessively hard and impairing the feel, compared to when the joints are formed continuously over a wide area, for example, when the joints are formed over the entire surface of the sealing portion 20.

[0048] The means for forming the joints 30, 30, ... are not particularly limited, and any means that the stacked packaging sheets 10 are pressed and / or heated to form a joint between the packaging sheets 10 can be used, such as heat sealing, ultrasonic sealing, or mechanical compression. These means can be appropriately selected and used depending on the material of the packaging sheets 10. For example, if the packaging sheets 10 are made of a material containing resin film and / or resin fibers, it is preferable to form the joint by partially fusing the packaging sheets 10 by heat sealing or ultrasonic sealing. If the packaging sheets 10 contain paper, it is preferable to form the joint by a mechanical joining method such as compression. In that case, the seal portion 20 can be formed using, for example, a pair of rolls consisting of a roll having a surface with an uneven pattern corresponding to the pattern of the joints 30, 30, ... and a counter roll with a surface without unevenness facing the said roll. Adhesives and the like can also be used instead of or in addition to any of the above joining methods.

[0049] As shown in Figure 4, the seal portion 20 has an inner region 21, an intermediate region 22, and an outer region 23, extending from the inside to the outside in the lateral direction D2. These regions 21, 22, and 23 each contain a plurality of joint portions 30, 30, ... that are spaced apart from each other. The inner region 21 includes inner joint portions 31, 31, ..., the intermediate region 22 includes intermediate joint portions 32, 32, ..., and the outer region 23 includes outer joint portions 33, 33, .... In this embodiment, the joint strength in the inner region 21 is greater than the joint strength in the intermediate region 22, and the joint strength in the outer region 23 is greater than the joint strength in the intermediate region 22. The joint strength of each region can be obtained by cutting out each region and measuring it using a tensile testing machine.

[0050] In the individually packaged absorbent article 100 having the packaging structure described above, the position where the seal portion 20 is likely to peel off, or where the seal portion 20 begins to peel off, is on the inside of the seal portion 20 in the lateral direction D2 (closer to the lateral center). For example, it is the edge of the first region R1 of the packaging sheet 10, that is, the edge of the seal portion 20 at one end 11 of the packaging sheet 10, close to the center in the lateral direction D2. Therefore, by making the bonding strength of the inner region 21 of the seal portion 20 greater than the bonding strength of the intermediate region 22, the bonding at the position where the seal portion 20 is likely to begin to peel off can be strengthened. This prevents unintended opening before use without increasing the overall bonding strength of the seal portion 20. In other words, the sealing performance can be improved. Furthermore, since the bonding strength in the intermediate region 22 is lower than that in the inner region 21, when a user intentionally opens the individually packaged absorbent article 100 at the start of use, simply peeling off the seal in the inner region 21 makes it easy to peel off the seal in the intermediate region 22 that extends laterally D2 to the inner region 21, resulting in a smooth opening operation. In other words, ease of opening is ensured. In this way, this embodiment provides a seal portion that has both sealing properties and ease of opening.

[0051] Furthermore, in this embodiment, the bonding strength in the outer region 23 is greater than the bonding strength in the intermediate region 22, thus preventing unintended opening from the lateral D2 edge of the individually packaged absorbent article 100. When the seal portion 20 is composed of multiple bonded portions 30, 30, ... that are spaced apart from each other, there are also unbonded portions at the lateral D2 edge of the packaging sheet 10. The packaging sheet 10 may peel off unintentionally from such unbonded portions (non-bonded portions), so this embodiment prevents peeling from such lateral D2 edges. Therefore, the overall sealing performance of the seal portion 20 can be improved.

[0052] The method for adjusting the bonding strength by region within the seal portion 20 is not particularly limited, but it can be adjusted by drawing a straight line (imaginary line) through the joint portions 30, 30, ... in the vertical direction D1 within each region, and then adjusting the bonding strength by the ratio of the total length of the joint portions 30, 30, ... in the vertical direction D1 to the length of the seal portion 20 in the vertical direction D1 (referred to as the longitudinal joint presence rate in this specification).

[0053] Here, we will briefly explain the relationship between the prevalence of the longitudinal joints and the joint strength. The seal portion 20 can be formed, for example, in a manufacturing line, using a pair of rolls arranged so that their axes are aligned in an orthogonal direction (longitudinal direction D1 of the individually packaged absorbent article 100) perpendicular to the product transport direction (lateral direction D2 of the individually packaged absorbent article 100). The pair of rolls may consist of a roll with a surface pattern of irregularities corresponding to the patterns of the joints 30, 30, ... and an opposing roll. Therefore, at positions where the proportion of the total longitudinal D1 length of the joints 30, 30, ... is large, the roll pressure is dispersed, the linear pressure (force applied per unit length in the longitudinal direction when forming the seal portion) becomes smaller, and the joint strength of the joints 30, 30, ... and consequently the seal portion 20 tends to decrease. On the other hand, at positions where the proportion of the total longitudinal length is small, the linear pressure increases, and the joint strength of the joints 30, 30, ... and consequently the seal portion 20 tends to increase.

[0054] Adjusting the joint strength by the proportion of joints in the longitudinal direction means adjusting the joint strength by the two-dimensional configuration (size, pitch, etc.) of the joints 30, 30,.... Therefore, the joint strength can be changed for each region within the seal portion 20 without requiring complex modifications to the apparatus for forming the seal portion 20, for example, without changing the roll pressure in the lateral direction D2 or changing the height of the uneven pattern on the roll surface.

[0055] In this embodiment, the bonding strength of the inner region 21 is increased by making the proportion of longitudinal joints in the inner region 21 smaller than the proportion of longitudinal joints in the intermediate region 22. In the example in Figure 4, the ratio of the total length in the longitudinal D1 of the inner joints 31, 31, ... to the length in the longitudinal D1 of the seal portion 20 on a straight line Y1 passing through the inner joints 31, 31, ... in the inner region 21 is smaller than the ratio of the total length in the longitudinal D1 of the intermediate joints 32, 32, ... to the length in the longitudinal D1 of the seal portion 20 on a straight line Y2 passing through the intermediate joints 32, 32, ... in the intermediate region 22.

[0056] Furthermore, in this embodiment, the bonding strength of the outer region 23 is increased because the proportion of longitudinal joints in the outer region 23 is smaller than that of the intermediate region 22. In the example in Figure 4, the ratio of the total length of the outer joints 33, 33, ... in the vertical direction D1 to the length of the seal portion 20 on a straight line Y3 passing through the outer joints 33, 33, ... in the vertical direction D1 in the outer region 23 is smaller than the ratio of the total length of the intermediate joints 32, 32, ... in the intermediate region 22 to the length of the seal portion 20 on a straight line Y2 passing through the intermediate joints 32, 32, ... in the vertical direction D1 in the intermediate region 22.

[0057] Preferably, the inner region 21 has a longitudinal joint presence rate of 5-50%, the intermediate region 22 has a longitudinal joint presence rate of 30-70%, and the outer region 23 has a longitudinal joint presence rate of 5-50%.

[0058] As shown in Figure 4, the vertical distance D1 between the inner joints 31, 31, ... included in the inner region 21 is greater than the vertical distance D1 between the intermediate joints 32, 32, ... included in the intermediate region 22. This further improves the joint strength in the inner region 21. In other words, the improvement in joint strength in the inner region 21 is achieved by increasing the vertical distance D1 between the inner joints 31, 31, ...

[0059] Furthermore, if the inner joints 31, 31, ... of the inner region 21 are densely packed in the vertical direction D1, depending on the material of the packaging sheet 10, when the packaging sheet 10 is pulled during opening, the packaging sheet 10 may tear along the inner edges of the inner joints 31, 31, .... In contrast, as described above, by increasing the distance between the inner joints 31, 31, ... included in the inner region 21 in the vertical direction D1, such tearing of the packaging sheet 10 can be prevented.

[0060] The vertical spacing d1 (Figure 4) between the inner joints 31, 31, ... may be preferably 0.75 to 3.0 mm, more preferably 1.0 to 2.0 mm. The vertical spacing d2 (Figure 4) between the intermediate joints 32, 32, ... may be preferably 0.2 to 1.5 mm, more preferably 0.5 to 1.0 mm.

[0061] As shown in Figure 4, when looking at the entire sealing portion 20, the area per joint 30, 30, ... may decrease gradually or sequentially from the inside to the outside. In the example shown in Figure 4, the area per joint of the inner joint 31, the intermediate joint 32, and the outer joint 33 decreases in this order. This makes it possible to reduce the rigidity of the edge as it moves outward in the lateral direction D2. Since the edge of the individually packaged absorbent article 100 is more likely to be touched by the user's hand as it moves outward in the lateral direction D2, reducing the rigidity of the part closer to the outside in the lateral direction D2 reduces the discomfort the user feels when holding the individually packaged absorbent article 100 and provides a softer feel.

[0062] Preferably, the area of ​​each outer joint 33, 33, ... in the outer region 23 is smaller than the area of ​​each intermediate joint 32, 32, ... in the intermediate region 22. This further improves the joint strength in the outer region 23. Alternatively, the improvement in joint strength in the outer region 23 is achieved by reducing the area of ​​each outer joint 33, 33, ...

[0063] Furthermore, by reducing the area of ​​each of the outer joints 33, 33, ..., the rigidity of the outer region 23 can be lowered. The outer region 23 is located at the end of the lateral direction D2 within the seal portion 20 and is an area that is easily touched by the hand. Therefore, by lowering the rigidity of the outer region 23, it is possible to reduce the discomfort felt by the outer region 23, which is easily touched by the hand when the user holds the individually packaged absorbent article 100, and to provide a soft tactile feel. In addition, by lowering the rigidity of the outer region 23, which is susceptible to external forces, the outer region 23 can deform flexibly against external forces, and it is possible to prevent the packaging sheet 10, which was joined together, from peeling off when the user holds it or when the individually packaged absorbent article 100 is packed into the package.

[0064] Furthermore, as shown in Figure 4, it is preferable that the area per unit of the inner joints 31, 31, ... in the inner region 21 is larger than the area per unit of the intermediate joints 32, 32, ... in the intermediate region 22. A larger area per unit of the inner joints 31 makes the area where the seal portion 20 is provided more visible, giving the user a sense of security that the individually packaged absorbent article is securely sealed. Moreover, a larger area per unit of the inner joints 31, especially a larger area for the innermost inner joints 31 located in the lateral direction D2, results in a larger area of ​​the joint that is released first in the lateral direction D2 when peeling off the packaging sheet 10 of the seal portion 20 during opening. This helps to suppress small fluctuations in the peeling resistance for peeling off the packaging sheet 10, resulting in a smoother opening operation.

[0065] The area of ​​the largest joint 30 within the seal portion 20 may be equivalent to a square with sides of 0.75 to 2.0 mm. In the example shown in Figure 4, the joint 30 with the largest area is the inner joint 31 in the inner region 21. The area of ​​the smallest joint 30 within the seal portion 20 may be equivalent to a square with sides of 0.25 to 0.75 mm. In the example shown in Figure 4, the joint 30 with the largest area is the inner joint 33 in the outer region 23.

[0066] In the example shown in Figure 4, each of the inner region 21, intermediate region 22, and outer region 23 contains two rows of joints 30, 30, ... arranged in the vertical direction D1. However, the number of rows of joints is not limited to two rows per region; it may be one row or three or more rows. Furthermore, the joints 30, 30, ... do not necessarily form rows in the vertical direction D1 or the horizontal direction D2, but may be randomly scattered.

[0067] The plan view shape of each joint 30, 30, ... is not limited to a square as shown in Figure 4, but may be a quadrilateral other than a square, a polygon other than a quadrilateral, or a circle, ellipse, heart shape, star shape, teardrop shape, etc.

[0068] <Second Embodiment> Figure 5 shows an individually packaged absorbent article 200 according to a second embodiment of the present invention. The basic structure of the individually packaged absorbent article 200 is the same as that of the individually packaged absorbent article 100 according to the first embodiment, but the individually packaged absorbent article 200 differs from the individually packaged absorbent article 100 in that the structure of the sealing portion is different.

[0069] In the individually packaged absorbent article 200, after the packaging sheet 10 is folded in the vertical direction D1, seal portions 220, 220 are formed on both edges in the horizontal direction D2. However, as shown in Figure 1, the inner contour of the seal portion 220 is not straight but wavy. Figure 6 shows an enlarged view of part III, which includes a portion of the seal portion 220 in the individually packaged absorbent article 200.

[0070] As shown in Figure 6, the sealing portion 220 may also include a plurality of joint portions 30, 30, ... that are spaced apart from each other in a plan view. In this embodiment, the joint portions 30, 30, ... are circular in a plan view.

[0071] The inner contour EL of the individually packaged absorbent article 200 may be a contour obtained by connecting the inner edges in the lateral direction D2 of the joints 30, 30, ... (and the inner joints 31, 31, ... located in the lateral direction D2) that are located furthest inward in the lateral direction D2. The inner contour EL may have a shape in which the convex portion 28 and the concave portion 29 are continuous in the vertical direction D1. Here, the distance h in the lateral direction D2 between the vertex of the convex portion 28 and the bottom point of the concave portion 29 of the inner contour EL may be 0.75 to 3 mm.

[0072] The seal portion 220 may also have an inner region 221, an intermediate region 222, and an outer region 223, extending from the inside to the outside in the lateral direction D2. The inner region 221 may include inner joints 31, 31, ..., the intermediate region 222 may include intermediate joints 32, 32, ..., and the outer region 223 may include outer joints 33, 33, .... In this embodiment as well, the bonding strength in the inner region 221 is greater than the bonding strength in the intermediate region 222, and the bonding strength in the outer region 223 is greater than the bonding strength in the intermediate region 222, thus obtaining the same effects as described in the first embodiment.

[0073] In this embodiment, because the inner contour EL of the seal portion 220 is wave-shaped, the proportion of longitudinal joints in the inner region 221 is reduced. That is, when a straight line is drawn through the joints 30, 30, ... in the longitudinal direction D1, the ratio of the sum of the longitudinal D1 lengths of the joints 30, 30, ... to the longitudinal D1 length of the seal portion 220 along that line is reduced. This allows for a higher linear pressure when forming the inner region 21, and thus increases the bonding strength in the inner region 21. More specifically, the joints 30, 30, ... (inner joints 31, 31, ...) in the region near the convex portion 28 of the inner contour EL can be pressed with high pressure, thereby increasing the bonding strength. In other words, in the example shown in Figure 6, the inner joints 31, 31, ... are arranged in the inner region 21 such that the parts with high bonding strength appear intermittently in the longitudinal direction D1.

[0074] Furthermore, in this embodiment as well, the prevalence of longitudinal joints in the outer region 223 is smaller than the prevalence of longitudinal joints in the intermediate region 222. More specifically, in the outer region 223, the ratio of the total length in the longitudinal D1 of the outer joints 33, 33, ... to the length in the longitudinal D1 of the seal portion 220 along a straight line passing through the outer joints 33, 33, ... may be smaller than the ratio of the total length in the longitudinal D1 of the intermediate joints 32, 32, ... to the length in the longitudinal D1 of the seal portion 220 along a straight line passing through the intermediate joints 32, 32, ... in the intermediate region 222. And in this embodiment as well, the reduction in the prevalence of longitudinal joints in the outer region 223 is achieved by making the area per unit of the outer joints 33, 33, ... in the outer region 223 smaller than the area per unit of the intermediate joints 32, 32, ... in the intermediate region 222.

[0075] Furthermore, the wavy shape of the inner contour of the sealing portion 220 improves the design of the sealing portion 220 and enhances the aesthetic appeal of the individually packaged absorbent articles 200.

[0076] Figure 7 shows a modified example of the seal portion 220 of the individually packaged absorbent article 200 according to the second embodiment. In the example shown in Figure 7, the inner contour EL of the seal portion 220 can be described as wave-shaped, but there is only one joint portion 30 located at the apex of the convex portion 28 of the inner contour EL shown in Figure 7, and only one joint portion 30 located at the bottom of the concave portion 29. The inner contour EL shown in Figure 7 can be described as zigzag-shaped. Thus, the inner contour EL of the seal portion 220 may be curved, straight, or include both, as long as it has an uneven shape. This makes it possible to reduce the proportion of longitudinal joints in the inner region 221 and increase the bonding strength in the inner region 221.

[0077] Although the present invention has been described above based on embodiments, the present invention is not limited to these embodiments. The above embodiments can be modified, altered, replaced, added, deleted, and combined in various ways within the scope of the claims, and these also fall within the technical scope of the present invention. Furthermore, the above-mentioned components can be combined in any way. [Explanation of Symbols]

[0078] 1. Absorbent articles 3 Top Sheet 4 Absorbent 7 Side Seats 10 Packaging Sheets 11 One end in the vertical direction 12 The other end in the vertical direction 20, 220 sealing part 21, 221 inner region 22, 222 intermediate area 23, 223 outer area 28. Protrusions on the inner contour of the seal portion 29 Recess in the inner contour of the sealing portion 30 Joint 31 Inner joint 32 Intermediate joint 33 Outer joint 50 Fastening Tapes 100, 200 individually packaged absorbent articles D1 Longitudinal direction of the packaging sheet D2 Transverse direction of the packaging sheet EL seal inner contour F1 First fold line F2 Second fold line R1 1st area R2 2nd area R3 3rd area

Claims

1. An individually packaged absorbent article comprising a packaging sheet and an absorbent article individually packaged by the packaging sheet, The packaging sheet has a vertical direction and a horizontal direction perpendicular to the vertical direction, The packaging sheet is folded in the vertical direction, and the horizontal edges are sealed to form a sealed portion, and the sealed portion includes a plurality of joints spaced apart from each other. The sealing portion has an inner region, an intermediate region, and an outer region in this order from the inside to the outside in the lateral direction. The bonding strength in the inner region is greater than the bonding strength in the intermediate region. The bonding strength in the outer region is greater than the bonding strength in the intermediate region. Individually packaged absorbent article, wherein the vertical spacing between the joints in the inner region is greater than the vertical spacing between the joints in the intermediate region.

2. An individually packaged absorbent article comprising a packaging sheet and an absorbent article individually packaged by the packaging sheet, The packaging sheet has a vertical direction and a horizontal direction perpendicular to the vertical direction, The packaging sheet is folded in the vertical direction, and the horizontal edges are sealed to form a sealed portion, and the sealed portion includes a plurality of joints spaced apart from each other. The sealing portion has an inner region, an intermediate region, and an outer region in this order from the inside to the outside in the lateral direction. The bonding strength in the inner region is greater than the bonding strength in the intermediate region. The bonding strength in the outer region is greater than the bonding strength in the intermediate region. Individually packaged absorbent articles, wherein the area of ​​each joint decreases from the inside to the outside in the lateral direction.

3. An individually packaged absorbent article comprising a packaging sheet and an absorbent article individually packaged by the packaging sheet, The packaging sheet has a vertical direction and a horizontal direction perpendicular to the vertical direction, The packaging sheet is folded in the vertical direction, and the horizontal edges are sealed to form a sealed portion, and the sealed portion includes a plurality of joints spaced apart from each other. The sealing portion has an inner region, an intermediate region, and an outer region in this order from the inside to the outside in the lateral direction. The bonding strength in the inner region is greater than the bonding strength in the intermediate region. The bonding strength in the outer region is greater than the bonding strength in the intermediate region. Individually packaged absorbent articles, wherein the inner contour of the sealing portion is wavy.

4. In the inner region, the ratio of the total length of the joint portion to the total length of the seal portion on a straight line passing through the joint portion in the longitudinal direction is smaller than the ratio of the total length of the joint portion to the total length of the seal portion on a straight line passing through the joint portion in the longitudinal direction in the intermediate region. The individually packaged absorbent article according to any one of claims 1 to 3, wherein in the outer region, the ratio of the total length of the joint to the length of the seal on a straight line passing through the joint in the longitudinal direction is smaller than the ratio of the total length of the joint to the length of the seal on a straight line passing through the joint in the longitudinal direction in the intermediate region.

5. The individually packaged absorbent article according to any one of claims 1 to 3, wherein the packaging sheet includes paper.

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