Packaging bags and packaging

Abstract

To provide a packaging bag 1 that achieves both recyclability and sealability.SOLUTION: A packaging bag 1 of the present invention is formed into a bag shape by folding back a belt-like paper base material 2 along a longitudinal direction and sealing the folded back paper base materials 2 and 2 together. The paper base material 2 includes three layers of a base paper layer 3 made of paper, an outer adhesive layer 4 coated on an outer side of the base paper layer 3, and an inner adhesive layer 6 coated on an inner side of the base paper layer 3. The outer adhesive layer 4 and the inner adhesive layer 6 are formed of a heat-sealable heat-sealing adhesive coated on a surface of the base paper layer 3. One of bag-making seal parts 19 that seal the paper base materials 2 and 2 together during bag making has a multiple-seal structure 14 that is heat-sealed in a state in which four or more sheets are laminated so that two or more layers of the outer adhesive layer 4 and the inner adhesive layer 6, the outer adhesive layers 4 and 4, or the inner adhesive layers 6 and 6 are in contact with each other in a plane state.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a packaging bag and a package used for packaging an item such as a diaper. [Background technology]

[0002] Conventionally, packaging materials made of films (synthetic resin films) have been used for packaging bags for packaging sanitary products (body fluid absorbent articles) such as diapers and napkins. For example, Patent Document 1 discloses a packaging body in which contents are contained inside a bag-shaped film body that is open at one end, the packaging body having an end face including a sealed portion to which the one end of the film body is welded, and a first surface and a second surface that sandwich the sealed portion, the first surface and the second surface each having an identifiable mark portion, the first surface and the second surface being located on opposite sides of each other in the packaging body before the contents are contained, the mark portion on the first surface and the mark portion on the second surface have a relationship in which, when the mark portion on the first surface is projected onto the second surface in the packaging body before the contents are contained, at least a portion of the mark portion on the first surface and at least a portion of the mark portion on the second surface overlap each other, and the mark portions are provided in positions in the film body that will appear on the first surface and the second surface when the contents are contained in the film body and the seal portion is formed.

[0003] Patent Document 2 also describes a package for packaging a plurality of absorbent articles in a folded state, the package comprising a bag portion formed of a film-like packaging material and configured to enclose the plurality of absorbent articles, the absorbent articles enclosed in the bag portion in a folded state having a product longitudinal direction, a product width direction and a product thickness direction which are mutually perpendicular, the bag portion having a vertical direction, a horizontal direction and a thickness direction which are mutually perpendicular, the bag portion having a bottom surface formed at at least one end in the vertical direction, and side surfaces formed at both ends in the horizontal direction, The package disclosed has a bottom surface having a fixing region where the packaging materials are fixed to each other, which is formed along the left-right direction, and on at least one of the side surfaces, a skirt portion where the packaging materials are fixed to each other and extending in the left-right direction is formed in a ring shape along the outer edge of the side surface, and the plurality of absorbent articles are contained within the bag portion with the product thickness direction of each of the absorbent articles aligned with the thickness direction and the product longitudinal direction or the product width direction of each of the absorbent articles aligned with the left-right direction. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6859904 [Patent Document 2] JP 2015-71427 A Summary of the Invention [Problem to be solved by the invention]

[0005] When considering the provision of packaging materials with an awareness of the recent SDGs (an abbreviation for Sustainable Development Goals, a set of 17 goals adopted at the UN Summit in September 2015 by the 193 member states of the United Nations to achieve over the 15 years from 2016; in this specification, it particularly refers to measures related to the 14th goal, "Conserve and sustainably use the oceans and their marine life"), there is a demand to reduce the use of film, which is a cause of marine plastic problems, and instead, paper, a biodegradable material, is attracting attention.

[0006] Therefore, it is preferable to form a packaging bag whose main material does not include a film, in other words, whose main material is only paper. When forming a packaging bag whose main material is only paper, it is necessary to seal a sheet-like paper base material to form a bag. In such a case, the seal strength and productivity of the paper base material become particularly problematic. In other words, packaging bags made of paper alone do not have a laminated film, so they cannot be glued as is. One possible solution is to apply glue to the paper and then seal it. However, when using a typical vinyl acetate glue, the glue will adhere to the paper after application. Since the bags had to be attached within a set time, the adhesive had to be applied separately when making the bags and when packaging the bags, resulting in poor productivity.

[0007] In addition, some types of adhesives can be a hindrance when recycling paper, because when recycling is taken into consideration, it is necessary to use adhesives that can be peeled off from the paper during processes such as deinking in paper recycling, in other words, adhesives that have releasability during processes such as deinking. On the other hand, when packaging diapers and other packaged items, the diapers and other packaged items are packed in a compressed state, and a large repulsive force is applied to the packaging material as the compressed package tries to expand. If the adhesive strength is insufficient, the repulsive force of the packaged item may be overcome, and the sealed part may be opened at an undesired time (for example, opening during transportation or sales when the user does not want the box to be opened after it has been sealed; the same applies below).

[0008] In other words, in order to realize a packaging bag that has good recyclability and productivity using only paper without any film, it is essential to use an adhesive with heat-sealing properties and to provide some means to compensate for the seal strength, which tends to decrease. The present invention has been made in consideration of the above-mentioned problems, and aims to provide a packaging bag and a packaging body that do not contain a film, yet are capable of preventing undesired opening (peeling), and that can satisfy all of the requirements for productivity, recyclability, and sealability. [Means for solving the problem]

[0009] In order to solve the above problems, the packaging bag and packaging body of the present invention employ the following technical measures. That is, the packaging bag of the present invention is a packaging bag that is made into a bag shape by folding back a strip-shaped paper base material along the longitudinal direction and sealing the folded back paper base material together, and the paper base material has three layers: a base paper layer formed of paper, an outer adhesive layer coated on the outside of the base paper layer, and an inner adhesive layer coated on the inside of the base paper layer, and the outer adhesive layer and The above The inner adhesive layer is formed of a heat-sealable adhesive coated on the surface of the base paper layer, and one of the bag-making seal parts that seal the paper base materials together when making a bag is , etc. Side adhesive layers and the above Inner adhesive layers but It is characterized by having a multiple seal structure in which four or more sheets of the paper base material are stacked and heat-sealed so that they are in surface contact with each other.

[0010] Preferably, the paper base material has a tensile elongation at break of 3% or more. Preferably, the heat seal adhesive used is a dispersion type or emulsion type heat seal adhesive that can be easily separated from the paper substrate during the recycling process. Preferably, the packaging bag has a water-repellent layer on the outermost layer of the paper base material that faces outward when the bag is made.

[0011] The packaging body of the present invention is a packaging body including a packaging bag formed into a bag shape by folding a strip-shaped paper base material along the longitudinal direction and sealing the folded-over paper base material together, and an item to be packaged contained in the packaging bag, in which the packaging bag is capable of being filled with the item to be packaged in a state in which the packaging bag is deformed from the bag shape after the bag formation into a closed rectangular tubular shape having front, rear, left and right sides, a top and a bottom, and the paper base material includes three layers: a base paper layer formed of paper, an outer adhesive layer coated on the outside of the base paper layer, and an inner adhesive layer coated on the inside of the base paper layer, and the outer adhesive layer and The above The inner adhesive layer is formed by coating a heat-sealable adhesive on the surface of the base paper layer, and the inner adhesive layer is applied to a packaged body obtained by sealing the packaging bag filled with the packaged item. The above Any of all the seals provided on the packaging The above The seal portion is formed by bonding the outer adhesive layers together. and the above Inner adhesive layers but The paper base material has a multi-seal structure in which four or more sheets are stacked and heat-sealed so that they come into surface contact with each other.

[0012] Preferably, the packaging bag has a product insertion portion for allowing the packaged item to be inserted at least in one of the front, rear, left and right sides, the top portion and the bottom portion, and the product insertion portion is The bag can be sealed by the heat seal after the packaged item is inserted, and it is preferable that either the bag making seal section, which seals the paper base materials together when making the bag, or the bag sealing section, which seals the product insertion section when sealing the bag, is equipped with the multiple seal structure.

[0013] Preferably, the box seal portion has at least the multiple seal structure. Effect of the Invention

[0014] The packaging bag and packaging body of the present invention, while not including a film, can prevent undesired opening (peeling), and can satisfy all of the requirements for productivity, recyclability, and sealability. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2(a) is a perspective view showing a packaging bag of a first embodiment, and FIG. 2(b) is a cross-sectional view taken along line AA of FIG. [Diagram 2] FIG. 2(a) is a development view of the front side of the paper base material of the first embodiment, and FIG. 2(b) is a development view of the back side. [Diagram 3] FIG. 2 is a schematic diagram showing a procedure for producing the packaging bag of the first embodiment. [Figure 4] 1. (a) shows the layer structure of the paper base material in part B of FIG. 1, (b) shows the layer structure of the paper base material in part C, and (c) shows the laminated state of the paper base material in part D. [Diagram 5] 2 is a perspective view of the packaging body of the first embodiment and an enlarged view of part D. FIG. [Figure 6] 3A to 3C are schematic diagrams illustrating a filling procedure for the packaging body of the first embodiment. [Figure 7] FIG. 10(a) is a diagram showing another embodiment of the second seal portion (top surface 45° seal), and FIG. 10(b) is a diagram showing another embodiment of the end cut. [Figure 8] FIG. 10(a) is a perspective view showing a packaging bag of a second embodiment, and (b) is a cross-sectional view taken along line EE of (a). [Figure 9] FIG. 13(a) is a development view of the front side of the paper base material of the second embodiment, and (b) is a development view of the back side. [Figure 10] 5A to 5C are schematic diagrams illustrating a procedure for producing a packaging bag according to a second embodiment. [Figure 11] 8(a) is a diagram showing the laminated state of the paper base material in part H of FIG. 8(a). [Figure 12] 13 is a perspective view of a packaging body according to a second embodiment and an enlarged view of a portion H. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] [First embodiment] Hereinafter, an embodiment of the packaging bag 1 of the present invention will be described in detail with reference to the drawings. Fig. 1(a) is a perspective view that shows a schematic view of a packaging bag 1 of a first embodiment, and is a perspective view that shows the appearance of the packaging bag 1 in a state before packaging an item to be packaged P. Also, Fig. 1(b) is a cross-sectional view of the packaging bag 1 of the first embodiment cut along the longitudinal direction (height direction).

[0017] In the following explanation, the state before the packaged item P is packaged, in other words, the bag alone, will be referred to as the "packaging bag 1," and the state after the packaged item P is packaged, in other words, the packaging bag 1 filled with the packaged item P and sealed, will be referred to as the "packaging body 17." As shown in Figures 1 and 2, the packaging bag 1 of the first embodiment is a packaging member for packaging multiple sheets (pieces) of body fluid absorbent articles such as diapers as packaged items P, and is formed into a flat folded bag shape by bonding together paper base material 2, which has excellent recyclability (compared to plastic, etc.).

[0018] When the packaging bag 1 of the first embodiment is filled with the packaged items P, it is deformed into a covered rectangular tubular shape described below, and filled in a position in which the product insertion section 16 shown in Fig. 1(a) is open downward (as shown in Fig. 6(a)). Hereinafter, the position in which the product insertion section 16 faces downward is used as a reference, and the top, bottom, left, right, front and back of the packaging body 17 in this position will be referred to as top, bottom, left, right, front and back when describing the configuration of the packaging bag 1 and the packaging body 17. These directions are shown in Fig. 5.

[0019] Specifically, the packaged item P to be packaged in the packaging bag 1 of the first embodiment can be a bodily fluid absorbent article (sanitary product) such as a diaper, sanitary product, pet sheet, or nursing sheet. Although the packaging bag 1 of the first embodiment uses a bodily fluid absorbent article as the packaged item P, the packaging bag 1 of the present invention can also package articles other than bodily fluid absorbent articles, such as food, clothing, and daily necessities, as the packaged item P. Furthermore, the packaging bag 1 of the present invention is particularly suitable for packaging a packaged item P that is filled in a compressed state.

[0020] The packaging bag 1 of the first embodiment is formed into a flat folded bag shape as described above by folding a strip-shaped paper base material 2 along the longitudinal direction and sealing the ends of the folded paper base material 2 to form a bag. Next, the layer structure of the paper base material 2 that constitutes the packaging bag 1 will be described. As shown in Figure 4(a), the paper base material 2 has three layers: a base paper layer 3 made of paper, an outer adhesive layer 4 coated on the outer side of the base paper layer 3 (representing the surface that faces the outer side of the bag after the bag is made, the same applies below), and an inner adhesive layer 6 coated on the inner side of the base paper layer 3 (representing the surface that faces the inner side of the bag after the bag is made, the same applies below).

[0021] The base paper layer 3 is a paper material that is the main material that constitutes the paper base material 2, and in order to achieve both shape retention during packaging and processability during bag making and packaging, the tensile breaking elongation of the paper base material 2 is desirably 3% or more. The tensile breaking elongation is a value measured based on JIS P8113, and specifically, the tensile breaking elongation includes elongation along the papermaking direction (MD direction, longitudinal direction) of the papermaking machine and elongation along the direction perpendicular to the papermaking direction (CD direction, transverse direction), and it is preferable that the paper base material 2 of this embodiment has elongation in both directions of 3% or more, preferably 5% or more. In addition, it is desirably configured so that the direction in which the restoring force of the compressed and filled packaged item is strong (the left-right direction in FIG. 5) is the CD direction.

[0022] Such a base paper layer 3 preferably has a basis weight of 30 to 150 g / m 2 , more preferably 50 to 100 g / m 2 For the base paper layer 3, unbleached paper with excellent strength, such as heavy duty sack kraft paper or semi-bleached kraft paper, or bleached kraft paper with excellent printability, can be used. In addition, paper that has been processed or treated to give it extensibility can be used. The above-mentioned outer adhesive layer 4 and inner adhesive layer 6 can use the following heat seal adhesives. The type of heat seal adhesive used for the outer adhesive layer 4 and the type of heat seal adhesive used for the inner adhesive layer 6 may be the same or different. The thickness of the outer adhesive layer 4 and the thickness of the inner adhesive layer 6 may be the same or different.

[0023] The above-mentioned heat seal adhesives may be dispersion type adhesives in which a binder such as synthetic resin is dissolved or dispersed in a dispersion medium, or emulsion type adhesives in which a binder such as synthetic resin is emulsified and dispersed in a dispersion medium. Examples of dispersion media include water and organic solvents, which may be used alone or in combination of two or more. These adhesives dry and solidify as the dispersion medium such as water or solvent evaporates, and are then coated (applied) on the surface of the paper substrate 2. When sealing, heat is applied to the solidified solids, causing the binder synthetic resin to soften and melt, and the softened and melted synthetic resin is cooled and solidified, enabling sealing (adhesion).

[0024] Emulsion-type heat seal adhesives can be EVA (ethylene vinyl acetate copolymer resin)-based adhesives or acrylic-based adhesives. Dispersion-type adhesives can be urethane-based adhesives. When considering environmental impact and recyclability, it is desirable for the solvents of these adhesives to be water-based. These adhesives can also demonstrate good adhesive strength when used to adhere paper, and can be coated using a coater using a gravure roll, which will be described later.

[0025] The outer adhesive layer 4 is coated on the outer surface of the base paper layer 3 using a gravure coater or a roll coater. The coating weight of the outer adhesive layer 4 is, for example, 1.5 g / m2 (DRY). 2 ~15g / m 2 From the viewpoint of providing sealing strength and blocking resistance, it is recommended to use a dry 7g / m 2 ~15g / m2 The coating weight of the outer adhesive layer 4 may be less than the coating weight of the inner adhesive layer 6.

[0026] Similarly to the outer adhesive layer 4, the inner adhesive layer 6 is also coated on the inner surface of the base paper layer 3 using a gravure coater or roll coater. The coating weight of the inner adhesive layer 6 is, for example, 1.5 g / m2 (DRY). 2 ~15g / m 2 The inner adhesive layers 6, 6 are in surface contact with each other. In the case where the layer structure includes the inner adhesive layer 6, the coating weight of the inner adhesive layer 6 is set to DRY 7 g / m 2 ~15g / m 2 This makes it possible to exhibit excellent blocking resistance and to prevent peeling of the seal portion 8 even when packaging a compressed packaged item P, such as a diaper.

[0027] As shown in FIG. 4(b), the paper substrate 2 may have a water-repellent coating layer 7 on the outside of the outer adhesive layer 4 in addition to the three layers of the base paper layer 3, the outer adhesive layer 4, and the inner adhesive layer 6 described above. The water-repellent coating layer 7 may be made of a coating agent containing a water-repellent component such as a fluorine-based compound such as PTFE resin (polytetrafluoroethylene resin), silica or silicone-based compound, or a hydrocarbon-based compound such as polyolefin or paraffin. Examples of the dispersion medium include water and solvents such as organic solvents, which can be used alone or in combination of two or more. The coating agent may also contain a coating film-forming component other than the water-repellent component described above. These coating agents can impart high water repellency to the outer surface of the outer adhesive layer 4 by the action of the water-repellent component contained therein. When applying the coating agent, a gravure coater or roll coater can be used in the same way as the outer adhesive layer 4 and the inner adhesive layer 6. The amount of coating varies depending on the content of the active ingredient, but is preferably 0.5 to 3 g / m2 (DRY). 2 The water-repellent coating layer 7 desirably has a water-repellency of R8 or more as evaluated in accordance with the water-repellency test (JAPAN TAPPI paper pulp test method No. 68).

[0028] In addition, when the water-repellent coating layer 7 is provided on the surface of the paper base material 2, it may inhibit the adhesion between the outer adhesive layer 4 and the paper base material 2 and the adhesion between the inner adhesive layer 6 and the paper base material 2. Therefore, it is desirable that the water-repellent coating layer 7 be provided at locations other than the locations where the seal portions 8 are provided. Further, a printing layer (not shown) may be provided on the outer surface of the outer adhesive layer 4 or between the outer adhesive layer 4 and the water-repellent coating layer 7.

[0029] For example, taking the example of FIG. 1(a), the location indicated by "C" in FIG. 1(a) corresponds to the above-mentioned "locations other than the locations where the seal portions 8 are provided" and is suitable for providing the water-repellent coating layer 7. If the water-repellent coating layer 7 is provided at the location indicated by "C", even if rainwater or the like falls on the packaging bag 1, it is possible to suppress the intrusion of water into the bag interior, and it becomes possible to further improve the convenience and durability (water resistance) of the packaging bag 1.

[0030] On the other hand, in FIG. 1(a), the location indicated by "D" is where the outer adhesive layers 4 are in contact with each other and the inner adhesive layers 6 are in contact with each other in a planar state and are sealed, and it is not suitable for providing the water-repellent coating layer 7. Also, the location indicated by "B" is where the inner adhesive layers 6 are in contact with each other in a planar state and are sealed, and it is not suitable for providing the water-repellent coating layer 7. If the water-repellent coating layer 7 is provided at these locations, the water-repellent coating layer 7 intervenes between the outer adhesive layers 4, reducing the adhesion strength and making peeling easier. Therefore, at the locations indicated by "D" and "B", it is preferable to use the paper base material 2 having a layer structure (a layer structure without the water-repellent coating layer 7) as shown in FIG. 4(a).

[0031] Next, the procedure for forming the packaging bag 1 from the flatly unfolded paper base material 2 will be described in detail. FIG. 2(a) shows a plan view of the front side of the paper base material 2, and FIG. 1(b) shows a plan view of the back side of the paper base material 2. As shown in FIGS. 2(a) and 2(b), the paper base material 2 of the first embodiment is formed in a rectangle having a short side Sn and a long side Sw. Note that the length L2 of the long side Sw with respect to the length L1 of the short side Sn has a relationship of L1 < L2.

[0032] The above-mentioned paper base material 2 has two planned mountain fold lines α and α' that extend parallel to the long side Sw, and two planned mountain fold lines β and β' that extend parallel to the short side Sn. These planned mountain fold lines α and α' indicate the positions that naturally become mountain fold lines when the packaged item is packaged as shown in FIG. 5. The planned mountain fold lines β and β' indicate the positions that become mountain fold lines when the bag is made as shown in FIG. 3. In this embodiment, the planned mountain fold lines α, α', β, and β' indicate the positions that become mountain fold lines by folding back during packaging or bag making, and no lines or the like are formed on the paper base material 2 before bag making. However, it is also possible to form lines in advance on the paper base material 2 before bag making and to give it a fold habit before packaging.

[0033] In addition, between the two planned mountain fold lines β and β' extending parallel to the short side Sn, a planned valley fold line δ extends in a direction parallel to the short side Sn so that the packaging bag 1 after the bag manufacturing process can be easily folded in a valley during storage, etc. The planned mountain fold lines β, β' are formed as line segments from the planned mountain fold line α to the planned mountain fold line α', and the planned mountain fold lines γ, γ' are provided outside the planned mountain fold lines α, α'. In other words, the planned mountain fold lines β, β' and the planned mountain fold lines γ, γ' are arranged side by side on the same line (along a direction parallel to the short side Sn). The planned mountain fold lines γ, γ' also indicate the locations that will become mountain fold lines when a bag is made as shown in FIG. 3, and no lines or the like are formed on the paper base material 2 before the bag is made. However, as described above, it is also possible to form lines in advance on the paper base material 2 before the bag is made, and to give a fold habit before packaging.

[0034] That is, the parts indicated by "B" and "D" in Fig. 1(a) are bag-making seal sections 19 where the paper base materials 2 are heat-sealed together during bag making. This bag-making seal section 19 is formed by sealing using a seal bar or the like in the bag making process, and the planned locations to be sealed are indicated by thick lines in Fig. 2, which shows the state before sealing. This bag-making seal section 19 has a first seal section 9 that extends parallel to the long side Sw of the paper base material 2, and a second seal section 10 that extends at an angle so as to intersect both the short side Sn and the long side Sw of the paper base material 2 at 45°.

[0035] As shown in FIG. 2(a) and FIG. 2(b), the planned sealing line 9' of the first sealing portion 9 is formed in a straight line parallel to the long side Sw, and is provided at a position a distance D0 away from the edge of the paper base material 2 in the direction toward the planned mountain fold lines α, α'. The distance D0 between the planned sealing line 9' of the first sealing portion 9 and the long side Sw is the length of the "glue allowance" provided on the edge of the paper base material 2. The seal may be made on the inside of the edge of the paper base material 2 so that the seal bar does not protrude outside the paper base material 2, or may be made up to the edge of the paper base material 2 (i.e., the entire glue allowance). The edge of the glue allowance may be cut as necessary during or after sealing.

[0036] Specifically, as shown in Fig. 5, if the width in the left-right direction of the packaging body 17 (packaging bag 1 after bag production) is "a", the depth in the front-back direction is "b", and the height in the up-down direction is "c", the length L1 of the short side Sn of the paper base material 2 shown in Fig. 2 is formed to a dimension obtained by adding the above-mentioned "glue allowance" to the sum of the width a and the depth b (0.5b x 2 to be precise). Also, the length L2 of the long side Sw of the paper base material 2 is formed to a dimension obtained by adding the height c x 2 and the depth b (0.5b x 2 to be precise), and further adding the dimension for forming the bottom of the sealed box described later (depth b (0.5b x 2 to be precise) and the above-mentioned "glue allowance").

[0037] In addition, the planned sealing line 10' of the second sealed portion 10 is formed so as to intersect at an angle of 45° with both the planned sealing line 9' of the first sealed portion 9 and the planned mountain fold lines γ and γ', and both ends intersect the planned sealing line 9' and the planned mountain fold lines γ and γ'. Specifically, the planned sealing lines 10' of the second sealed portion 10 are formed in a total of four lines, two on both sides of the planned mountain fold line γ so as to be line-symmetrical with respect to the planned mountain fold line γ, and two on both sides of the planned mountain fold line γ' so as to be line-symmetrical with respect to the planned mountain fold line γ'. These four planned sealing lines 10' of the second sealed portion 10 are inclined so as to approach the planned mountain fold lines γ and γ' as they approach the planned mountain fold lines α and α' from above the planned sealing line 9', and are formed in a folded line bent in a W-shape or an inverted W-shape in the paper base material 2 in the developed state.

[0038] As shown in FIG. 3(1), when the packaging bag 1 of the first embodiment is made from the paper base material 2 before bag making, the paper base material 2 is folded back along a direction parallel to the long side Sw, with the mountain fold lines β and β' as the boundary. At this time, the paper base material 2 between the mountain fold lines β and β' is valley-folded with the valley fold line δ as the boundary, and the valley-folded portion is folded to form a gusset portion 18 (gusset portion). In this way, as shown in FIG. 3(2), it is possible to form an intermediate body 11 in which a gusset portion 18 is formed between two overlapping paper base materials 2. The folds may be formed sequentially or simultaneously.

[0039] Next, the intermediate 11 (two-ply paper base material 2 with gusset portion 18 formed thereon) is heat-sealed using a seal bar along the intended seal line 9' of the first seal portion 9, and also along the intended seal line 10' of the second seal portion 10. The intended seal line 9' and the intended seal line 10' may be formed sequentially or simultaneously.

[0040] If heat sealing is performed on the above-mentioned intended sealing line 10' using a seal bar, The side adhesive layers 6, 6 are heat-sealed so that they come into contact with each other in a flush state, forming a triangular fold-up piece 12. Furthermore, by performing heat sealing with a seal bar along the intended sealing line 9', the outer adhesive layers 4, 4 formed at the ends of the fold-up piece 12 are heat-sealed so that they come into contact with each other in a flush state, and the outer adhesive layers 4, 4 and the inner adhesive layers 6, 6 are heat-sealed together in a four-layer stacked state, making it possible to form an integrated multi-seal structure 14.

[0041] Here, the packaging bag 1 produced as described above has a plurality of bag-making and sealing sections 19 (a plurality of first sealing sections 9 and second sealing sections 10) and is formed into a flat folded bag shape. The packaging bag 1 can be filled with the packaged item P in a state in which it is deformed from the bag shape after the above-mentioned bag production into a covered rectangular tubular shape with front, back, left and right sides, a top and a bottom. In addition, this "covered square tube" means "a square tube in which only the bottom is open." More specifically, it means that of the six sections - the front, back, left and right sides, the top and the bottom - five sections excluding the bottom are closed, and only the bottom is open downwards.

[0042] In the present invention, the deformed shape of the packaging bag 1 is referred to as a "lidded square tube (lidded cylindrical shape)" because it is assumed that it will be used in a filling facility where the packaged items are filled from the product insertion section 16 on the bottom side at the packaging site, but the packaging bag 1 of the present invention also includes those in which the product insertion section 16 is provided on the side or on the top (top). In addition, once filling of the packaged items is completed, the product insertion section 16 on the bottom side is sealed and closed (sealed), and the packaging bag 1 after filling and sealing becomes a hexahedral (rectangular parallelepiped) package 17 with a closed bottom as shown in Fig. 5.

[0043] The multiple seal structure 14 provided in the package 17 of the present invention is a portion in which four or more sheets of paper base material 2 are laminated and heat-sealed so that two or more of the outer adhesive layer 4 and the inner adhesive layer 6, the outer adhesive layers 4, 4 together, or the inner adhesive layers 6, 6 together are in surface contact with each other. Such a multiple seal structure 14 is provided in any one of all the seal parts 8 provided in the package 17 when the packaged item P is filled and sealed.

[0044] Specifically, the sealed portion 8 includes a bag making seal portion 19 formed during bag making, a box closure seal portion 13 that seals the product insertion portion 16 when sealing the box, and other sealed portions that are not classified as either the box closure seal portion 13 or the bag making seal portion 19. In contrast to these sealed portions 8, the package 17 of the present invention has a multiple seal structure 14 provided in any of the sealed portions 8. That is, in the package 17, it is sufficient that either the bag making seal section 19 or the box sealing section 13 has the multiple seal structure 14. In this case, the bag making seal section 19 may have the multiple seal structure 14, the box sealing section 13 may have the multiple seal structure 14, or both the bag making seal section 19 and the box sealing section 13 may have the multiple seal structure 14. Also, a part of the bag making seal section 19 or the box sealing section 13 may have the multiple seal structure 14. That is, the cases where a part of the bag making seal section 19 has the multiple seal structure 14, a part of the box sealing section 13 has the multiple seal structure 14, or both a part of the bag making seal section 19 and a part of the box sealing section 13 have the multiple seal structure 14 are included in the case of "a case where a part of the bag making seal section 19 and the box sealing section 13 has the multiple seal structure 14." In addition, in an embodiment in which the packaging bag 1 before filling and sealing has a multiple seal structure 14, any one of the multiple bag-making and sealing sections 19 (first seal section 9 and second seal section 10) may have the multiple seal structure 14. In this case, the first seal section 9 may have the multiple seal structure 14, the second seal section 10 may have the multiple seal structure 14, or both the first seal section 9 and the second seal section 10 may have the multiple seal structure 14. Also, a part of the bag-making and sealing section 19 formed by bag making may have the multiple seal structure 14. In other words, the cases where a part of the first seal section 9 has the multiple seal structure 14, a part of the second seal section 10 has the multiple seal structure 14, or both a part of the first seal section 9 and a part of the second seal section 10 have the multiple seal structure 14 are included in the case of "a part of the bag-making and sealing section 19 has the multiple seal structure 14".

[0045] Next, the multiple seal structure 14 of the first embodiment will be described. As shown in FIG. 4(c), the multiple seal structure 14 of the first embodiment includes, in order from the left, The first embodiment is made up of four pieces, namely, the left piece of the left-side fold piece 12, the right piece of the left-side fold piece 12, the left piece of the right-side fold piece 12, and the right piece of the right-side fold piece 12, and the four pieces of paper in one paper base material 2 are sealed together in a stacked state. If these four pieces of paper, i.e., the left piece of the left-side fold piece 12, the right piece of the left-side fold piece 12, the left piece of the right-side fold piece 12, and the right piece of the right-side fold piece 12, are referred to as a first piece 121, a second piece 122, a third piece 123, and a fourth piece 124, respectively, the multiple seal structure 14 of the first embodiment is made up of, from the left, the outer adhesive layer 4 of the first piece 121, the second piece 122, the third piece 123, and the fourth piece 124. The structure has a 12-layer structure consisting of a base paper layer 3 of first piece 121, an inner adhesive layer 6 of first piece 121, an inner adhesive layer 6 of second piece 122, a base paper layer 3 of second piece 122, an outer adhesive layer 4 of second piece 122, an outer adhesive layer 4 of third piece 123, a base paper layer 3 of third piece 123, an inner adhesive layer 6 of third piece 123, an inner adhesive layer 6 of fourth piece 124, a base paper layer 3 of fourth piece 124, and an outer adhesive layer 4 of fourth piece 124 laminated together.

[0046] In this multiple seal structure 14, the inner adhesive layer 6 of the first piece 121 and the inner adhesive layer 6 of the second piece 122, the outer adhesive layer 4 of the second piece 122 and the outer adhesive layer 4 of the third piece 123, and the inner adhesive layer 6 of the third piece 123 and the inner adhesive layer 6 of the fourth piece 124 constitute the first seal portion 9, thereby making all four paper base materials 2 (12 layers) into a single unit. In addition, in the multiple seal structure 14 of the first embodiment, the inner adhesive layer 6 of the first piece 121 and the inner adhesive layer 6 of the second piece 122 constitute the second seal portion 10, and the inner adhesive layer 6 of the third piece 123 and the inner adhesive layer 6 of the fourth piece 124 constitute the second seal portion 10, and these two seal portions overlap with the outer adhesive layer 4 of the second piece 122 and the outer adhesive layer 4 of the third piece 123, thereby including a portion where all four paper base materials 2 (12 layers) are integrated into one body.

[0047] If such a multi-seal structure 14 is provided in which four sheets of paper base material 2 (paper pieces that are part of the paper base material 2) are overlapped and integrated, an external force applied to the multi-seal structure 14 can be received by the four sheets of paper base material 2 as a whole, and peeling of the sealed portion 8 is unlikely to occur. In other words, the external force applied to the multi-seal structure 14 is distributed to all adhesive surfaces between the 12 layers that make up the multi-seal structure 14, and the force applied to each adhesive surface is weak. Therefore, peeling of the sealed portion 8 is unlikely to occur in the multi-seal structure 14. As a result, in the packaging bag 1 of the first embodiment provided with the above-mentioned multi-seal structure 14, even if an adhesive with releasability is used during recycling, opening (peeling) of the sealed portion 8 after bag making can be suppressed, and it is possible to achieve both recyclability and sealability.

[0048] If the end of the sealed portion is separated into two pieces of overlapping paper (i.e., if the outer adhesive layer of the second piece of the multi-seal structure is not sealed with the outer adhesive layer of the third piece, and two overlapping pieces of paper base material are provided), there is a high possibility that the corner of the paper piece will get caught on something, so there is a risk of the sealed portion being opened inadvertently. However, if a multi-seal structure 14 is provided in which the end is integrated by overlapping four pieces as described above, there will be only one corner that can get caught on something, and as a result, peeling of the sealed portion 8 can be prevented.

[0049] The packaging body 17 of the present invention is formed by deforming the above-mentioned pre-made packaging bag 1 into a lidded cylindrical shape with front, back, left and right sides and a lid (top), filling it with the packaged item P, and sealing it after filling (inserting) the packaged item P, such as a diaper. In other words, the packaging body 17 of the present invention comprises the packaging bag 1 which is made into a tubular shape with a lid, and the packaged item P which is accommodated in the packaging bag 1.

[0050] The packaging body 17 of the present invention only needs to be a sealed packaging bag 1 containing the packaged item P, so it may be sealed by heat sealing the product insertion section 16 as in this embodiment, or it may be sealed by tape or the like. Next, a procedure for filling the packaging bag 1 of this embodiment with the packaged item P and sealing the product insertion section 16 after filling, in other words, a filling and sealing method by heat sealing of this embodiment, will be described.

[0051] The packaging bag 1 of the first embodiment after the bag is made is deformed into a lidded tubular shape, and the front, back, left and right sides and the top are closed, and the bag is open downward. The lower opening (bottom opening) serves as a product insertion section 16 into which the packaged item P is inserted. As shown in FIG. 6(a), in the filling equipment for the packaged items P, the packaging bag 1 is set in the filling equipment with the opening (product insertion section 16) facing downward. Once the packaging bag 1 is set in the filling equipment, the packaged items P are supplied from below the packaging bag 1. The packaged items P supplied from below are a bundle of multiple body fluid absorbent articles such as diapers in a folded state. In this embodiment, a total of 30 body fluid absorbent articles, each of which is a bundle of 15 pieces, are stacked in two upper and lower layers, and used as the packaged items P. Note that, in this figure, the packaged items P are supplied to the packaging bag 1 that has been deformed into a tubular shape with a lid in advance, but the bag may be deformed into a tubular shape with a lid as the packaged items P are supplied.

[0052] As shown in FIG. 6(b), when the packaged items P are filled up to the top of the packaging bag 1, the opening (item insertion portion 16) is sealed. The product insertion section 16 is sealed by folding the opposing short sides (left and right) inward so that they come close to each other (folding in the direction of 1 in the figure), and then folding the opposing long sides (front and back) inward so that they come close to each other (folding in the direction of 2 in the figure).The folded ends of the long sides (front and back) folded inward are then heat sealed to close the product insertion section 16.

[0053] The sealing section that seals the product insertion section 16 during this type of sealing is the box sealing section 13, which is provided separately from the bag making and sealing section 19 that seals the paper base materials together during the above-mentioned bag making. In the package 17 of this embodiment, the box sealing section 13 and the bag making and sealing section 19 constitute one package 17. In addition, the packaging body 17 may also be provided with sealing sections (other sealing sections) that are not classified as either the box sealing section 13 or the bag making sealing section 19, such as a handle sealing section for attaching components such as a handle to the packaging bag, and a reinforcing sealing section that reinforces weaker parts of the packaging bag by overlapping a paper base material.

[0054] The packaging body of the present invention employs a multiple seal structure 14 in any of the above-mentioned box sealing section 13, bag making sealing section 19, and other seal sections not classified as these (handle seal section, reinforcing seal section, etc.), in other words, in any of the seal sections 8. By employing the multiple seal structure 14 in any of the above-mentioned seal sections 8, it is possible to reinforce the portions of the package 17 that have low seal strength and are prone to peeling. In other words, since the box-closing seal section 13 and the bag-making seal section 19 generally tend to have low seal strength, it is preferable to reinforce these seal sections 8 with the multiple seal structure 14. In this way, even though the package does not include a film, it is possible to prevent unopening (peeling) at undesired times, and it is possible to achieve both productivity, recyclability and sealability. [Second embodiment] Next, a packaging bag 1 according to a second embodiment will be described.

[0055] As shown in Figures 8 and 9, the packaging bag 1 of the second embodiment has a rectangular tubular appearance, similar to the first embodiment, but the shape of the bag making and sealing portion 19 formed on the left and right side surfaces is different. That is, as shown in FIG. 8, the packaging bag 1 of the second embodiment has a structure in which a linear first seal portion 9 and two linear second seal portions 10 are connected while crossing in a trifurcated shape, and a multiple seal structure 14 is provided at the contact point between the first seal portion 9 and the two second seal portions 10. Note that "F" in FIG. 8 is a portion corresponding to "B" in FIG. 1, and shows the first seal portion 9 in which the inner adhesive layers 6, 6 are heat-sealed together, as in the packaging bag 1 of the first embodiment. Also, "G" in FIG. 8 is a portion corresponding to "C" in FIG. 1, and corresponds to "a portion other than the portion where the seal portion 8 is provided" as in the packaging bag 1 of the first embodiment, and is suitable for providing a water-repellent coating layer 7. Furthermore, "H" in FIG. 8 is a portion corresponding to "D" in FIG. 1, and a multiple seal structure 14 is provided as in the packaging bag 1 of the first embodiment.

[0056] In other words, as shown in Figure 8, the bag making and sealing section 19 provided in the packaging bag 1 of the first embodiment is approximately I-shaped with ends extending linearly in the vertical direction when viewed from the side, whereas the bag making and sealing section 19 provided in the packaging bag 1 of the second embodiment is approximately Y-shaped, and the shapes of the bag making and sealing section 19 are significantly different. Such differences in the shape of the bag making seal portion 19 are brought about by changing the shape of the paper base material 2 before bag making, the arrangement of the planned mountain fold lines / valley fold lines, or by including an end cutting process in the bag making process.

[0057] Specifically, the paper base material 2 of the second embodiment, when laid out in a plane, is configured as follows. Figure 9(a) shows an expanded view of the front side of the paper base material 2 of the second embodiment expanded into a flat surface, and Figure 9(b) shows an expanded view of the back side of the paper base material 2 of the second embodiment expanded into a flat surface. As shown in Figures 9(a) and 9(b), the paper base material 2 of the second embodiment is formed in a shape close to a rectangle with short sides Sn and long sides Sw, similar to the first embodiment. The paper base material 2 of the second embodiment also has two mountain fold lines α, α' extending parallel to the long sides Sw, and two mountain fold lines β, β' extending parallel to the short sides Sn, and between the two mountain fold lines β, β' extending parallel to the short sides Sn, one valley fold line δ extending parallel to the short side Sn is formed.

[0058] The paper base material 2 of the second embodiment differs from that of the first embodiment in that the middle of the long side Sw is cut out in a W-shape or an inverted W-shape when viewed from above. That is, the paper base material 2 of the second embodiment is cut out in a folded line shape at the center side in the longitudinal direction, and the planned sealing line 9' of the first sealed portion 9 on the left side and the planned sealing line 9' of the first sealed portion 9 on the right side are connected by the planned sealing line 10' of the second sealed portion 10 in a folded line shape.

[0059] In other words, the intended sealing line 9' of the first sealing portion 9 formed on the paper base material 2 in the second embodiment is not the same length as the long side Sw as in the first embodiment, but rather two straight intended sealing lines 9' of the first sealing portion 9 that are shorter than the long side L2 are formed, one on each side of the intended sealing line 10' of the second sealing portion 10. 10, when making a package 17 from the paper base material 2, the paper base material 2 is folded back at the planned mountain fold lines β and β' as in the first embodiment, and a gusset portion 18 is formed between the planned mountain fold lines β and β'. Then, the first sealed portion 9 and the second sealed portion 10 of the two overlapping paper base materials 2 are heat-sealed using a seal bar.

[0060] The bag making method of the second embodiment differs from the first embodiment in that, as shown in Figure 10 (4), after the first sealed section 9 and the second sealed section 10 have been completed, a diagonal cut is made along the second sealed section 10 to cut the corners of the overlapped paper base material 2. Note that, although the corners are cut after heat sealing has been completed in Figure 10, heat sealing may be performed after the corners are cut, or the corners may be cut and heat sealed simultaneously.

[0061] By performing this type of corner cutting, the left and right fold pieces 12 located on the outside of the second seal portion 10 are cut away, and the middle of the long side Sw can be cut out in a W-shape or an inverted W-shape, making it possible to form a bag making seal portion 19 that is approximately Y-shaped when viewed from the side after bag making. 11 and 12, in the packaging bag 1 of the second embodiment, the portion of the substantially Y-shaped bag-making seal portion 19 that extends vertically corresponding to the lower part of the Y becomes the first seal portion 9 where the inner adhesive layers 6, 6 are bonded together. Also, the inclined portion (V-shaped portion) corresponding to the upper part of the Y becomes the second seal portion 10 where the inner adhesive layers 6, 6 are bonded together. Both the first seal portion 9 and the second seal portion 10 are formed by laminating the inner adhesive layers 6, 6 of the paper base material 2 in two layers and sealing them, and are not a multiple seal structure 14 where the inner adhesive layers 6, 6 are laminated in four layers.

[0062] However, at one point where the bottom of the Y and the top of the Y join, a multiple seal structure 14 is formed. Specifically, as shown in FIG. 11, the multiple seal structure 14 provided in the packaging bag 1 of the second embodiment is formed at the contact point between the first seal portion 9 and the second seal portion 10 described above. In other words, when considering the layer structure of the portion that crosses along a line ε extending horizontally relative to the contact point between the first sealed portion 9 and the second sealed portion 10, from the left, the outer adhesive layer 4 of the first piece 121, the base paper layer 3 of the first piece 121, the inner adhesive layer 6 of the first piece 121, the inner adhesive layer 6 of the second piece 122, the base paper layer 3 of the second piece 122, the outer adhesive layer 4 of the second piece 122, the outer adhesive layer 4 of the third piece 123, the base paper layer 3 of the third piece 123, the inner adhesive layer 6 of the third piece 123, the inner adhesive layer 6 of the fourth piece 124, the base paper layer 3 of the fourth piece 124, and the outer adhesive layer 4 of the fourth piece 124 are laminated in that order, and the multiple seal structure 14 of the present invention is formed in which all 12 layers are sealed together.

[0063] That is, in the packaging bag 1 of the second embodiment, as in the first embodiment, the external force applied to the multiple seal structure 14 is distributed to all adhesive surfaces between the 12 layers, so peeling of the sealed portion 8 is unlikely to occur, as in the first embodiment. As a result, even in the case of using an adhesive with releasability during recycling, the packaging bag 1 of the second embodiment can prevent undesired opening of the sealed portion 8 after the bag is made, making it possible to achieve both recyclability and sealability. [Other embodiments] Incidentally, the above-mentioned multiple seal structures 14 are all provided in the bag-making seal section 19 which seals the folded ends of the paper base material 2, and serve to reinforce the bag-making seal section 19 which is prone to becoming a starting point for peeling.

[0064] However, the multiple seal structure 14 of the packaging bag 1 of the present invention is provided for the purpose of reinforcing weak points in the seal section 8. And, the weak points in the packaging bag 1 of the present invention are not limited to the bag-making seal section 19. For example, the packaging bag 1 of the first and second embodiments described above is designed to fill the packaged item, such as a diaper, from the product insertion section 16 on the bottom side, and close (seal) the bag making and sealing section 19 on the bottom side after filling. The above-mentioned multiple seal structure 14 may be provided in the sealing section 13 that seals this opening.

[0065] In other words, the packaging bag 1 before filling may not have the multiple seal structure 14, and the multiple seal structure may be formed in the state of the package 17 after the product insertion portion 16 is sealed. Also, for example, a multiple seal structure may be provided in a seal section other than the box sealing section 13 and the bag making sealing section 19, in other words, in the reinforcing sealing section 8. For example, in the box sealing method shown in Fig. 6, a multiple seal structure 14 can be provided in the box sealing section 13 by folding part of the side (left and right) into the section to be heat sealed at the folded-back end of the long side (front and back) and heat sealing four or more sheets of the paper base material 2 overlapping each other.

[0066] Furthermore, the packaging bag 1 in the first and second embodiments has a product insertion section 16 at the bottom, but if the product insertion section 16 is provided at the side or top, a multiple seal structure 14 may be provided at the product insertion section 16 at the side or top. With such a packaging body 17, it is possible to increase the sealing strength of the sealing portion 13 that seals the product insertion portion 16. As a result, as with the first and second embodiments, even if an adhesive with releasability is used during recycling, it is possible to prevent the sealing portion 8 from being opened after the bag is made (after the opening is closed), making it possible to achieve both recyclability and sealing ability.

[0067] In addition, the multiple seal structure 14 may be provided in a location unrelated to the box sealing section 13 or the bag making sealing section 19. For example, consider a case where packaging body 17 is provided with a seal section 8 (other seal section) that is not classified as either the box sealing section 13 or the bag making seal section 19. Such other seal sections may be, for example, a handle seal section for attaching a member such as a handle to the packaging bag, or a reinforcing seal section that reinforces a weaker portion of the packaging bag by overlapping a paper base material. In such a case, the handle seal section and the reinforcing seal section are also prone to damage. Therefore, by providing a multiple seal structure 14 to these handle seal sections and reinforcing seal sections, the strength of packaging body 17 can be increased.

[0068] It should be noted that the embodiments disclosed herein are illustrative in all respects and should not be considered as limiting. In particular, in the embodiments disclosed herein, matters not expressly disclosed, such as operating conditions, operating conditions, various parameters, dimensions, weights, volumes of components, etc., do not deviate from the scope of ordinary practice by a person skilled in the art, and values ​​that can be easily assumed by a person skilled in the art are adopted.

[0069] For example, as shown on the left side of FIG. 7(a), a straight seal can be used for the second seal section 10 of the bag making and sealing section 19, but as shown in the center of FIG. 7(a), a ring-shaped seal 1 can also be used. It is also possible to use a circular seal 10a or a curved seal 10b as shown on the right side of Fig. 7(a). The circular seal 10a or curved seal 10b can have a larger seal area (longer seal length) than a straight seal, and therefore can increase the seal strength.

[0070] Furthermore, as shown on the left side of Figure 7(b), the packaging bag 1 of the first and second embodiments employs straight end cuts 15a at both ends in the left-right direction, but in order to improve the design of the appearance, it is also possible to use wavy end cuts 15b or broken line end cuts 15c as shown in the center of Figure 7(b), or curved end cuts 15d cut in a curved shape as shown on the right side of Figure 7(b).

[0071] Furthermore, in the packaging bag 1 of the first embodiment, it is not necessary to provide the layer structure in which the inner adhesive layer 6, the outer adhesive layer 4, and the base paper layer 3 are laminated over the entire surface of the paper base material 2. For example, the inner adhesive layer 6 can be coated over the entire surface of the back surface (b) of the paper base material 2, and the outer adhesive layer 4 can be provided only near the bottom opening (the portion that is bonded when sealing the box; in FIG. 2, the edge of the short side Sn) and the portion where the folded-back fold-in piece 12 is bonded (between γ and γ' of the intended sealing line 9' in FIG. 2). If the outer adhesive layer 4 can be provided partially in this way, it is possible to reduce the amount of adhesive used and keep manufacturing costs low. [Explanation of symbols]

[0072] 1 packaging bag 2 Paper base material 3. Base paper layer 4 Outer adhesive layer 6 Inner adhesive layer 7 Water-repellent coating layer 8 Seal Part 9 First seal part 10 Second seal part 10a Annular seal 10b Curved seal 11 Intermediates 12 Fold-in piece 13 Enclosure seal 14 Multiple seal structure 15a Straight end cut 15b Wavy end cut 15c Broken line end cut 15d Curved End Cut 16 Product Insertion Section 17 Packaging 18 Guazette Department 19 Bag making and sealing section 121 1st piece 122 2nd piece 123 3rd piece 124 4th piece a Width along the left-right direction of the package b Depth along the front-to-back direction of the package c Height of the package along the vertical direction D0 Distance between the planned line 9' of the first seal part and the long side Sw Sn Short side of paper substrate Sw Long side of paper base material α Mountain fold line provided on horizontally laid paper base material α' A mountain fold line provided on a horizontally laid paper base material β Planned mountain fold line on horizontally laid paper base material β' A mountain fold line provided on the horizontally laid paper base material δ A valley fold line provided on a horizontally laid paper base material γ Mountain fold line provided on horizontally laid paper base material γ' A mountain fold line provided on a horizontally developed paper base material

Claims

1. A packaging bag is made into a bag shape by folding a strip-shaped paper base material along the longitudinal direction and sealing the folded paper base material together, The paper substrate has three layers: a base paper layer made of paper, an outer adhesive layer coated on the outer side of the base paper layer, and an inner adhesive layer coated on the inner side of the base paper layer; the outer adhesive layer and the inner adhesive layer are formed of a heat-sealable adhesive coated on the surface of the base paper layer, Any one of the bag-making and sealing sections that seal the paper base materials together during bag making has a multi-seal structure in which four or more of the paper base materials are heat-sealed in a stacked state so that the outer adhesive layers and the inner adhesive layers are in surface contact with each other. A packaging bag characterized by:

2. The paper base material has a tensile elongation at break of 3% or more. The packaging bag according to claim 1 .

3. The heat seal adhesive comprises: A dispersion or emulsion type heat seal adhesive is used, which allows the paper substrate to be easily separated from the paper during the recycling process. The packaging bag according to claim 1 or 2.

4. The packaging bag has a water-repellent layer on the outermost layer of the paper base material that faces the outside when the bag is made. The packaging bag according to any one of claims 1 to 3.

5. A packaging bag formed by folding a strip-shaped paper base material along a longitudinal direction and sealing the folded paper base material together, and an item to be packaged contained in the packaging bag, The packaging bag is capable of being filled with the packaged item in a state in which the bag shape after the bag formation is transformed into a covered rectangular tubular shape having front, rear, left and right sides, a top and a bottom, The paper substrate has three layers: a base paper layer made of paper, an outer adhesive layer coated on the outer side of the base paper layer, and an inner adhesive layer coated on the inner side of the base paper layer; The outer adhesive layer and the inner adhesive layer are formed by coating a heat-sealable adhesive on the surface of the base paper layer, Of all the seal parts provided on the package obtained by sealing the packaging bag filled with the packaged item, any of the seal parts has a multiple seal structure in which four or more sheets of the paper base material are heat-sealed in a stacked state so that the outer adhesive layers and the inner adhesive layers are in surface contact with each other. A package comprising:

6. The packaging bag has a product insertion portion at least at one of the front, rear, left and right sides, the top portion and the bottom portion, into which the packaged product can be inserted; The product insertion section can be sealed by the heat seal after the packaged item is inserted, Either a bag making and sealing section that seals the paper base materials together when making a bag, or a box sealing section that seals the product insertion section when sealing a box, has the multiple seal structure.

6. The package according to claim 5.

7. The case seal portion is provided with at least the multiple seal structure.

7. The package according to claim 6.

Images