JP7658863B2 - Packaging bags and packaging - Google Patents

Description

The present invention relates to packaging bags and packages used for packaging items such as diapers.

2. Description of the Related Art 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 that includes a seal portion to which the one end of the film body is welded, and a first surface and a second surface that sandwich the seal 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.

Furthermore, Patent Document 2 describes a package for packaging multiple absorbent articles in a folded state, which is formed from a film-like packaging material and includes a bag portion configured to enclose the multiple absorbent articles, and the absorbent articles enclosed in the bag portion in a folded state have a product longitudinal direction, a product width direction, and a product thickness direction that are perpendicular to one another, and the bag portion has a vertical direction, a horizontal direction, and a thickness direction that are perpendicular to one another, and the bag portion has 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 has a bottom surface, a fixing region where the packaging materials are fixed to each other 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 stored in 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.

Patent No. 6859904 JP 2015-71427 A

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 refers specifically to the 14th goal, "Protect 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.

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 as the main material 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 typical vinyl acetate glue, the paper needs to be attached within a certain amount of time after application, so the glue needs to be applied separately when making the bag and when packaging, which causes a problem of poor productivity.

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 items such as diapers, the diapers are packed in a compressed state, and the large repulsive force of the compressed packaged item trying to expand is applied to the packaging material. If the adhesive strength is insufficient, the sealed part may be defeated by the repulsive force of the packaged item and 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).

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 can prevent opening (peeling) at undesired times, and can satisfy all of the requirements for productivity, recyclability, and sealability.

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 a strip-shaped paper base material along the longitudinal direction and sealing the folded 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 inner adhesive layer are formed of a heat-sealable heat-seal 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 during bag making has a multiple seal structure in which four or more paper base materials are stacked and heat-sealed so that the outer adhesive layers and the inner adhesive layers are in surface contact with each other.

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.

The packaging body of the present invention is a packaging body comprising 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, wherein the packaging bag is capable of being filled with the item in a state in which it has been deformed from the bag shape after the bag formation into a covered rectangular tubular shape having front, back, left and right sides, a top and a bottom, and the paper base material comprises 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 inner adhesive layer are formed by coating a heat-sealable heat-seal adhesive on the surface of the base paper layer, and the packaging body obtained by sealing the packaging bag filled with the item to be packaged has a multiple seal structure in which four or more paper base materials are stacked and heat-sealed in a state where the outer adhesive layers and the inner adhesive layers are in contact with each other in a surface state among all the seal parts provided on the packaging body.

Preferably, the packaging bag has a product insertion section at least at one of the front, back, left, right, and right sides, the top, and the bottom, which allows the packaged item to be inserted, and the product insertion section can be sealed by the heat seal after the packaged item is inserted, and either the bag making seal section, which seals the paper base materials together when making the bag, or the sealing seal section, which seals the product insertion section when sealing the bag, has the multiple seal structure.

Preferably, the box seal portion has at least the multiple seal structure.

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.

1A is a perspective view showing a packaging bag of a first embodiment, and FIG. 1B is a cross-sectional view taken along line AA of FIG. FIG. 2A is a development view of the front side of the paper base material of the first embodiment, and FIG. 2B is a development view of the back side. 3A to 3C are schematic diagrams illustrating a procedure for manufacturing the packaging bag of the first embodiment. 1A shows the layer structure of the paper base material in part B of FIG. 1, FIG. 1B shows the layer structure of the paper base material in part C, and FIG. 1C shows the laminated state of the paper base material in part D. 2 is a perspective view of the packaging body of the first embodiment and an enlarged view of a portion D. FIG. 5A to 5C are schematic diagrams illustrating a filling procedure of the package of the first embodiment. 13A is a diagram showing another embodiment of the second seal portion (45° seal on the top surface), and FIG. 13B is a diagram showing another embodiment of the end cut. 1A is a perspective view showing a packaging bag of a second embodiment, and FIG. 1B is a cross-sectional view taken along line E-E of FIG. 13A is a development view of the front side of a paper base material of a second embodiment, and FIG. 13B is a development view of the back side. 13A to 13C are schematic diagrams illustrating a procedure for manufacturing a packaging bag according to a second embodiment. FIG. 9 is a diagram showing the laminated state of the paper base material in part H of FIG. 8( a ). 13 is a perspective view of a packaging body according to a second embodiment and an enlarged view of a portion H. FIG.

[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. Fig. 1(b) is a cross-sectional view of the packaging bag 1 of the first embodiment cut along the longitudinal direction (height direction).

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 a plurality of sheets (a plurality of 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.).

When the packaging bag 1 of the first embodiment is filled with the packaged item P, it is deformed into a covered rectangular tube 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 the 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 packaging body 17. These directions are shown in FIG. 5.

Specifically, the packaged item P to be packaged in the packaging bag 1 of the first embodiment can be a bodily fluid absorbent article (hygienic product) such as a diaper, sanitary product, pet sheet, or nursing sheet. Note that while 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 items 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.

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 bag making, 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 bag making, the same applies below).

The base paper layer 3 is a paper material that is the main material that constitutes the paper base material 2. In order to achieve both shape retention during packaging and workability during bag making and packaging, it is desirable for the paper base material 2 to have a tensile breaking elongation of 3% or more when used as the paper base material 2. The tensile breaking elongation is a value measured based on JIS P8113. Specifically, the tensile breaking elongation includes elongation along the papermaking direction of the papermaking machine (MD direction, longitudinal direction) and elongation along the direction perpendicular to the papermaking direction (CD direction, transverse direction). In this embodiment, the paper base material 2 has an elongation in both directions of 3% or more, preferably 5% or more. It is also desirable to configure the paper base material 2 so that the direction in which the restoring force of the compressed and filled packaged item is most effective (the left-right direction in FIG. 5) is the CD direction.

For such 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, each having a basis weight of preferably 30 to 150 g/ ^m2 , more preferably 50 to 100 g/ ^m2 , can be used. Furthermore, for the base paper layer 3, paper that has been processed or treated to impart 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.

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 base material 2. When sealing, the solidified solids are heated to soften and melt the binder synthetic resin, and the softened and melted synthetic resin cools and solidifies, making it possible to seal (adhere).

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 exhibit good adhesive strength when used to adhere to paper, and can be coated using a coater using a gravure roll, as described below.

The outer adhesive layer 4 is coated on the outer surface of the base paper layer 3 using a gravure coater or roll coater. The coating weight of the outer adhesive layer 4 is, for example, 1.5 g/ ^m2 to 15 g/ ^m2 dry. From the viewpoint of providing sealing strength and blocking resistance, it is preferable that the coating weight is 7 g/ ^m2 to 15 g/ ^m2 dry. The coating weight of the outer adhesive layer 4 may be less than the coating weight of the inner adhesive layer 6.

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 amount of the inner adhesive layer 6 is, for example, 1.5 g/m ² to 15 g/m ² dry. When the inner adhesive layers 6, 6 include a layer structure in which they are in surface contact with each other, by setting the coating amount of the inner adhesive layer 6 to 7 g/m ² to 15 g/m ² dry, it is possible to achieve excellent blocking resistance and to suppress peeling of the seal portion 8 even when a compressed packaged item P such as a diaper is packaged.

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 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 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 can be coated to a dryness of 0.5 to 3 g/m ² . The water-repellent coating layer 7 preferably has a water-repellency of R8 or more as evaluated according to the water-repellency test (JAPAN TAPPI paper pulp test method No. 68).

When the above-mentioned water-repellent coating layer 7 is provided on the surface of the paper substrate 2, it may hinder the adhesion between the outer adhesive layer 4 and the paper substrate 2 and between the inner adhesive layer 6 and the paper substrate 2. Therefore, it is preferable that the water-repellent coating layer 7 is provided in a location other than where the seal portion 8 is provided. In addition, a printed 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.

For example, in the example of FIG. 1(a), the area indicated by "C" in FIG. 1(a) corresponds to the above-mentioned "area other than the area where the seal portion 8 is provided" and is suitable for providing a water-repellent coating layer 7. By providing the water-repellent coating layer 7 at the area indicated by "C", it is possible to prevent water from entering the inside of the bag even if rainwater or the like gets on the packaging bag 1, and it is possible to further improve the convenience and durability (water resistance) of the packaging bag 1.

On the other hand, in the area indicated by "D" in FIG. 1(a), the outer adhesive layers 4, 4 and the inner adhesive layers 6, 6 are in contact with each other in a surface state to seal, and are not suitable for providing a water-repellent coating layer 7. In addition, the area indicated by "B" is also sealed by the inner adhesive layers 6, 6 in a surface state to seal, and is not suitable for providing a water-repellent coating layer 7. If a water-repellent coating layer 7 is provided in these areas, the water-repellent coating layer 7 will be interposed between the outer adhesive layers 4, 4, reducing the adhesive strength and making them more likely to peel off. Therefore, in the areas indicated by "D" and "B", it is preferable to use a paper base material 2 with a layer structure as shown in FIG. 4(a) (a layer structure without a water-repellent coating layer 7).

Next, a procedure for forming the flatly developed paper base material 2 into the packaging bag 1 will be described in detail.
FIG. 2( a ) shows a planar development of the front side of the paper base material 2 , and FIG. 1( b ) shows a planar development of the back side of the paper base material 2 .
2(a) and 2(b), the paper base material 2 of the first embodiment is formed into a rectangle having a short side Sn and a long side Sw. Note that the length L1 of the short side Sn and the length L2 of the long side Sw have a relationship of L1<L2.

The paper base material 2 described above has two planned mountain fold lines α and α' that run parallel to the long side Sw, and two planned mountain fold lines β and β' that run parallel to the short side Sn. These planned mountain fold lines α and α' indicate the locations that will 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 locations that will 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 locations that will become mountain fold lines by folding back during packaging or bag making, and no lines 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.

In addition, between the two planned mountain fold lines β, β' extending parallel to the short side Sn, a planned valley fold line δ is formed so as to extend in a direction parallel to the short side Sn so that the packaging bag 1 after bag making can be easily valley-folded 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 the 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.

In other words, the parts indicated by "B" and "D" in Fig. 1(a) are the bag-making seal section 19 where the paper base material 2 is heat-sealed together during bag making. This bag-making seal section 19 is formed by sealing using a seal bar or the like during 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 a 45° angle.

As shown in FIG. 2(a) and FIG. 2(b), the planned seal line 9' of the first seal portion 9 is formed in a straight line parallel to the long side Sw, and is provided at a position away from the edge of the paper base material 2 by a distance D ₀ in the direction toward the planned mountain fold lines α, α'. The distance D ₀ provided between the planned seal line 9' of the first seal 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.

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). In addition, 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").

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

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 described above, 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 boundaries. 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 boundaries, and the valley folded part 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. Note that each fold may be formed sequentially or simultaneously.

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

When heat sealing is performed along the above-mentioned intended sealing line 10' using a seal bar, the inner adhesive layers 6, 6 are heat sealed so as to come into contact with each other in a flat state, forming a triangular folded piece 12. Furthermore, when heat sealing is performed along the intended sealing line 9' using a seal bar, the outer adhesive layers 4, 4 formed at the ends of the folded piece 12 are heat sealed so as to come into contact with each other in a flat state, making it possible to form a multi-sealed structure 14 in which the outer adhesive layers 4, 4 and the inner adhesive layers 6, 6 are heat sealed together in a four-layer stacked state, forming an integrated product.

Here, the packaging bag 1 that has been manufactured as described above has a plurality of manufacturing 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 is capable of being filled with the packaged item P in a state in which it has been deformed from the bag shape after the manufacturing as described above into a covered rectangular tubular shape with front, rear, left and right sides, a top and a bottom.
It should be noted that 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.

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 bags in which the product insertion section 16 is provided on the side or on the top (top). In addition, once the 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 Figure 5.

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 stacked 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 the seal parts 8 of all the seal parts 8 provided in the package 17 when the packaged item P is filled and sealed.

Specifically, the sealed portion 8 includes a bag making seal portion 19 formed during bag making, a box sealing 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 sealing 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 being filled and sealed has the multiple seal structure 14, it is sufficient that any one of the multiple bag making and sealing sections 19 (the first seal section 9 and the second seal section 10) has 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 case where a part of the first seal section 9 has the multiple seal structure 14, the case where a part of the second seal section 10 has the multiple seal structure 14, or the case where 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 "the case where a part of the bag making and sealing section 19 has the multiple seal structure 14".

Next, the multiple seal structure 14 of the first embodiment will be described.
4(c), the multiple seal structure 14 of the first embodiment is composed of four pieces, in order from the left, the left piece of the left fold piece 12, the right piece of the left fold piece 12, the left piece of the right fold piece 12, and the right piece of the right fold piece 12, and is formed by sealing four pieces of paper in a stacked state in one paper base material 2. If these four pieces of paper, i.e., the left piece of the left fold piece 12, the right piece of the left fold piece 12, the left piece of the right fold piece 12, and the right piece of the right fold piece 12 are referred to as the first piece 121, the second piece 122, the third piece 123, and the fourth piece 124, respectively, the multiple seal structure 14 of the first embodiment is composed of the outer adhesive layer 4 of the first piece 121, the second piece 122, the third piece 123, and the fourth piece 124, in order from the left. The laminate has a 12-layer structure consisting of a base paper layer 3 of the first piece 121, an inner adhesive layer 6 of the first piece 121, an inner adhesive layer 6 of the second piece 122, a base paper layer 3 of the second piece 122, an outer adhesive layer 4 of the second piece 122, an outer adhesive layer 4 of the third piece 123, a base paper layer 3 of the third piece 123, an inner adhesive layer 6 of the third piece 123, an inner adhesive layer 6 of the fourth piece 124, a base paper layer 3 of the fourth piece 124, and an outer adhesive layer 4 of the fourth piece 124.

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 further 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 section 9, whereby all four paper base materials 2 (12 layers) are integrated into one body. 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 form 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 form 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.

By providing a multi-seal structure 14 in which four such paper base materials 2 (paper pieces that are part of the paper base material 2) are stacked together to form a single unit, the external force applied to the multi-seal structure 14 can be received by the entire four paper base materials 2, making it difficult for the seal portion 8 to peel off. In other words, the external force applied to the multi-seal structure 14 is distributed to all of the 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 seal portion 8 is difficult 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 a releasable adhesive is used during recycling, opening (peeling) of the seal portion 8 after bag making can be suppressed, making it possible to achieve both recyclability and sealability.

In addition, 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, and there is a risk that the sealed portion will be inadvertently opened. However, if a multi-seal structure 14 is provided in which four pieces of overlapping ends are integrated 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.

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 a packaging bag 1 formed into a tubular shape with a lid, and an item P to be packaged that is accommodated in the packaging bag 1.

In addition, since the packaging body 17 of the present invention is sufficient as long as the packaging bag 1 containing the packaged item P is sealed, it may be sealed by heat sealing the product insertion section 16 as in this embodiment, but it may also be sealed with 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.

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, right, and top are closed, and the opening on the lower side (bottom opening) of the packaging bag 1 after the bag is made serves as a product insertion portion 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 body fluid absorbent articles, are stacked in two upper and lower layers, and used as the packaged items P. Note that, although the figure shows that the packaged items P are supplied to the packaging bag 1 that has been deformed into a tubular shape with a lid in advance, the bag may be deformed into a tubular shape with a lid as the packaged items P are supplied.

As shown in FIG. 6(b), when the packaged items P are filled up to the top of the packaging bag 1, the opening (product 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.

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.

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 sealing sections not classified as these (handle seal section, reinforcing seal section, etc.), in other words, in any of the sealing sections 8.
By employing the multiple seal structure 14 in any of the above-mentioned seal parts 8, it is possible to reinforce the parts of the package 17 that have low seal strength and are prone to peeling. In other words, since the box sealing part 13 and the bag making seal part 19 generally tend to have low seal strength, it is preferable to reinforce these seal parts 8 with the multiple seal structure 14. In this way, even though the package does not include a film, it is possible to prevent opening (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.

As shown in Figures 8 and 9, the packaging bag 1 of the second embodiment has a rectangular tubular appearance like 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 corresponds 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 corresponds 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 corresponds to "D" in Fig. 1, and a multiple seal structure 14 is provided as in the packaging bag 1 of the first embodiment.

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.

Specifically, the paper base material 2 of the second embodiment, when laid out in a plane, is configured as follows.
FIG. 9(a) shows an expanded view of the front side of the paper base material 2 of the second embodiment expanded into a plane, and FIG. 9(b) shows an expanded view of the back side of the paper base material 2 of the second embodiment expanded into a plane.
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, as in 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.

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. In other words, 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 sealing portion 9 on the left side and the planned sealing line 9' of the first sealing portion 9 on the right side are connected by the planned sealing line 10' of the folded line-shaped second sealing portion 10.

In other words, the 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 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 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.

The bag making method of the second embodiment differs from the first embodiment in that, as shown in FIG. 10 (4), after the first and second sealing sections 9 and 10 have been completed, a slanted cut is made along the second sealing 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 FIG. 10, heat sealing may be performed after the corners are cut, or the corners may be cut and heat sealed simultaneously.

By performing this type of corner cutting, the left and right folding pieces 12 located on the outside of the second seal section 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 section 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 section 19 that extends vertically corresponding to the lower part of the Y becomes the first seal section 9 in which 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 section 10 in which the inner adhesive layers 6, 6 are bonded together. Both the first seal section 9 and the second seal section 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 in which the inner adhesive layers 6, 6 are laminated in four layers.

However, at one point where the bottom of the Y character and the top of the Y character 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 stacked in that order, and the multiple seal structure 14 of the present invention is formed in which all 12 layers are sealed together.

That is, in the packaging bag 1 of the second embodiment, as in the first embodiment, an external force applied to the multiple seal structure 14 is dispersed among all adhesive surfaces between the 12 layers, so that 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, and it becomes possible to achieve both recyclability and sealability.
[Other embodiments]
Incidentally, each of the above-mentioned multiple seal structures 14 is provided in the bag-making seal section 19 which seals the folded ends of the paper base material 2, and serves to reinforce the bag-making seal section 19 which is prone to becoming a starting point for peeling.

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 configured so that the packaged item, such as a diaper, is filled from the product insertion section 16 on the bottom side, and after filling, the bag making and sealing section 19 on the bottom side is closed (sealed). The above-mentioned multiple seal structure 14 may be provided in the sealing section 13 that seals this opening.

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 section 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 a part of the side (left and right) into the portion to be heat sealed at the folded end of the long side (front and back) and heat sealing four or more sheets of the paper base material 2 overlapping each other.

Furthermore, the packaging bag 1 in the first and second embodiments has a product insertion section 16 provided 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.

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 the package 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 include, for example, a handle seal section for attaching a member such as a handle to the packaging bag, and a reinforcing seal section for reinforcing 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 the package 17 can be increased.

The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. In particular, matters not expressly disclosed in the embodiments disclosed herein, such as operating conditions, operating conditions, various parameters, dimensions, weights, volumes of components, etc., do not deviate from the scope of what a person skilled in the art would normally do, and values that a person skilled in the art would easily imagine are used.

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. However, as shown in the center of FIG. 7(a), a ring-shaped seal 1 is also used.
7A , a curved seal 10b can be used as well. The annular seal 10a and curved seal 10b can have a larger seal area (longer seal length) than a straight seal, and therefore can have a higher seal strength.

As shown on the left side of FIG. 7(b), the packaging bag 1 of the first and second embodiments has straight edge cuts 15a on both left and right ends. However, to improve the design of the appearance, it is also possible to use wavy edge cuts 15b or broken line edge cuts 15c as shown in the center of FIG. 7(b), or curved edge cuts 15d cut in a curved line as shown on the right side of FIG. 7(b).

Furthermore, in the packaging bag 1 of the first embodiment, it is not necessary to provide a layered 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 area that is bonded when sealing the box; in FIG. 2, the edge of the short side Sn) and the area where the folded-back fold-in piece 12 is bonded (in FIG. 2, between γ and γ' of the planned sealing line 9'). 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.

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 Sealed portion 9 First sealed portion 10 Second sealed portion 10a Annular seal 10b Curved seal 11 Intermediate body 12 Fold-in piece 13 Box sealing portion 14 Multiple seal structure 15a Straight edge cut 15b Wavy edge cut 15c Folded edge cut 15d Curved edge cut 16 Product insertion portion 17 Packaging body 18 Gusset portion 19 Bag-making seal portion 121 First piece 122 Second piece 123 Third piece 124 Fourth piece a Width along the left-right direction of the packaging body b Depth along the front-back direction of the packaging body c Height along the top-bottom direction of the packaging body D ₀ Distance between the planned line 9' of the first sealed portion and the long side Sw Sn Short side of the paper base material Sw Long side of the paper base material α Planned mountain fold line on the horizontally laid paper base material α' Planned mountain fold line on the horizontally laid paper base material β Planned mountain fold line on the horizontally laid paper base material β' Planned mountain fold line on the horizontally laid paper base material δ Planned valley fold line on the horizontally laid paper base material γ Planned mountain fold line on the horizontally laid paper base material γ' Planned mountain fold line on the horizontally laid paper base material

Claims (7)

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,
a packaging bag characterized in that any one of the bag making and sealing sections that seal the paper base materials together during bag making 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. The packaging bag according to claim 1, wherein the paper base material has a tensile breaking elongation of 3% or more. The heat seal adhesive comprises:
3. The packaging bag according to claim 1, wherein a dispersion type or emulsion type heat seal adhesive is used, which allows the paper base material to be easily separated from the paper in a recycling process. The packaging bag according to any one of claims 1 to 3, characterized in that the packaging bag has a water-repellent layer on the outermost layer of the paper base material that faces outward in a manufactured state. 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 is made is transformed into a covered rectangular tubular shape having front, back, 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,
A package comprising a sealed packaging bag filled with the packaged item, wherein among all the seal portions provided on the package , any one of the seal portions has a multiple seal structure in which four or more sheets of the paper base material are stacked and heat-sealed so that the outer adhesive layers and the inner adhesive layers are in surface contact with each other. 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,
The packaging body according to claim 5, characterized in that either a bag making seal section that seals the paper base materials together when making a bag, or a box closing seal section that seals the product insertion section when sealing the box, has the multiple seal structure. The package according to claim 6, wherein the closure seal portion comprises at least the multiple seal structure.

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