JP7622407B2 - Self-supporting packaging bag - Google Patents

Description

This disclosure relates to self-supporting packaging bags.

Packaging bags are made from a variety of materials and are made to suit the nature and quantity of the contents, post-processing to protect the contents from deterioration, the form in which the package (the bag containing the contents) will be transported, the method of opening the package, and the method of disposal.

Standing pouches and other self-supporting packaging bags are becoming more widely used because they can make products stand out on store shelves. To ensure that the entire surface of the pouch is visible without bending along the way, the laminate that makes up the pouch must have a certain degree of rigidity. Furthermore, if the pouch contains liquid, it must be strong enough not to break when dropped and leak the liquid. To meet these requirements, laminates that combine polyester films, nylon films, polyolefin films, etc. have been used (see Patent Documents 1 and 2).

Japanese Patent Application Publication No. 7-237281 Japanese Patent Application Publication No. 7-241967

In recent years, growing awareness of environmental issues has led to demands for resource conservation and reuse in the field of packaging bags. For example, from the perspective of resource conservation, there is a trend for one refill pouch to be filled with enough material for multiple refills. However, as the volume of the contents increases, the impact when dropped increases, increasing the risk of the contents leaking out due to the pouch being dropped. One way to improve impact resistance is to thicken the film that makes up the pouch (e.g., sealant film). However, this approach runs counter to the reduction in the amount of plastic used.

From the perspective of reuse, technology is being considered to reuse the packaging as a single material by constructing the laminates that make up the packaging from the same type of material. This is called mono-materializing the packaging. As mentioned above, conventional packaging materials have improved required physical properties such as impact resistance by combining a variety of different materials. However, when constructing packaging from the same type of material, there is an issue that it is difficult to ensure sufficient drop resistance.

This disclosure provides a self-supporting packaging bag with excellent drop resistance.

The self-supporting packaging bag according to the present disclosure is formed of a laminate including a base layer and a sealant layer, and includes a body portion in which contents are accommodated, and a bottom portion. The bottom portion has a pair of valley folds formed by folding the laminate, a mountain fold portion formed between the pair of valley folds, and an air-sealing portion formed by heat-sealing the area between the valley folds and the mountain folds in the lateral direction of the bottom portion.

As described above, the self-supporting packaging bag has an air-sealed portion at the bottom, and therefore has excellent drop resistance. The height of the air-sealed portion can be set according to the type and amount of the contents, and is, for example, 5 to 30 mm.

The self-supporting packaging bag may have at least a pair of cutouts or cutout holes in a region between the valley fold and the mountain fold and on a side of the laminate, and may have a fused portion in which the sealant layers are locally fused to each other through the pair of cutouts or the pair of cutout holes. The fused portion may have a semicircular shape, for example. This configuration can further improve the self-supporting ability and drop resistance of the packaging bag. From the viewpoint of excellent drop resistance, the area ratio of the fused portion is preferably 30 to 70%. The area ratio here means a value calculated by the following formula (1).
Area ratio (%) = (area of fused portion) / (L x 10) x 100 ... (1)
[In formula (1), L represents the distance (unit: mm) from the valley fold to the mountain fold.]
When there are multiple fused portions in the target region, the "area of the fused portion" in formula (1) is the "total area of the multiple fused portions."

In the present disclosure, the base layer and the sealant layer are preferably made of the same type of resin material. By using the same type of resin material for these layers, the self-supporting packaging bag can be made of a mono-material, which contributes to promoting the recycling of resin materials. The laminate may further include a gas barrier layer depending on the type of contents, etc.

The present disclosure provides a self-supporting packaging bag with excellent drop resistance.

FIG. 1 is a front view showing a schematic diagram of a self-supporting packaging bag according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view showing a schematic view of the air-filled portion of the self-supporting packaging bag shown in FIG. FIG. 3 is a perspective view showing a schematic state of the laminate folded into a W shape. FIG. 4 is a plan view showing a state in which a plurality of through holes are provided in an original sheet of a laminate. FIG. 5 is a front view showing a schematic diagram of a self-supporting packaging bag according to a comparative example. FIG. 6 is a cross-sectional view that typically shows the structure of the packaging bag shown in FIG.

The following describes in detail the embodiments of the present disclosure. Here, a mono-material standing pouch is used as an example. Standing pouches are used as refill pouches for shampoo, hand soap, detergent, etc., and as pouches for soup, seasonings, etc. Note that the present invention is not limited to the following embodiments.

<Standing pouch>
FIG. 1 is a front view showing a standing pouch (self-supporting packaging bag) according to the present embodiment. The standing pouch 10 shown in this figure includes a body 10a in which contents are accommodated and a bottom 10b, and air-filled portions 5 and 6 are formed in the bottom 10b. FIG. 2 is a cross-sectional view showing an enlarged view of the air-filled portions 5 and 6 of the standing pouch 10. The air-filled portions 5 and 6 act as cushions, thereby preventing the standing pouch 10 from breaking due to the impact of being dropped. According to the study by the present inventors, conventional standing pouches containing liquids often fall with their bottoms facing downward, and when dropped in such a state, the bottoms are easily broken.

The standing pouch 10 is manufactured through a process of folding a laminate 3 including at least a base layer 1 and a sealant layer 2 into a W shape. Fig. 3 is a perspective view showing a state in which the laminate 3 is folded into a W shape. As shown in Fig. 3, the laminate 3 is folded into a W shape so that the base layer 1 is disposed on the outside and the sealant layer 2 is disposed on the inside. By folding the laminate 3 into a W shape, the laminate 3 is divided into the following four regions R1a, R1b, R2b, and R2a.
Region R1a: Region from the end of the laminate 3 to the valley fold V1 Region R1b: Region from the valley fold V1 to the mountain fold M1 Region R2b: Region from the mountain fold M1 to the valley fold V2 Region R2a: Region from the valley fold V2 to the end of the laminate 3

The sides of the standing pouch 10 are made up of heat-sealed sections 11. The width of the heat-sealed section 11 shown in FIG. 1 is, for example, 5 to 18 mm, and may be 7 to 15 mm. A width of the heat-sealed section 11 of 5 mm or more tends to achieve sufficient seal strength, while a width of 18 mm or less tends to ensure sufficient content capacity of the standing pouch 10.

The bottom 10b has a pair of valley folds V1, V2 formed by folding the laminate 3 into a W shape, and a mountain fold M1 formed between them. The distance L (see FIG. 1) from the valley fold V1 or the valley fold V2 to the mountain fold M1 is, for example, 10 to 60 mm, and may be 15 to 50 mm. When the distance L is 10 mm or more, it is easy to ensure a sufficient height for the air-enclosed portions 5, 6, and the drop resistance of the standing pouch 10 tends to be further improved. On the other hand, when the distance L is 60 mm or less, it is easy to ensure a sufficient content volume of the standing pouch 10.

The air-filled portions 5 and 6 are formed by heat-sealing the area between the valley fold V1 and the mountain fold M1 across the entire width of the bottom 10b. That is, the heat-sealed portion 12 constituting the air-filled portion 5 is formed by heat-sealing the sealant layer 2 in the region R1a and the sealant layer 2 in the region R1b in the width direction. On the other hand, the heat-sealed portion 12 constituting the air-filled portion 6 is formed by heat-sealing the sealant layer 2 in the region R2a and the sealant layer 2 in the region R2b in the width direction. The width W (see FIG. 1) of the heat-sealed portion 12 is, for example, 5 to 15 mm, and may be 7 to 12 mm. A width of the heat-sealed portion 12 of 5 mm or more tends to achieve sufficient seal strength, while a width of 15 mm or less tends to make it easier to ensure both the capacity of the standing pouch 10 and the height of the air-filled portions 5 and 6. The air-filled portions 5 and 6 are isolated from the body 10a by the heat-sealed portion 12. This has the advantage that even if the valley folds V1 and V2 are damaged, for example, by friction, the contents will not leak.

When forming the air-filled sections 5, 6 by heat sealing, air may be injected or blown into the sections that will become the air-filled sections 5, 6 using a nozzle or the like while heat sealing is performed, but it is not necessary to inject or blow air. The laminate 3 that constitutes the standing pouch 10 has a certain degree of rigidity and has the ability to recover even after being folded once, so a sufficient amount of air can be accommodated in the air-filled sections 5, 6 even without injecting or blowing air.

The height H (see FIG. 1) of the air-filled portions 5, 6 is, for example, 5 to 30 mm, and may be 8 to 25 mm. A height H of 5 mm or more tends to further improve the drop resistance of the standing pouch 10, while a height H of 30 mm or less tends to make it easier to ensure a sufficient content volume of the standing pouch 10.

As shown in FIG. 1, the standing pouch 10 has fusion parts 9 on both sides of the bottom 10b. In this embodiment, two fusion parts 9 are formed vertically side by side on one side of the standing pouch 10, and two fusion parts 9 are also formed vertically side by side on the other side. The fusion parts 9 of the standing pouch 10 join the regions R1a and R2a of the laminate 3. The fusion parts 9 are portions where the sealant layers 2 of the regions R1a and R2a are locally fused to each other through the cutout parts 8a and 8b provided in the regions R1b and R2b. As shown in FIG. 3, the cutout parts 8a and 8b are provided on the sides of the regions R1b and R2b. By providing the fusion parts 9 on both sides of the bottom 10b, the self-supporting property and drop resistance of the standing pouch 10 can be further improved. From the viewpoint of excellent drop resistance of the standing pouch 10, the area ratio of the fused portion 9 is preferably 30 to 70%, and more preferably 32 to 50%. This area ratio is a value calculated by the following formula (1).
Area ratio (%)=(area of fused portion 9)/(L×10)×100 (1)
In formula (1), L represents the distance (unit: mm) from valley fold V1 to mountain fold M1. The number "10" in the denominator of formula (1) represents the width of the region where fused portion 9 is formed on the side of bottom portion 10b.

<Laminate>
In this embodiment, from the viewpoint of achieving mono-materialization, both the base material layer 1 and the sealant layer 2 are composed of polyester resin. The polyester content in the laminate 3 according to this embodiment is preferably 90% by mass or more. From the viewpoint of achieving mono-materialization to a higher degree, the polyester content in the laminate 3 is more preferably 92% by mass or more, and even more preferably 95% by mass or more. The configuration of the laminate 3 will be described below.

[Base layer]
The substrate layer 1 is a film (base film) that serves as a support. The thickness of the substrate layer 1 can be, for example, 5 μm to 1 mm or less, and may be 5 to 800 μm, or may be 5 to 500 μm. For example, a crystalline polyester can be used as the substrate layer 1, and specific examples thereof include polybutylene terephthalate, polybutylene naphthalate, and polyethylene terephthalate.

The base layer 1 may contain recycled polyester. Examples of recycled polyester include chemically recycled polyester obtained by chemically recycling a container made of polyester mainly composed of ethylene terephthalate units, and mechanically recycled polyester obtained by mechanically recycling a container made of polyester mainly composed of ethylene terephthalate units.

[Sealant layer]
The sealant layer 2 is a layer that imparts heat-sealing properties to the laminate 3. From the viewpoint of excellent shielding strength, the thickness of the sealant layer 2 is, for example, 15 μm or more, and may be 15 to 100 μm or 20 to 60 μm.

In this embodiment, the sealant layer 2 is composed of a polyester film that has a lower melting point than the base layer 1 or does not exhibit a melting point. The melting point of the sealant layer 2 is, for example, 200°C or less, and may be 130 to 150°C. Amorphous polyester films that do not exhibit a melting point have sufficient fluidity when heated to a temperature equal to or higher than the glass transition temperature, and therefore can be fused at low temperatures. The crystallinity of the polyester film can be adjusted by changing the type of monomer used for copolymerization. In addition, the degree of crystallization can be adjusted by changing the cooling rate when forming the polyester film, thereby adjusting the crystallinity. The crystallinity may also be adjusted by subjecting the formed polyester film to a heat treatment.

In order to fully exert the function of the sealant layer 2 of the standing pouch 10, it is possible to use polybutylene terephthalate, polybutylene naphthalate, polyethylene terephthalate, etc. as the polyester. The sealant layer 2 may contain recycled polyester, as in the base layer 1. The sealant layer 2 may contain various additives such as a flame retardant, a slip agent, an antiblocking agent, an antioxidant, a light stabilizer, and a tackifier. Examples of methods for forming the sealant layer L2 include a casting method and an inflation method.

The laminate 3 may further include a gas barrier layer, for example, from the viewpoint of improving the gas barrier property against water vapor and oxygen. The gas barrier layer may be provided between the base layer 1 and the sealant layer 2, or may be provided on the surface of the base layer 1 opposite to the sealant layer 2. The water vapor transmission rate of the laminate 3 may be, for example, 5 g/m ² ·day, and may be 1 g/m ² ·day or less, or 0.5 g/m ² ·day or less. The oxygen transmission rate of the laminate 3 may be, for example, 1 cc/m ² ·atm ·day, and may be 0.5 g/m ² ·atm ·day or less, or 0.2 g/m ² ·atm ·day or less. By including a gas barrier layer in the laminate 3, the contents are protected from deterioration due to water vapor and oxygen, and the quality is easily maintained for a long time.

An example of a gas barrier layer is a vapor deposition layer of an inorganic oxide. By using a vapor deposition layer of an inorganic oxide, high barrier properties can be obtained with a very thin layer that does not affect the recyclability of the laminate 3. Examples of inorganic oxides include aluminum oxide, silicon oxide, magnesium oxide, and tin oxide. From the viewpoint of transparency and barrier properties, the inorganic oxide may be selected from the group consisting of aluminum oxide, silicon oxide, and magnesium oxide. The thickness of the vapor deposition layer of the inorganic oxide can be, for example, 5 nm to 100 nm, and may be 10 nm to 50 nm. A thickness of 5 nm or more makes it easier to exhibit good barrier properties, and a thickness of 100 nm or less makes it easier to maintain the flexibility of the laminate 3. The vapor deposition layer can be formed by, for example, physical vapor deposition, chemical vapor deposition, etc.

The laminate 3 may include a metal layer (metal foil) instead of or in addition to the inorganic oxide vapor deposition layer. As the metal layer, various metal foils made of aluminum, stainless steel, etc. can be used. Among these, aluminum foil is preferred in terms of moisture resistance, workability such as ductility, cost, etc. As the aluminum foil, a general soft aluminum foil can be used. Among them, aluminum foil containing iron is preferred in terms of excellent pinhole resistance and ductility during molding. When a metal layer is provided, its thickness may be 7 to 50 μm, or 9 to 15 μm in terms of barrier properties, pinhole resistance, workability, etc.

The laminate 3 may have an anchor coat layer between the base layer 1 and the sealant layer 2. The anchor coat layer may be a very thin layer that does not affect the recyclability of the laminate 3, and can be formed using an anchor coat agent. Examples of anchor coat agents include acrylic resins, epoxy resins, acrylic urethane resins, polyester polyurethane resins, polyether polyurethane resins, and polyvinyl alcohol resins. From the viewpoints of heat resistance and interlayer adhesive strength, acrylic urethane resins and polyester polyurethane resins are preferred as anchor coat agents.

The laminate 3 may further include, for example, a printed layer. The printed layer may be provided between the base material layer 1 and the sealant layer 2, or may be provided on the surface of the base material layer 1 opposite the sealant layer 2. When providing a printed layer, it is preferable to use a printing ink that does not contain chlorine in order to prevent the printed layer from discoloring or generating an odor when remelted. In addition, it is preferable to use a biomass material as a compound contained in the printing ink from the viewpoint of environmental consideration.

<Manufacturing method of standing pouch>
The standing pouch 10 is manufactured through the following steps.
(A) A step of forming a plurality of through holes 20a, which will later become the cutout portions 8a, 8b, in the original roll 20 of the laminate 3 (see FIG. 4).
(B) A step of folding the original roll 20 into a W shape.
(C) A step of forming a heat-sealed portion 11 on the W-shaped raw material roll 20.
(D) A step of forming a heat-sealed portion 12 on the raw material roll 20 to form an air-enclosed portion.
(E) A step of obtaining a plurality of standing pouches 10 by cutting the original roll 20 to a predetermined length.

This method allows the efficient manufacture of the standing pouch 10. Because the air-enclosed portion 5 of the standing pouch 10 acts as a cushion, excellent drop resistance can be achieved, despite the limitations on the materials that can be used from the perspective of mono-materialization. Therefore, even if the contents are liquid and the content volume is large, for example, 200 mL or more, the risk of the bag breaking due to being dropped can be sufficiently reduced.

Although the embodiments of the present disclosure have been described in detail above, the present invention is not limited to the above embodiments. For example, the above embodiment illustrates a case in which two pairs of cutout portions 8a, 8b are provided on one side of the standing pouch 10 to form two fused portions 9, but it is also possible to provide a pair of cutout portions to form one fused portion 9. Also, the fused portion may be formed by providing a cutout hole instead of the cutout portions.

In the above embodiment, the mono-material is realized with polyester resin, but the mono-material may be realized with polyolefin resin (e.g., polyethylene resin or polypropylene resin). From the viewpoint of realizing a high degree of mono-materialization, the content of a specific material (e.g., polyethylene resin or polypropylene resin) in the standing pouch is preferably 90% by mass or more, more preferably 92% by mass or more, and even more preferably 95% by mass or more. On the other hand, when the standing pouch is not required to be mono-material, a laminate combining polyester film, nylon film, polyolefin film, etc. may be used as in the conventional case to constitute the self-supporting packaging bag according to the present disclosure.

The present disclosure will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

Example 1
A biaxially oriented PET film (PET film, thickness: 12 μm) and an oriented nylon film (ONY film, thickness: 15 μm) were used as the substrate layer. A linear low-density polyethylene film (LLDPE film, thickness: 50 μm) was used as the sealant layer. The PET film, the ONY film, and the LLDPE film were laminated in this order by the dry lamination method. A urethane resin adhesive was used as the adhesive for dry lamination. The amount of the adhesive applied was adjusted to 3 g/m ² (thickness 3 μm). Multiple notches were provided on both sides of the obtained laminate.

The laminate was folded into a W shape, and then both sides and the bottom were heat sealed to obtain a packaging bag as shown in Fig. 1. The sizes of the packaging bags were as follows:
・Package width: 130mm
・Package height: 250mm
Distance L from valley fold to mountain fold: 50 mm
-Width of the vertical heat seal parts on both sides of the packaging bag: 10 mm
Width of horizontal heat seal part for forming air sealed part: 10 mm
Height of air-filled section: 15 mm
-Fusing part: φ15mm semicircle (2 pieces)

Example 2
A packaging bag was obtained in the same manner as in Example 1, except that an unstretched high-density polyethylene film (HDPE film, thickness: 32 μm) was used as the base layer, and a linear low-density polyethylene film (LLDPE film, thickness: 50 μm) was used as the sealant layer.

Example 3
A packaging bag was obtained in the same manner as in Example 1, except that a stretched polypropylene film (OPP film, thickness: 20 μm) was used as the base layer, and a non-stretched polypropylene film (CPP film, thickness: 50 μm) was used as the sealant layer.

Example 4
A biaxially oriented PET film (thickness: 25 μm) and a biaxially oriented PET film (thickness: 12 μm) were used as the base layer. A packaging bag was obtained in the same manner as in Example 1, except that an amorphous PET sealant film (thickness: 50 μm) was used as the sealant layer.

Example 5
A packaging bag was obtained in the same manner as in Example 4, except that instead of providing two fused portions formed by cutouts on each side of the packaging bag, one was provided on each side.

Example 6
A packaging bag was obtained in the same manner as in Example 4, except that the cutout portion was a semicircle having a diameter of 20 mm instead of a semicircle having a diameter of 15 mm.

Example 7
A packaging bag was obtained in the same manner as in Example 4, except that a silica vapor deposition film was provided on one side of the biaxially oriented PET film (thickness: 12 μm) in Example 4 to form a barrier film.

Example 8
A packaging bag was obtained in the same manner as in Example 7, except that the height H of the air-filled portion was 3 mm instead of 15 mm.

<Example 9>
A packaging bag was obtained in the same manner as in Example 7, except that the height H of the air-filled portion was 30 mm instead of 15 mm.

<Comparative Example 1>
A packaging bag having the structure shown in Figures 5 and 6 was obtained using a laminate having the same structure as in Example 1. That is, the sealant layers of the front laminate 3a and the back laminate 3b were placed facing each other, and the bottom laminate 3c, which was folded in half, was placed between them. The bottom laminate 3c was folded so that the sealant layer was on the outside. The facing sealant layers were heat-sealed to obtain a packaging bag according to Comparative Example 1. The size of the packaging bag was as follows.
・Package width: 130mm
・Package height: 250mm
Distance L1 from the bottom of the packaging bag to the fold of the bottom laminate 3c: 40 mm
-Width of the vertical heat seal parts on both sides of the packaging bag: 10 mm
・Seal shape at the bottom of the packaging bag: curve with a radius of 60 mm ・Fusing part: semicircle with a diameter of 15 mm (2 parts)
The distance L1 shown in FIG. 5 is the distance when the inner surfaces (sealant layers) of the laminate 3a and the laminate 3b are in contact with each other.

<Comparative Example 2>
A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same configuration as in Example 2 was used.

<Comparative Example 3>
A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same structure as in Example 3 was used.

<Comparative Example 4>
A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same configuration as in Example 4 was used.

<Comparative Example 5>
A packaging bag was obtained in the same manner as in Comparative Example 1, except that a laminate having the same configuration as in Example 7 was used.

[Drop test]
The contents of the packaging bag were 50 ml, 100 ml, 200 ml, 300 ml, 400 ml, or 500 ml of water, and the top of the packaging bag was heat-sealed to obtain a package. These packages were stored in an environment of 5°C for 24 hours. Thereafter, the packaging bag was dropped vertically from a height of 1 m so that the bottom of the bag was facing down, and the number of times the bag was dropped until it broke was counted. Tests were carried out on 20 samples under the same conditions, and the samples were evaluated according to the following criteria. The results are shown in Tables 1 to 3.
A: 90% or more of the samples did not break after 20 drops. B: 50% or more but less than 90% of the samples did not break after 20 drops. C: Less than 50% of the samples did not break after 20 drops.

[Evaluation of oxygen and water vapor barrier properties]
The oxygen permeability and water vapor permeability of the laminate were measured in accordance with the method described in JIS K7126B. The results are shown in Tables 1 to 3.

From the evaluation results of the Examples and Comparative Examples, even if the laminate structure is the same, the drop resistance is significantly improved by providing an air-enclosed portion at the bottom of the packaging bag. Even with a structure made of a single material (Examples 4 to 9), sufficient drop resistance is obtained, making it possible to provide a packaging bag that combines the preservation and recyclability of the contents. In Tables 1 to 3, the area ratio of the fused portion in the Examples is a value calculated by the above formula (1), and the area ratio of the fused portion in the Comparative Examples is a value calculated by the following formula (2).
Area ratio (%) = (total area of fused parts) / (L1 x 10) x 100 ... (2)
[In formula (2), L1 represents the distance (unit: mm) from the bottom side of the packaging bag to the fold of the bottom laminate.]

1...base layer, 2...sealant layer, 3...laminated body, 5...air-sealed portion, 8a, 8b...cutout portion, 9...sealed portion, 10a...body portion, 10b...bottom portion, 10...standing pouch (self-supporting packaging bag), 11, 12...heat-sealed portion, M1...mountain fold portion, V1, V2...valley fold portion

Claims (8)

A self-supporting packaging bag formed by a laminate having a base layer and a sealant layer,
A body portion in which contents are accommodated;
The bottom and
Equipped with
The bottom portion is
A pair of valley folds formed by folding the laminate;
a mountain fold portion formed between the pair of valley fold portions;
an air enclosure formed by heat sealing the area between the valley fold and the mountain fold laterally of the base;
having
the air sealed portion has an upper end configured by the heat sealed portion formed by the heat sealing and a lower end configured by the valley fold portion, and has a portion in which the distance between inner surfaces of the laminate increases from the upper end toward the lower end,
The self-supporting packaging bag, wherein the valley fold portion forms a lower end of the self-supporting packaging bag . The self-supporting packaging bag according to claim 1, wherein the height of the air-sealed portion is 5 to 30 mm. The laminate has at least one pair of cutouts or holes in a region between the valley fold and the mountain fold and on a side of the laminate,
The self-supporting packaging bag according to claim 1 or 2, wherein a fused portion is provided in which the sealant layers are locally fused to each other through the pair of cutout portions or punched holes. The self-supporting packaging bag according to claim 3, wherein the area ratio of the fused portion calculated by the following formula (1) is 30 to 70%.
Area ratio (%)=(area of the fused portion)/(L×10)×100
[In formula (1), L represents the distance (unit: mm) from the valley fold to the mountain fold.] The self-supporting packaging bag according to claim 3 or 4, wherein the fused portion has a semicircular shape. the base layer is made of a first polyester resin, the sealant layer is made of a second polyester resin ,
The self-supporting packaging bag according to any one of claims 1 to 5 , wherein the melting point of the second polyester resin is lower than the melting point of the first polyester resin . the base layer is made of a first polyolefin resin, the sealant layer is made of a second polyolefin resin,
The self-supporting packaging bag according to any one of claims 1 to 5, wherein the melting point of the second polyolefin resin is lower than the melting point of the first polyolefin resin. The self-supporting packaging bag according to any one of claims 1 to 7 , wherein the laminate further comprises a gas barrier layer.

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