JP6897005B2 - Free-standing flexible packaging bag - Google Patents

Description

The present invention relates to a flexible packaging bag that can stand on its own.

Patent Document 1 discloses a self-supporting flexible packaging bag as a packaging bag for packaging contents such as liquid, viscous body, powder, and solid. FIG. 4A shows a perspective view of the flexible packaging container in a self-standing state. Such a flexible packaging bag includes a first side film 101 having a thermoplastic resin layer as the innermost layer, a second side film 102, and a bottom film 103 inserted between them in a folded state from the crease side. Including. In these films, the peripheral edge portion 104 is sealed, and the portion surrounded by the peripheral edge portion 104 becomes the storage portion 105. Polypropylene resin or polyethylene resin is often used as the material of the thermoplastic resin layer.

As a material for the packaging bag, a biaxially stretched polyester film such as a biaxially stretched polyethylene terephthalate film having excellent strength, heat resistance, dimensional stability, chemical resistance, fragrance retention and the like is also known. A flexible packaging bag formed by heat-sealing stretched polyethylene terephthalate films with each other is expected. However, the oriented film has poor heat sealability. Therefore, Patent Document 2 discloses a method of imparting heat sealability by irradiating the surface of a biaxially stretched polyester film with a short pulse of electromagnetic waves and modifying the surface.

Japanese Unexamined Patent Publication No. 2016-003059 Tokusho 4-263339

The polypropylene-based resin and polyethylene-based resin used in the flexible packaging bag disclosed in Patent Document 1 have a property of adsorbing various substances. Therefore, when these are used for the innermost layer of the film, the components contained in the contents of the flexible packaging bag may be adsorbed and the quality may be deteriorated. In addition, since these substances emit an odor, the quality may be impaired depending on the properties of the contents.

Therefore, based on the technology disclosed in Patent Document 2, a flexible packaging bag capable of self-supporting is manufactured by using a laminate in which a biaxially stretched polyester film imparted with heat sealability is laminated on the innermost layer, thereby forming a content. It is possible to provide a flexible packaging bag in which the adsorption of contained components is suppressed.

However, a flexible packaging bag using a laminate having a biaxially stretched polyester film as the innermost layer may cause heat seal failure for the following reasons. FIG. 4B shows a partial cross-sectional view of the bottom film 103 around the folded-back portion 106, which is obtained by cutting the flexible packaging bag of FIG. 4A along the AA'line. As shown in FIG. 4B, in the flexible packaging bag using the biaxially stretched polyester film, a portion where the first side film 101 and the second side film 102 are in contact with each other around the folded portion 106 of the bottom film 103 and a second. A step is formed due to the difference in the thickness of the portion where the bottom film 103 is located between the side film 101 of 1 and the second side film 102. The low-fluidity biaxially stretched polyester films constituting the films 101, 102, 103 cannot sufficiently fill this step even by the pressurization during the heat seal treatment, and the heat seals of the films 101, 102, 103 are heat-sealed. Was inadequate.

The present invention has been made in view of such a problem, and an object of the present invention is to provide a self-supporting flexible packaging bag which has low adsorptivity of contents and does not cause heat seal failure.

One aspect of the present invention for solving the above problems includes a first side film, a second side film, and a bottom film inserted between them in a folded state from the crease side. A self-supporting flexible packaging bag in which the peripheral portion is sealed and the portion surrounded by the sealed peripheral portion serves as a storage portion, and the first side film, the second side film, and the bottom film are A flexible laminate including a biaxially oriented polyethylene terephthalate layer laminated on the innermost layer, which is a layer facing the space inside the storage portion, and an olefin layer laminated adjacent to the biaxially oriented polyethylene terephthalate layer. It is a packaging bag.

According to an object of the present invention, it is an object of the present invention to provide a self-supporting flexible packaging bag having low adsorptivity of contents and not causing heat seal failure.

Top view of side film Top view of bottom film Top view of the packaging bag Cross-sectional view of the laminate Cross-sectional view of the laminate Cross-sectional view of the laminate Partial cross-sectional view of the packaging bag in the heat sealing process Partial cross-sectional view of the packaging bag in the heat sealing process Perspective view of the packaging bag Partial cross-sectional view of the packaging bag

Hereinafter, the laminated body 200, which is an example of the flexible packaging bag 100 (hereinafter, simply referred to as the packaging bag 100) and the laminated body used for the flexible packaging bag 100, will be described with reference to the drawings. The same or corresponding elements in each modification are designated by the same reference numerals and the description thereof will be omitted as appropriate.

(Packaging bag)
1A shows a plan view of the first side film 101 and the second side film 102, FIG. 1B shows a plan view of the bottom film 103, and FIG. 1C shows the bottom film 103 folded back. The plan view of the package bag 100 in a folded state is shown. The packaging bag 100 is formed by forming the laminate 200 into a predetermined shape, the first side film 101, the second side film 102, and the bottom film 103 inserted between them in a folded state from the crease side. And have. The shapes of the first side film and the second side film are the same. With the bottom film 103 inserted between the first side film 101 and the second side film 102, the peripheral edge 104 of each film shown by hatching is heat-sealed to be surrounded by the peripheral edge 104. A storage portion 105 is formed. By opening the bottom film 103 folded in half, the bottom film 103 becomes the bottom of the packaging bag 100, and the packaging bag 103 can stand on its own.

The width of the first side film 101 and the second side film 102 can be appropriately set in the range of 80 mm or more and 300 mm or less, and the height can be appropriately set in the range of 120 mm or more and 400 mm or less. The folding width of the bottom film 103 can be appropriately set in the range of 20 mm or more and 70 mm or less. The folding width of the bottom film 103 is the distance from the folded portion 106 of the bottom film 103 in the folded state of the bottom film 103 to the lower end of the packaging bag 100 (distance indicated by h in FIG. 1C).

The shapes of the side films 101 and 102 are not limited to a rectangular shape, and for example, a recess or the like may be provided in the peripheral edge portion 104 in consideration of operability. Any shape can be adopted depending on the situation.

(Laminated body)
FIG. 2A is a cross-sectional view of the laminated body 200. As shown in FIG. 2A, the laminated body 200 has polyester layers 210 / aluminum layers 220 / olefin layers 230 / biaxially oriented polyester layers 240 laminated in this order from the outer layer to the inner layer of the packaging bag 100.

The polyester layer 210 is formed by being laminated on the outer layer of the aluminum layer 220 by using, for example, polyethylene terephthalate (PET). The thickness of the polyester layer 210 is, for example, 12 μm, and can be appropriately set in the range of 6 μm or more and 25 μm or less.

The aluminum layer 220 is formed by laminating an aluminum foil on the outer layer of the olefin layer 230 by dry laminating or the like. The thickness of the aluminum layer 220 is, for example, 9 μm, and can be appropriately set in the range of 5 μm or more and 15 μm or less.

The olefin layer 230 is an acid copolymer such as a linear low density polyethylene resin (LLDPE), a low density polyethylene resin (LDPE), an ethylene / methacrylic acid copolymer (EMAA), or an ethylene / acrylic acid copolymer (EAA). It is formed on the outer layer of the biaxially oriented polyester layer 240 by dry lamination, extrusion lamination or the like using an ester copolymer such as ethylene / methyl acrylate copolymer (EMA) or ionomer (ION), modified polyethylene or the like. The thickness of the olefin layer 230 is, for example, 30 μm, and can be appropriately set in the range of 20 μm or more and 100 μm or less. In particular, it is preferably 30 μm or more and 80 μm or less. If the thickness of the olefin layer 130 is thinner than 20 μm, the strength of the laminate 200 becomes low and it becomes difficult for the packaging bag 100 to stand on its own. Further, if the thickness of the olefin layer 130 is thicker than 100 μm, the laminate 200 becomes too hard and the packaging bag 100 becomes difficult to operate.

The biaxially oriented polyester layer 240 is formed in the inner layer of the olefin layer 230 by using, for example, biaxially oriented PET. By preferably selecting the biaxially oriented polyester layer 240, it is adsorbed on polyethylene resins and polypropylene resins such as d-camphor, l-menthol, methyl salicylate, ethyl caproate, turobterol, acetate-dl-α-tocopherol and the like. The amount of substances that are easily adsorbed can be reduced. An anchor coating agent may be used between the olefin layer 230 and the biaxially oriented polyester layer 240, or an anchor coating agent may not be used by applying a corona treatment to the biaxially oriented polyester layer 240. The thickness of the biaxially oriented polyester layer 240 is 12 μm, and can be appropriately set in the range of 6 μm or more and 25 μm or less.

The layer structure of the laminated body is not limited to the laminated body 200. A modified example will be described below. FIG. 2B is a cross-sectional view of the laminated body 201. As shown in FIG. 2B, the laminated body 201 is laminated with polyester layer 210 / aluminum layer 220 / nylon layer 250 / olefin layer 230 / biaxially oriented polyester layer 240 in this order from the outer layer to the inner layer of the packaging bag 100. The difference between the laminate 201 and the laminate 200 is that a nylon layer 250 is provided between the aluminum layer 220 and the olefin layer 230.

The nylon layer 250 is formed on the outer layer of the olefin layer 230 using nylon. The thickness of the nylon layer 250 is, for example, 15 μm, and can be appropriately set in the range of 6 μm or more and 25 μm or less.

By providing the nylon layer 250, the laminate 201 can have higher strength than the laminate 200.

FIG. 2C is a cross-sectional view of the laminated body 202. As shown in FIG. 2C, the laminated body 202 is laminated with aluminum-deposited polyester layer 260 / nylon layer 250 / olefin layer 230 / biaxially oriented polyester layer 240 in this order from the outer layer to the inner layer of the packaging bag 100. The difference between the laminate 202 and the laminate 201 is that a vapor-deposited polyester layer 260 is provided instead of the polyester layer 210 / aluminum layer 220.

The thin-film vapor-deposited polyester layer 260 is a thin-film film in which a metal such as aluminum, silica, alumina or the like is deposited on a polyester layer such as PET. The thickness of the vapor-deposited polyester layer 260 is, for example, 12 μm, the thickness of the vapor-deposited layer is 5 nm or more and 100 nm or less, and the thickness of the polyester layer can be appropriately set in the range of 6 μm or more and 25 μm or less.

By providing the laminated body 202 with the vapor-deposited polyester layer 260, it is possible to realize the same barrier properties and strength as the laminated body 201 while being a laminated body thinner than the laminated body 201.

The laminate used for the packaging bag 100 functions as the packaging bag 100 if the biaxially oriented polyester layer 240 laminated on the innermost layer and the olefin layer 230 laminated adjacent to the biaxially oriented polyester layer 240 are included. Various layers may be added depending on the situation. Further, if the olefin layer 230 is formed adjacent to the biaxially oriented polyester layer 240 of the innermost layer, the stacking order of each layer is appropriately changed, for example, the order of the aluminum layer 220 and the nylon layer 250 is changed. be able to. Further, the thickness of each layer is not limited and can be set as appropriate.

(Manufacturing method of packaging bag)
The method for manufacturing the packaging bag 100 includes a step of imparting heat sealability to the peripheral edges 104 of the first side film 101, the second side film 102, and the bottom film 103, and the first side film 101. It includes a step of inserting the bottom film 103 from the crease side in a state of being folded in half with the second side film 102, and a step of heat-sealing the peripheral edges 104 to which the heat-sealing property of these films is imparted.

Since a film having orientation usually has poor heat-sealing property, it is preferable that the biaxially oriented polyester layer 240 improves the heat-sealing property at least at the peripheral edge portion 104 by a predetermined method. As a method for improving the heat sealability, for example, an electromagnetic irradiation method as described in Japanese Patent Application Laid-Open No. 4-263339 may be used, or another known method may be used. In addition, other new methods such as laser light irradiation may be used.

As a heat sealing method, a method such as impulse sealing, hot air, ultrasonic sealing, high frequency sealing or the like can be used.

3A and 3B are partial cross-sectional views of the bottom film 103 around the folded-back portion 106 in the heat sealing process. For the sake of clarity, only the polyester layer 210, the olefin layer 230, and the biaxially oriented polyester layer 240 are shown in FIGS. 3A and 3B.

The films 101, 102, 103 have an olefin layer 230 adjacent to the biaxially oriented polyester layer 240. Therefore, as shown in FIG. 3A, when the bottom film 103 is pressed between the first side film 101 and the second side film 102 while being heated as shown by the white arrow in the heat sealing step. The olefin layer 240, which has become fluid due to heat, can be deformed between the polyester layer 210 and the biaxially oriented polyester layer 250. When the pressure is further continued in this state, the olefin layers 230 of the films 101, 102, and 103 flow so as to fill the gaps between the biaxially oriented polyester layers 240. In particular, the two axes of the films 101, 102, and 103 are located in the vicinity of the folded portion of the bottom film 103 and are sandwiched between the biaxially oriented polyester layer 240 of the first side film and the second side film. The oriented polyester layer 240 is pressed by the olefin layer 240 so as to fill the gap. As a result, as shown in FIG. 3B, the biaxially oriented polyester layers 240 of the films 101, 102, and 103 can be heat-sealed in a state of being in close contact with each other without gaps or steps. No defects occur.

Laminates according to Examples 1 to 3 and Comparative Examples 1 to 3 were prepared, and packaging bags were prepared using the respective laminates, and the adsorptivity and sealing performance of the packaging bags were evaluated. Further, using the laminates according to Examples 1 to 3, packaging bags having different dimensions were produced, and the independence and operability were evaluated.

(Example 1)
The laminate according to Example 1 was formed by laminating PET (12 μm) / aluminum (9 μm) / polyethylene (30 μm) / biaxially oriented PET (12 μm) in this order from the outer layer to the inner layer.

(Example 2)
The laminate according to Example 2 was formed by laminating PET (12 μm) / aluminum (9 μm) / nylon (30 μm) / polyethylene (30 μm) / biaxially oriented PET (12 μm) in this order from the outer layer to the inner layer.

(Example 3)
The laminate according to Example 3 was formed by laminating aluminum-deposited PET (12 μm) / nylon (30 μm) / polyethylene (30 μm) / biaxially oriented PET (12 μm) in this order from the outer layer to the inner layer.

(Comparative Example 1)
The laminate according to Comparative Example 1 was formed by laminating PET (12 μm) / aluminum (9 μm) / biaxially oriented PET (12 μm) in this order from the outer layer to the inner layer.

(Comparative Example 2)
The laminate according to Comparative Example 2 was formed by laminating PET (12 μm) / aluminum (9 μm) / polyethylene (30 μm) in this order from the outer layer to the inner layer.

(Comparative Example 3)
The laminate according to Comparative Example 3 was formed by laminating PET (12 μm) / aluminum (9 μm) / nylon (30 μm) / polyethylene (30 μm) in this order from the outer layer to the inner layer.

Laminations of Examples 1 to 3 and Comparative Example 1 in which biaxially oriented PET is provided in the innermost layer in order to impart heat sealability after forming the respective laminates into the shapes of two side films and a bottom film. The peripheral edge of the innermost layer of the body was irradiated with laser light. A carbon dioxide laser device (ML-Z9510, manufactured by KEYENCE) was used for irradiating the laser light.

Then, the produced laminate was heat-sealed to produce a packaging bag. The heat seal was performed by applying a load of 0.2 MPa at a temperature of 170 ° C. for 2 seconds. The dimensions of the packaging bag used for purposes other than the evaluation of independence and operability were an outer width of 120 mm, a height of 240 mm, and a folding width of 34 mm.

(Adsorption evaluation)
The adsorptivity was evaluated by the following procedure. First, each packaging bag containing shochu as a content liquid was prepared, and these were stored at 40 ° C. for one month. Then, 1 ml of the content of each packaging bag was collected using a micropipette, sealed in a vial, SPME fiber was inserted into the vial, and this was heated at 60 ° C. for 20 minutes. Finally, the SPME fiber was inserted into the inlet of a gas chromatograph / mass spectrometer (GC6890 / MSD56973, manufactured by Agilent), and the residual amount of fatty acid ester in the content liquid was analyzed.

(Seal property evaluation)
The sealability was evaluated by visually confirming the presence or absence of a gap between the first side film 101 and the second side film 102 in the vicinity of the folded portion of the bottom film 103 for each of the produced packaging bags.

The evaluation results are shown in Table 1. Table 1 shows the peak area value of the residual amount of fatty acid ester in the content liquid measured by the gas chromatograph / mass spectrometer, which is the result of the adsorptivity evaluation, and the presence or absence of gaps in each packaging bag, which is the result of the sealability evaluation. The comprehensive evaluation results obtained from the two evaluation results are shown. As a result of the comprehensive evaluation, "+" was added when it was suitable for a packaging bag containing an adsorbent substance, and "-" was added when it was not suitable.

As shown in Table 1, in the packaging bags of Examples 1 to 3 and Comparative Example 1, since the innermost layer is formed of PET, it is compared with the packaging bags of Comparative Examples 2 and 3 in which the innermost layer is formed of polyethylene. Therefore, it was confirmed that the residual amount of fatty acid ester was large, that is, the amount of adsorbed content liquid was small. Further, in the packaging bags of Examples 1 to 3, since polyethylene is formed adjacent to the biaxially oriented PET of the innermost layer, the biaxially oriented PET has a gap even in the vicinity of the folded portion of the bottom film of the side film. It was confirmed that there was no heat sealing. From these results, it was confirmed that the laminate according to Examples 1 to 3 is suitable for a packaging bag for storing an adsorptive substance.

(Evaluation of independence and operability)
Using the laminates of Examples 1 to 3, a packaging bag having the following dimensions 1 to 6 of the films 101, 102, and 103 was prepared, and the independence and operability of each packaging bag were evaluated. Dimension 1 has an outer width of 70 mm, a height of 100 mm, and a bottom folding width of 15 mm. Dimension 2 has an outer width of 80 mm, a height of 120 mm, and a bottom folding width of 20 mm. Dimension 3 has an outer width of 100 mm, a height of 150 mm, and a bottom folding width of 25 mm. Dimension 4 has an outer width of 200 mm, a height of 280 mm, and a bottom folding width of 35 mm. The dimensions 5 are an outer width of 300 mm, a height of 400 mm, and a bottom folding width of 70 mm. Dimension 6 has an outer width of 350 mm, a height of 500 mm, and a bottom folding width of 85 mm. The outer width and height of each dimension are the dimensions of the first side film and the second side film, and the distance between the ends in the left-right direction when the packaging bag is upright, and the distance between the ends, respectively. The distance between the ends in the vertical direction. The bottom folding width is the distance from the folded portion 106 of the bottom film 103 in the folded state of the bottom film 103 to the lower end of the packaging bag 100.

The independence evaluation evaluated the ease of independence of each packaging bag filled with water as the content liquid. In the operability evaluation, each packaging bag filled with water was opened, and the ease of operation when pouring out the content liquid was evaluated by a sensory test.

The evaluation results are shown in Table 2. In Table 2, as a result of the independence evaluation, the bottom film 103 was sufficiently opened to become the bottom surface, and the packaging bag that could be easily made to stand on its own was marked with "++", and it was possible to make it stand on its own. Packaging bags that were not as easy as "++" are shown with "+". In addition, as a result of the operability evaluation, "++" is attached to the packaging bag that can be easily operated, and "+" is attached to the packaging bag that can be operated but not as easy as "++". Indicated.

As shown in Table 2, when the folding width was smaller than 20 mm, the bottom film 103 was difficult to bend and the bottom film 103 was difficult to open stably. When the first side film 101 and the second side film 102 are larger than the width 300 × the height 400, the first side film 101 and the second side film 102 are bent due to the size of the first side film 101 and the second side film 102 to operate the packaging bag. The sex has decreased. From these results, the packaging bag of the present invention can be manufactured in various dimensions, but the width of the first side film 101 and the second side film 102 is 80 mm or more and 300 mm or less, and the height is 120 mm. It was confirmed that the case where the thickness is 400 mm or less and the folding width of the bottom film 103 is 20 mm or more and 70 mm or less is particularly preferable.

As described above, according to the present invention, the adsorption amount of a specific substance can be suppressed to be low as compared with a laminate using polyethylene or polypropylene as the innermost layer. Further, since it is difficult for gaps and steps to be formed around the bent portion of the laminated body during heat sealing, it is possible to provide a packaging bag in which heat sealing failure does not occur. Further, since the high-strength biaxially oriented polyester layer 240 is provided with heat-sealing property and used for the laminate, the thickness of the laminate can be made thinner than that when the olefin layer 230 is used for the sealant, and the packaging can be performed. The weight of the bag can be reduced.

The present invention is useful for packaging bags and the like.

100 Flexible packaging bag 101 1st side film 102 2nd side film 103 Bottom film 104 Peripheral part 105 Storage part 106 Folded part 200, 201, 202 Laminated body 210 Polyester layer 220 Aluminum layer 230 Olefin layer 240 Biaxially oriented polyester layer 250 Olefin layer 260 Aluminum vapor-deposited polyester layer

Claims (2)

It has a first side film, a second side film, and a bottom film inserted between them in a folded state from the crease side, and the peripheral edge is sealed, and the sealed peripheral edge is sealed. It is a self-supporting flexible packaging bag in which the part surrounded by is a storage part.
The first side film, the second side film, and the bottom film are
A biaxially oriented polyethylene terephthalate layer laminated on the innermost layer, which is a layer facing the space inside the storage portion, and
A flexible packaging bag which is a laminate containing an olefin layer laminated adjacent to the biaxially oriented polyethylene terephthalate layer. The width of the first side film and the second side film is 80 mm or more and 300 mm or less.
The heights of the first side film and the second side film are 120 mm or more and 400 mm or less.
The flexible packaging bag according to claim 1, wherein the folding width of the bottom film is 20 mm or more and 70 mm or less.

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