Packaging bags

Abstract

To provide a back pasted bag-shaped packaging bag causing no unexpected rupture of a steam passing planed part in a circulation course, and having an automated steam passing function allowing smooth steam ejection in heating time.SOLUTION: A back pasted bag-shaped packaging bag 1 has a bag body 10 formed by pasting a plastic resin film or a laminate thereof and having a storing part 15 therein. An arch-shaped non-seal part 13 communicating with the storing part is formed in a back pasted seal part 11, and a steam passing planned part 14 is formed at a part covered with the back pasted seal part of the bag body.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a packaging bag in the shape of a back - pasted bag having an automatic steam - venting function that automatically vents the water vapor generated when the contents are heated.

Background Art

[0002] There are known packaging bags used for heating contents. Such a packaging bag may be provided with a planned steam - venting portion for discharging the water vapor generated from the contents by heating to the outside of the packaging bag. Patent Document 1 discloses an example of a packaging bag including a planned steam - venting portion. The sheet constituting this packaging bag is provided with a planned steam - venting portion having a low strength so as to break when the pressure inside the packaging bag rises. When this packaging bag is heated by a heating means such as a microwave oven, the sheet expands due to the water vapor generated from the contents, and as the sheet expands, the planned steam - venting portion breaks, and the water vapor inside the packaging bag is discharged from the broken portion.

[0003] However, in the packaging bag of Patent Document 1, when an external force is applied to the packaging bag during the distribution process such as during transportation, or when the packaging bag is pulled by a consumer during handling, the planned steam - venting portion may break unintentionally, and the function of the planned steam - venting portion may be impaired.

[0004] Among packaging bags, there is known a packaging bag called a back - pasted bag 4 having a shape in which a single film is sealed back - to - back to form a cylinder, and both ends of the cylinder are adhered and cut at a predetermined length. It is also called a clasp - sealed bag or a pillow bag. The portion sealed back - to - back becomes the back - pasted seal portion 21, and it protrudes from the bag body across the seal portions 12 at both adhered ends. The protruding back - pasted seal portion 21 is normally in a state 21´ where it falls along the bag body and covers the bag body.

[0005] When forming a steam-permeable portion in such a back-sealed bag, in order to prevent unintended rupture as described above, the steam-permeable portion 14 is formed in the area covered by the back-seal portion 21 of the bag body 20 so that the steam-permeable portion 14 is not exposed. However, with such a structure, when the bag is heated by a heating means such as a microwave oven to heat the contents 16 and expands, the back-seal portion 21 is pressed tightly against the bag body 20 without any gaps, as illustrated in Figure 8, a schematic cross-sectional view of line segment DD. As a result, the opening 14' formed when the steam-permeable portion 14 ruptures due to expansion is blocked by the back-seal portion 21, preventing the smooth release of water vapor 17 generated from the contents 16, etc., which can cause the internal pressure to rise too high and the bag to burst. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 3942709 [Overview of the project] [Problems that the invention aims to solve]

[0007] Therefore, the object of the present invention is to provide a packaging bag in the shape of a back-sealed bag that prevents the steam-permeable portion from being unintentionally ruptured during the distribution process, and that has an automatic steam-permeable function that allows for the smooth release of steam when heated. [Means for solving the problem]

[0008] To solve the above problems, the present invention provides a back-sealed packaging bag having a bag body formed by laminating a plastic resin film or a laminate thereof, with a storage compartment formed inside, This packaging bag is characterized by having an arch-shaped non-sealed section that communicates with the storage section formed on the sealed portion, and a steam-permeable section formed on the part of the bag body that is covered by the back sealed portion.

[0009] The present invention also relates to a packaging bag in the shape of a back-sealed bag having a bag body formed by bonding a plastic resin film or a laminate thereof, wherein an arch-shaped non-seal portion communicating with the storage portion is formed on the back-sealed portion, and a steam-permeable portion is formed on the side of the non-sealed portion that faces the bag body when the back-sealed portion covers the bag body.

[0010] Furthermore, the present invention relates to a packaging bag in the shape of a back-sealed bag having a bag body formed by laminating a plastic resin film or a laminate thereof, wherein the back-sealed portion is embossed, and a steam-permeable portion is formed in the part of the bag body that is covered by the back-sealed portion.

[0011] In the above-mentioned packaging bag, the area intended for steam passage may be formed by scratching. [Effects of the Invention]

[0012] According to the present invention, [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic external view of one embodiment of the packaging bag of the present invention. [Figure 2] This is a schematic cross-sectional view of one embodiment of the packaging bag of the present invention. [Figure 3] This is a schematic external view of a second embodiment of the packaging bag of the present invention. [Figure 4] This is a schematic cross-sectional view of a second embodiment of the packaging bag of the present invention. [Figure 5] This is a schematic external view of a third embodiment of the packaging bag of the present invention. [Figure 6] This is a schematic cross-sectional view of a third embodiment of the packaging bag of the present invention. [Figure 7] This is a schematic diagram of a conventional packaging bag. [Figure 8] This is a schematic cross-sectional view of a conventional packaging bag. [Modes for carrying out the invention]

[0014] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The present invention is not limited to the embodiments described below. In the following, the same reference numerals may be assigned to equivalent members and the description thereof may be omitted.

[0015] FIG. 1 is a schematic external view of an embodiment of the packaging bag of the present invention. FIG. 2 is a schematic cross-sectional view taken along line segment A-A. The packaging bag 1 of the present invention generally has a shape called a back-pasted bag. A single plastic film or a laminate thereof is sealed back-to-back to form a tube, and both ends of the tube are adhered at the seal portions 12 at a predetermined length to form a bag body 10 having a storage portion 15 inside. The portion sealed back-to-back becomes the back-pasted seal portion 11, which is formed to protrude from the bag body 10 over both ends that are adhered. The protruding back-pasted seal portion 11 normally falls along the bag body 10 and assumes a state 11' covering the bag body.

[0016] An unsealed portion 13 that is not sealed is formed in an arch shape in a part of the back-pasted seal portion 11. There is no boundary or the like between the internal space of the unsealed portion 13 and the storage portion 15, and they are in communication. And a steaming planned portion 14 is formed at a portion of the bag body 10 covered by the back-pasted seal portion 11. Therefore, the steaming planned portion 14 is normally covered by the back-pasted seal portion 11. The steaming planned portion 14 can be provided by applying a known scoring method without particular limitation, and is, for example, a fragile processed portion formed by knife processing, laser processing, half-cut processing, or the like.

[0017] Therefore, normally, the steaming planned portion, which is a fragile processed portion, is not exposed, and there is no risk of being broken by contacting other articles during the distribution process or the like. Or, for example, even if adhesive tapes are wound around a plurality of packaging bags 1 and bundled together, the adhesive tape will not be directly attached to the steaming planned portion, and there is no risk that the consumer will accidentally break the steaming planned portion when peeling off the adhesive tape.

[0018] The plastic film constituting the packaging bag 1 is not particularly limited. For example, biaxially stretched nylon film (ONY), biaxially stretched polypropylene film (OPP), biaxially stretched polyester film (PET), unstretched nylon film (NY), unstretched polypropylene film (PP), etc. can be exemplified. When applying a laminate, for example, those in which a sealant layer is laminated on each of the above plastic films can be mentioned. As the sealant layer, layers of various resins having heat-sealability can be applied, such as polyolefins (polyethylene (PE), ethylene-vinyl acetate copolymer (EVA), ethylene-acrylate copolymer, ionomer, ethylene-propylene copolymer, etc.), polyester, acrylic copolymer. Among them, low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) can be exemplified as suitable ones, but it is not limited thereto. Each of the above films can be used alone or in various combinations.

[0019] Also, depending on the characteristics and uses of the contents, layers other than the above may be provided, which are not particularly limited, but a barrier layer, a light-shielding layer, a stain-preventing layer, a printing layer, etc. can be exemplified.

[0020] When the contents 16 are stored in the packaging bag 1 and heated in a microwave oven, as shown in the lower figure of FIG. 2, moisture such as the contents vaporizes to generate water vapor 17, causing the storage part 15 to expand and the internal pressure to increase. As a result, the internal space of the non-sealing part 13 also expands integrally with the storage part 15, so that the back sticker seal part 11 naturally rises and the planned steam passage part 14 is exposed. As the internal pressure further increases, the planned steam passage part 14, which is a fragile processing part, is automatically broken to become an opening part 14', and the water vapor 17 jets out to lower the internal pressure, preventing the packaging bag 1 from bursting and enabling steaming cooking to be performed while maintaining an appropriate internal pressure.

[0021] The formation of the arch-shaped non-sealing part 13 enables the back sticker seal part 11 to rise preferably during heating in a microwave oven, and the opening part 14' is exposed, allowing the water vapor 17 to be discharged smoothly.

[0022] Figure 3 is a schematic external view of a second embodiment of the packaging bag of the present invention. Figure 4 is a schematic cross-sectional view along line segment BB. The packaging bag 2 in this embodiment can be equivalent to the embodiment described above in terms of its basic structure and materials, but the steam-permeable portion 14 is formed on the side of the non-seal portion 13 that normally lies along the bag body 10 and covers the bag body 10. That is, it is provided on the side facing the bag body 10 when the back-seal portion 11 is in the configuration 11' that covers the bag body 10.

[0023] When the contents 16 are placed in the packaging bag 2 and heated in a microwave oven, similar to the embodiment described above, moisture in the contents vaporizes, generating steam 17, causing the storage section 15 to expand, the internal space of the unsealed section 13 to expand, the back-sealed section 11 to rise, and the steam-permeable section 14 formed in the unsealed section 13 to be exposed. As the internal pressure increases further, the steam-permeable section 14 automatically ruptures to become an opening 14', allowing the steam 17 to escape and reduce the internal pressure, preventing the packaging bag 1 from bursting, and maintaining an appropriate internal pressure to allow for steam cooking.

[0024] The steam-passing portion 14 formed in the arch-shaped non-sealed portion 13 is exposed when the back-sealed portion 11 rises during heating in the microwave oven, and remains exposed when it becomes an opening 14', allowing for smooth discharge of steam 17.

[0025] Figure 5 is a schematic external view of a third embodiment of the packaging bag of the present invention. Figure 6 is a schematic cross-sectional view along line segment CC. The packaging bag 3 in this embodiment can be the same as the embodiments described above in terms of its basic structure and materials, but the back seal portion 11 is embossed to create a textured surface. The steam-permeable portion 14 is formed on the bag body 10 in the area covered by the back seal portion 11. Therefore, the steam-permeable portion 14 is normally covered by the back seal portion 11.

[0026] When the contents 16 are placed in the packaging bag 3 and heated in a microwave oven, similar to the embodiment described above, the moisture in the contents vaporizes, generating steam 17, causing the storage section 15 to expand and grow. As the internal pressure increases further, the steam-passing section 14, which is a fragile processed part, automatically ruptures to become an opening 14', allowing the steam 17 to escape and reduce the internal pressure, preventing the packaging bag 3 from bursting, while also maintaining an appropriate internal pressure to allow for steam cooking.

[0027] Unlike the embodiments described above, the back seal portion 11 does not stand up clearly, but because the back seal portion 11 is embossed to form indentations 18, the back seal portion does not press tightly against the bag body and eliminate any gaps as in conventional packaging bags. As a result, the water vapor 17 that is ejected from the opening 14' is released by passing through the spaces created in the indentations 18, allowing for smooth discharge of the water vapor 17.

[0028] As described above, in the packaging bag of the present invention, the steam-permeable portion, which is a fragile processed part, is covered by the back seal portion under normal conditions, so there is no risk of it being unintentionally broken during the distribution process or while being handled by the consumer. On the other hand, when heated in a microwave oven, the opening formed when the steam-permeable portion is broken is not blocked by the back seal portion, and a packaging bag is provided that allows steam to be released smoothly. [Examples]

[0029] The present invention will be described in more detail below with reference to examples.

[0030] <Composition of the packaging bag> • Laminate: Outer surface: PET (12 μm) / Inner surface: LLDPE (40 μm) • Size: 140mm (height) x 100mm (width) • Sealing section: Heat-seal both ends in the top and bottom directions with a width of 10 mm. • Back adhesive section: Apply with a 10mm width so that it is approximately in the center in the left-right direction. • Areas to be steamed: Scratches are made in the designated locations and shapes on the PET film.

[0031] <Evaluation Method> (1) Distribution test 50 sealed bags, each containing one commercially available hamburger patty (80g), are packed into a cardboard box and cooled to -15°C. Vibration tests (JIS Z0232:2004 (Level 1)) and drop tests (JIS Z0200:2013 (Level 1)) were conducted on the four cardboard cases. • Count the number of damaged packaging bags. (2) Range-up test - Prepare 20 sealed bags, each containing one commercially available hamburger patty (80g). Heat them in a microwave (500W) for 3 minutes and visually check if they are properly steamed.

[0032] <Example 1> • Characteristics of the back seal: There is an arched, unsealed section. • Location of the distressed area: The area covered by the back seal of the bag itself. • Shape of the scratch: A straight line 20mm in length. The results are summarized in Table 1.

[0033] <Example 2> • Characteristics of the back seal: There is an arched, unsealed section. • Location of the scratching: On the side of the bag body opposite the non-sealed portion of the back seal. • Shape of the scratch: A straight line 20mm in length. The results are summarized in Table 1.

[0034] <Example 3> • Characteristics of the back seal: Embossed, no non-sealed area. • Location of the distressed area: The area covered by the back seal of the bag itself. • Shape of the scratch: A straight line 20mm in length. The results are summarized in Table 1.

[0035] <Comparative Example 1> • Condition of the back seal: No non-sealed area. • Location of the distressed area: The area covered by the back seal of the bag itself. • Shape of the scratch: A straight line 20mm in length. The results are summarized in Table 1.

[0036] <Comparative Example 2> • Condition of the back seal: No non-sealed area. • Location of the distressed area: Approximately in the center of the bag body (opposite the side covered by the back seal). • Shape of the scratch: 5mm in diameter, resembling a hole. The results are summarized in Table 1.

[0037] [Table 1]

[0038] In each of the examples, there was no damage during the distribution test, and the results were good. Furthermore, steaming by microwave heating was performed appropriately. On the other hand, in Comparative Example 1, damage occurred during the distribution test, and some items could not be properly processed, resulting in an overall inferior result. In Comparative Example 2, steaming was performed appropriately, but a large amount of damage occurred during the distribution test. [Explanation of Symbols]

[0039] 1, 2, 3...Packaging bag 10...Bag body 11... Back sticker section 12. Seal part 13. Non-sealed section 14...Steam-filled section 14'···Opening 15. Storage compartment 16...Contents 17. Water vapor 18...Unevenness

Claims

1. A packaging bag in the shape of a back-sealed bag having a bag body formed by laminating a plastic resin film or a laminate thereof, wherein an arch-shaped non-sealed portion communicating with the storage portion is formed in the back-sealed portion, and a steam-permeable portion is formed in the part of the bag body that is covered by the back-sealed portion.

2. The packaging bag according to claim 1, characterized in that the steam-permeable portion is formed by scratch processing.

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