Packaging bags

Abstract

To provide a packaging bag capable of efficiently discharging steam, that exhibits excellent productivity.SOLUTION: According to a packaging bag relating to the present invention, the packaging bag in which a packaged article is stored in a sealing state to subject the packaged article to a heat treatment comprises a pair of sheets. The sheets comprise a seal part whose at least part of a peripheral edge part is sealed in an overlapping state in a peelable manner. The seal part comprises a notch capable of cutting the sheets at a central part in a length direction. It is so constituted that the seal part is peelable via rise of an inner pressure during heating of the packaged article, and communicates an inside and an outside of the bag through the notch by peeling the seal part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a packaging bag.

Background Art

[0002] Conventionally, a packaging bag for heat-treating a packaged product in a sealed state using a microwave oven or the like is known. When the pressure inside the packaging bag rises due to steam generated during the heat treatment of the packaged product, a predetermined position opens to release the steam, thereby preventing the packaging bag from bursting.

[0003] For example, Patent Document 1 discloses a heating pouch provided with an easily peelable pressure-relieving seal portion in a part of a bag body that forms an internal accommodation space. An easily peelable tape is disposed between sheet-like bodies stacked in the thickness direction of the pressure-relieving seal portion, whereby when the pressure inside the packaging bag rises, the pressure-relieving seal portion peels off to release the steam.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, a method of interposing an easily peelable film between stacked sheets like the packaging bag of Patent Document 1 has problems from the viewpoint of productivity.

[0006] The present invention has been made in view of such a situation, and an object thereof is to provide a packaging bag that can efficiently discharge steam and is excellent in productivity.

Means for Solving the Problems

[0007] The packaging bag according to the present invention is a packaging bag for containing an object to be packaged in a sealed state and for heat-treating the object to be packaged, comprising a pair of sheets, the sheets having a seal portion in which at least a part of the peripheral edge is peelably sealed when the sheets are overlapped, the seal portion has a notch in the center in the longitudinal direction that allows the sheet to be cut, the seal portion is peelable due to the increase in internal pressure when the object to be packaged is heated, and the peeling of the seal portion is configured to allow communication between the inside and outside of the bag through the notch.

[0008] The aforementioned packaging bag has a seal portion with a notch in the center in the longitudinal direction that can cut the sheet, and the seal portion is detachable due to the increase in internal pressure when the packaged item is heated, and the detachment of the seal portion allows communication between the inside and outside of the bag through the notch, thereby enabling efficient steam discharge and excellent productivity. More specifically, when the packaged item is heated, the central part of the packaging bag expands, causing the central part in the longitudinal direction of the seal portion to detach and easily form an opening. Therefore, it is possible to efficiently discharge steam without interposing an easily detachable film in the seal portion, and the production process of the packaging bag can be simplified. In addition, since the notch can cut the sheet, the number of opening means provided in the packaging bag can be reduced. As a result, the production process of the packaging bag can be reduced.

[0009] The packaging bag according to the present invention may be formed such that the bottom of the notch follows the inner edge of the sealing portion.

[0010] With this configuration, the bottom of the notch in the packaging bag extends, making it easier to form an opening and allowing steam to be discharged more efficiently.

[0011] In the packaging bag according to the present invention, the distance between the bottom of the notch and the inner edge of the seal portion in the width direction of the seal portion may be 1 mm or more and 10 mm or less.

[0012] The aforementioned packaging bag, with this configuration, can more efficiently discharge steam. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a packaging bag that can efficiently discharge steam and has excellent productivity. [Brief explanation of the drawing]

[0014] [Figure 1] Figure 1 is a front view of a packaging bag 1 according to the first embodiment of the present invention. [Figure 2] Figure 2 shows the packaging bag 1 from Figure 1 with the packaged items placed inside and sealed. [Figure 3] Figure 3 is a front view of a packaging bag 10 according to a second embodiment of the present invention. [Modes for carrying out the invention]

[0015] The packaging bag 1 according to this embodiment will be described below with reference to the drawings. In the following drawings, the same or corresponding parts will be denoted by the same reference numerals, and their descriptions will not be repeated.

[0016] [First Embodiment] The following describes a packaging bag 1 according to the first embodiment of the present invention. Figure 1 is a front view of the packaging bag 1 according to the first embodiment of the present invention. Figure 2 is a diagram showing the packaging bag 1 of Figure 1 with the packaged items contained and sealed.

[0017] The packaging bag 1 is a packaging bag for containing the packaged item in a sealed state and for heat-treating the packaged item. As shown in Figure 1, the packaging bag 1 comprises a pair of sheets 2, and the sheets 2, when overlapped, have a seal portion 3 in which at least a part of the peripheral edge is peelably sealed.

[0018] The sheet 2 is formed in a square shape in a plan view. The pair of sheets 2, 2 having the same shape are arranged so that their surfaces overlap. As the sheet 2, a sheet having heat-sealability capable of heat-sealing the pair of sheets 2, 2 and having an adjustable peel strength between the heat-sealed sheets of 3 N or more and 20 N or less can be used. Specifically, for example, a film, non-woven fabric, paper, etc. formed from a resin such as nylon, polyethylene terephthalate, polypropylene, polyethylene can be used. Among these, as the sheet 2, it is preferable to use an easy-peel film formed from a resin such as nylon, polyethylene terephthalate, polyethylene, polypropylene. Also, from the viewpoint of excellent sealability for contaminants, the peel form of the easy-peel film is preferably cohesive peeling. In this specification, the easy-peel film means a film whose peel form is interfacial peeling, cohesive peeling, or interlayer peeling and whose peel strength is 3 N or more and 20 N or less.

[0019] As the seal part 3, seal parts respectively formed at the edges of three sides of the square sheet 2 are provided, that is, a pair of first seal parts 31 formed at the edges along the longitudinal direction in the packaging bag 1 and a second seal part 32 formed at one edge along the short side direction in the packaging bag. The length in the width direction of the seal part 3 (that is, the distance from the inner edge 35 to the outer edge 36 in the seal part 3) is preferably, for example, 3 mm or more and 20 mm or less, and more preferably 6 mm or more and 15 mm or less from the viewpoint of protecting the contents.

[0020] The seal part 3 is an easily peelable seal part and has a heat-seal strength of 3 N or more and 20 N or less. The heat-seal strength can be measured by the heat-seal strength test method for bags described in JIS Z 0238:1998. In this measurement of the heat-seal strength, a test piece with a width of 15 mm and a developed length of 100 mm is used, and the relative movement speed between the gripping parts is set to 300 mm / min. In this embodiment, the average value of a plurality of measured values obtained by this measurement is used as the heat-seal strength.

[0021] One of the first seal portions 31a has a notch 4 at the central portion in the longitudinal direction of the one first seal portion 31a. In this specification, the central portion refers to a portion that is 0.5 ± 0.1 away from the end of the seal portion 3 when the length of the seal portion 3 in the longitudinal direction is taken as 1. The notch 4 is formed in a V shape whose width narrows from the outer edge 36 to the inner edge 35 of the seal portion 3 and has a corner portion 41 at the tip. The ratio (L1 / L2) of the shortest distance L1 from the virtual line M overlapping the outer edge 36 of the seal portion 3 to the corner portion 41 to the distance L2 from the corner portion 41 to the inner edge 35 of the seal portion 3 is preferably 1.0 or more and 19.0 or less, and more preferably 1.0 or more and 2.5 or less. By the ratio (L1 / L2) of the shortest distance L1 from the virtual line M overlapping the outer edge 36 of the seal portion 3 to the corner portion 41 to the distance L2 from the corner portion 41 to the inner edge 35 of the seal portion 3 being within the above range, when the packaging bag 1 containing the packaged article 6 is being transported, the seal portion 3 can be held, and when heated in a microwave oven, steam can easily escape.

[0022] The notch 4 is configured to be able to cut the sheet 2. Specifically, after the packaged article 6 is accommodated in the packaging bag 1, when a person applies a tearing force, the sheet 2 can be torn from the corner portion 41 of the notch 4 toward the other first seal portion 31b facing the one first seal portion 31a. Thereby, the packaging bag 1 can be opened.

[0023] The seal portion 3 is designed to be removable due to the increase in internal pressure when the packaged item 6 is heated, and the removal of the seal portion 3 allows communication between the inside and outside of the bag through the notch 4. Specifically, the packaged item 6 is placed into the storage space of the packaging bag 1 from one edge of the packaging bag 1 where the seal portion 3 is not formed (i.e., the other edge along the shorter direction of the packaging bag 1). After being placed in the storage space, as shown in Figure 2, a third seal portion 33 is formed on the other edge along the shorter direction of the packaging bag 1, sealing the packaging bag 1. When the sealed packaging bag 1 is heated in a microwave oven, the steam generated from the packaged item 6 increases the internal pressure of the packaging bag 1, causing the packaging bag 1 to expand. As a result, one of the first seal portions 31a peels off around the corner 41 of the notch 4, forming an opening (steam discharge passage), and allowing communication between the inside and outside of the bag. The steam is discharged to the outside through the opening.

[0024] In the first embodiment, a notch 5 is formed in the central part of the other first seal portion 31b in the longitudinal direction, as shown in Figures 1 and 2. The notch 5 is formed in a V shape, narrowing in width from the outer edge 36 to the inner edge 35 of the seal portion 3, and has a corner portion 51 at its tip. In the width direction of the seal portion 3, the shortest distance from the imaginary line overlapping the outer edge 36 of the seal portion 3 to the corner portion 51 is formed to be shorter than the distance from the corner portion 51 to the inner edge 35 of the seal portion 3. By forming a notch 5 in the other first seal portion 31b, the sheet 2 can be torn starting from the corner portion 51 of the notch 5.

[0025] The packaging bag 1 according to the first embodiment has a seal portion 3 with a notch 4 in the center in the longitudinal direction that can cut the sheet 2, and the seal portion 3 is removable due to the increase in internal pressure when the packaged item 6 is heated, and the removal of the seal portion 3 allows communication between the inside and outside of the bag through the notch 4, thereby enabling efficient steam discharge and excellent productivity. More specifically, when the packaged item 6 is heated, the packaging bag 1 expands from the central part, so the central part in the longitudinal direction of the seal portion 3 peels off and an opening is easily formed. Therefore, it is possible to efficiently discharge steam without interposing an easily removable film in the seal portion 3, and the production process of the packaging bag 1 can be simplified. In addition, since the notch can cut the sheet, the number of opening means to be provided on the packaging bag can be reduced. As a result, the production process of the packaging bag can be reduced.

[0026] [Second Embodiment] The following describes the differences between the packaging bag 10 according to the second embodiment of the present invention and the first embodiment, with reference to the drawings.

[0027] Figure 3 is a front view of a packaging bag 10 according to a second embodiment of the present invention. As shown in Figure 3, the packaging bag 10 comprises a pair of sheets 2, and the sheets 2, when overlapped, have a seal portion 3 on which at least a part of the peripheral edge is peelably sealed. The seal portion 3 comprises a pair of first seal portions 31 formed on the edge along the longitudinal direction of the packaging bag 1, and a second seal portion 32 formed on one edge along the short direction of the packaging bag 1. The sheet 2 and the seal portion 3 have the same configuration as the sheet 2 and seal portion 3 in the first embodiment.

[0028] One of the first seal portions 31a has a notch 40 in the center of its length. The notch 40 is trapezoidal in shape, widening from the outer edge 36 to the inner edge 35 of the seal portion 3, and includes two corners 43 and a bottom 44 that extends along the inner edge 35 of the seal portion 3. The ratio (L3 / L4) of the shortest distance L3 from a virtual line overlapping the outer edge 36 of the seal portion 3 to the bottom 44 to the length L4 from the bottom 44 to the inner edge 35 of the seal portion 3 is preferably 1.0 or more and 19.0 or less, and more preferably 1.0 or more and 2.5 or less. The ratio (L3 / L4) of the shortest distance L3 from the imaginary line overlapping the outer edge 36 of the seal portion 3 to the bottom 44 to the length L4 from the bottom 44 to the inner edge 35 of the seal portion 3 is within the aforementioned range. This allows the seal portion 3 to be maintained during transport of the packaging bag 1 containing the packaged goods 6, and also allows steam to escape easily when heated in a microwave oven.

[0029] Furthermore, the distance between the bottom 44 constituting the notch 40 and the inner edge 35 of the seal portion 3 in the width direction of the seal portion 3 is preferably 1 mm or more and 10 mm or less, and preferably 3 mm or more and 7 mm or less.

[0030] The notch 40 is configured to cut the sheet 2. Specifically, after the packaged items are placed in the packaging bag 10, if a tearing force is applied by a person, the sheet 2 can be torn starting from the corner 43 of the notch 40 toward the second seal portion 32 or the third seal portion. This allows the packaging bag 1 to be opened.

[0031] The seal portion 3 is designed to be detachable due to the increase in internal pressure when the packaged item is heated, and the detachment of the seal portion 3 allows communication between the inside and outside of the bag through the notch 40. Specifically, similar to the first embodiment, the packaged item is placed into the storage space of the packaging bag 10 from the edge of one side of the packaging bag 10 where the seal portion 3 is not formed (i.e., the other edge along the shorter direction of the packaging bag 1). Once the item is placed in the storage space, a third seal portion is formed on the other edge along the shorter direction of the packaging bag 1, sealing the packaging bag 10. When the sealed packaging bag 10 is heated in a microwave oven, the steam generated from the packaged item increases the internal pressure of the packaging bag 10, causing the packaging bag 10 to expand. As a result, one of the first seal portions 31a detaches around the corner 43 and bottom 44 of the notch 40, forming an opening (steam discharge passage) and allowing communication between the inside and outside of the bag. The steam is discharged to the outside through the opening.

[0032] The packaging bag 10 according to the second embodiment has a seal portion 3 with a notch 40 in the center in the longitudinal direction that can cut the sheet 2, and the seal portion 3 is detachable due to the increase in internal pressure when the packaged item 6 is heated, and the detachment of the seal portion 3 allows communication between the inside and outside of the bag through the notch 40, thereby enabling efficient steam discharge and excellent productivity. More specifically, when the packaged item is heated, the packaging bag 10 expands from the central part, so the central part in the longitudinal direction of the seal portion 3 peels off and an opening is easily formed. Therefore, it is possible to efficiently discharge steam without interposing an easily detachable film in the seal portion 3, and the production process of the packaging bag 1 can be simplified. In addition, since the notch can cut the sheet, the number of opening means to be provided on the packaging bag 10 can be reduced. As a result, the production process of the packaging bag can be reduced.

[0033] In the packaging bag 10 according to the second embodiment, the bottom 44 of the notch 40 is formed to follow the inner edge of the sealing portion 3, which makes it easier to form an opening by the amount that the bottom of the notch extends, and allows for more efficient discharge of steam.

[0034] In the packaging bag 10 according to the second embodiment, the distance between the bottom 44 constituting the notch 40 and the inner edge 35 of the seal portion 3 in the width direction of the seal portion 3 is 1 mm or more and 10 mm or less, thereby enabling more efficient discharge of steam.

[0035] [Other embodiments] Although the first and second embodiments of the present invention have been described above, the packaging bag according to the present invention is not limited to the above embodiments, and various modifications are possible without departing from the spirit of the present invention. Furthermore, the configurations and methods of the above-described multiple embodiments may be arbitrarily adopted and combined (configurations and methods of one embodiment may be applied to configurations and methods of other embodiments), and of course, configurations and methods related to the various modification examples below may be arbitrarily selected and adopted in the configurations and methods of the above embodiments.

[0036] For example, the above embodiment described a case where the packaging bag 1,10 is a three-sided bag. However, the present invention is not limited to this configuration, and may also be a two-sided bag, a gusseted bag, a stand-up pouch, etc.

[0037] For example, the above embodiment described a case in which sheet 2 is formed in a rectangular shape in a plan view. However, the present invention is not limited to this configuration, and may be formed in a circular shape, an elliptical shape, a polygonal shape, or the like.

[0038] Furthermore, the above embodiments described the case where the shape of the notches 4 and 40 is V-shaped or trapezoidal. However, the present invention is not limited to these configurations, and may also be polygonal in shape, such as a quadrilateral.

[0039] Furthermore, the above embodiment described the case in which the notches 4 and 40 are located in one of the first seal portions 31a. However, the present invention is not limited to this configuration, and for example, they may be located in the second seal portion 32, or they may be located in both the first seal portion 31a and the other first seal portion 31b.

[0040] Furthermore, in the above embodiment, the case in which the notch 5 is formed in the central part of the other first sealing portion 31b in the longitudinal direction was described. However, the present invention is not limited to this configuration, and for example, it may be formed in a part other than the central part, or the notch 5 may not be formed at all. If the notch 5 is not formed, the production process of the packaging bag can be further reduced. [Explanation of symbols]

[0041] 1 packaging bag 2 sheets 3. Sealing part 4 Notches 6 Items to be packaged 10 packaging bags 35 Inner edge of the seal 40 Notches 44 bottom

Claims

1. A packaging bag that contains the packaged goods in a sealed state and heat-treats the packaged goods, Equipped with a pair of seats, The sheets, when stacked, have a sealing portion in which at least a part of the peripheral edge is peelably sealed. The sealing portion has a notch in the center in the longitudinal direction that allows the pair of sheets to be cut and peeled off by the increase in internal pressure when the packaged item is heated, and is configured to allow communication between the inside and outside of the bag when the sealing portion is peeled off. The sealing portion has a notch in the center in the longitudinal direction that allows the pair of sheets to be cut. The aforementioned notch is positioned to face the aforementioned notch across the storage space of the bag, A packaging bag in which the shortest distance from the bottom of the notch to the inner edge of the sealing portion is longer than the shortest distance from the bottom of the notch to the inner edge of the sealing portion.

2. The packaging bag according to claim 1, wherein the bottom of the notch is formed to follow the inner edge of the sealing portion.

3. The packaging bag according to claim 2, wherein the distance between the bottom of the notch and the inner edge of the sealing portion in the width direction of the sealing portion is 1 mm or more and 10 mm or less.

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