JP6974695B2 - Packaging bag - Google Patents

Description

In the present invention, when a packaging bag filled with contents such as a liquid substance, a solid substance, or a mixture thereof, such as a retort food, is heated in a microwave oven or the like, water vapor or the like generated inside the packaging bag is released to the outside. Regarding the packaging bag to be released.

When a packaging bag filled with contents such as retort food is heated in a microwave oven or the like, the pressure inside the packaging bag rises due to steam generated from the contents due to the heating, and the packaging bag bursts and the contents. May be scattered.

For this reason, there is a packaging bag provided with a steam venting portion for avoiding an increase in pressure inside the packaging bag (Patent Document 1).

WO2013 / 100058

By the way, depending on the contents to be accommodated, the packaging bag may be longer and thinner than those disclosed in Patent Document 1. In such an elongated packaging bag, when an attempt is made to discharge steam from the steam venting portion, a phenomenon may occur in which the steam is not discharged from the steam venting portion and another portion bursts.

The present invention has been made in view of such circumstances, and provides a packaging bag capable of appropriately discharging steam even in an elongated packaging bag.

According to the present invention, a packaging bag in which a flexible film is formed in a bag shape, the packaging bag includes a front portion and a back portion, and the front portion and the back portion are peripheral edges. The front portion is heat-sealed to each other in the heat-sealed portion, and the front portion includes a front lower portion and a front upper portion, and the front lower portion and the front upper portion are connected by a gassho portion formed by being overlapped with each other in a folded state. , The gassho portion is provided with a steam venting portion that forms a steam vent as the internal pressure rises, and the packaging bag has an upper side, a lower side, a right side side, and a left side side, and W2, L2, and A2 are as follows. A packaging bag is provided that meets the relationship.
W2: Length between the right side and the left side at the inner edge of the heat seal portion L2: Length between the upper side and the lower side at the inner edge of the heat seal portion A2: Inner edge of the heat seal portion Length A2 / L2 ≦ 0.30 from the upper side and the lower side, whichever is closer to the gassho portion, to the gassho portion.
A2 / W2 ≤ 0.41

As a result of diligent studies by the present inventor, in an elongated packaging bag, the closer the position where the gassho portion is provided to the center in the longitudinal direction of the packaging bag, the more the gassho portion collapses when the packaging bag inflates and the surface of the packaging bag is covered. It turned out that it was easy to be pressed. Then, it was found that when the gassho portion is pressed against the surface of the packaging bag, it becomes difficult for steam to enter the gassho portion, and as a result, steam may not be discharged from the steam venting portion. As a result of further examination, by setting the position where the gassho portion is provided to a specific position defined by A2 / L2 and A2 / W2, it is possible to prevent the gassho portion from falling even in an elongated packaging bag. We have found that steam is properly discharged from the steam vent, and have completed the present invention.

Hereinafter, various embodiments of the present invention will be illustrated. The embodiments shown below can be combined with each other.
Preferably, W2 / L2 ≦ 0.66.
Preferably, A2 / L2 ≧ 0.03.
Preferably, W1, L1 and A1 satisfy the following relationship.
W1: Length between the right side and the left side at the outer edge of the heat seal portion L1: Length between the upper side and the lower side at the outer edge of the heat seal portion A1: Outer edge of the heat seal portion Length A1 / L1 ≦ 0.30 from the upper side and the lower side, whichever is closer to the gassho portion, to the gassho portion.
A1 / W1 ≤ 0.39
Preferably, W1 / L1 ≦ 0.70.
Preferably, A1 / L1 ≧ 0.05.

It is a perspective view of the packaging bag 1 of one Embodiment of this invention. 2A is a front view of the packaging bag 1, and FIG. 2B is a right side view of the packaging bag 1. FIG. 2 is a cross-sectional view taken along the line AA in FIG. 2A. It is a perspective view which shows the state which contains the contents L in a packaging bag 1. It is a perspective view which shows the state after the content L was put in the packaging bag 1 and the lower side 1b was heat-sealed. It is a right side view which shows the state which the packaging bag 1 after accommodating and heat-sealing the contents L is heated by a microwave oven, and steam is discharged from a steam vent part 8.

Hereinafter, embodiments of the present invention will be described. The various features shown in the embodiments shown below can be combined with each other. In addition, the invention is independently established for each characteristic item.

As shown in FIGS. 1 to 6, the packaging bag 1 according to the embodiment of the present invention is a bag-shaped flexible film. The packaging bag 1 includes a front surface portion 2 and a back surface portion 3. The front surface portion 2 and the back surface portion 3 are heat-sealed at the peripheral heat-sealing portion 4. The heat seal portion 4 is provided along the upper side 1t, the right side 1r, and the left side 1l of the packaging bag 1. The lower side 1b of the packaging bag 1 is not heat-sealed before the contents L are stored, and is heat-sealed after the contents L are stored in the packaging bag 1 as shown in FIGS. 4 to 5. As a result, the heat seal portion 4 is provided on the entire circumference of the packaging bag 1, and the inside of the packaging bag 1 is sealed.

As the film constituting the packaging bag 1, any film can be applied as long as the films are heat-sealed when heat-sealed. For example, a plastic film having a heat-sealing property used for a normal packaging bag. Is applicable. Examples of the material constituting the plastic film include a single-layer film and sheets made of a thermoplastic resin having a heat-sealing property, and a multilayer film in which a thermoplastic resin having a heat-sealing property is laminated with another thermoplastic resin and the like. And so on.

Examples of materials having good heat-sealing properties include known low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, propylene-ethylene copolymer, and other ethylene-based unsaturated carboxylic acids or anhydrides thereof. Examples thereof include olefin resins such as olefin resins graft-modified with, polyamide resins having a relatively low melting point to a low softening point, polyester resins, polyethylene-vinyl acetate copolymer resins and the like.

In addition, various barrier films can be used as other plastic materials to be laminated. When a laminated film with these thermoplastic resins is used, it is preferable to heat-seal so that the thermoplastic resin layers having good heat-sealing properties such as a resin having a low melting point are on the inner surface.

The front surface portion 2 includes a front surface lower portion 2d and a front surface upper portion 2u. The lower front portion 2d and the upper front portion 2u are each heat-sealed on the back surface portion 3. As shown in FIG. 3, the front lower portion 2d and the front upper portion 2u are connected by a gassho portion 5 formed by being overlapped with each other in a folded state. In the gassho portion 5, the front lower portion 2d and the front upper portion 2u are heat-sealed in the heat-sealed portions 6a and 6b. The heat seal portion 6a is provided at a position along the right side side 1r and the left side side 1l in the gassho portion 5. The heat seal portion 6b is provided so as to connect the heat seal portion 6a. The width of the heat-sealed portion 6b narrows from the heat-sealed portion 6a toward the center of the heat-sealed portion 6b. The heat-sealed portion 6b has a lower peel strength than the other heat-sealed portions. The heat-sealed portion 6b has a starting point 7 that is curved toward the inside of the packaging bag 1 and has a narrow width at substantially the center of the packaging bag 1 in the width direction. Unsealed portions 6c are provided on both sides of the starting point 7. When the packaging bag 1 is filled with the contents and the packaging bag 1 is heated in a microwave oven or the like with the front portion 2 and the back portion 3 heat-sealed on the lower side 1b of the packaging bag 1, the packaging is packaged by the steam generated by the heating. The internal pressure of the bag 1 rises. When the internal pressure of the packaging bag 1 rises, as shown in FIG. 6, the packaging bag 1 expands, and a force is applied to the films constituting the packaging bag 1 so as to be separated from each other. The peeling strength of the heat-sealed portion 6b is lower than that of other heat-sealed portions, and the peeling force applied to the heat-sealed portion 6b is easily concentrated at the starting point 7. Therefore, the peeling force of the heat-sealing portion 6b is easily concentrated at the starting point 7. Is started, and when the inside and outside of the packaging bag 1 are communicated by peeling off the heat seal portion 6b, the water vapor inside the packaging bag 1 is released. Therefore, the portion of the heat seal portion 6b in the vicinity of the start point 7 becomes the steam vent portion 8 that forms the steam vent.

As shown in FIG. 2A, the packaging bag 1 has a rectangular shape in a plan view, and the rectangular shape is formed by the four sides of the upper side 1t, the lower side 1b, the right side 1r, and the left side 1l. The rectangular corners may be rounded or chamfered. In the state of FIG. 2A, the heat seal portion 4 is provided on the upper side 1t, the right side 1r, and the left side 1l. The width of the heat-sealed portion 4 on the upper side 1t is smaller than the width of the heat-sealed portion 4 on the right side 1r and the left side 1l. The width of the heat-sealed portion 4 may be the same over the entire circumference of the packaging bag. Since the lower side 1b is not heat-sealed before accommodating the content L, FIG. 2A illustrates a heat-sealed planned portion 4a, which is a portion to be heat-sealed. In the following description, the heat seal scheduled portion 4a will be treated as the heat seal portion 4 for explanation.

The width of the heat-sealed portion 4 and the average width of the heat-sealed portion 4 on each of the upper side 1t, the lower side 1b, the right side side 1r, and the left side side 1l are, for example, 2 to 20 mm. For example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 mm, and the numerical values exemplified here are used. It may be within the range between any two. The average width of the heat-sealed portion 4 can be calculated by (area of the heat-sealed portion 4) / (length of the heat-sealed portion 4). The widths of the widths of the heat-sealed portions 4 on the upper side 1t, the lower side 1b, the right side 1r, and the left side 1l may be the same or different from each other.

Here, as shown in FIG. 2A, W1, L1, A1, W2, L2, and A2 are defined as follows.
W1: Length between the right side 1r and the left side 1l at the outer edge 4o of the heat seal portion 4 L1: Length between the upper side 1t and the lower side 1b at the outer edge 4o of the heat seal portion 4 A1: Heat seal portion 4 Length 1t from the upper side 1t and lower side 1b of the outer edge 4o from the side closer to the gassho portion 5 to the gassho portion 5 W2: Length between the right side 1r and the left side 1l at the inner edge 4i of the heat seal portion 4 L2: Length between the upper side 1t and the lower side 1b at the inner edge 4i of the heat seal portion 4 A2: The gassho portion 5 from the side of the upper side 1t and the lower side 1b at the inner edge 4i of the heat seal portion 4 closer to the gassho portion 5. Length up to

W1 is preferably 50 to 200 mm, specifically, for example, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200 mm. Yes, it may be within the range between any two of the numerical values exemplified here.

L1 is preferably 150 to 300 mm, specifically, for example, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300 mm. Yes, it may be within the range between any two of the numerical values exemplified here.

A1 is preferably 5 to 50 mm, specifically, for example, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 mm, and any two of the numerical values exemplified here. It may be within the range between.

W2, L2, and A2 have lengths obtained by subtracting twice the width of the heat-sealed portion 4 described above from W1, L1, and A1, respectively.

W1 / L1 is preferably 0.70 or less, for example, 0.20 to 0.70. W2 / L2 is preferably 0.66 or less, for example, 0.15 to 0.66. Specifically, W1 / L1 and W1 / L2 are, for example, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, 0.45, 0.50, 0.55. , 0.60, 0.65, 0.66, 0.70, and may be within the range between any two of the numerical values exemplified here. When W1 / L1 or W1 / L2 is in the above range, the packaging bag 1 has an elongated shape, and when the packaging bag 1 is inflated, the gassho portion 5 falls down and is easily pressed against the surface of the packaging bag 1. Therefore, the significance of applying the present invention is particularly great. Further, since the longer the packaging bag 1 is, the greater the significance of applying the present invention, W1 / L is more preferably 0.54 or less, and W2 / L2 is further preferably 0.49 or less.

A1 / L1 is preferably 0.30 or less, for example, 0.01 to 0.30, and preferably 0.05 to 0.30. A2 / L2 is preferably 0.30 or less, for example, 0.00 to 0.30, preferably 0.03 to 0.30, and particularly preferably 0.11 to 0.19. Specifically, A1 / L1 and A2 / L2 are, for example, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08. , 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0 .21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, and any of the numerical values exemplified here 2 It may be within the range between the two. When A1 / L1 or A2 / L2 is in the above range, the gassho portion 5 does not fall down and is pressed against the surface of the packaging bag 1 when the packaging bag 1 is inflated, and the steam provided in the gassho portion 5 is provided. It becomes easy for steam to be appropriately discharged from the punching portion 8.

A1 / W1 is preferably 0.39 or less, for example, 0.01 to 0.39, and preferably 0.08 to 0.39. A2 / W2 is preferably 0.41 or less, for example, 0.00 to 0.41, preferably 0.05 to 0.41, and particularly preferably 0.16 to 0.35. Specifically, A1 / W1 and A2 / W2 are, for example, 0.00, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08. , 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0 .21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33 , 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41 and within the range between any two of the numerical values exemplified here. There may be. When A1 / W1 or A2 / W2 is in the above range, the gassho portion 5 does not fall down and is pressed against the surface of the packaging bag 1 when the packaging bag 1 is inflated, and the steam provided in the gassho portion 5 is provided. It becomes easy for steam to be appropriately discharged from the punching portion 8.

Further, it is particularly important to set A2 / L2 ≦ 0.30 and A2 / W2 ≦ 0.41 or A1 / L1 ≦ 0.30 and A1 / W1 ≦ 0.39. The portion 5 is particularly difficult to be pressed against the surface of the packaging bag 1. Further, it is extremely important to set 0.11 ≦ A2 / L2 ≦ 0.19 and 0.16 ≦ A2 / W2 ≦ 0.35, and in this case, a large opening is not formed in the steam venting portion 8. Can emit steam.

A packaging bag 1 having the basic shape shown in FIG. 1 and having the dimensions shown in Table 1 is produced, and after filling the packaging bag 1 with curry, the lower side 1b of the packaging bag 1 is subjected to the heat-sealed planned portion 4a of FIG. 2A. Samples of Examples and Comparative Examples were prepared by heat-sealing at the position of. The shapes A to I in Table 1 have a length L1 and a width W1 different from each other. Further, in the examples and comparative examples having the same shape, the positions of the gassho portions 5 are different from each other. Five samples of each Example / Comparative Example were prepared. The width of the heat seal portion 4 was 5 mm on the upper side, 10 mm on the lower side, 10 mm on the right side, and 10 mm on the left side.

Each sample was heated in a 500 W microwave oven. The heating was continued until the steam was discharged from the packaging bag 1. The evaluation was performed according to the following criteria according to the steam discharge mode. Since it is preferable that the opening width of the steam venting portion 8 when the steam is discharged is too large, the case where the opening width is more than 20 mm is designated as Δ.

⊚: In all five samples, steam was discharged from the steam venting portion 8, and the opening width of the steam venting portion 8 was within 20 mm.
◯: In at least one sample, steam was discharged from the steam venting portion 8, and the opening width of the steam venting portion 8 was more than 20 mm.
Δ: In at least one sample, steam was discharged from the steam venting portion 8, the opening width of the steam venting portion 8 was more than 20 mm, and blowout occurred during steam discharge.
X: In at least one sample, the bag was broken except for the steam venting portion 8, and steam was discharged.

Referring to Table 1, in all the examples in which A2 / L2 ≦ 0.30 and A2 / W2 ≦ 0.41, the evaluation result was Δ, ◯ or ⊚. On the other hand, in all the comparative examples in which A2 / W2> 0.41, the evaluation result was x.

Further, in Examples 1, 4, 7, 12, 17, 22, and 27 in which A2 / L2 <0.03, the evaluation result was Δ. The reason why the evaluation result is Δ is considered to be as follows. When the bag swells, the upper front portion 2u and its back surface swell. As a result, the upper side 1t may be bent toward the inner surface of the bag, and the steam venting portion in the gassho portion may be blocked. As a result, the steam cannot be smoothly discharged from the steam venting portion, a loud noise is generated at the time of steam discharge, the opening width becomes large, and a spillage occurs.

In all the remaining examples in which A2 / L2 ≧ 0.03, the evaluation result is ○ or ⊚, and 0.11 ≦ A2 / L2 ≦ 0.19 and 0.16 ≦ A2 / W2 ≦ 0.35. In all the examples, the evaluation result was ⊚.

From the above, it was demonstrated that the steam is appropriately discharged from the steam venting portion 8 by providing the gassho portion 5 so that A2 / L2 ≦ 0.30 and A2 / W2 ≦ 0.41. In addition, it was demonstrated that the steam was discharged more appropriately by providing the gassho portion 5 so that A2 / L2 ≧ 0.03. Further, it was demonstrated that the steam is discharged more appropriately by providing the gassho portion 5 so that 0.11 ≦ A2 / L2 ≦ 0.19 and 0.16 ≦ A2 / W2 ≦ 0.35. ..

By the way, the more the bag swells in an elongated shape (W1 / L1 ≦ 0.70), the more easily the body becomes cylindrical, and accordingly, the gassho part becomes a lying shape (shape along the body). It is easy, especially in a bag with a narrow width (W1 ≦ 135), since the radius of curvature of the inflated cylinder is small, it is difficult for the gassho portion to rise. Therefore, it is particularly significant to apply the present invention in such a case. On the other hand, as shown in Reference Examples 1 and 2, in a bag having W2 / L2 ≧ 0.70 or more, steam is appropriately discharged even if the gassho portion is provided in the center in the longitudinal direction. The significance of applying the invention is small.

1: Packaging bag 1b: Lower side 1l: Left side 1r: Right side 1t: Upper side 2: Front part 2d: Front lower part 2u: Front upper part 3: Back part 4: Heat seal part 4a: Heat seal planned part 4i: Inner edge 4o: Outer edge 5: Gassho part 6a: Heat-sealed part 6b: Heat-sealed part 6c: Unsealed part 7: Starting point 8: Steam venting part A: Shape L: Contents

Claims (3)

A packaging bag in which a flexible film is formed in the shape of a bag.
The packaging bag includes a front portion and a back portion, and the packaging bag has a front portion and a back portion.
The front surface portion and the back surface portion are heat-sealed to each other at the peripheral heat-sealed portion.
The front portion includes a lower front portion and an upper front portion.
The lower front surface and the upper front surface are connected by a gassho portion formed by being overlapped with each other in a folded state.
The gassho portion is provided with a steam venting portion that forms a steam vent as the internal pressure rises.
The packaging bag comprises an upper side, a lower side, a right side, and a left side.
A packaging bag in which W1, L1, W2, L2, and A2 satisfy the following conditions.
W1: Length between the right side and the left side at the outer edge of the heat seal portion L1: Length between the upper side and the lower side at the outer edge of the heat seal portion W2: Inner edge of the heat seal portion Length between the right side and the left side L2: Length between the upper side and the lower side at the inner edge of the heat seal portion A2: The upper side and the lower side at the inner edge of the heat seal portion Length from the side closer to the gassho part to the gassho part W1 ≤ 135 mm
W1 / L1 ≤ 0.70
0.11 ≤ A2 / L2 ≤ 0.19
0. 22 ≤ A2 / W2 ≤ 0. 35
W2 / L2 ≤ 0.66 The packaging bag according to claim 1, wherein W1, L1, and A1 satisfy the following relationship.
A1: The length from the upper side and the lower side of the outer edge of the heat seal portion, whichever is closer to the gassho portion, to the gassho portion A1 / L1 ≦ 0.30
A1 / W1 ≤ 0.39 A1 / L1 ≧ 0.05
The packaging bag according to claim 2.

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