JP2008273538A - Microwave heatable packaging bag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microwave heatable packaging bag preventing a leakage of content from a steam releasing means. <P>SOLUTION: The microwave heatable packaging bag 10 is formed in a bag shape by laminating synthetic resin films 11 constituted with a base layer and a sealant layer such that the sealant layers of the films are opposed, and heat adhering the sealant layers. The packaging bag includes a steam releasing means 40 provided in a portion or in proximity to the heat seal portion 12, through which steam is discharged at the time of microwave heating. The packaging bag also includes protruding portions 30 protruding outwardly in a flap shape by folding a portion of both the synthetic resin films, and communicating inside thereof with inside of the packaging bag. Each of the protruding portions 30 is disposed at a position closer to the steam releasing means 40. When an inside pressure is increased as the packaging bag is placed flat and heated with microwaves, the lower protruding portion 40 is expanded to move the steam releasing means 40 to a position higher than that at the time of non-heating. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a bag for hermetically storing contents such as food to be cooked in a microwave oven. In particular, when the internal pressure rises due to heating of the microwave oven, the internal pressure (steam) is automatically released to prevent explosion. The present invention relates to a packaging bag for heating a range.

  Contents such as cooked or semi-cooked food stored in a sealed state in a plastic packaging bag are cooked in a microwave when eating. When heated in a microwave oven, the internal pressure of the packaging bag rises due to the thermal expansion of the steam and internal air generated from the contents, and the packaging bag expands. However, if it expands too much, the packaging bag may break and the contents stored in the packaging bag may scatter.

  Therefore, conventionally, the microwave oven heating packaging bag is provided with a vapor venting means for venting the steam when heating the microwave oven so as to automatically release the internal pressure and prevent bursting when the internal pressure of the packaging bag rises due to heating of the microwave oven. ing.

  FIG. 16 is a perspective view showing a conventional packaging bag 100 for heating a microwave oven. In this microwave heating packaging bag 100, the ends of one synthetic resin film are joined together to form a joined part 101, the film is formed into a cylindrical shape, and the joined part 101 is arranged in the center. In this way, the opening at the upper end and the opening at the lower end of the cylinder are heat sealed. Here, the steam venting means is formed by weakening a part or all of the joints.

  When the microwave heating packaging bag 100 containing the contents such as food is heated in the microwave oven, the microwave heating packaging bag 100 expands as shown in FIG. As a result, peeling occurs in the palm portion 101, and gas such as water vapor and expanded air inside escapes out of the bag through the resulting hole.

As described above, Patent Literatures 1 to 3 disclose microwave oven heating packaging bags provided with vapor venting means for preventing the bag from overexpanding and bursting due to heating of the microwave oven.
Moreover, when releasing the internal pressure at the time of expansion outside the bag, a microwave heating packaging bag in which the vapor venting means is moved upward to prevent leakage of contents from the vent hole of the vapor venting means is disclosed in Patent Document 4, 5 is disclosed.
Japanese Patent No. 3035484 JP 2000-159276 A Japanese Unexamined Patent Publication No. 2000-168851 Japanese Patent No. 3597656 (FIG. 3) Japanese Patent Laying-Open No. 2005-59870 (FIG. 3) JP 2006-62672 A

  However, in the microwave oven heating packaging bags shown in Patent Documents 4 and 5, the position of the vapor venting means moves upward during heating expansion. However, if the heating is stopped after the vapor or the like has escaped from the vapor venting means, Then, there is a risk that the steam venting means that has risen will fall and return to the original position to touch the contents. In this case, the contents may leak from the holes.

  In addition, when the heating method of the microwave heating packaging bag 100 is mistaken and the heating is performed in the microwave with the palm portion 101 side down as shown in FIG. Resulting in. If the packaging bag for heating a microwave oven shown in Patent Document 4 is also used upside down, the contents may leak from the hole.

  The present invention was created in view of the above points, and an object of the present invention is to provide a heating packaging bag for a microwave oven that prevents the contents from leaking out from the vapor venting means.

  In order to achieve the above object, a first configuration of the present invention is a heat seal portion in which a synthetic resin film having a base material layer and a sealant layer is overlapped with the sealant layers facing each other, and the sealant layers are thermally welded to each other. A packaging bag for heating a microwave oven having a vapor venting means for releasing steam at the time of range heating at a part of or around the heat seal portion, and a part of both synthetic resin films Folded and protruded outward in the form of a flap, the inside is provided with protruding pieces that communicate with the inside of the packaging bag, and each protruding piece is placed at a position close to the steam venting means, and is heated in the range in a flat state. When the internal pressure rises, the lower protruding piece portion expands and the vapor venting means moves to a position higher than the non-heated position.

  Further, the second configuration of the present invention is a bag-like shape sealed with a heat seal part in which a synthetic resin film having a base material layer and a sealant layer is overlapped with each other with the sealant layers facing each other, and the sealant layers are thermally welded to each other. And a microwave heating packaging bag having a vapor venting means through which steam at the time of range heating escapes at a part of the heat seal portion or around the heat seal portion, and two protruding pieces are provided apart from each other on each synthetic resin film Each projecting piece part is formed by folding a part of the synthetic resin film so that it protrudes outward in a flap shape, and the inside communicates with the inside of the packaging bag, and one projecting piece of each synthetic resin film Is placed in a position close to the steam venting means, and when the range pressure is raised in a flat state and the internal pressure rises, the lower protruding piece expands and the steam venting means is at a position higher than the non-heating position. To move It is characterized.

  According to the present invention, the vapor venting means is lifted along with the expansion, but since the vapor venting means is held at a high position even after the heating is completed, the contents can be prevented from leaking from the vent hole. Moreover, since the protrusions are provided on the front and back, it is possible to prevent the contents from leaking from the hole even if the front and back are reversed due to misuse.

Hereinafter, the present invention will be described in detail based on some embodiments shown in the drawings.
[First Embodiment]
FIG. 1 shows a microwave heating packaging bag (hereinafter simply referred to as a packaging bag) 10 according to a first embodiment of the present invention, in which (A) is a perspective view, (B) is a front view, and (C). Is a side view, and (D) is a plan view. 2 is a cross-sectional view taken along line AA in FIG.

  The packaging bag 10 includes a bag main body portion 20, a protruding piece portion 30 protruding from both surfaces of the bag main body portion 20, and a vapor venting means 40.

  The bag body portion 20 is configured by stacking two rectangular synthetic resin films 11 and 11 and sealing the inside with a heat seal portion 12 formed in four directions along the periphery. As shown in FIG. 2, each synthetic resin film 11 is configured as a laminate of a base material layer 11 </ b> A and a sealant layer 11 </ b> B provided on the entire surface of one surface, that is, a heat-sealing layer. Constructed with the faces facing each other.

  The synthetic resin film 11 is not particularly limited as long as it has the sealant layer 11B on one surface of the base material layer 11A. For the base material layer 11A, for example, polyester, polypropylene, polyamide, or the like can be used. Further, as a multilayer film or sheet, in addition to a laminate of a plurality of different resins, a film or sheet with a metal or a vapor deposition layer such as a metal oxide such as alumina or silica is used as the base layer 11A. Can do. For example, an intermediate layer may be provided between the base material layer 11A and the sealant layer 11B. The material used as the intermediate layer may be a film of polyolefin such as polyethylene terephthalate, polyamide, polyethylene, polypropylene, or the like.

  The resin constituting the sealant layer 11B can be selected from general heat-sealable resins in consideration of the melting point and the seal strength. Specifically, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, An ethylene-methyl acrylate copolymer, an ethylene-ethyl acrylate copolymer, an ethylene-methyl acrylate copolymer, an ionomer resin, or the like can be used.

  As shown in FIG. 1 (B), the bag body 20 has the same length (L1) on both sides, and the upper side and the lower side are the same length (L2) and in parallel. Further, the side is set longer than the upper side (L1> L2), and the outer shape thereof is configured as a vertically long rectangle.

  The projecting piece 30 is configured by folding a part of the synthetic resin film 11 constituting the surface of the bag body 20 and projecting it outward in a flap shape. FIG. 3 is a schematic cross-sectional view taken along line BB in FIG. 1B, and FIG. 4 is a schematic cross-sectional view taken along line CC in FIG. As shown in these drawings, the projecting piece 30 is configured such that a part of the synthetic resin film 11 is folded into a rectangular shape and both side edges 31 (FIG. 4) are brought into close contact with each other by heat sealing. As described above, since the inner region of the projecting piece 30 is not sealed, a space S1 is defined inside. In addition, since the projecting piece 30 is formed integrally with the bag body 20 by projecting a part of the synthetic resin film 11 in the space S1, the interior of the bag body 20 as shown in FIG. It communicates with the space S2.

The projecting piece portion 30 is arranged in parallel with the upper edge portion 21 of the bag main body portion 20, and the dimension of the protruding piece portion 30 is set to be the same as the length L <b> 2 of the upper edge portion 21.
In addition, as shown in FIG. 1C, the projecting piece portion 30 provided on one film outer surface and the projecting piece portion 30 provided on the other film surface have a surface α that is defined as α. It is provided at the position of the surface object as a reference. That is, each projecting piece 30 is disposed at a position opposite to each other.

  The vapor venting means 40 is provided in the heat seal portion 12A formed along the upper edge portion 21 of the bag body portion 20 or in the peripheral region thereof. The vapor venting means 40 is configured to form a hole for venting steam or the like in the bag when the internal pressure of the bag rises by heating with a microwave oven and the internal pressure reaches a certain value or more. Yes. Its structure will be described later.

  In the present embodiment, each projecting piece 30 is disposed close to the vapor venting means 40. Specifically, in FIG. 1 (B), each protruding piece portion 30 is provided in the upper region A with a boundary line β that bisects the bag body portion 20 in the vertical direction.

  The heat seal part 12 is formed by directly heat-sealing the two sealant layers 11B that overlap each other. 1A, 1 </ b> B, and 1 </ b> D, the heat seal portion 12 formed along the peripheral edge of the bag main body portion 20 is shown by cross hatching and formed on both side edge portions 31 of the projecting piece portion 30. The heat seal portion 32 thus formed is indicated by hatching.

Next, an example of the manufacturing method of the packaging bag 10 which concerns on this embodiment is demonstrated based on FIG.
First, as shown in FIG. 5 (A), two rectangular synthetic resin films 11 and 11 are prepared, and as shown in FIG. 5 (B), a part of each synthetic film 11 protrudes outward. Flap 11D is formed. At this time, a part of each synthetic film 11 is folded so as to protrude outward on the base layer 11A side, and the flap 11D is brought close to one short side edge 11E of the synthetic resin film 11, and the It is formed so as to be parallel to the short edge 11E. Next, as shown in FIG. 5C, the two synthetic resin films 11 and 11 are overlapped so that the sealant layer 11B faces each other, and the long side edges 11F of the films 11 and 11 are heat-sealed. At this time, the flap 11D is laid down on the surface of each synthetic resin film, and both edges of the flap 11D are heat-sealed. Thereby, the protruding piece 30 is formed. Note that the flap 11D does not adhere to the synthetic resin film 11 because there is no sealant layer 11B on the surface of the synthetic resin film that comes into contact with the flap surface. Further, as shown in FIG. 5D, the short side edge 11E of the synthetic resin film 11 with the protruding piece portion 30 brought close is heat-sealed. At this time, the vapor venting means 40 is provided in the heat seal portion of the short edge 11E. As a result, a bag sealed on three sides is formed. And after putting contents, such as frozen food, from the opening, the other short edge 11G is heat-sealed as shown in FIG.5 (E), and the packaging bag 10 with which the contents were sealed is completed. . In addition, it is possible to deaerate the inside of a bag in the case of the last heat seal process.

When the packaging bag 10 is heated in a flat state on the tray of the microwave oven, i.e., placed on the tray so that one surface faces the tray surface, Water vapor is generated in the bag, and the air in the bag is thermally expanded to increase the internal pressure. Thereby, the packaging bag 10 expand | swells.
During the expansion process, the expanded air in the bag main body 20 spreads into the space S1 in the protruding piece 30 and an internal pressure is applied to the inner surface of the protruding piece 30 as well. As this internal pressure rises, as shown in FIG. 6, the opposing surfaces 30A and 30B constituting the projecting piece 30 are pushed and expanded from the inside in the direction of arrow B, and the projecting piece 30 expands and expands. . At this time, the film surface 20A disposed from the base 33 of the projecting piece 30 to the upper edge portion 21 provided with the vapor venting means 40 is also pushed and expanded in the direction of arrow C in FIG.
Thereby, as shown in FIG. 7, the projecting piece 30 expands and the vapor venting means 40 moves to a position higher than the non-heating position. When the internal pressure in the bag reaches a certain value or more, a hole is formed in the vapor venting means 40, and the inside expanded air or the like is released from the hole. This prevents the bag from rupturing due to overexpansion.
When heating of the microwave oven is stopped, the internal pressure of the packaging bag 10 becomes the same as that of the outside, but as shown in FIG. 7, the projecting piece 30 disposed on the lower side and the film surface 20A adjacent thereto expand to release steam. The wall part 35A that supports the means 40 is configured, and the protruding piece part 30 disposed on the upper side and the film surface 20A adjacent thereto expand to form the wall part 35B that supports the vapor venting means 40. Since the wall portions 35A and 35B of the wall portions do not collapse even when the internal pressure in the bag is lowered, the vapor venting means 40 is maintained at a high position.

  Thus, according to the packaging bag 10 which concerns on this embodiment, since the vapor venting means 40 is lifted with expansion | swelling and the vapor venting means 40 is hold | maintained in a high position even after completion | finish of a heating, the contents are removed from a punched hole. Leakage can be prevented.

  Further, since the packaging bag 10 is provided with the projecting portions 30 and 30 on both sides of the packaging bag 10 close to the steam venting means 40, even if the front and back are used incorrectly, the steam can be surely vented. Leakage of things can be prevented.

  Since each protruding piece 30 is provided at a symmetrical position in the packaging bag 10 and is formed in the same shape, each protruding piece 30 expands in the same shape during heating expansion. As a result, the forces exerted on each other at the time of expansion become substantially balanced, and the expanded projecting piece portions 30 maintain a constant posture. In the packaging bag shown in Patent Document 4, there is a risk that the vapor venting means that has risen due to expansion falls after the heating is completed and returns to the original position, and the contents may leak out. , 35B does not collapse even when the internal pressure in the bag is lowered, so that leakage of contents can be prevented.

[Second Embodiment]
Next, a packaging bag 10A according to a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the same member as the packaging bag 10 of 1st Embodiment, and the description is abbreviate | omitted.
FIG. 8 is a view showing a packaging bag 10A according to a second embodiment of the present invention, in which (A) is a perspective view and (B) is a side view. Unlike the packaging bag 10A according to the first embodiment, the packaging bag 10A according to the second embodiment also includes a pair of projecting pieces 30 and 30 on the lower side of each synthetic resin film surface of the bag body 20. That is, the packaging bag 10 </ b> A has a pair of protruding pieces 30, 30 on the upper edge portion 21 side and a pair of protruding pieces 30, 30 on the lower edge portion 25 side. Each projecting piece portion 30 is configured to have the same size and shape, and each pair of projecting piece portions 30 and 30 is arranged symmetrically on the opposite surfaces of the synthetic resin film, and further provided on the same synthetic resin film. The two projecting pieces 30 are arranged symmetrically with respect to a boundary line β that bisects the bag body 20.

  In order to heat the packaging bag 10A according to the second embodiment with a microwave oven, first, as shown in FIG. 9A, the packaging bag 10A is placed in the microwave oven with either side facing down. When heated in this state, internal pressure is also applied to the inner surfaces of the four protruding piece portions 30 due to the expansion of the bag accompanying the increase in internal pressure, and the protruding piece portions 30 expand. At this time, the film surface 20 </ b> A disposed from the root of each projecting piece 30 to the short edge close to the base is also expanded by the internal pressure. As a result, as shown in FIG. 9B, the protruding piece 30 on the upper edge 21 side expands and the vapor venting means 40 moves to a position higher than the non-heated position. The protruding piece 30 on the lower edge 25 side also expands, and the lower side region of the bag body 20 is also pushed upward. When the internal pressure in the bag reaches a certain value or more, a hole is formed in the vapor venting means 40, and the inside expanded air or the like is released from the hole. This prevents the bag from rupturing due to overexpansion. In addition, in FIG. 9, the cross-sectional structure of 10 A of packaging bags is represented roughly.

  In the packaging bag 10A according to the second embodiment, as shown in FIG. 9B, the packaging bag 10A can expand more than the packaging bag 10 of the first embodiment. Thus, the volume which can expand | swell becomes large, and it becomes possible to steam the foodstuff as a content for a longer time. Therefore, it is possible to obtain a better taste.

[Third Embodiment]
Next, a packaging bag 10B according to a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the same member as the packaging bag 10 of 1st Embodiment, and the description is abbreviate | omitted.
FIG. 10 is a perspective view showing a packaging bag 10B according to a third embodiment of the present invention. The packaging bag 10B according to the third embodiment is different in the configuration of the projecting piece 30 from that according to the first embodiment. As shown in FIG. 10, the protruding piece 30 of the packaging bag 10 </ b> B is characterized by having a knob 38 on both side edges 31. In addition, the upper edge 36 which tied the upper end of the side edge parts 31 and 31 of both sides is comprised as a line which folded the synthetic resin film 11. FIG.
The knob 38 is formed in such a size that the both side edges 31 of the protruding piece 30 can be picked with a finger. This area is heat-sealed and does not swell when the packaging bag 10B is heated and expanded. Maintain form. Specifically, as shown in FIG. 11 (A), the knob 38 has a first portion 33 where the root 33 of the projecting piece 30 intersects with the inner edge of the heat seal portion 12 formed along the periphery of the bag body 20. The outer region A1 is heat-sealed at a line L3 connecting the first point P1 to the third point P3 on the center side of the second point P2 corresponding to the first point P1 at the upper edge 36 of the protruding piece 30. Configured. In addition, as shown by a dashed-dotted line in FIG. 11A, a line L3 may be set so as to connect the first points P1 and P1 on both sides with the intermediate point P4 on the upper edge. The size and dimensions of the projecting piece 30 are selected so that the angle θ formed by the line L3 and the line L3 on the left side of the projecting piece becomes an obtuse angle.

Since the packaging bag 10B includes the knob portion 38, the user can easily have the packaging bag 10B at the knob portion 38, and the handling of the packaging bag 10B containing the contents heated by the microwave heating can be handled. It becomes easy.
Moreover, in the packaging bag 10 shown in FIG. 1, the corner C is formed in the corner inside the protruding piece portion 30, and when the content is put out on the plate as shown in FIG. The contents F accumulated in C and could not be taken out of the packaging bag 10 cleanly. On the other hand, in the packaging bag 10B of the present embodiment, with the formation of the knob 38, the corner C is closed inside the protruding piece 30 as shown in FIG. Since the corner is not formed, the contents in the protruding piece 30 can be easily taken out without any leakage. Furthermore, when the lines L3 and L3 are set so that the first points P1 and P1 on both sides are connected to the intermediate point P4 on the upper edge, and the angle θ is an obtuse angle, the contents in the projecting piece 30 are completely removed. Can be taken out.
On the other hand, when the packaging bag 10 according to the first embodiment is expanded, the corner C region hardly expands. On the contrary, since the overlapped synthetic resin film surfaces easily move in the corner C region as the packaging bag 10 expands, there is a possibility that the operation of lifting the vapor venting means 40 may be hindered. On the other hand, in the packaging bag 10B according to the third embodiment, the above-mentioned corner C region is sealed and is not easily deformed, and the region where the projecting piece 30 should swell is narrowed. Since the internal pressure is sufficiently applied to the inside of the piece 30 at the time of heating and expanding, the expansion of the protruding piece 30 is improved.

  Next, the structure of the vapor venting means 40 provided in the packaging bags 10, 10A, 10B (and 10C described later) of the present embodiment will be described.

[First configuration example of steam venting means]
FIG. 12 is a view for explaining a first configuration example of the vapor venting means 40 according to the embodiment of the present invention. As shown in FIG. 12A, when two synthetic resin films 11, 11 are overlapped and joined, an easily peelable film 41 is interposed between the two synthetic resin films along the upper edge portion 21. The easily peelable film 41 is sandwiched between two synthetic resin films 11 and 11 and bonded to both synthetic resin films 11 by heat sealing. In this manner, the vapor venting means 40 is attached to the bag main body 20 integrally with the heat seal portion 12A (shaded portion in FIG. 12B) formed on the upper edge portion 21 of the bag main body 20.

  The shape of the easily peelable film 41 is not limited to the rectangular shape shown in FIG. 12 (A), but a plurality of angled protrusions 41A are arranged side by side like a sawtooth as shown in FIG. 12 (C). 12B, one angle protrusion 41B is provided at the center of one long edge as shown in FIG. 12D, or one long edge as shown in FIG. The part may be formed in a waveform 41C. Such an easily peelable film 41 is placed between the synthetic resin films 11 and 11 so that the area decreases from the inner edge (inner side of the bag) of the heat seal portion 12A toward the outer edge (outer side of the bag). Be placed.

  The easily peelable film 41 is used to release the heat seal portion 12A of the upper edge portion 21 due to an increase in internal pressure when the sealed packaging bag is heated in a microwave oven, and to release vapor generated inside. A resin film 11 having a certain degree of heat-fusibility to the sealant layer 11B and capable of reducing the sealing strength of the heat seal portion 12A when at least the packaging bag is heated in a microwave oven is used. For example, a single-layer synthetic resin film having a weak heat-sealing force with the sealant layer 11B of the synthetic resin film 11, a laminated synthetic resin film that easily peels between layers, a laminated synthetic resin film having an agglomerated release layer, or the like can be used. Specific examples include a polymer alloy of polypropylene and polystyrene, a mixed resin of polypropylene and polyethylene, a polypropylene-based multilayer resin, an ethylene-vinyl acetate copolymer film, and the like, and the material of the sealant layer 11B of the synthetic resin film 11 Can be selected.

  According to such a configuration, due to the increase in internal pressure accompanying heating by the microwave oven of the packaging bag, the heat seal portion 12A of the upper edge portion 21 sandwiching the easily peelable film 41 is partially peeled by the internal pressure, thereby Steam can escape through the open hole.

[Second configuration example of vapor venting means]
FIG. 13 is a view for explaining a second configuration example of the vapor venting means 40 according to the embodiment of the present invention. As shown in FIG. 13, the vapor venting means 40 according to the second configuration example is an overhang portion formed by extending the substantially central portion of the heat seal portion 12 </ b> A of the upper edge portion 21 into the bag inside in a substantially semicircular shape. 42A and a substantially circular notch 42B provided in one synthetic resin film 11 in the region of the overhanging portion 42A. In the case of this example, the sealant layer 11B is made of a heat-adhesive resin having easy peelability.

  According to such a structure, a packaging bag will be in the state swelled to the bread bread | pan by the internal pressure rise accompanying the heating by the microwave oven of a packaging bag. And when the internal pressure rises further, peeling of the sealant layer 11B occurs from the inner side of the packaging bag in the substantially semicircular protruding portion 42A provided on the heat seal portion 12A of the upper edge portion 21 of the packaging bag by the internal pressure, Progress towards the outer edge. Eventually, the peeling reaches the notch 42B, and the vapor or the like escapes from the notch (ie, a hole) 42B.

Here, FIG. 14 is a diagram showing a modification of the second configuration example of the vapor venting means 40.
The steam venting means 40 shown in FIG. 14 includes a circular weak heat seal portion 42D formed at a predetermined interval D inside the heat seal portion 12A along the upper edge portion 21, and the weak heat seal portion 42D region. The opening 42E is formed in one of the synthetic resin films 11. In the case of this second modified example, only the weak heat seal portion 42D may be made of a heat-adhesive resin having easy peelability. The shapes of the opening 42E and the weak heat seal portion 42D are not limited to the illustrated example.
According to such vapor venting means 40, when the packaging bag is heated and the internal pressure of the bag is increased by the vapor generated inside, the weak heat seal portion 42D starts to peel off. When the peeling reaches the opening 42E, steam or the like generated inside the bag can escape from the opening (that is, a hole) 42E to the outside.

  Although detailed above, the present invention can be implemented in various forms without departing from the spirit of the present invention. In addition to the above-described flat-type packaging bags, as shown in FIG. 15, the present invention can also be applied to a self-standing bag 10C called a so-called standing pouch. The self-supporting bag 10C shown in the figure has a steam venting means 40 at the upper edge portion 21 and approaches the steam venting means 40 so that the projecting piece portions 30 are parallel to the upper edge portion 21 and one each on the front and back surfaces. Is provided. According to this self-supporting bag 10C, even when the bag is heated while standing in a microwave oven, even if the bag falls down during heating, the protruding piece 30 expands and raises the vapor venting means 40 to a high position. Therefore, the leakage of the contents can be prevented from the hole in the vapor venting means 40.

  Further, the present invention is not limited to the dimensions and shape of the above configuration. The vapor venting means may be a known means other than those described above. The packaging bags 10, 10A, and 10B shown in FIGS. 1, 8, and 10 are provided with a plurality of projecting pieces 30, but each projecting piece of the same packaging bag has a different shape, different dimensions, surface α, You may mutually arrange | position so that it may become an asymmetrical position on the basis of line (beta).

BRIEF DESCRIPTION OF THE DRAWINGS The microwave oven packaging bag which concerns on 1st Embodiment of this invention is shown, (A) is a perspective view, (B) is a front view, (C) is a side view, (D) is a top view. It is the sectional view on the AA line of FIG. It is a schematic sectional drawing in alignment with the BB line of FIG. 1 (B). It is a schematic sectional drawing in alignment with CC line of FIG.1 (D). It is a figure which shows an example of the manufacturing process of the packaging bag for microwave ovens heating of FIG. It is a schematic sectional drawing of the packaging bag for microwave ovens of FIG. It is a perspective view which shows the expansion state of the packaging bag for microwave ovens of FIG. The packaging bag for microwave oven heating which concerns on 2nd Embodiment is shown, (A) is a perspective view, (B) is a side view. The schematic cross-sectional structure of the packaging bag for microwave oven heating of FIG. 8 is represented, (A) shows the state before expansion | swelling, (B) shows the state after expansion | swelling. It is a perspective view which shows the packaging bag for microwave oven heating which concerns on 3rd Embodiment. (A) is a top view which shows the protrusion part of the packaging bag for microwave oven heating which concerns on 3rd Embodiment, (B) is a top view which shows the protrusion part of the packaging bag for microwave oven heating which concerns on 1st Embodiment. is there. It is a figure for demonstrating the 1st structural example of the vapor venting means which concerns on embodiment of this invention. FIG. 9 is a perspective view of a peripheral region of an upper edge portion of a bag main body portion, illustrating a second configuration example of a vapor venting unit according to an embodiment of the present invention. It is a figure which shows the modification of the 2nd structural example of a vapor venting means. The self-supporting bag which concerns on embodiment of this invention is shown, (A) is a perspective view, (B) is a side view. It is a perspective view which shows the conventional packaging bag for microwave oven heating. It is a figure which shows the use condition of the packaging bag for microwave ovens of FIG. It is a figure which shows the use condition of the packaging bag for microwave ovens of FIG.

Explanation of symbols

10, 10A, 10B, 10C Microwave heating packaging bag 11 Synthetic resin film 11A Base material layer 11B Sealant layer 11D Flap 11E, 11G Short edge 11F Side edge 12, 12A, 32 Heat seal part 20 Bag body part 20A Film surface 21 Upper edge portion 30 Projection piece portion 30A, 30B surface 31 Side edge portion 33 Base 35A, 35B Wall portion 40 Vapor venting means 41 Easily peelable film 41A, 41B Yamagata protrusion 41C Waveform 42A Overhang portion 42B Notch 42D Weak heat seal Part 42E Opening S1, S2 space

Claims (6)

A synthetic resin film having a base material layer and a sealant layer is stacked with the sealant layers facing each other, and is formed into a bag shape sealed by a heat seal part in which the sealant layers are thermally welded to each other. A microwave oven heating packaging bag having a steam venting means through which steam at the time of range heating escapes in part or in the vicinity thereof,
Folding part of both synthetic resin films and projecting outward in the form of a flap, the inside has a protruding piece part communicating with the inside of the packaging bag,
Each protruding piece is arranged at a position approaching the steam venting means,
When the microwave oven is heated in a flat state and the internal pressure rises, the lower protruding piece expands and the vapor venting means moves to a position higher than the non-heated position. bag. A synthetic resin film having a base material layer and a sealant layer is stacked with the sealant layers facing each other, and is formed into a bag shape sealed by a heat seal part in which the sealant layers are thermally welded to each other. A microwave oven heating packaging bag having a steam venting means through which steam at the time of range heating escapes in part or in the vicinity thereof,
Each synthetic resin film is provided with two protruding pieces separated from each other,
Each protruding piece part is formed by folding a part of the synthetic resin film to protrude outward in a flap shape, and communicating the inside with the inside of the packaging bag,
One projecting piece of each synthetic resin film is arranged at a position approaching the vapor venting means,
When the microwave oven is heated in a flat state and the internal pressure rises, the lower protruding piece expands and the vapor venting means moves to a position higher than the non-heated position. bag.   The protruding piece portion provided on the outer surface of one synthetic resin film and the protruding piece portion provided on the other synthetic resin film surface are provided so as to be opposite to each other with respect to the bonding surface of the synthetic resin film. The packaging bag for heating a microwave oven according to claim 1, wherein the packaging bag is for heating with a microwave oven.   A bag having an outer shape formed in a square shape, wherein the heat seal portion is formed along the outer peripheral edge of the bag, and the steam venting means is formed in or around the heat seal portion along one side of the square outer peripheral edge. The microwave heating packaging bag according to any one of claims 1 to 3, wherein the protruding piece portion is provided in parallel with the one side.   The packaging bag for heating a microwave oven according to claim 1, wherein the packaging bag is a self-standing bag. The protruding piece portion includes a side edge portion formed by heat-sealing both sides, and an upper edge connecting the upper ends of the side edge portions on both sides,
Each side edge has a knob,
The knob part connects from the first point where the base of the protruding piece part intersects the heat seal part to the third point on the upper edge center side from the second point corresponding to the first point on the upper edge. The packaging bag for heating a microwave oven according to any one of claims 1 to 5, wherein the packaging bag is heat sealed from a line to a side edge.

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