JP2005320023A - Horizontally placed packaging bag for microwave oven - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horizontally placed packaging bag for a microwave oven which can be manufactured at a low cost by a manufacturing process for an ordinary packaging bag without requiring special material and process, and can prevent a content from leaking out from an opened steam venting seal part caused by erroneous use characteristic to the horizontally placed packaging bag for the microwave oven. <P>SOLUTION: In the horizontally placed packaging bag for the microwave oven in which the steam venting seal part is formed by curving the peripheral edge seal part of the packaging bag sealed by heat-sealing a plastic film inward of the bag into a U shape, an unsealed part is provided outside of the curved part of the steam venting seal part, and it is so constituted that a width (a) on the extension line of the inner edge of the peripheral edge seal part of the unsealed part, a length b from the outer edge of the unsealed part to the extension line of the inner edge of the peripheral edge seal part, and a seal width d of the peripheral edge seal part are 1.5b≤a≤8b and a≤4d. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention automatically escapes the steam generated inside the packaging bag when the packaging bag filled with contents such as retort food made of liquid, solid, or a mixture thereof is heated in a microwave oven, The present invention relates to a flat-type microwave packaging bag that can prevent rupture, deformation, and scattering of contents of the packaging bag.

  When a packaging bag with hermetically sealed retort food, frozen food, etc. is heated in a microwave oven, the pressure inside the bag rises due to water vapor generated from the contents during heating, and the packaging bag bursts and the contents scatter. At the same time, the inside of the microwave oven may be soiled, or the human body may be burned.

For this reason, before such a packaging bag is cooked in a microwave oven, the packaging bag is partially opened in advance, or water vapor generated in the packaging bag is generated by opening a hole in the packaging bag body. In order to prevent the packaging bag from being broken, a method has been adopted.
However, such a method is time-consuming for general consumers, and since steam generated by microwave heating is immediately discharged out of the packaging bag, the steaming effect by steam is reduced and the taste is reduced. There is a drawback of falling.

  As such a packaging bag for a microwave oven having an automatic opening mechanism for automatically releasing the increase in the internal pressure of the packaging bag during heating of the microwave oven, the standing for heating the packaging bag independently in the microwave oven Pouches (see, for example, Patent Document 1), flat bags, flat-type packaging bags such as a flat bag or a branch type pouch provided with an automatic opening mechanism at a branching portion, etc. 2-4), various types are known.

JP 2002-249176 A Japanese Patent Publication No. 8-25583 Japanese Patent Laid-Open No. 2002-80072 JP 2001-106270 A

  However, with a flat-type microwave packaging bag, when taking out the packaging bag that has been automatically opened after cooking from the microwave oven, the packaging bag may be turned upside down by accidentally grasping the side opposite to the automatic opening side of the packaging bag. There were dangers due to misuse, such as the contents leaking out from the automatic opening for steam removal and contaminating the surroundings, or causing burns.

In the above-mentioned patent document 4, in order to prevent the leakage of the contents due to such misuse, the easy-opening seal in which the joint part of the packaging bag provided with the joint part is located on the contents side of the packaging bag. There has been proposed a microwave oven packaging bag that is divided into a part and a complete seal part connected to the easy-open seal part, and a passage for releasing pressure to the outside is provided in the complete seal part.
However, in this packaging bag, the joint-joining portion that provides a mechanism that automatically opens when heating in a microwave oven is configured by two seal portions having different unsealing properties, and a passage that releases pressure to the outside is provided only on the outer complete seal portion. For this reason, there is a drawback in that a complicated manufacturing process that is not required for a normal manufacturing process of a packaging bag is required, resulting in an increase in cost. In addition, this mechanism has a problem that it cannot be applied to a flat bag.

  Therefore, the present invention can eliminate the danger due to misuse peculiar to such flat-type microwave packaging bags, and does not require special materials or processes, and can produce ordinary packaging bags. An object of the present invention is to provide a flat-type microwave packaging bag that can be manufactured at low cost by a process.

  As a result of intensive studies, the inventors of the present invention have found that in a flat-type microwave packaging bag in which a steam vent seal portion is formed by bending the peripheral seal portion of the packaging bag toward the inside of the bag, the outside of the curved portion In addition to providing an unsealed part on the top, the shape of the steam vented seal part, the shape and dimensions of the unsealed part are specified, and the packaging bag with the steam vented seal part automatically opened after cooking is On the other hand, the present invention has been completed by discovering that, when taken out, the open steam release seal portion is blocked by the stress caused by the weight of the contents, and leakage of the contents can be prevented.

That is, the present invention employs the following configurations 1 to 11.
1. In a flat-type microwave packaging bag in which a steam vent seal part is formed by curving a peripheral seal part of a packaging bag sealed by heat-sealing a plastic film in a U shape toward the inside of the bag, An unsealed portion is provided outside the curved portion of the steam release seal portion, and the width a on the extension line of the inner edge of the peripheral seal portion of the unsealed portion and the extension line of the inner edge of the peripheral seal portion from the outer edge of the unsealed portion A flat-type microwave packaging bag, wherein the length b and the seal width d of the peripheral seal portion are 1.5b ≦ a ≦ 8b and a ≦ 4d.
2. 2. The flat-type microwave packaging bag according to 1, wherein a width c on an extension line of an outer edge of the peripheral seal portion of the unsealed portion is 2 mm or more.
3. The inner angle θ of the isosceles triangle with the full width of the unsealed portion on the extension line of the inner edge of the peripheral seal portion as the base and the center of the outer edge of the unsealed portion as the apex is 80 ° ≦ θ ≦ 150 °. The flat-type microwave packaging bag according to 1 or 2, wherein the packaging bag is configured as described above.
4). The flat-type electron according to any one of 1 to 3, wherein the outer edge of the unsealed portion provided outside the curved portion of the steam release seal portion is formed inside the extension line of the outer edge of the peripheral seal portion. Packaging bag for range.
5). The flat-type microwave packaging bag according to any one of claims 1 to 4, wherein a branch portion is provided in the packaging bag, and a steam release seal portion is formed at a peripheral seal portion of the branch portion.
6). 6. The flat-type microwave packaging bag according to 5, wherein a spout forming means is provided at a planned opening position of the peripheral seal portion of the packaging bag body facing the branching portion.
7). 5. The flat-type microwave packaging bag according to any one of claims 1 to 4, wherein the packaging bag is a flat bag, and a steam release seal portion is formed at a peripheral seal portion on one side of the flat bag.
8). The width a on the extension line of the inner edge of the peripheral seal portion of the unsealed portion and the length b from the outer edge of the unsealed portion to the extension line of the inner edge of the peripheral seal portion are configured to satisfy 1.5b ≦ a ≦ 5b. 8. The flat-type microwave packaging bag according to 7, wherein
9. 9. The flat-type microwave packaging bag according to 7 or 8, wherein a spout forming means is provided at a planned opening position of the peripheral seal portion of the packaging bag.
10. The flat-type microwave packaging bag according to any one of 1 to 9, wherein the sealing strength of the peripheral seal part and the steam release seal part is 2.3 kg / 15 mm or more.
11. The microwave oven packaging bag according to any one of 1 to 10, wherein a spout forming means is provided by applying laser processing to a planned opening position of the packaging bag.

In the flat-type microwave packaging bag of the present invention, by adopting the above configuration, when taking out the flat-type microwave packaging bag automatically opened after cooking from the microwave oven, When taken out upside down, the contents can leak out from the automatic opening to contaminate the surroundings and prevent problems such as burns.
Further, the packaging bag of the present invention does not require any special materials or processes, and can be manufactured by a normal manufacturing process of the packaging bag, and thus has high practical value.

  As the plastic film constituting the packaging bag for a microwave oven in the present invention, a plastic material having heat sealing properties usually used for manufacturing a packaging bag is used. Examples of such a plastic material include a single-layer film made of a thermoplastic resin having heat-sealability, a sheet, a multilayer film in which a thermoplastic resin having heat-sealability is laminated with another thermoplastic resin, and the like. Can be mentioned.

  Examples of such a heat-sealable plastic material include known low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, propylene-ethylene copolymer, and ethylene-vinyl acetate copolymer. Olefin resins such as olefin resins graft-modified with ethylenically unsaturated carboxylic acids or their anhydrides, polyamides or copolyamide resins having a relatively low melting point or low softening point, polyesters or copolyester resins, polycarbonate resins, etc. Is done.

Further, as other plastic materials laminated with the plastic material having heat sealability, thermoplastic resins and various barrier films having or not having heat sealability can be used.
Examples of such thermoplastic resins include crystalline polypropylene, crystalline propylene-ethylene copolymer, crystalline polybutene-1, crystalline poly-4-methylpentene-1, low-, medium-, or high-density polyethylene, Polyolefins such as ethylene-vinyl acetate copolymer (EVA), EVA saponified product, ethylene-ethyl acrylate copolymer (EEA), ion-crosslinked olefin copolymer (ionomer); polystyrene, styrene-butadiene copolymer, etc. Aromatic vinyl copolymers; halogenated vinyl polymers such as polyvinyl chloride and vinylidene chloride resins; polyacrylic resins; nitrile polymers such as acrylonitrile-styrene copolymers, acrylonitrile-styrene-butadiene copolymers; polyethylene Terephthalate, polytetramethylene terephthalate Can be exemplified thermoplastic resins such as polyacetal such as polyoxymethylene and the like; over polyesters such as preparative; various polycarbonates; fluorine-based resin. These thermoplastic resins can be used alone or in combination of two or more, and various additives may be blended and used.

  Various barrier films include silica-deposited polyester film, alumina-deposited polyester film, silica-deposited nylon film, alumina-deposited nylon film, alumina-deposited polypropylene film, carbon film-deposited polyester film, carbon film-deposited nylon film, and alumina and silica. Binary vapor-deposited film co-deposited on base film such as polyester film and nylon film, nylon 6 / metaxylylenediamine nylon 6 co-extruded film, polypropylene / ethylene-vinyl alcohol copolymer co-extruded film, and polyvinyl alcohol coated polypropylene Film, Polyvinyl Alcohol Coated Polyester Film, Polyvinyl Alcohol Coated Nylon Film, Polyacrylic Acid Tree Coated polyester film, polyacrylic acid resin coated nylon film, polyacrylic acid resin coated polypropylene film, polyglycolic acid resin coated polyester film, polyglycolic acid resin coated nylon film, organic resin coating such as polyglycolic acid resin coated polypropylene film Examples thereof include a film, and a hybrid coating material made of an organic resin material and an inorganic material coated on a base film such as a polyester film, a nylon film, or a polypropylene film. These barrier films can be used alone or in combination of two or more.

  In this invention, the packaging bag for microwave ovens is comprised by heat-sealing the unstretched film comprised by the said plastic material, or the uniaxially or biaxially stretched by the conventional method. When the film is a laminated film of a thermoplastic resin having heat sealing properties and a thermoplastic resin having no heat sealing properties, heat sealing is performed so that the thermoplastic resin layers having heat sealing properties become inner surfaces. .

Hereinafter, the structure of the packaging bag for microwave ovens of this invention is demonstrated based on drawing.
1-3 is a figure which shows one example which applied this invention to the flat-type microwave packaging bag which provided the branch part, FIG. 1 is a perspective view of the state which raised the branch part of the packaging bag, FIG. 2 is a partially enlarged view of the steam release seal portion provided at the branch portion, and FIG. 3 is a schematic view for explaining the procedure for producing this packaging bag.
One side of the packaging bag 1 is provided with a collapsible branch portion 3, and a steam release seal portion is formed by curving a peripheral seal portion at the upper edge of the branch portion 3 toward the inside of the bag in a U shape. 4 and an unsealed portion 5 is provided outside the curved portion of the steam release seal portion. Moreover, the spout formation means 7 by a notch is formed in the opening expected position of the peripheral seal part of the opposing part 6 which opposes the branch part 3 of a packaging bag main body.

As shown in FIG. 2, the width on the extension line of the inner edge of the peripheral seal portion of the unsealed portion 5 is a, and the length from the outer edge of the unsealed portion 5 to the extension line of the inner edge of the peripheral seal portion is b. Further, when the seal width of the peripheral seal portion is d, the configuration is such that 1.5b ≦ a ≦ 8b and a ≦ 4d.
At that time, it is preferable that the sealing width of the curved portion is the same as or smaller than the sealing width d of the peripheral seal portion. Moreover, it is preferable to comprise so that the width | variety c on the extension line of the outer edge of the peripheral seal part of the unsealed part 5 may be 2 mm or more.

The shapes of the steam-sealed seal part 4 and the unsealed part 5 are not limited to those shown in FIG. 2. For example, the configuration is such that a> c as shown in FIG. It can be selected as appropriate, for example, by further providing a recess 8 at the lower end (inner side of the bag).
By setting a, b and d in such a range, when taking out the packaging bag automatically opened after cooking from the microwave oven, the side opposite to the side automatically opened of the packaging bag (filling port 10). Even if the packaging bag is taken out upside down by grasping the side), the unsealed part 5 outside the steam-opening seal part 4 that is automatically opened is blocked by the weight of the contents, and the contents leak from the automatic opening part. It is possible to prevent danger due to misuse, such as putting out and polluting the surroundings or causing burns.

  For example, as shown in FIG. 3, the packaging bag 1 can be manufactured by heat-sealing the peripheral portions of the three plastic films 1a, 1b, and 1c. At that time, one short side of the packaging bag body is unsealed to form a filling port 10 for the contents, and after filling the contents from this filling port 10, the filling port 10 is sealed by heat sealing, and 120 Retort treatment is performed under the condition of 30 ° C.

Next, when this microwave packaging bag is cooked in a microwave oven, when the steam vent seal part 4 of the packaging bag is automatically opened, and when the automatically opened packaging bag is accidentally taken upside down, A state in which the unsealed portion 5 provided outside the automatically vented steam vent seal portion 4 is closed will be described with reference to FIGS.
When the packaging bag 1 filled and sealed with the contents is cooked in a microwave oven, as shown in FIG. 6, the packaging bag 1 expands due to water vapor or the like generated from the contents, and particularly at the branch portion 3 and the facing portion 6. As a result, the steam vent seal portion 4 is concentrated, and the steam vent seal portion 4 begins to peel from the inner tip of the curved portion near the center of the bag. As the internal pressure of the bag rises, the sealing part 4 moves backward, and when the peeling reaches the unsealed part 5, the packaging bag 1 is partially opened, and water vapor and the like are discharged from the unsealed part 5 to prevent bag breakage. be able to.

After the automatic opening, the internal pressure of the packaging bag 1 decreases, and the packaging bag 1 is in a deflated state as seen in FIG.
When the packaging bag 1 is removed by holding the opening 10 side of the opened packaging bag 1, as shown in the schematic cross-sectional view (A) of FIG. 8, the opened steam release seal portion 4 and the unsealed portion 5. In this case, an internal pressure is applied due to the weight of the contents, and a force is applied in the direction in which the inner surface of the unsealed portion 5 is brought into close contact with the lever principle to try to close the unsealed portion 5.

FIG. 8B is a schematic diagram illustrating the force point Q, the fulcrum P, and the closing point C when the internal pressure is applied. The force point Q exists in the approximate center of the width a on the extension line of the inner edge of the peripheral seal portion of the unsealed portion 5, and the fulcrum P exists in the approximate center of the closing point C and the force point Q. Then, the sectional shape of the opening changes due to the internal pressure due to the weight of the contents, and the position of the force point Q changes in the direction indicated by the two arrows at the top of FIG. The position of point C changes.
At that time, the width a on the extension line of the inner edge of the peripheral seal part of the unsealed part 5, the length b from the outer edge of the unsealed part 5 to the extension line of the inner edge of the peripheral seal part, and the seal width d of the peripheral seal part 1.5b ≦ a ≦ 8b and a ≦ 4d, the closing point C due to the action of internal pressure can be located in the unsealed portion 5 (FIG. 8B )), And the unsealed portion 5 can be brought into close contact with the contents to prevent leakage.

  The width c on the extension line of the outer edge of the peripheral seal part of the unsealed part 5 is set to 2 mm or more, and as shown in FIG. 9, the unsealed part on the extension line of the inner edge 21 of the peripheral seal part 2 When the internal angle θ of an isosceles triangle having the width overall length XY (= a) of the portion 5 as the base and the center Z of the outer edge of the unsealed portion as the apex is 80 ° ≦ θ ≦ 150 ° It is preferable because the closing point C can be positioned in the unsealed portion 5 more reliably and leakage of contents can be prevented.

As shown in FIGS. 2, 4, and 5, the shape of the outer edge of the unsealed portion 5 provided on the outer side of the steam release seal portion 4 of the microwave packaging bag of the present invention is an extension line of the outer edge of the peripheral seal portion 2. And the same straight line.
9 and 10, the outer edge of the unsealed portion 5 may be formed inside the extension line of the peripheral seal portion 2 in a convex arc shape inward of the bag.
Further, a concave portion 23 is provided only at the center of the outer edge of the unsealed portion 5 configured linearly (see FIG. 11), or a slit 24 substantially orthogonal to the outer edge is provided at the center of the linear outer edge (see FIG. 12). ), Can be changed as appropriate.

Although the shape of the lower end part (bag inner side) of the steam release seal part 4 formed by curving the peripheral seal part 2 of the packaging bag in a U shape toward the inside of the bag is arbitrary, FIG. When it forms so that it may become linear as seen in ~ 12, when the packaging bag filled with the content is dropped, the packaging bag breaks at the steam release seal part 4 and the content is Since it can prevent leaking, it is preferable.
Also, the shape of the curved portion is such that the width a of the inner edge portion of the unsealed portion 5 and the width c of the outer edge portion of the unsealed portion 5 are substantially the same as shown in FIG. 14 has an unsealed portion where the width a of the inner edge portion of the unsealed portion 5 and the width c of the outer edge portion are substantially the same width, and are wide below a, as shown in FIG. It is possible to appropriately change the one or the one that is configured so that the unsealed portion 5 is gradually narrowed toward the lower end portion. When the width of both sides of the unsealed portion 5 is the same width or widened downward (see FIGS. 2, 13 and 14), the unsealed portion 5 after automatic opening is stably blocked. This is preferable because it can be realized.

FIG. 15: is a top view which shows one example which applied this invention to the packaging bag for microwave ovens of a flat bag.
In this packaging bag 11, the steam seal part 4 is formed by curving the peripheral seal part 2 on one short side of the flat bag in a U shape toward the inside of the bag, and at the outside of the curved part. A seal portion 5 is provided. The configurations of the steam release seal part 4 and the unsealed part 5 are basically the same as those of the packaging bag for microwave ovens having the branch part 3 described above, but in this type of packaging bag 11, the peripheral seal of the unsealed part. The width a on the extension line of the inner edge of the part, the length b from the outer edge of the unsealed part to the extension line of the inner edge of the peripheral seal part, and the seal width d of the peripheral seal part are 1.5b ≦ a ≦ 5b, and It is preferable to configure so that a ≦ 4d.

In the peripheral seal portion 2 on the side where the long side steam vent seal portion 4 of the packaging bag 11 is provided, a spout forming means is provided at the planned opening position of the bag by laser processing, perforation processing, notching processing, or the like. Can do. Moreover, you may make it provide the steam-release seal | sticker part 4 in the peripheral seal part of the long side of a bag.
In order to heat cook this type of microwave packaging bag 11 in the microwave oven, place the side of the packaging bag on which the steam release seal 4 is provided on a stand or the like, hold it high, and heat it. Is preferred.

FIG. 16: is a perspective view which shows one example which applied this invention to the packaging bag for microwave ovens which has a gusset part.
In this packaging bag 31, the peripheral seal portion 2 of one gusset portion 32 of the bag is bent in a U shape toward the inside of the bag to form the steam release seal portion 4, and at the outside of the curved portion, A seal portion 5 is provided. The configurations of the steam release seal part 4 and the non-seal part 5 are basically the same as the packaging bag for a microwave oven having the branch part 3 described above. In this type of packaging bag 31, the width a on the extension line of the inner edge of the peripheral seal portion of the unsealed portion and the outer edge of the unsealed portion from the outer edge of the peripheral seal portion is the same as the packaging bag provided with the branch portion of FIG. It is preferable that the length b to the extension line and the seal width d of the peripheral seal portion are 1.5b ≦ a ≦ 8b and a ≦ 4d.

FIG. 17 is a perspective view showing another example in which the present invention is applied to a flat-type microwave packaging bag provided with a branch portion.
In this example, the knob 9 is formed by making the main body of the packaging bag 41 and the corner part of the branch part round, and by forming the peripheral seal part of the corner part of the branch part 3 and the opposing part 6 wide. It is. The structure of the steam vent seal part 4 provided in the branch part 3 is the same as that of the packaging bag of FIG.

Next, the microwave packaging bag of the present invention will be further described with reference to examples, but the following specific examples do not limit the present invention.
Example 1
A polypropylene composition in which a rubber component is blended with a 12 μm biaxially stretched polyester film, a 15 μm biaxially stretched nylon film, and a 70 μm ethylene propylene block copolymer in order from the outer layer (the blending amount of the rubber component is about 30% of the composition). A roll-shaped laminate was produced by dry lamination using a polyurethane-based adhesive using a film comprising a weight%).
The laminated body was attached to a bag making machine, and a packaging bag 41 having a branch portion 3 shown in FIG. The inner dimension of the short side (l in FIG. 17) of this packaging bag 41 is 118 mm, the inner dimension of the long side (m in FIG. 17) is 154 mm, and the height of the inner dimension of the branch part 3 (h in FIG. 17) is 14 mm. The width a on the extension line of the inner edge of the peripheral seal portion of the unsealed portion 5 is 12 mm, the length b from the outer edge of the unsealed portion 5 to the extension line of the inner edge of the peripheral seal portion is 2.5 mm, and the width of the peripheral seal portion The seal width d was 4.5 mm.

About 200 g of commercially available retort curry was filled in this packaging bag 41, and 10 bags were produced by heat-sealing the filling port 10. This bag was placed in a microwave oven (RO-LF9, manufactured by Mitsubishi Electric Corporation) with the branching portion 3 facing upward, and cooked for 120 seconds at an output of 600 W. About 70 seconds after the heating, the steam release seal part 4 was peeled off by the increased internal pressure and automatically opened to release the internal pressure.
After cooking, when the internal pressure decreased and the bag was squeezed, the filling port 10 was pinched and the bag was taken out of the microwave oven so that the automatically opened steam vent seal part 4 faced downward. Then, it hold | maintained for 10 seconds in the state which faced the steam release seal | sticker part 4, and when the presence or absence of the leakage of the content was confirmed, the leakage of the content was not recognized by having put in all 10 bags.

(Comparative Example 1)
In Example 1, a packaging bag was produced in the same manner as in Example 1 except that the unsealed portion 5 was not provided outside the curved portion of the steam vent seal portion 4 of the packaging bag. This packaging bag was filled with a commercially available retort curry in the same manner as in Example 1, and 10 sealed ones were produced. When it was taken out from the microwave oven and held for 10 seconds with the steam release seal part 4 facing downward, leakage of the contents was observed in all the bags. The amount of content leaked out in 10 seconds was 1.5 g at the minimum, 2.8 g at the maximum, and the average value was 2.3 g.

It is a perspective view which shows one example which applied this invention to the flat type packaging bag for microwave ovens which provided the branch part. It is the elements on larger scale of the steam removal seal | sticker part provided in the branch part of the packaging bag of FIG. It is a figure which shows the preparation procedures of the packaging bag of FIG. It is a figure explaining other examples of a steam release seal part and a non-seal part formed in a flat type microwave packaging bag of the present invention. It is a figure explaining the other example of the steam release seal | sticker part formed in the flat type microwave packaging bag of this invention, and an unsealed part. It is a figure explaining a state when the packaging bag of FIG. 1 is cooked with a microwave oven. It is a figure explaining the state after cooking the packaging bag of FIG. 1 with a microwave oven, and opening automatically. It is a figure explaining the state when taking out the packaging bag of FIG. 1 upside down from the microwave oven automatically, (A) is a cross-sectional schematic diagram of the packaging bag, and (B) is an internal pressure acting on the packaging bag. It is a schematic diagram explaining the power point, fulcrum, and obstruction | occlusion point at the time of doing. It is a figure explaining the steam release seal part and unsealed part which are formed in the packaging bag for microwave ovens of the flat type of the present invention. It is a figure explaining the steam release seal part and unsealed part which are formed in the packaging bag for microwave ovens of the flat type of the present invention. It is a figure explaining other examples of a steam release seal part and a non-seal part formed in a flat type microwave packaging bag of the present invention. It is a figure explaining other examples of a steam release seal part and a non-seal part formed in a flat type microwave packaging bag of the present invention. It is a figure explaining other examples of a steam release seal part and a non-seal part formed in a flat type microwave packaging bag of the present invention. It is a figure explaining the other example of the steam release seal | sticker part formed in the flat type microwave packaging bag of this invention, and an unsealed part. It is a top view which shows one example which applied this invention to the packaging bag for microwave ovens of a flat bag. It is a perspective view which shows one example which applied this invention to the packaging bag for microwave ovens which has a gusset part. It is a perspective view which shows the other example which applied this invention to the flat type packaging bag for microwave ovens which provided the branch part.

Explanation of symbols

1, 11, 31, 41 Packaging bag 2 Peripheral seal part 3 Branch part 4 Steam release seal part 5 Unsealed part 6 Opposing part 7 Outlet forming means 8, 23 Recess 9 Knob 10 Filling port 21 Edge of peripheral seal part 24 Slit 32 Gusset part

Claims (11)

  In a flat-type microwave packaging bag in which a steam vent seal part is formed by curving a peripheral seal part of a packaging bag sealed by heat-sealing a plastic film in a U shape toward the inside of the bag, An unsealed portion is provided outside the curved portion of the steam release seal portion, and the width a on the extension line of the inner edge of the peripheral seal portion of the unsealed portion and the extension line of the inner edge of the peripheral seal portion from the outer edge of the unsealed portion A flat-type microwave packaging bag, wherein the length b and the seal width d of the peripheral seal portion are 1.5b ≦ a ≦ 8b and a ≦ 4d.   The flat-type microwave packaging bag according to claim 1, wherein a width c on an extension line of an outer edge of the peripheral seal portion of the unsealed portion is 2 mm or more.   The inner angle θ of the isosceles triangle with the full width of the unsealed portion on the extension line of the inner edge of the peripheral seal portion as the base and the center of the outer edge of the unsealed portion as the apex is 80 ° ≦ θ ≦ 150 °. The flat-type microwave packaging bag according to claim 1 or 2, characterized in that it is configured as described above.   The flat type according to any one of claims 1 to 3, wherein an outer edge of the unsealed portion provided outside the curved portion of the steam release seal portion is formed inside an extension line of the outer edge of the peripheral seal portion. Packaging bags for microwave ovens.   The flat type microwave packaging bag according to any one of claims 1 to 4, wherein a branch portion is provided in the packaging bag, and a steam release seal portion is formed at a peripheral seal portion of the branch portion.   6. The flat-type microwave packaging bag according to claim 5, wherein a spout forming means is provided at a planned opening position of the peripheral seal portion of the packaging bag body facing the branch portion.   The flat packaging bag for a microwave oven according to any one of claims 1 to 4, wherein the packaging bag is a flat bag, and a steam release seal portion is formed at a peripheral seal portion on one side of the flat bag.   The width a on the extension line of the inner edge of the peripheral seal portion of the unsealed portion and the length b from the outer edge of the unsealed portion to the extension line of the inner edge of the peripheral seal portion are configured to satisfy 1.5b ≦ a ≦ 5b. The flat packaging bag for a microwave oven according to claim 7, wherein the packaging bag is a flat type microwave oven.   The flat-type microwave packaging bag according to claim 7 or 8, wherein a spout forming means is provided at a scheduled opening position of the peripheral seal portion of the packaging bag.   10. The flat-type microwave packaging bag according to claim 1, wherein the seal strength of the peripheral seal portion and the steam release seal portion is 2.3 kg / 15 mm or more.   The packaging bag for microwave ovens according to any one of claims 1 to 10, wherein a spout forming means is provided by performing laser processing on a planned opening position of the packaging bag.

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