JP2000168851A - Microwave oven-oriented packing bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an entire simple structure, facilitate its manufacturing operation, prevent a bag from being ruptured even through the bag is put in a microwave over and heated there, enable an opening for extracting vapor to be easily made and a heating operation for the bag to be carried out while the vapor is being effectively released. SOLUTION: A folding sheet 4 folded into two segments is inserted at the bottom side of a bag between a front sheet 2 and a rear sheet 3 forming the bag. The front sheet 2 and the rear sheet 3 are heat sealed 5 at their both sides. At the bottom side of the bag, the front sheet 2 and the rear sheet 3 as well as the folding sheet 4 are heat sealed 6 to make a bag having the bottom part. Strength of the heat seal part 6 is made weaker than that of the heat-seal part 5 between the front sheet and the rear sheet. A front side bottom seal 61 has narrower width than the rear side bottom seal 62. When a packing bag 1 having contents sealingly enclosed therein is put in a microwave over and heated therein, moisture content in the bag is evaporated to expand the bag, and the pressure increasing while the contents in the bag are being wet with vapor is transmitted in a concentric manner from the central part of the bag toward the circumferential edge. Then, a small opening is formed at the central part of the front sheet bottom seal 61 of narrow width to cause excessive vapor to be released and then the contents can be heated while being contained in the bag.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a packaging bag, and more particularly to a packaging bag which can be heated in a microwave oven while the contents are sealed.

[0002]

2. Description of the Related Art Conventionally, cooked foods in which a sour pork, hamburger steak, stew, curry, Happo greens, and other foods are sealed in a packaging bag are kept as they are when the food is eaten. When heated in a microwave oven in the state of で, the bag expands and breaks as it is heated, so the cooked food is taken out of the packaging bag in advance to the dishes and heated in the microwave oven. , It takes some time to use it.

[0003] Therefore, there has been a demand for a packaging bag in which the contents are enclosed, which can be directly heated in a microwave oven as it is. As described above, when the contents are placed in a microwave oven while being sealed in the packaging bag and heated, the moisture in the bags evaporates rapidly, the volume increases, the bags burst, and the contents scatter. I will come out. Therefore, the steam generated by the above-mentioned heating must be escaped from the bag little by little.

Various means have been conceived for releasing the steam generated during such heating from the inside of the bag. For example, as shown in FIG. 6, an opening 21 is provided on one side, the periphery of the sheet is sealed 22, and one side of the sheet is
If the bag is filled with the contents and the opening 21 is sealed, the sealed state can be maintained. When the package is placed in a microwave oven and heated, the pressure of the generated steam peels off the seal portion 24 of the gasket sticking portion 23 first to allow steam to enter the buffer portion 25, and then the seal portion 26 or the seal portion 27 Peeled off, allowing steam to escape outwards. However, this packaging bag is complicated in shape and seal structure, and the operation is complicated in order to increase the accuracy of bag production. In addition, due to the structure of the processing machine, bags can be made only one by one, and there are dimensional restrictions, so that the manufacturing cost is greatly increased.

[0005]

SUMMARY OF THE INVENTION The present invention has a simple structure as a whole, is easy to manufacture, and does not break the bag even when heated in a microwave oven. It is intended to obtain something that can be heated while effectively releasing steam.

[0006]

Means for Solving the Problems When a packaging bag filled with contents and sealed is put in a microwave oven and heated, the packaging bag is heated from the center and the volume is increased by vaporization of moisture. However, the increase in the internal pressure accompanying this spreads concentrically from the center of the bag toward the periphery of the bag. According to the present invention, a folded sheet is inserted between the front and back sheets to heat seal the front and back sheets and the folded sheet to form a bottomed bag, which is heated by a microwave oven. The folded sheet and the front and back sheets are formed such that the sealing strength between the front and back sheets is weaker than the sealing strength between the front and back sheets, and the folded sheet and the front and back sheets forming the bottom are formed. The width of one of the heat seals is reduced.

[0007] When the packaged bag filled with the contents is heated in a microwave oven, the increase in the internal pressure due to the above-mentioned heating causes the sealing strength of the bottom portion to decrease with the heating, resulting in a narrow width of the sheet. A small opening is formed by peeling off the seal in this part reaching the center of the seal part, and steam gradually escapes from this part, so that other seal parts are peeled off or the front and back sheets are broken. The contents can be heated to a desired state without breaking the packaging bag.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a bag 1 shown in the drawings, a folded sheet 4 is inserted between a front sheet 2 and a back sheet 3 from the bottom side, and the front and back sheets are heated on both sides. At the bottom, the front and back sheets and the folded sheet 4 are heat-sealed 6 to form a bag with a bottom 7. The strength of the heat seal 6 between the front and back sheets 2 and 3 and the folding sheet 4 is lower than the strength of the heat seal 5 between the front and back sheets when heated in a microwave oven. It is formed by changing the material of the sheet or changing the sealant.

[0009] In the heat seal 6 forming the bottom 7, the outer bottom seal 61 between the front sheet 2 and the folding sheet 4 is connected to the back sheet 3. The width of the heat seal is made smaller than that of the back bottom seal 62 between the folding sheet 4. It is safer to form the heat seal 5 of the front and back sheets 2 and 3 on both sides wider than the front bottom seal 61.

[0010] Such a bag 1 is filled with sweet and sour pork, hamburger, and other prepared food (not shown), and the space between the front and back sheets 2 and 3 at the top of the bag is usually wider than the above-mentioned front bottom seal 61. When the sealer 8 is used, the cooked food inside is held in a sealed state in the bag, so that heat sterilization is performed according to the contents as necessary. The cooked food is kept sealed by the packaging bag, and can be stored in this state.

When this is used, it is placed in a microwave oven with the front sheet 2 of the packaging bag 1 facing upward. that time,
It is advisable to put it on a plate or the like before use as a precaution. When heating with a microwave oven, heating starts from the center of the bag, the moisture in the bag evaporates and expands the bag, and the water vapor is held in the bag and heated while steaming the contents. The increasing pressure spreads concentrically 9 from the center of the bag toward the periphery as shown in FIG.

The increased pressure acts on the heat seal portion of the bag to peel it off. When heated, the sealing strength of the bottom seal 6 is reduced by the seal 5 between the front and back sheets.
And the outer bottom seal 61 in the bottom seal 6.
When the pressure in the bag reaches a certain level or more, the central portion 63 of the outsole seal 61 is peeled off first, and a small opening is formed in the central portion. Become like

The extra steam generated by heating is
As the bag 1 expands, the outer bottom seal 61 is directed upward, so that the vapor naturally escapes upward and the liquid in the bag is released. Nothing overflows. Further, when the pressure in the bag is further increased, the opening can be further expanded, and the other portion of the bag is not broken. Uniform heating can be performed while obtaining a small and moderate steaming action. When the heating is completed, the heated contents are taken out of the microwave oven and opened using the opening notch 10 of the packaging bag or the like, so that the heated contents can be taken out and used.

When this packaging bag 1 is manufactured, a front sheet 2
And the back sheet 3 are superimposed on each other, and the folded sheet 4 folded in between is inserted from the bottom side to seal both sides and the bottom.
If the bottom side of the front sheet 2 is cut off to a fixed width, the narrow bottom sole 61 is formed, so that the production can be performed simply and efficiently.

Further, two folded sheets 4 are supplied from both sides of the unwound front sheet 2 and the back sheet 3 and inserted, and a heat seal 5 is provided between the front and back sheets 2 and 3. And
Also, heat seal 6 is applied between the front and back sheets on both sides and the folding sheet 4 to cut off the front sheet 2 side to a narrow width, and the front and back sheets 2 and 3 are cut at the center, thereby simultaneously producing two bags. Can be more efficient.

FIG. 5 shows a case where a notch 12 having an arc shape or the like is formed from the outside at a center portion 63 of the above-mentioned outer bottom seal 61 having a small seal width. The center portion 63 is heated by a microwave oven. A small opening can be formed in the bag 63 more reliably, and an excess amount of water vapor filled in the bag can be removed.

[0017]

As described above, according to the present invention, the sealing strength at the time of heating the seal portion forming the bottom of the bag is made smaller than the other portions, and the seal width of a part of the bottom seal is provided. When a microwave oven is heated, a small opening is formed in the narrow seal portion by the internal pressure that increases in the bag due to the generation of steam, so that the steam can be surely released therefrom. Since the bag does not break and the contents come out, the bag can be placed in a microwave and heated as it is. it can. Further, the narrow seal portion at the bottom can be easily formed by cutting a part of the seal portion into a narrow width, so that the manufacture is easy and economical.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a partially omitted perspective view showing a bottom portion of FIG. 1 for easy understanding.

FIG. 3 is a partially omitted sectional view of a bottom portion of FIG. 1;

FIG. 4 is an explanatory view showing a state in which pressure in a bag spreads during heating.

FIG. 5 is a partially omitted perspective view showing the bottom of another embodiment of the present invention for easy understanding.

FIG. 6 is a perspective view showing a conventional packaging bag.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Packaging bag 2 Front sheet 3 Back sheet 4 Folding sheet 5 Both side seal 6 Bottom heat seal 61 Outer bottom seal 62 Back bottom seal 63 Center of outer bottom seal Part 7 bottomed 8 upper heat seal 12 notch

Claims (2)

[Claims] 1. A bag for storing contents has a bottom part formed by inserting a fold sheet between the front and back sheets and heat sealing the front and back sheets and the fold sheet. The bottomed bag is formed such that when heated by a microwave oven, the sealing strength of the folded sheet and the front and back sheets is lower than the sealing strength between the front and back sheets. A microwave-compatible packaging bag, characterized in that one of the widths of the heat seal between the folded sheet and the front and back sheets is narrow. 2. The packaging bag for a microwave oven according to claim 1, wherein a notch is provided from the outside at the center of the heat seal formed with a narrow width forming the bottom.