JPH1095470A - Package for microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive package for a microwave oven, which can stably and securely discharge steam generated from food to be cooked in cooking the food in the microwave oven. SOLUTION: In a package for a microwave oven, in which food to be cooked is contained in the package body 1 in which the connection parts 8c of the packaging materials 5 are mutually connected, at least one 13a of belt-form heat-shrinkable films 13 is held between the packaging materials 5 of the connection parts 8c and futher, the film 13a is constituted so that it slips off from the connection parts 8c by the longitudinal shrink of the heat-shrinkable film 13 with the cooking heat of the microwave oven. And a steam relief opening connected to the inside of package body 1 is formed at the connection parts 8c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for a microwave oven, in which an article to be cooked can be heated and cooked in a microwave oven.

[0002]

2. Description of the Related Art Conventionally, an article to be cooked and sealed in a packaging bag is limited to a cooking method by heating in hot water, and when a microwave oven is used, the internal pressure increases due to moisture evaporated from the article to be cooked during heating and cooking. As a result, the packaging sheet may expand like a balloon and burst.

Therefore, when cooking in a microwave oven,
It is necessary to devise a way to escape the internal steam. Therefore, conventionally, a valve for discharging steam is attached to the packaging bag, or a material such as silicon for reducing the heat sealing strength is applied between the joined ends of the packaging sheet, and this portion is used for cooking. It has been devised to allow the steam to escape by expanding the internal pressure.

[0004]

However, when a valve for discharging steam is used, it is not functionally incomplete or the cost is high, so that it has not been widely used. Further, when a material for preventing heat sealing is applied between the ends to be joined of the packaging sheet, such a material is applied by printing, so that the process becomes complicated and the amount of application is adjusted. The escape rate of steam was unstable because it did not work or the opening that was pushed out was too large.

The present invention has been made in view of the above-mentioned conventional problems, and can stably and surely discharge steam generated from an article to be cooked when heating and cooking in a microwave oven, and at a low cost. It is an object to provide a package for a microwave oven.

[0006]

The technical measures taken by the present invention to solve the above-mentioned problems include the joint 8c of the packaging material 5.
In the microwave oven package in which the article to be cooked 3 is accommodated in the package body 1 formed by joining together, the joining portion 8c
At least one of the strip-shaped heat-shrinkable films 13 is sandwiched between the packaging materials 5, and the one 13 a is joined by shrinking the heat-shrinkable film 13 in the longitudinal direction by cooking heat from a microwave oven. The joint 8c is configured to escape from the portion 8c.
Is formed.

[0007] A container 20 containing the article 3 to be cooked is provided.
In the microwave oven package in which the closing sheet 22 is adhered to the opening edge 20a of the container, at least one of the strip-shaped heat-shrinkable films 13 is provided between the opening edge 20a of the container 20 and the closing sheet 22. The heat-shrinkable film 13 shrinks in the longitudinal direction by the cooking heat of the microwave oven, so that the heat-shrinkable film 13a comes out from between the opening edge portion 20a and the closing sheet 22. That is, a vapor release opening 15 communicating with the inside of the container 20 is formed between the portion 20a and the closing sheet 22.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment In FIGS. 1 to 3, reference numeral 1 denotes a packaging bag as a package body for packaging an article to be cooked 3 such as frozen food or dried food, and the packaging bag 1 is made of biaxially stretched polyester; Packaging as a well-known packaging material in which a plastic film such as biaxially stretched polyamide having a thickness of about 10 to 30 μm is used as a base material and a low-density polyethylene resin (about 20 to 60 μm in thickness) is laminated as a heat sealing layer on the innermost layer. The seat 5 is configured.

The packaging bag 1 is provided with edges 8 on both sides of the sheet 5.
This is a so-called pillow packaging type in which a bag is formed in a hermetically sealed shape by heat sealing the back affixed portion 8c (joined portion) rising a, 8b and upward. In addition, the packaging bag shown in FIG. 1 shows a bag made by heat-sealing the sheet 5 in an empty state where the article to be cooked 3 is not stored for the description of the present invention.

Reference numeral 7 denotes a vapor passage formed in the back affixing portion 8c, which communicates with a housing space 9 for housing the article 3 to be cooked in the packaging bag 1. That is, the steam passage 7 is formed by leaving a non-seal portion when the back pasting portions 8c are heat-sealed to each other in a sealed manner, and is a large first passage communicating with the article storage space 9. 10 and a second passage 11 having a small width.

The first passage 10 is located substantially at the center of the back stuck portion 8c in the longitudinal direction, and its width L1 is approximately 1/3 of the length L (corresponding to the length of the packaging bag 1) of the back stuck portion 8c. Is set to Further, the second passage 11 is moved from the position above the first passage 10 to
Extending along the longitudinal direction (lateral direction) of the
Is approximately half the width L1 of the first passage 10 (for example, 2 to 10
mm). In addition, the first passage 10 of the back pasting portion 8c
The length L3 of the side seal portion 12b is equal to the length of the second passage 11 side seal portion.
It is longer than the length L4 of 12a.

Reference numeral 13 denotes a narrow band heat-shrinkable film having the same width, which is provided in the longitudinal direction of the back pasting portion 8c.
That is, as shown in FIG. 2A, both ends 13a and 13b of the heat-shrinkable film 13 are attached to the back adhering portion 8c so as to cross the first passage 10 and be located in the second passage 11. It is pinched. The heat-shrinkable film 13 is made of a material that does not thermally fuse with a low-density polyethylene resin such as uniaxially-stretched polyester or uniaxially-stretched polypropylene, or that easily peels off. It is preferably 20% or more at 80 ° C and 30% or more at 90 ° C in the longitudinal direction.

Here, the term “clamping” means that the heat-shrinkable film 13 having no heat-sealing property between the back-sticking portion 8c and the back-sticking portion 8c.
Is heat-sealed, so that both surfaces are pressed in close contact with the back affixing portion 8c and held by the pressing force (frictional force), or a pseudo-adhesion such as a case having a weak heat bonding property. It means when it is done.

Further, one end 13 of the heat-shrinkable film 13
a is sandwiched by a seal portion 12a having a small seal area of the back sticking portion 8c, and the other is a seal portion 12a having a large seal area.
b. Note that the force with which the seal portion 12a sandwiches one end 13a of the heat-shrinkable film 13 needs to be set smaller than the contraction force of the heat-shrinkable film 13.

Therefore, when the heat-shrinkable film 13 is heated, the other end 13b is held by the seal portion 12b because of high frictional resistance or adhesive force, and one end 13a is held by the heat-shrinkable film 13 itself. By the contraction force, it comes out of the seal portion 12a and separates. As a result, a vapor release opening 15 communicating with the second passage 11 is formed in a portion where one end 13a of the heat-shrinkable film 13 has been inserted.

Next, the article to be cooked 3 packed in a package
Is cooked in a microwave oven.

First, when the food 3 is cooked by placing the packaging bag 1 in a microwave oven, microwaves generated from the microwave oven are absorbed in the food 3 and the food 3 is heated. During this heating, the liquid in the article to be cooked 3 becomes vapor, the pressure in the packaging bag 1 increases, and the packaging bag 1 expands.
The steam heats the heat-shrinkable film 13 and the packaging bag 1 (see FIG. 2B).

When the heat-shrinkable film 13 is heated, the other end 13b is held by the back pasting portion 8c, so that one end 13a comes out of the back pasting portion 8c due to the contraction force. And a steam release opening 15 is provided on the seal portion 12a side.
Are formed so as to communicate with the second passage 11 (FIG. 2C).
And FIG. 3). Therefore, the steam in the packaging bag 1 is supplied to the first passage 10, the second passage 11, and the expanded steam release opening 15.
Is discharged as appropriate.

Second Embodiment FIGS. 4 to 6 show a second embodiment.
The four edges 18a, 18b, 18c and 18d of the film 17 are heat-sealed. Then, one end 13a of the heat-shrinkable film 13 is sandwiched by one edge 18a, and the other end 13b is opposed to one edge 18a.
It is pinched.

In order to manufacture such a package, FIG.
Along with the long film 17 wound up as shown in FIG. 4 arranged vertically, the long heat-shrinkable film 13 similarly wound between them is unwound from the long film 17. Place along the direction.

The upper and lower films 17 are heat-sealed from above and below by a heat-sealing device (not shown). At this time, an edge 18c parallel to the heat-shrinkable film 13 is opened without sealing. , Other edges 18
a, 18b and 18d are closed (see FIG. 6 (b)). Since both end portions 13a and 13b of the heat-shrinkable film 13 are momentarily pressed by the film 17, the heat shrinkage hardly occurs at this time. Furthermore, the continuous packaging bag 1 may be cut and separated at the same time as the heat sealing, or may be cut by a cutter in a separate step.

Further, after accommodating the article to be cooked 3 through the opening, the edge 18c is heat-sealed and closed, thereby completing the production of the package.

In such a package, as shown in FIGS. 5A and 5B, the heat-shrinkable film 13 contracts and one end 13a comes off the edge 18a. Alternatively, since both ends 13a and 13b of the heat-shrinkable film 13 are sandwiched between the edges 18a and 18b under substantially the same conditions, when the heat-shrinkable film 13 contracts, both of the 13a and 13b become It may come out, but in this case, on both sides of the package,
The vapor release openings 15 are respectively formed.

Also, one end 13 of the heat-shrinkable film 13
In the case where only a is removed, as shown in FIG. 6, a resin 19 having good sealing properties may be applied on both surfaces of the heat-shrinkable film 13 located at the edge portion 18b at predetermined intervals. It is possible.

Third Embodiment FIG. 7 shows a third embodiment, in which a package has a bottomed container 20 made of a rigid synthetic resin and an upper surface opening of the container 20.
It comprises a closing sheet 22 that closes the 21 in a releasable manner. The container 20 is formed by molding a polypropylene resin sheet (about 0.8 mm in thickness), and the closing sheet 22 is formed of a biaxially stretched polyamide film, a sealant resin having an easy peeling property with respect to polypropylene (for example, a mixture of polypropylene and polyethylene). Resin etc.).

The heat-shrinkable film 13 is provided in the diameter direction of the container 20, and both ends 13 a and 13 b are sandwiched between the closing sheet 22 and the flange-shaped opening edge 20 a of the container 20. . Therefore, when the heat-shrinkable film 13 shrinks, one or both of them come off in the same manner as described above.

The heat-shrinkable film 13 is not necessarily a container on both sides.
It is not necessary to pinch between 20 and the closing sheet 22, and FIG.
As shown in (c), the other end 13b side may be fixed to the back surface of the closing sheet 22 or may be fixed to the inner surface of the container 20.

The present invention is not limited to each of the above embodiments.
The width of the heat-shrinkable film 13 is not limited to one, and the width of the heat-shrinkable film 13 is appropriately set according to the size of the vapor release opening. The packaging material may have a configuration in which a pair of container-like rigid materials are joined, and the form is not particularly limited.

[0029]

According to the present invention, at least one of a strip-shaped heat-shrinkable film is sandwiched at the joint of the packaging material, and one of the strip-shaped heat-shrinkable films shrinks in the longitudinal direction due to cooking heat by a microwave oven. By doing so, it is configured to come out of the joint, and a vapor release opening communicating with the inside of the packaging material is formed in the joint, so that when cooking in a microwave oven, heat shrinkage is performed without special processing. It is possible to reliably form the vapor release opening by utilizing the contractive force of the conductive film.

Further, since the width of the heat-shrinkable film is constant, the size of the above-mentioned vapor release opening can be easily made constant. In comparison with the case where a material that prevents heat sealing is applied, the production is simpler, and steam can be discharged to each package in a stable state, and the finished state of cooking is good. Becomes

In addition, as compared with the case where a conventional check valve is provided, it can be manufactured by a simple process of sandwiching the heat-shrinkable film at the same time when the packaging material is joined, so that the cost is advantageously reduced.

[Brief description of the drawings]

FIG. 1 is an overall perspective view of a packaging bag showing a first embodiment of the present invention.

2 (a) is a cross-sectional view of the back-adhered portion before cooking, (b) is a cross-sectional view taken along the line AA in FIG. 3, and (c) is FIG. BB sectional drawing of FIG.

FIG. 3 is a perspective view of the package during cooking.

FIGS. 4A and 4B show a second embodiment of the present invention, wherein FIG. 4A is an overall sectional view, and FIG.

FIG. 5A is an overall cross-sectional view of a state in which the heat-shrinkable film has shrunk, and FIG.

FIGS. 6A and 6B show a manufacturing process of the present invention, wherein FIG. 6A is a perspective view showing a main part before heat-sealing the film and the heat-shrinkable film, and FIG. FIG.

FIGS. 7A and 7B show a third embodiment of the present invention, wherein FIG. 7A is an overall sectional view, FIG.
(C) is a sectional view showing a main part.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Package body, 3 ... Cooked article, 5 ... Packing sheet (packing material), 8c ... Joint part (back bonding part), 15 ... Steam release opening, 20 ... Container, 20a ... Opening edge, 22 ... Clogging Sheet

Claims (2)

[Claims] 1. A package for a microwave oven in which an article to be cooked (3) is housed in a package body (1) formed by joining joints (8c) of packaging materials (5) to each other. Department (8
Between the packaging materials (5) in c), a strip-shaped heat-shrinkable film (1)
At least one (13a) of 3) is pinched, and
a) shows that the heat-shrinkable film (13) shrinks in the longitudinal direction due to the cooking heat from the microwave oven, so that the joint (8c)
The package (8c) has a vapor release opening (15) communicating with the inside of the package body (1). 2. A package for a microwave oven wherein a closing sheet (22) is adhered to an opening edge (20a) of a container (20) containing a product to be cooked (3). ), At least one of the strip-shaped heat-shrinkable films (13) is sandwiched between the opening edge (20a) and the closing sheet (22), and the one (13a) is formed by a microwave oven. The heat-shrinkable film (13) contracts in the longitudinal direction due to cooking heat, so that the heat-shrinkable film (13) comes out from between the opening edge (20a) and the closing sheet (22), and the opening edge (20a) and the closing sheet ( Steam release opening (1) communicating with the inside of vessel (20) between 22)
5) A package for a microwave oven, wherein the package is formed.