JP2002059982A - Package to be heated in microwave oven - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a package to be heated in a microwave oven wherein a pressurized gas inside the package by heating in a cooker such as the microwave oven can be smoothly exhausted with a quiet unsealing sound from a spotlike opening formed on a part of a surface material of the package. SOLUTION: The package to be heated in a microwave oven is formed with chevron-shaped cuts whose tips are opposite to each other at a distance of 2 mm or less with a tip angle of 15 to 100 deg. on a layer except an innermost layer of a laminate film. A symmetry axis connecting between the tips of the chevron-shaped cuts is formed in parallel to or with an inclination of 10 deg. or less from a seal in the proximity. In addition, a carbon dioxide laser which forms the chevron-shaped cuts only on surface layers can be used in combination by forming an external layer of the laminate film of a polyethylene terephthalate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a package for heating a microwave oven in which cooked or semi-cooked food or the like is sealed by heat sealing or the like, and more particularly to cooking of a microwave oven or the like. The present invention relates to a package for heating a microwave oven in which only gas inside a package pressurized by heating in a vessel is quietly and smoothly exhausted without accompanying a bursting sound or an explosion sound.

[0002]

2. Description of the Related Art In recent years, with the development of materials having excellent properties for use in packaging, there has been a remarkable development of packaging in the food field. There are many food packages on the market that can be provided to consumers without losing taste.

As these food packages, a bag-like package in which the contents are sealed by heat-sealing the periphery of two films, or a standing package in which the periphery of two films is heat-sealed through the bottom. A package called a pouch and a cup-shaped package in which a flange portion of a round or square cup-shaped container is heat-sealed with a film are known.

When these packages are used, they are heated by a heating cooker such as a microwave oven until they are restored to the state at the time of cooking. Therefore, these packages have heat resistance enough to withstand the heating. It is desired to provide a means for avoiding a situation in which the gas or water vapor in the package expands due to heating during cooking, the pressure increases, and the package eventually bursts.

[0005] In order to solve such a problem, a part of the heat seal portion of the package is configured to be peelable, and a technique of discharging gas from the package to the outside from the heat seal portion, or a heat seal portion is used. There is a lot of proposals for making a cut in a part of the surface material of the package body, and when the internal pressure of the package body rises, an opening is formed starting from the cut and the gas in the package body is discharged from that part. Have been.

Japanese Patent Application Laid-Open No. H10-9547 discloses an example of a technique in which a part of a heat seal portion can be peeled off.
As disclosed in Japanese Patent Application Publication No. 1 (1999), "a part having a lower sealing strength than the other side is provided on the entire side of the heat seal part constituting the periphery of the package, and steam or gas generated in the package is discharged from the part to the outside. "Packages configured to release" are known. When the internal pressure of the package increases, the portion of the package having a weak seal strength can be delaminated and release the internal pressure to the outside.

Further, as an example in which a cut is made in a part of the surface material of the package instead of the heat seal portion, for example, a method disclosed in Japanese Patent Application Laid-Open No. H11-147559 is disclosed.
"In a lid material comprising a laminated film in which a heat-resistant base material film, a first heat-adhesive resin layer, and a second heat-adhesive resin layer are laminated in order from at least the outside, a heat-resistant base A lid material provided with a score line penetrating from the material film to the first heat-adhesive resin ", or disclosed in JP-A-11-139466.
"In a bag heat-sealed by disposing the sealant layers of the first film and the second film having the layer structure consisting of the base film and the sealant layer so as to face each other, only the layer structure part of the second film is used. Prior art such as "a packaging bag having an opening formed by punching out or notching in the thickness direction through it" is known.

[0008] In addition, Japanese Patent Application Laid-Open No. 11-91832 discloses an example of a package in which a cut is formed in a part of the surface material of the package to form an opening for discharging the pressure in the package.
It is also disclosed in JP-A-11-79260.

However, in the technique in which a part of the heat seal portion is configured to be peelable, since the heat seal portion is configured to be easily peelable, there is a possibility that the bag may be broken by an impact during transportation. Rather, once peeling has begun, the peeling opening is severely ruptured, and at that time, there is a possibility that a loud opening sound may be caused, and further, the contents may be scattered. Further, in order to form a peelable portion in the heat seal portion, a special device is required for the seal bar, and there is a problem in the manufacturing process that a separate member must be used.

Regarding the prior art in which a cut is formed in a part of the surface material of the package, a cut is made in the outer layer of the laminated film, and when the internal pressure increases, the inner layer is easily broken from the cut portion of the outer layer. This prevents bag breakage due to peeling of the heat seal portion. However, in any of the prior arts, the shape of the cut is only disclosed in the form of an X-shaped or U-shaped cut. In this shape, when the inner layer is broken, the internal gas is immediately released. Since it is released from the part, there is a possibility that a loud popping sound is generated or, in a severe case, the contents pop out.

Accordingly, an object of the present invention is to provide a microwave oven for heating a package for heating a microwave oven, wherein when the pressure inside the package increases, the two opposing ∨-shaped portions formed in the outer layer gradually expand. Only when the two ∨-shaped tips are unified when they are opened, a small spot-shaped opening communicating from the inside of the package to the outside is formed, from which only gas can be discharged to the outside. An object of the present invention is to provide a heating package. Another object of the present invention is to provide a package for heating a microwave oven, in which the gas is discharged without explosion or explosion, thereby creating a comfortable cooking environment.

[0012]

DISCLOSURE OF THE INVENTION The present invention has been proposed to achieve the above-mentioned object. The present invention relates to a pouch made of a laminated film and a package of a cup-shaped container using a sealing lid. This has an important feature in forming a specific cut in a layer except for the innermost layer.

That is, according to the present invention, in a package for heating a microwave oven, a square-shaped notch having a tip angle of 15 ° to 100 ° is formed in a layer excluding the innermost layer of the laminated film at an interval of 2.0 mm or less. And the て い る -shaped cuts are provided in the sealing portion of the package, or in the central portion of the portion surrounded by the fold portion, or in the portion excluding the vicinity of the central portion. A package for heating a microwave oven is provided.

Further, according to the present invention, there is provided the package for heating a microwave oven, wherein the ∨-shaped cut is formed at a central portion or near a central portion of at least one side of the seal portion. Is done.

Further, according to the present invention, there is provided the package for heating a microwave oven, wherein a symmetric axis connecting the tips of the ∨-shaped cuts is formed in parallel with an adjacent seal portion. Is done.

According to the present invention, the microwave oven is characterized in that the axis of symmetry connecting the tips of the ∨-shaped cuts has an inclination of 10 ° or less with respect to the adjacent seal portion. A package for heating is provided.

Further, according to the present invention, there is provided the package for heating a microwave oven, wherein the end of the の -shaped cut is formed in a hook shape or a state where the ends are connected to each other. .

Further, according to the present invention, the laminated film is formed in such a manner that the layer cut in the shape of a letter "C" is made of polyethylene terephthalate, and the other layer is made of a film or sheet of another polymer. The above-mentioned package for heating a microwave oven is provided.

Further, according to the present invention, there is provided the package for heating a microwave oven, wherein the innermost layer of the laminated film is formed of polypropylene.

Further, according to the present invention, there is provided the package for heating a microwave oven, wherein the ∨-shaped cut is formed by a carbon dioxide laser.

[0021]

DETAILED DESCRIPTION OF THE INVENTION An object of the present invention is to heat a package containing foods or the like with a microwave oven or the like, without causing an opening sound such as a rupture or explosion with only an internal pressure increased by heating. That is, the package body is provided with a function of discharging the package smoothly and smoothly to the outside.

Hereinafter, the configuration of the present invention will be described in detail with reference to the drawings. Based on the above-described prior art, the greatest feature of the configuration of the package conceived by the present inventors to achieve the above object is that two end portions near the center of one of the seal portions 12 and 13 of the package are provided. Is formed so that the tips of the ∨-shaped cuts 11 face each other. The seal portion in the present invention includes not only a portion sealed by heat sealing but also a portion sealed by an adhesive. The state in which the tips of the ∨-shaped cuts 11 face each other means the state shown in FIG.
The ∨-shaped cuts 11 are not connected to each other. The tip angle θ of the ∨-shaped cut is 15 ° to 100 °.
°, and preferably from 20 to 90 °. If the angle θ is less than 15 °, the processed portion becomes close to being parallel to the sealing direction, and there is a possibility that an opening larger than necessary may be formed. Unintentionally, the bag may break from other unexpected parts.

The distance W between the tips of the ∨-shaped cuts is
Is 2.0 mm or less, there is no lower limit as far as it is technically possible to form a cut, but the lower limit is about 0.5 mm from processing accuracy, preferably 1.0 to 2.0
mm.

The mechanism leading to the opening of the package with the formation of the ∨-shaped cut 11 is as shown in FIG. 1. First, (a) in the initial stage when the internal pressure of the package increases with heating. In, force is applied in the direction of the arrow,
As this state progresses, it gradually becomes a ∨-shaped notch 11 ′ in an expanded state as shown in FIG. At this stage, the direction of the expansion proceeds in an oblique direction according to the angle of the 切 -shaped cut 11 ′ as indicated by the arrow, and at the tip of the ∨-shaped cut, the spread is made in a direction in which the tips come closer to each other. Advances. When this state further proceeds, as shown in (c), the tips of the ∨-shaped cuts communicate with each other, leading to the formation of a small opening 14 at the center thereof.

The preferred formation position of the ∨-shaped cut 11 differs depending on the type of the package, and a preferred example is shown in FIG. In any case, it is desirable to be formed at the place where the stress is first concentrated when the pressure inside the package increases,
In the case of a four-sided seal pouch or a three-sided seal pouch, it is preferably located near the center of the long side seal portion 12 or the center of the short side seal portion 13, and especially near the center of the long side seal portion 12. Is more preferable. In the case where the package is a standing pouch, it is preferable that the package is formed in the vicinity of the upper seal portion, and in the case of the cup, it is formed in the vicinity of the annular seal portion.

The distance between the seal portion and the ∨-shaped cut is not particularly limited, but is usually about 10 to 20 mm. The distance between the seal and the cut is too large,
For example, if it is formed in the center of the package, not only leakage of the contents may occur, but also the opening will not be performed unless the pressure in the package has significantly increased, so a loud popping sound will occur when opening. It is feared that it will occur.

The shape of the ∨-shaped notch is preferably such that the axis of symmetry connecting its ends is parallel to the seal portion.
If the axis of symmetry connecting the tips of the ∨-shaped cuts is within 10 ° with respect to the adjacent seal portion, it may be formed in an inclined shape. FIG. 3 shows the positional relationship between the seal portion and the 切 -shaped notch close to each other. If the angle α between the axis of symmetry and the seal portion exceeds 10 °, the opening may be excessively cracked in parallel with the seal direction (see FIG. 4). No phenomenon occurs. Further, the number of the ∨-shaped cuts facing each other may be two or more.

In the present invention, in order to prevent the end of the を -shaped notch from opening excessively when the package is opened, for example, the end of the ∨-shaped notch as shown in FIG. It is preferable to form it in a hook shape or a state where the ends are connected. By making the end shape of the ∨-shaped cut in this way, the shape at the time of opening always terminates at the end of the ∨-shaped cut, and no excessive opening is formed. It is possible to prevent unexpected leakage and generation of a popping sound.

Further, when the package of the present invention is cut out from a raw film, as shown in FIG. 6 (B), the axes of the ∨-shaped cuts are perpendicular to the film flow direction. This is very important. This is because the raw film is often stretched in the flow direction and the molecules in the film are oriented in many cases. In other words, as shown in FIG. 6A, when the package is cut out so that the axes of the cuts in the shape of a letter are parallel to the film flow direction, the package is heated.
The opening of the character-shaped cut portion corresponds to the opening 14 at the center of the cut portion.
In addition, there is a possibility that undesired phenomena such as excessive crack progress along the molecular orientation and loud plosive noise may occur. On the other hand, as shown in FIG. 6 (B), when the package is cut out so that the axes of the ∨-shaped cuts are perpendicular to the film flow direction, it is possible to prevent such excessive crack progress. it can.

Accordingly, a preferred embodiment of the present invention described in the present specification relates to a package using a film cut out so that the axes of the cuts are perpendicular to the film flow direction. Should be understood.

The ∨-shaped cut in the laminated film of the present invention can be formed by any means, but the most preferable means is a forming means using a carbon dioxide laser. When a carbon dioxide laser is used as the notch forming means, the outer layer of the laminated film is preferably made of polyethylene terephthalate, and the adjacent layer is preferably made of a polymer other than polyethylene terephthalate.

A carbon dioxide laser has a wavelength of 10.6 μm, and polyethylene terephthalate absorbs light of this wavelength efficiently. By irradiation with a carbon dioxide gas laser having a high energy density, processing such as cutting and removal can be performed. Therefore, when a carbon dioxide laser is irradiated to a laminate of polyethylene terephthalate and another polymer having a low absorption of the carbon dioxide laser, only a layer of polyethylene terephthalate having a high absorption rate can be selectively processed.

Therefore, when a laminated film using polyethylene terephthalate as the outer layer of the laminated film and a polymer having a low absorptivity of the carbon dioxide laser, for example, a polypropylene layer, other than polyethylene terephthalate as the inner layer, is irradiated with the carbon dioxide laser, Notches are formed only in the polyethylene terephthalate layer,
No cut is formed in the inner layer. For these reasons,
According to the present invention, it is possible to easily obtain a package composed of a laminated film in which a cut is formed only in a layer excluding the innermost layer. Forming a cut only in the layer excluding the innermost layer means that, for example, the cut is made in the outer layer in the case of two layers, the middle layer or the outermost layer in the case of three layers, or both the middle layer and the outermost layer. To tell.

Another advantage of forming a cut in the laminated film using a carbon dioxide laser is that the cut is easily formed in only a part of the package even after the laminated film is formed in a bag shape. That you can do it.

Usually, in order to form a cut in only a part of the layered film, a film in which a cut is made in advance and a film in which a cut is not made are pasted together by bonding or the like, and then formed into a bag. Is performed. However,
If the cut film is previously formed into a bag shape by heat sealing the laminated film, it is extremely difficult to fix the cut portion to a fixed portion of the bag, and a remarkable restriction is required in the working process.

On the other hand, as described above, in the method of forming the cut by the carbon dioxide gas laser after forming the laminated film into a bag shape, the carbon dioxide gas laser may be applied to an arbitrary portion of the bag. In addition, the position of the cut can be easily formed at the optimum position.

As described above, the use of the carbon dioxide laser as a means for forming a cut in a part of the layer of the laminated film brings a remarkably excellent advantage.
The greatest feature of the present invention resides in that the shape of the cut and the place where the cut is formed are specified, and the means for forming the cut is not limited to the one using a carbon dioxide laser.

Therefore, when a carbon dioxide laser is used as the means for forming the cut, it is necessary to use polyethylene terephthalate as the outer layer of the laminated film constituting the package, but in other cases,
A laminated film compatible with ordinary microwave heating can be used without limitation.

As the inner layer of such a laminated film,
Polypropylene, or a copolymer of propylene and an α-olefin other than propylene such as ethylene, butene-1, hexene-1, and octene-1; a heat-sealing thermoplastic resin such as polyester and nylon; You.

The outer layer laminated with these inner layers may be a thermoplastic resin having or not having a heat sealing property, for example, biaxially oriented polypropylene, ethylene-vinyl acetate copolymer (EVA), saponified EVA, etc. , Polyolefins such as ion-crosslinked olefin copolymers (ionomers): aromatic vinyl copolymers such as polystyrene and styrene-butadiene copolymer: halogenated vinyl polymers such as polyvinyl chloride and vinylidene chloride resin: polyacrylic Nitrile polymers such as resin, acrylonitrile-styrene copolymer, acrylonitrile-styrene-butadiene copolymer: polyesters such as biaxially stretched polyethylene terephthalate and polytetraoxymethylene terephthalate: various polycarbonates: polyacetals such as polyoxymethylene: Aliphatic-based, it can be aromatic polyamides, thermoplastic resin such as polyimide alone or by laminating two or more use. Further, for the purpose of imparting gas barrier properties, a non-metallic vapor-deposited film, scale-like substance, or oxygen-absorbing substance may be used. The laminated film may have not only a structure of two layers but also a structure of three or more layers in terms of oxygen barrier properties.

The package applied to the present invention is not limited to pouches (four-side seal pouch, three-side seal pouch, pillow pouch, standing pouch, etc.), but can also be applied to trays, cups and the like. Further, the laminated film used for the package is not particularly limited in the production method, and any means such as a means for bonding the inner layer and the outer layer with an adhesive, a bonding means by thermal lamination, a bonding means by co-extrusion, etc. Can be taken.

[0042]

According to the present invention, in a package which is heated and cooked in a microwave oven or the like, gas swelled in the package due to heating is quiet from a portion which is opened in a spot on a part of the surface material of the package. Provided is a package for heating a microwave oven which can be smoothly discharged out of the package under a gentle opening sound.

[0043]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below based on embodiments.
This example is intended to illustrate a preferred embodiment of the present invention and is not intended to limit the present invention.

Example 1 As a film for a package,
A laminated film in which a biaxially stretched polyethylene terephthalate (PET) having a thickness of 12 μm and a polypropylene film having a thickness of 50 μm were bonded by ordinary dry lamination was used. This film was cut out to 110 × 120 mm, and a three-sided heat-sealed pouch as shown in FIG. 2 was prepared. A carbon dioxide laser having a wavelength of 10.6 μm, an output of 10 W, and a spot diameter (half width) of 285 μm was applied to one surface of this pouch at a processing speed of 1 μm.
By applying a speed of 5.2 cm / sec, cuts of various shapes were formed. 100 cc of water in this pouch
And sealed with heat seal, and microwave oven E made by Toshiba
The package was heated with R-V11 (rated high-frequency output: 500 W), and the time until the package (pouch) was opened or burst and the state thereof were observed. The width of each seal is 10mm
It is. The results are shown in Table 1.

[0045]

[Table 1]

The processing shape is as shown in Table 1. Laser processing was performed on the center of the long side of the pouch such that the position 10 mm from the seal portion was the center of the processing shape. The width (X) and height (Y) of the processed portion differ depending on the processed shape, but both X and Y are 10 to 15 mm. However,
No. Nos. 2 and 3 do not consider the width and height directions, respectively.
8, X = 10 mm and Y = 20 mm. As can be seen from Table 1, a small opening was obtained from the processed part only when a pair of ∨-shaped processing in which the tips faced each other was performed, and the pressure inside the package could be released safely. In other shapes, it bursts from a part other than the processed part together with the plosive sound, for example, from a seal part, and in some cases, water as contents may jump out.

<Example 2> As a film for a package,
A laminated film in which a biaxially stretched polyethylene terephthalate (PET) having a thickness of 12 μm and a polypropylene film having a thickness of 50 μm were bonded by ordinary dry lamination was used. This film was cut into a size of 130 × 170 mm, and a three-sided pouch as shown in FIG. 2 was heat-sealed on only three sides to make a pouch. A carbon dioxide laser having a wavelength of 10.6 μm, an output of 10 W, and a spot diameter (half width) of 285 μm was processed on one side of this pouch at a processing speed of 15.2.
The cut was formed by applying a speed of cm / sec. The shape of the cut is a pair of ∨-shapes whose tips face each other, w = 1.3 mm, θ = 60 °, height (Y) = 1
0 mm and width (X) = 20 mm. Water 2 in this pouch
Then, the container was sealed with a heat seal, heated with a microwave oven ER-V11 manufactured by Toshiba (rated high-frequency output: 500 W), and the time until the package (pouch) was opened or burst and its state were observed. The width of each seal portion is 10 mm. The results are shown in Table 2.

[0048]

[Table 2]

As can be seen from Table 2, when processing was performed near the center of the long side of the pouch, a preferable opening was obtained even when processing was performed at a portion 30 mm away from the seal portion, but 15 mm away from the seal portion. , 40mm from center or 60
When processed into a portion shifted by mm, bag breakage occurred with a loud popping sound from other portions. From this result, it is understood that it is preferable to perform a notch forming process near the center of the side formed by the seal.

Example 3 As a film for a package,
A laminated film in which a biaxially stretched polyethylene terephthalate (PET) having a thickness of 12 μm and a polypropylene film having a thickness of 50 μm were bonded by ordinary dry lamination was used. This film was cut out into a size of 130 × 170 mm, and a three-sided heat-sealed pouch as shown in FIG. 2 was heat-sealed on only three sides. A carbon dioxide laser having a wavelength of 10.6 μm, an output of 10 W, and a spot diameter (half width) of 285 μm was processed on one side of this pouch at a processing speed of 15.2.
The cut was formed by applying a speed of cm / sec.

The shape of the cut was a pair of ∨-shapes whose tips face each other, and the experiment was performed by changing the values of w, θ, and α. Although the size of the processed portion is different, both the width (X) and the height (Y) are set so as not to exceed 20 mm. The processing position was such that the center of the processing portion was located at the center of the short side of the pouch and 10 mm from the seal portion. This pouch is filled with 200 cc of water, sealed with a heat seal, heated with a Toshiba microwave oven ER-V11 (rated high-frequency output 500 W), and the package (pouch) is opened.
Or the time to rupture and its condition were observed. The width of each seal portion is 10 mm. The results are shown in Table 3.

[0052]

[Table 3]

From the results shown in Table 3, the No. According to 1 to 8, θ
It can be seen that a preferred aperture can be obtained when the value of is between 20 and 90 °. In addition, No. 9 and 10, it can be seen that a preferable opening can be obtained if the value of w is 2 mm or less. In addition, No. According to 11 to 13, α is 10 °
It can be seen that a preferred opening is obtained in the following cases.

[Brief description of the drawings]

FIG. 1 shows the shape of a ∨-shaped notch formed in a part of the surface material of the package for heating a microwave oven of the present invention, and the state of change in the shape of the ∨-shaped notch as the internal pressure during heating increases. )
It is a figure shown by (b)-> (c).

FIG. 2 is a plan view for explaining a positional relationship of a ∨-shaped notch in the package for heating a microwave oven according to the present invention.

FIG. 3 is an explanatory view when a ∨-shaped notch is formed in an inclined shape with respect to a seal portion in the package for heating a microwave oven according to the present invention.

FIG. 4 is an explanatory view of an opening state of the cutout when the ∨-shaped cutout is formed to be inclined more than a prescribed angle with respect to a seal in the microwave oven heating package of the present invention.

FIG. 5 is a plan view showing an example of a terminal shape of a ∨-shaped cut.

FIG. 6 is a view for explaining the positional relationship between the flow direction of the film and the ∨-shaped cut when the film for a package of the present invention is cut out from a raw material, and FIG. 6B is a preferred example; (A) is an unsuitable example.

FIG. 7 is a perspective view showing a preferred formation position of a ∨-shaped notch depending on the type of a package.

FIG. 8 is a diagram for explaining parameters in Table 2 showing results of Example 2.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heating package for microwave oven 11 切 -shaped notch 11 '∨-shaped notch expanded by pressure inside the package 12 Long side seal portion 13 Short side seal portion 14 Opening θ Tip angle of ∨-shaped cut α seal portion Angle of the symmetry axis connecting the tips of the ∨-shaped notch and the distance between the ends of the ∨-shaped notch

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E064 AA05 BA30 BA55 BB03 HD10 HE03 HM01 HN05 4F100 AK01B AK07B AK42A BA02 DC13 DC13A GB15 GB16 GB23

Claims (8)

[Claims] 1. A package for heating a microwave oven, in which a 層 -shaped notch having a tip angle of 15 ° to 100 ° is formed in a layer excluding an innermost layer of a laminated film at intervals of 2.0 mm or less. Wherein the ∨-shaped cut is provided at a central portion of a portion surrounded by a seal portion or a fold portion of the package, or at a portion excluding the vicinity of the central portion. Microwave heating package. 2. The package for heating a microwave oven according to claim 1, wherein the ∨-shaped notch is formed at a central portion or near a central portion of at least one side of the seal portion. 3. The package for heating a microwave oven according to claim 1, wherein a symmetric axis connecting the tips of the ∨-shaped cuts is formed in parallel with an adjacent seal portion. 4. The method according to claim 1, wherein a symmetric axis connecting the tips of the ∨-shaped cuts has an inclination of 10 ° or less with respect to the adjacent seal portion. Item 7. The package for heating a microwave oven according to Item 1. 5. The microwave oven heating package according to claim 1, wherein an end of the ∨-shaped cut is formed in a hook shape or a state where the ends are connected to each other. body. 6. The laminated film according to claim 1, wherein the cut-shaped layer of the laminated film is made of polyethylene terephthalate, and the other layers are made of a film or sheet of another polymer. The package for heating a microwave oven according to any one of claims 1 to 4. 7. An apparatus according to claim 1, wherein an innermost layer of said laminated film is formed of polypropylene.
7. The package for heating a microwave oven according to any one of items 6 to 6. 8. The microwave oven package according to claim 1, wherein the ∨-shaped cut is formed by a carbon dioxide laser.