JP2003081360A - Packaging bag for microwave oven and manufacturing method for packaged item having content filled in packaging bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a packaging bag for a microwave oven at a low cost capable of being subjected to retort heat treatment with a content filled therein, keeping seal strength required for the packaging bag and automatically leaking pressure in the inner side of the packaging bag when it is heated in the microwave oven. SOLUTION: The packaging bag for the microwave oven is made by arranging a branch portion in the packaging bag sealed by heat-sealing a plastic film and forming a vapor vent seal portion having at least one weakened portion in the branch portion.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a liquid material, a solid material,
Or when the packaging bag filled with the contents such as retort foods made of these mixtures is heated in a microwave oven, steam and the like generated inside the packaging bag are automatically released, and the packaging bag is ruptured, deformed or the contents are The present invention relates to a packaging bag for a microwave oven capable of preventing scattering.

[0002]

2. Description of the Related Art When a packaging bag in which retort foods, frozen foods, etc. are hermetically filled is heated in a microwave oven, the pressure inside the bag rises due to steam generated from the contents accompanying heating and the packaging bag bursts. There is a risk that the contents will scatter, the inside of the microwave oven will become dirty, and the human body will be injured by burns.

Therefore, before such a packaging bag is cooked in a microwave oven, steam is generated in the packaging bag by partially opening the packaging bag in advance or by making a hole in the packaging bag body. Etc. are discharged to the outside to prevent the packaging bag from being broken. However, such a method is troublesome for general consumers, and since the steam generated by microwave heating is immediately discharged to the outside of the packaging bag, the steaming effect due to steam is reduced and the taste is reduced. It has the drawback of falling.

Further, in order to automatically release an increase in the internal pressure of the packaging bag during heating in a microwave oven, (1) a packaging joint portion which is joined in a palm-like shape by heat sealing with a predetermined width is provided on the packaging bag. A packaging bag having an easily-openable seal (Japanese Patent Laid-Open No. 2001-106270, Japanese Patent Laid-Open No. 2000-185).
777, JP-A-9-150864) (2)
A packaging bag in which a weak seal portion is formed on a part of the heat seal portion via a thin film, and a narrow seal portion having a narrow heat seal width is provided on a portion of the weak seal portion (JP-A-10-59433), (3) A weakly adhered part is provided on a part of the heat seal part,
A packaging bag formed with a non-sealing portion that narrows the width of the weakly bonded portion from the outer edge of the weakly bonded portion toward the inside (JP-A-10-95).
471), and (4) a packaging bag in which a non-sealing part in which the seal width is locally narrowed and a corresponding inward bulging seal part are provided in a part of the sealing part (JP-A-10-101154). (5) A packaging bag in which a heat-shrinkable film that forms an opening when heated is sandwiched in a part of the unsealed portion (JP-A-10-954).
No. 70) is proposed.

However, in these conventional packaging bags, a complicated process is required to form the unsealed portion, resulting in an increase in cost, and since the sealing strength of the unsealed portion is reduced, it is required in the retort food packaging bag. However, there is a problem in that the intended sealing strength (2.3 kg / 15 mm width or more) cannot be obtained, the planned opening portion or the peripheral sealing portion is broken during retort, and the content to be filled is limited. Further, there is a drawback that the bag is broken during transportation and storage after filling, and the hermeticity cannot be maintained.

[0006]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems in the prior art, allows a packaging bag filled with contents to be subjected to retort heat treatment, and has a sealing strength required for the packaging bag. An object of the present invention is to provide a packaging bag for a microwave oven, which is secured and can automatically release the pressure inside the packaging bag when heated in a microwave oven, at a low cost.

[0007]

In order to solve the above problems, the present invention employs the following configurations. 1. A packaging bag for a microwave oven, characterized in that a packaging bag which is sealed by heat-sealing a plastic film is provided with a branch portion, and a vapor vent seal portion having at least one weakened portion is formed at the branch portion. 2. 2. The packaging bag for a microwave oven according to 1, wherein the vapor vent sealing portion is formed separately from the peripheral sealing portion of the packaging bag. 3. 3. The packaging bag for a microwave oven according to 1 or 2, wherein the vapor vent sealing portion is formed by connecting to a peripheral sealing portion of the packaging bag. 4. The packaging bag for a microwave oven according to any one of claims 1 to 3, wherein the weakened portion is formed by providing a through hole, a half through hole, or a slit in the vapor vent seal portion. 5. A cutout is provided at the branch of the packaging bag toward the inside of the bag,
2. The packaging bag for a microwave oven according to 1, wherein the vapor vent seal portion having a weakened portion is formed by heat sealing the peripheral edge portion of the notch. 6. The seal strength of the peripheral seal portion and the steam removal seal portion is 2.3 kg / 15 mm or more.
The packaging bag for microwave ovens in any one of Claims 1-4. 7. 7. A packaging bag for a microwave oven according to any one of 1 to 6, wherein a spout forming means is provided in the vicinity of the vapor vent seal portion. 8. 8. The packaging bag for a microwave oven according to any one of 1 to 7, wherein the branching portion is provided on any of a bottom portion, a side portion, and a back attachment portion of the packaging bag. 9. The packaging bag for a microwave oven according to any one of 1 to 8, wherein the packaging bag is subjected to laser processing at an expected opening position. 10. 10. The method for producing a package in which the packaging bag for microwave oven is filled with the content, wherein the packaging bag and the filling of the content are continuously performed. 11. 10. The method for producing a package in which the contents are filled in the packaging bag for a microwave oven according to 1 to 9, wherein the packaging bag and the filling of the contents are separately performed.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION As a plastic film constituting a packaging bag for a microwave oven according to the present invention, a plastic material having a heat-sealing property which is usually used for producing a packaging bag is used. Examples of such a plastic material include a single-layer film made of a thermoplastic resin having a heat-sealing property, a sheet, and a multilayer film in which a thermoplastic resin having a heat-sealing property is laminated with another thermoplastic resin or the like. Can be mentioned.

Examples of such heat-sealable plastic materials include known low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, polypropylene, propylene-ethylene copolymer, ethylene-vinyl acetate. Copolymer, olefin resin such as olefin resin graft-modified with ethylenically unsaturated carboxylic acid or its anhydride, polyamide or copolyamide resin having relatively low melting point or low softening point, polyester or copolyester resin, polycarbonate resin Etc. are used.

As another plastic material to be laminated with the heat-sealing plastic material, a thermoplastic resin with or without heat-sealing property can be used. Examples of such a thermoplastic resin include crystalline polypropylene, crystalline propylene-ethylene copolymer, crystalline polybutene-1, crystalline poly-4-methylpentene-1, low-, medium- or high-density polyethylene, Ethylene-vinyl acetate copolymer (EVA), EVA
Saponified product, ethylene-ethyl acrylate copolymer (EE
A), ionic cross-linked olefin copolymer (ionomer)
Polyolefins such as polystyrene; aromatic vinyl copolymers such as polystyrene and styrene-butadiene copolymers; halogenated vinyl polymers such as polyvinyl chloride and vinylidene chloride resins; polyacrylic resins; acrylonitrile-styrene copolymers, acrylonitrile Examples thereof include nitrile polymers such as styrene-butadiene copolymers; polyesters such as polyethylene terephthalate and polytetramethylene terephthalate; various polycarbonates; fluororesins; thermoplastic resins such as polyacetals such as polyoxymethylene. These thermoplastic resins may be used alone or in a blend of two or more, and
You may mix and use various additives.

In the present invention, an unstretched or uniaxially or biaxially stretched film made of the above plastic material is heat-sealed by a conventional method to form a packaging bag for a microwave oven. 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 are on the inner surface. .

The structure of the packaging bag for a microwave oven according to the present invention will be described below with reference to the drawings. 1 to 4 are views showing an example of a microwave packaging bag of the present invention, FIG. 1 is a perspective view of the packaging bag, FIG. 2 is a plan view thereof, and FIGS.
[Fig. 3] is a schematic cross-sectional view showing a state when this packaging bag is heated in a microwave oven. Branches 3 and 3 are provided on one side of the packaging bag 1, and heat seal portions 2 are provided on the bag body and the peripheral portions of the branches 3 and 3. In addition, a circular vapor removal seal portion 4 having a weakened portion 5 is formed on one of the branch portions 3 by heat-sealing a film forming the front surface and the back surface of the branch portion 3.

When the packaging bag 1 is heated, the packaging bag 1 expands due to water vapor or the like generated from the contents, and especially the branch portions 3, 3
Then, as shown in FIG. 3, stress concentration occurs in the steam vent seal part 4 (white arrow in FIG. 3). Due to this stress concentration, in the vapor vent seal portion 4, peeling of the seal portion starts from the end portion near the center of the bag, and the seal portion recedes as the internal pressure of the bag rises, and when the peeling reaches the weakening portion 5, the packaging bag 1 Since it is partially opened and water vapor or the like is discharged to the outside, bag breakage can be prevented. In the case of a packaging bag having no branching portion, as shown in FIG. 5, the expansion of the bag at the peripheral edge seal portion 2 due to an increase in the internal pressure of the bag during heating is relatively small. Since the expansion of the bag becomes large and the stress concentration generated in the steam removal seal portion 4 becomes significantly larger than that in the peripheral edge seal portion 2, the opening in the steam removal seal portion 4 can be performed easily and reliably. In addition to heat sealing,
It can be formed by any method such as impulse sealing, ultrasonic sealing or adhesive.

In this packaging bag 1, a circular vapor removal seal portion 4 is provided in the branch portion 3 separately from the peripheral edge seal portion 2, and a weakened portion 5 is formed by providing a through hole in the vapor removal seal portion 4. I am doing it. The weakened portion 5 can be formed by providing a semi-through hole or a slit in addition to the through hole, and is also formed by partially weakening the vapor vent seal portion 4 by laser processing, machining, or the like. Good. The shapes of the vapor removing seal portion 4 and the weakening portion 5 are
The shape is arbitrary such as a circle, an oval, a triangle, a quadrangle, a trapezoid, and a rice ball shape, and the size thereof can be appropriately selected.

FIG. 6 is a plan view showing another example of the packaging bag for a microwave oven according to the present invention. In this packaging bag 1, the branch portion 3
It has the same structure as the packaging bag shown in FIG. 1, except that the substantially triangular steam removal seal portion 4 is formed at two locations. The vapor vent seal portion 4 may be formed on either of the branch portions 3, and the number thereof may be one or two or more.

FIG. 7 is a plan view showing another example of the packaging bag for a microwave oven according to the present invention. This packaging bag 1 is provided with a substantially rhombus vapor removal seal portion 4 continuous with the peripheral edge seal portion 2 at a corner portion of one branch portion 3. A notch 6 and a perforation 7 are provided in the vapor removing seal portion 4, and the packaging bag 1 is opened along the perforation 7 from the notch 6 after the heating of the packaging bag 1 is completed. The other structure of the packaging bag 1 is the same as that of the packaging bag of FIG. In this packaging bag 1, after the heating is completed, the branch portion 3 of the bag 1 can be opened from the notch 6 along the perforations 7 to form a spout (not shown). Instead of the notch 6 and the perforation 7, laser processing may be performed at the planned opening position.

FIG. 8 is a plan view showing another example of the packaging bag for a microwave oven according to the present invention. In this packaging bag 1, a notch 15 serving as a weakened portion is provided inwardly of the corner portion of one of the branch portions 3 and a weakened portion is formed by heat sealing the peripheral portion of the notch 15. The vapor vent seal portion 14 is formed. The other structure of the packaging bag 1 is the same as that of the packaging bag of FIG.

In each of the above examples, the branch portion of the packaging bag is replaced by
Although the example of providing it on the short side (bottom part) has been described, the branch part forming the vapor removal seal part may be provided on the long side (side part) of the bag, or the bag has a branch-shaped backing part. Provided,
You may make it form a vapor removal seal | sticker part in this spine attachment part.

The sealing strength of the peripheral seal portion and the steam removal seal portion of the packaging bag for a microwave oven of the present invention is 2.3 kg /
It is possible to make the width 15 mm or more. In the conventional packaging bag that is automatically opened when heated in a microwave oven, the sealing strength of the opening portion is significantly reduced when heated, and the sealing strength of 2.3 kg / 15 mm width or more required for the packaging bag for retort food is obtained. I couldn't. In the packaging bag for a microwave oven of the present invention, the sealing portion itself of the peripheral sealing portion and the steam removal sealing portion does not use or process a material whose sealing strength decreases during heating, so that the sealing strength is maintained. Is possible.

As a result, when the packaging bag is filled with the contents and then the retort treatment is performed, it is possible to prevent the bag from being broken from the vapor vent seal portion and the peripheral seal portion and to prevent the bag from being broken during transportation or storage. it can. Further, even when heated in a microwave oven, the steam vent seal portion maintains the seal strength for a certain period of time, the internal pressure in the packaging bag is maintained in a state of being increased by steam, and the heating and steaming effect is obtained, so that the contents It has a remarkable effect that the taste is improved and the cooking time can be shortened.

[0021]

EXAMPLES Next, the present invention will be further described with reference to examples, but the following specific examples do not limit the present invention. (Examples 1 to 6) Dry lamination of a 12 μm silica vapor-deposited biaxially stretched polyester film, a 15 μm biaxially stretched nylon film, and a 70 μm polypropylene film (block type) in order from the outer layer using a polyurethane adhesive. A roll-shaped laminate was prepared by. This laminated body is divided into a body material and a bottom material and attached to a bag-making machine.After the body material is slit and divided by a normal method, the bottom material is folded and supplied between the body materials, and the peripheral edge of the bottom material is It heat-sealed and formed the branch part. Next, after sealing the peripheral portion of the long side of the pouch, the lower portion of the branch portion is held in a folded state, and a steam removal seal portion having a round shape (diameter 12 mm) or a rice ball shape is held at a predetermined position of the upper branch portion. Was set up. Next, a weakened portion was formed by providing a through hole (diameter 4 mm) at the center of the vapor vent seal portion using a punch & die. By this method, the short side 130 mm × the long side 17
0 mm x bottom folding width 36 mm (inner dimension: 118 mm x 15
A 5 mm) branched pouch was prepared.

This branch pouch was filled with 220 g of curry, sealed, and retort sterilized at 120 ° C. for 30 minutes to prepare 20 bags each for each position of the steam vent sealing portion. The resulting curry-filled pouch was laid in a microwave oven with a rated output of 600 W and heated to observe the presence or absence of automatic opening of the vapor vent seal and the state of the peripheral seal. The results are shown in Table 1.

[0023]

[Table 1]

According to Table 1 above, by providing the vapor vent seal portion having the weakened portion at a predetermined position of the branch portion, the branch portion is greatly expanded by the rise of the pouch internal pressure due to the heating of the microwave oven, and the peripheral edge seal portion is retracted. Nonetheless, the steam vent seal part peeled off, the internal pressure was released, and the contents could be cooked without breaking the peripheral seal part. Further, even if the pouch is laid in a microwave oven and heated, the contents do not spill at the time of opening, and an individual packaging box for standing the pouch in the microwave oven is unnecessary. Furthermore, since the steam vent seal has high sealing strength, the pouch internal pressure can be maintained, and the contents can be cooked in a shorter time than a pouch without an automatic opening function, and the pouch has a good tasting effect. was gotten. The sealing strength of these curry-filled bags was on average 4.
It was 3 kg / 15 mm.

The packaging bag of the present invention is heated by various retort foods such as curry, stew, meat dumplings, soups, zenzai, chilled foods such as dumplings, sushi, pilaf and microwaves, or by boiling water. It is preferably used as a packaging bag for food.

As a method for producing a packaging body in which various foods are filled in the packaging bag for a microwave oven of the present invention, a so-called in-line sealing system is adopted in which the packaging bag is made and the contents are continuously filled. be able to. With this method,
Normally, the peripheral seal portion and the steam vent sealing portion are heat-sealed simultaneously, but the weakened portion provided in the steam vent sealing portion can be formed by a method such as drilling after heat sealing. Alternatively, a weakened portion may be formed in advance in the film raw material constituting the packaging bag, and the raw material film may be heat-sealed to form the bag.

As another method for producing a package in which a packaging bag is filled with contents, after the packaging bag is made in advance, a filling machine or a machine different from the bag-making machine is used to remove the contents. A so-called off-line method of sealing the filling port after filling may be adopted. The heat-sealing of the vapor vent sealing portion can be performed simultaneously with the sealing of the filling port, or may be performed in advance before the filling.

[0028]

EFFECTS OF THE INVENTION With the above-mentioned structure, the packaging bag for a microwave oven of the present invention has the following remarkable effects. (1) When heating in a microwave oven, the steam vent seal part breaks before the peripheral seal part breaks, and the bag is automatically and securely opened at a predetermined weakening part to prevent bag breakage. can do. (2) When heated in a microwave oven, the inner pressure of the packaging bag rises, so that the branch portion greatly expands, which facilitates automatic opening of the vapor vent seal portion. (3) Since a peripheral heat seal part and a steam vent seal part can be formed at the same time by a normal heat seal device during bag making without using a special material or a complicated process, it is possible to prevent an increase in cost. it can. In addition, the seal strength (2.3k) required to sterilize the retort after filling the contents.
g / 15 mm width or more) can be secured. (4) By laying the bag in a microwave oven with the branch portion formed with the vapor vent seal portion facing upward and heating the bag, the contents do not spill when the vapor vent seal portion is opened. Moreover, since the bag can be laid down and heated, an individual packaging box becomes unnecessary. (5) When heated in a microwave oven, the steam vent seal part maintains the seal strength for a certain period of time, and the internal pressure in the packaging bag is maintained in a state of being increased by steam, and a heating and steaming effect is obtained, so that the contents The taste can be improved and the cooking time can be shortened. (6) By providing the branch portion, the opening width can be widened when filling the contents, and the filling suitability is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a packaging bag for a microwave oven according to the present invention.

FIG. 2 is a plan view of the packaging bag of FIG.

FIG. 3 is a schematic diagram illustrating a heating state of the packaging bag of FIG.

FIG. 4 is a schematic cross-sectional view for explaining the state of breaking and opening of the vapor vent seal portion of the packaging bag of FIG.

FIG. 5 is a schematic diagram illustrating a conventional packaging bag during heating.

FIG. 6 is a plan view showing another example of the packaging bag for a microwave oven of the present invention.

FIG. 7 is a plan view showing another example of the packaging bag for the microwave oven of the present invention.

FIG. 8 is a plan view showing another example of the packaging bag for a microwave according to the present invention.

[Explanation of symbols] 1 packaging bag 2 Edge seal part 3 branches 4,14 Steam removal seal 5 Weakened section 6 notches 7 perforations 15 notches

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fumie Nishimoto             Kanagawa Prefecture Yokohama City Tsurumi Ward Yamu 1-1-70 East             Yokan Co., Ltd. F term (reference) 3E064 AA05 BA22 BB03 BC01 EA30                       GA04 HD03 HE02 HM01 HN05

Claims (11)

[Claims] 1. A microwave oven, characterized in that a packaging bag for sealing a plastic film by heat-sealing is provided with a branching portion, and a steam vent sealing portion having at least one weakening portion is formed at the branching portion. Packaging bag. 2. The packaging bag for a microwave oven according to claim 1, wherein the steam vent sealing portion is formed separately from the peripheral sealing portion of the packaging bag. 3. The steam removing seal portion is formed by being connected to a peripheral seal portion of the packaging bag.
Packaging bag for microwave oven described in. 4. The packaging bag for a microwave oven according to claim 1, wherein the weakened portion is formed by providing a through hole, a half through hole, or a slit in the vapor vent seal portion. 5. A notch is provided in a branch portion of the packaging bag toward the inside of the bag, and a peripheral edge portion of the notch is heat-sealed to form a vapor vent seal portion having a weakened portion. The packaging bag for a microwave oven according to claim 1. 6. The packaging bag for a microwave oven according to claim 1, wherein the peripheral edge seal portion and the steam vent seal portion have a sealing strength of 2.3 kg / 15 mm or more. 7. The packaging bag for a microwave oven according to claim 1, wherein a spout forming means is provided in the vicinity of the vapor vent seal portion. 8. The packaging bag for a microwave oven according to claim 1, wherein the branching portion is provided on any of a bottom portion, a side portion, and a back attachment portion of the packaging bag. 9. The packaging bag for a microwave oven according to claim 1, wherein a laser processing is applied to a planned opening position of the packaging bag. 10. The method for producing a package in which the packaging bag for a microwave oven is filled with the content according to claim 1, wherein the packaging bag and the filling of the content are continuously performed. 11. The method for producing a package in which the packaging bag for a microwave oven is filled with the contents as claimed in claim 1, wherein the packaging bag and the filling of the contents are separately performed.