WO2015166590A1

WO2015166590A1 - Microwaveable packaging bag

Info

Publication number: WO2015166590A1
Application number: PCT/JP2014/062537
Authority: WO
Inventors: 佐藤　陽一; 孝行宮崎
Original assignee: 株式会社カナオカ
Priority date: 2014-05-01
Filing date: 2014-05-01
Publication date: 2015-11-05

Abstract

Provided is a microwaveable food product packaging bag equipped with a pressure escape mechanism for preventing bursting due to thermal expansion. In a packaging bag manufactured by superimposing a front panel film (1) and a back panel film (8), heat sealing three of the sides, leaving the remaining one side as an open portion for filling the bag with contents, and providing the open portion with a heat-sealing location that is to be sealed after being filled with contents, the front panel film at the heat-sealing location is provided with a venting means (2) serving as a pressure release port, and a strip-shaped film (6) that covers the venting means is heat sealed to the rear surface of the front panel film where the venting means is located. The back panel film-side of the strip-shaped film constitutes a heat seal-targeted surface intended to undergo heat sealing to the rear surface of the back panel film during sealing of the packaging bag. The strength of heat sealing between the front panel film and the strip-shaped film is less than the strength of heat sealing to manufacture the packaging bag, and the strength of heat sealing between the strip-shaped film and the back panel film when the packaging bag is sealed.

Description

Microwave oven-compatible packaging bag

The present invention relates to a food packaging bag made of a synthetic resin film that is distributed in a sealed state after containing food. This food packaging bag can be heated in a microwave oven while containing food.

Packed foods that are sealed after the food is stored in a packaging bag made of a synthetic resin film corresponding to a microwave oven and are distributed for distribution in a sealed state are known, and are particularly popular for storing retort foods. . In this type of packaged food, a consumer who purchases the food heats the food inside by placing it in a microwave oven with the packaging bag sealed. Therefore, there is a risk of accidents in which food pressure etc. swells and eventually bursts due to the internal pressure of the packaging bag increasing due to the water vapor evaporated from the food by heating or the thermal expansion of the air in the packaging bag. .
Inventions for preventing this accident include a microwaveable packaging bag (Patent Document 1) in which a valve body for releasing the pressure generated by the heating is attached to the packaging bag in advance, and bonding of the packaging body by heat sealing There has been known a microwave-compatible packaging bag that weakens the heat seal strength of a part of the part so that the joined part can be easily peeled by an increase in internal pressure due to heating, and the pressure is released from this (Patent Document 2). .

Japanese Patent No. 3006528 JP 2000-025848 A

The known invention described in Patent Document 1 has a problem that the manufacturing cost of the packaging bag is increased due to the labor, process, and material cost of mounting the valve body. In addition, in the known invention described in Patent Document 2, it is difficult to set the heat seal strength, the output of the magnetron of the microwave oven is large, or the internal pressure suddenly increases due to the high water content of the food. In some cases, before the relief pressure due to the weak heat seal portion functions, other portions may be peeled off at the same time and the package may be destroyed.
The present invention has been created for the purpose of a microwave-compatible packaging bag that solves the above-mentioned problems.

The microwave oven-compatible packaging bag of the present invention is a bag made in a state where the front film and the rear film are overlapped and the three sides are heat-sealed and the remaining one side is an open part for filling the contents. In a packaging bag provided with a heat seal target location in the open part for sealing after filling with an object,
Ventilation means provided at the heat seal target location of the front film,
It is pre-heat sealed at a position that covers the ventilation means on the back surface of the front film, and a belt-like film is provided as a heat seal target surface for heat-sealing to the back surface of the back film when sealing the packaging bag,
The heat seal strength of the front film and the belt-like film is set to be weaker than the heat seal strength for making the packaging bag and the heat seal strength of the belt-like film and the rear film at the time of sealing the packaging bag.
In addition, in the microwave oven-compatible packaging bag according to the second aspect of the present invention, when the belt-shaped film and the front film are heat-sealed, the bottom side of the packaging bag is covered from the heat-sealed portion covering the ventilation means of the front film. In addition to providing a non-heat-sealed portion at a location toward the top, the heat-sealed target location at the time of sealing the packaging bag is set to end in the middle of the non-heat-sealed location.
Further, in the invention described in claim 3, in the microwave oven-compatible packaging bag, the ventilation means serving as a pressure release port that is opened in the front film at the heat seal target portion is a raised piece sandwiched between a pair of cuts. It has the structure which provided the through-hole in the upper part of.
The invention described in claim 4 is characterized in that, in the microwave oven-compatible packaging bag, the ventilation means serving as a pressure release port that is opened in the front film of the heat seal target portion is a through hole.
Further, in the food packaging bag according to claim 5, the ventilation means serving as a pressure release port opened in the front film of the heat seal target portion is a pulling piece sandwiched between a pair of cuts. It is characterized by that.
The invention described in claim 6 is characterized in that in the food packaging bag described above, the packaging bag is a self-supporting gusset bag that is made by sandwiching the folded gusset film into the bottom portion and making a bag. To do.

The microwave oven-compatible packaging bag of the present invention having the above configuration is kept in a sealed state by heat-sealing and sealing the open portion after containing food inside. At this time, a belt-like film covering the ventilation means of the front film is interposed between the front film and the rear film provided with ventilation means serving as a pressure release port, and heat sealing is performed. The belt-like film is heat-sealed in advance to the back surface of the front film at the stage of making the packaging bag, and the heat-sealing strength is the same as the heat-sealing strength for making the packaging bag and the sealing time of the packaging bag. It is set to be weaker than the heat seal strength between the belt-like film and the rear film.
When the packaging bag is heated in a microwave oven in a sealed state, the internal pressure of the packaging bag is increased due to the thermal expansion of water vapor evaporated from the food by the heating or air in the packaging bag, so that the packaging bag expands. Water vapor or expanded air acts to push and spread the bonding area of each film by heat sealing, and the bonding area of the front film and the belt-like film with the weakest heat seal strength of the bonding area is first expanded. . In this case, since the front film is provided with ventilation means, the strip-like film covering it is peeled off, so that water vapor or expanded air escapes from there to prevent the internal pressure from rising, and the other film is attached. The mating point is not spread out and the packaging bag is prevented from rupturing.
In the present invention, the heat seal strength between the belt-like film and the front film is set to be weaker than the heat seal strength of other locations, and the bonding location is expanded when the internal pressure in the packaging bag increases. To release the pressure. For this purpose, the end face of the laminating film, the front film, and the bonded portion must be exposed in the bag. Therefore, after the food is stored, when the open portion is heat-sealed and sealed, it is required to heat-seal the portion below the lower end of the belt-like film so that the end face is not hidden. On the contrary, if heat sealing is performed at a location above the lower end of the belt-like film, a non-heat-sealed portion is generated between the belt-like film and the rear film, and the end of the belt-like film is in a state of being swollen with respect to the rear film. In this case, since the entire front film side of the belt-shaped film is heat-sealed, even if the heat-seal strength between the belt-shaped film and the front film is set weak, the edge of the belt-shaped film and the rear surface that are in a drowned state There is a risk that the wrapping bag may be ruptured because the film is more easily spread by the internal pressure.
In order to avoid the above phenomenon, it is necessary to make the end of the sealing portion coincide with the lower end of the belt-like film when the open portion is sealed by heat sealing. However, the work of heat-sealing and sealing the open portion is not performed in the bag manufacturing factory of the bag manufacturer, but in the food factory of the food processor, so it is difficult to satisfy the above requirements that require processing accuracy. Arise.
Therefore, in the invention described in claim 2, when heat-sealing the belt-shaped film and the front film, a non-heat-sealed portion is provided at a location toward the bottom side of the packaging bag from the heat-sealed portion covering the ventilation means of the front film. While providing, it is set so that the heat seal target location at the time of sealing of a packaging bag may be terminated in the middle of the non-heat seal location. By doing this, the end of the band-shaped film is in a state of being swollen with respect to both the front film and the rear film near the end of the sealing portion, but the heat-seal strength between the band-shaped film and the front film is the band-shaped film and the rear film. Since it is set to be weaker than the interval, this portion is expanded by the internal pressure, and the predetermined effect of the present invention is exhibited. In this case, the end position of the sealing part when sealing the open part by heat sealing may be anywhere in the middle of the non-heat-sealed part, so that high processing accuracy is not required and it is a food factory of a food processor. However, the microwave oven-compatible packaging bag of the present invention can be used well.
In the invention described in claim 3, the ventilation means serving as the pressure release port opened in the front film at the heat seal target portion is provided with a through hole in the upper part of the raising piece sandwiched between the pair of cuts. . In this case, if the end position of the sealing portion when sealing the open portion of the packaging bag by heat-sealing is set so as to be applied to the pulling piece, the front film is pushed and spread on the belt-like film. It becomes smoother.
In the invention described in claim 6, the packaging bag is a self-supporting gusset bag having a gusset portion at the bottom. Such a bag has a structure in which a bag is made by sandwiching a gusset film folded in half as a bottom material at the bottom, so that the thickness on the bottom side increases with respect to the open side. As a result, there is a thickness difference between the open side and the bottom side, and there is a problem that when the packaging bags are stacked and set on the automatic filling machine for filling the contents, they do not overlap well due to the above thickness difference. It was. On the other hand, when the present invention for preventing bursting due to thermal expansion is implemented, since a strip-like film is interposed on the open side, the difference in thickness between the open side and the bottom side is reduced, and the composite is successfully overlapped. Effect will be obtained.

FIG. 1 is a partially cutaway perspective view of a microwaveable packaging bag of the present invention.
FIG. 2 is a perspective view of the front film of the microwaveable packaging bag of the present invention.
FIG. 3 is a perspective view of the rear film of the microwaveable packaging bag of the present invention.
FIG. 4 is a perspective view of a gusset film of the microwaveable packaging bag of the present invention.
FIG. 5 is a perspective view of a band-like film of the microwaveable packaging bag of the present invention.
FIG. 6 is an exploded perspective view of the microwave oven-compatible packaging bag of the present invention.
FIG. 7 is a perspective view after sealing the microwaveable packaging bag of the present invention.
FIG. 8 is a cross-sectional view of the microwaveable packaging bag of the present invention.
FIG. 9 is a partially cutaway perspective view of the microwave oven-compatible packaging bag of the present invention.
FIG. 10 is a cross-sectional view after sealing the microwaveable packaging bag of the present invention.
FIG. 11 is a cross-sectional view of the main part showing the operation of the microwaveable packaging bag of the present invention.
FIG. 12 is a cross-sectional view of the main part showing the operation of the microwaveable packaging bag of the present invention.
FIG. 13 is a cross-sectional view of the main part showing the laminated structure of the constituent films of the microwaveable packaging bag of the present invention.
FIG. 14 is a front view showing different embodiments of the ventilation means of the microwave oven-compatible packaging bag of the present invention.
FIG. 15 is a front view showing another embodiment of the ventilation means of the microwaveable packaging bag of the present invention.

Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings. Here, the embodiment is configured by taking a self-supporting gusset bag having a gusset portion at the bottom as a food packaging bag. FIG. 1 is a partially cutaway perspective view showing the structure of a packaging bag. 2 to 5 are diagrams showing components of the packaging bag. In this packaging bag, the front film 1 and the rear film 8 are opposed to each other, and the folded gusset film 9 is sandwiched between the bottom with the folds up, and the two sides of each film and the bottom are heat-sealed portions H1 and H2, respectively. The bag is made in a state in which three sides are sealed by heat sealing as H3 and the remaining one side is an open part for filling the contents (see FIG. 6, reference numeral 2 is provided on the front film 1). This venting means 2 is for communicating the inside and outside of the bag in order to release the internal pressure in the packaging bag, and when the gusset film 9 is widened to allow the packaging bag to expand into a three-dimensional shape and to be self-supporting. In this embodiment, the ventilation means 2 is constituted by providing a through hole 3 in the upper part of the raising piece 5 sandwiched between the pair of

cuts

4, 4. However, for example, only the through hole 20 as shown in FIG. 14 or only the raised piece 30 as shown in FIG. 15 may be used.
The aeration means 2 must be sealed in order to block communication with the outside after filling the contents and sealing the opening. In the present invention, for this purpose, a belt-like film 6 that covers the ventilation means is heat-sealed in advance on the back surface of the front film 1 where the ventilation means 2 is located in bag making (see FIGS. 1 and 8). In this embodiment, the belt-like film 6 has the same width as that of the front film 1, covers the ventilation means 2 of the front film, and has a lower end extending to the lower side. In addition, the rear film side of the belt-like film 6 is a heat seal target surface on which heat sealing is planned for the rear film rear surface when the packaging bag is sealed. And the heat seal strength of the heat seal location H4 of the front film 1 and the belt-like film 6 is the heat seal strength at the heat seal locations H1 and H2 and H3 for making a packaging bag, and when the packaging bag is sealed. It is set to be weaker than the heat seal strength between the belt-like film and the rear film 8. In this embodiment, the heat sealing portion H4 of the front film 1 and the belt-like film 6 is not the entire region of the belt-like film, but is terminated in the middle, so that the packaging bag is covered from the portion heat-sealed covering the ventilation means of the front film. A non-heat-sealed part is generated at a part toward the bottom side (see FIGS. 1 and 8).
Each member constituting the packaging bag of the present invention described above is made of a plastic film, and in this embodiment, each film is a laminated film composed of a base material layer and a sealant layer. FIG. 13 is a view showing a laminated structure of each film in that case.
Here, the front film 1 has ONY (stretched nylon film) as the base material layer A, CPP (unstretched polypropylene film) as the sealant layer B, and the rear film 8 has the same ONY (stretched nylon film) and sealant as the base material layer C. As the layer D, CPP (unstretched polypropylene film) is used.
Further, although not particularly shown, the gusset film 9 has the same configuration as described above.
On the other hand, the belt-like film 6 is obtained by laminating two kinds of sealant layers having different heat seal strengths on both surfaces of a base material layer, and a sealant layer for bag making as a sealant layer G on the rear film 8 side of the base material layer F. The same CPP (unstretched polypropylene film) is used, and the sealant layer E of the front film 1 is an EP (easy peel film) having a lower heat seal strength.
The microwave oven-compatible packaging bag of the present invention having the above-described configuration is packaged by filling the contents such as food from the open portion and then heat-sealing the heat-sealing target portion set in the open portion. It becomes food. In this case, the heat seal target portion is set such that the lower end ends at a midpoint of the non-heat seal portion of the front film 1 and the belt-like film 6. In the drawing, the imaginary line L2 indicates the end position of the belt-like film 6, and the imaginary line L1 indicates the end position of the heat-seal portion H4 of the belt-like film with respect to the front film 1. The heat seal of the open portion must be performed at least above the ventilation means 2 and between the end position L1 of the heat seal portion H4 of the belt-like film and the non-heat seal portion located between the end position L2 of the belt-like film (FIG. 9, (See FIG. 10).
Hereinafter, the action of the packaged food using the microwaveable packaging bag of the present invention will be described.
(1) At the time of heat sealing the belt-like film 6 and the front film 1, a location from the end L1 of the heat seal location H4 toward the bottom side of the packaging bag is defined as a non-heat seal location, and the location to be heat sealed when sealing the packaging bag Since the end L3 is set between the non-heat-sealed portions, the lower end 7 of the belt-like film 6 is in a state of being swollen with respect to both the front film 1 and the rear film 8 in the vicinity of the end L3 of the sealing portion. (See FIG. 11).
(2) When the packaged food is heated in a microwave oven in a sealed state, the internal pressure of the packaging bag increases due to the heat expansion of the water vapor evaporated from the food by the heating or the air in the packaging bag.
(3) The water vapor or the expanded air acts to push and spread the bonded portion by heat sealing between the films.
(4) Water vapor and expansion along the film wall surface between the lower end 7 of the belt-like film and the front film 1, and between the lower end 7 of the belt-like film and the rear film 8 are in a state where the belt-like film is rolled up in the bonding location. Since the air is guided in the wedge direction, it is easy to push.
(5) In the above case, since the heat seal strength of bonding between the lower end 7 of the belt-like film and the front film 1 is set lower than other bonding, this portion is first spread and peeled off. (See FIG. 12).
(6) As a result of the above, water vapor or expanded air is discharged to the outside through the ventilation means 2 (here, the raising piece 5 and the through hole 3) from the gap formed by peeling, and the relief pressure in the packaging bag is released. Realized. 4
(7) The increase in the internal pressure in the packaging bag is suppressed by the relief pressure, and other bonding locations are not pushed out and the packaging bag is prevented from being ruptured.

DESCRIPTION OF SYMBOLS 1 Front film 2 Ventilation means 6 Band-shaped film 8 Rear film

Claims

The front film and the rear film are overlapped to heat-seal three sides, and the remaining one side is made into an open part for filling the contents, and the bag is sealed in order to seal the contents after filling. In the packaging bag provided with the target location in the open part,
Ventilation means provided at the heat seal target location of the front film,
It is pre-heat sealed at a position that covers the ventilation means on the back surface of the front film, and a belt-like film is provided as a heat seal target surface for heat-sealing to the back surface of the back film when sealing the packaging bag,
An electronic device characterized in that the heat seal strength of the front film and the belt-like film is set to be weaker than the heat seal strength for making the packaging bag and the heat-seal strength of the belt-like film and the rear film when the packaging bag is sealed. Range-compatible packaging bag.
When heat-sealing the belt-like film and the front film, a non-heat-sealed part is provided at the part from the heat-sealed part to the bottom side of the packaging bag, covering the ventilation means of the front film, and the heat at the time of sealing the packaging bag The microwave oven-compatible packaging bag according to claim 1, wherein the seal target portion is set to end in the middle of the non-heat seal portion.
The microwave oven-compatible type according to claim 2, wherein the ventilation means serving as a pressure release port that is opened in the front film at a heat seal target portion has a structure in which a through hole is provided in an upper portion of the raising piece sandwiched between the pair of cuts. Packaging bag.
The microwave oven-compatible packaging bag according to claim 2, wherein the ventilation means serving as a pressure release port opened in the front film of the heat seal target portion is a through hole.
3. The microwave oven-compatible packaging bag according to claim 2, wherein the ventilation means serving as a pressure release port opened in the front film at a location to be heat sealed is a raised piece sandwiched between a pair of cuts.
The packaging bag is a microwaveable packaging bag according to any one of claims 1 to 6, wherein the packaging bag is a self-supporting gusset bag that is made by sandwiching a folded gusset film between the bottom portion and the bottom portion.