JP2019038593A - Packaging bag - Google Patents

Abstract

To provide a packaging bag for microwave heating in which a steam release port for discharging the steam generated with the microwave heating is safely and stably opened, and an opening area is identified.SOLUTION: A packaging bag 1 is formed by facing sealant layers of a front surface laminated body 2 and a rear surface laminated body 3 respectively having base material layers and heat-sealable sealant layers, and heat-sealing peripheral edges, and includes: a point seal part 4 at a position on the inner side apart from the seal part on the peripheral edge, and a steam release port 5 formed by the half-cut penetrating the base material layer of the front surface laminated body on the front surface laminated body of the point seal part; and portions 6 where an adhesive for bonding the base material layer and the sealant layer is not applied on the point seal part of the front surface laminated body and its peripheral edge portion.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a packaging bag, and more particularly to a packaging bag having a function of releasing water vapor generated when food is stored and heated in a microwave oven.

  Foods in a packaged form in which cooked or semi-cooked foods are stored in soft packaging bags and can be eaten by simple cooking are widely sold. When heating with a microwave oven, the basic method is to open the packaging bag, transfer the contents to a heat-resistant porcelain or glass container, and heat it. There are also foods.

  When heating with a microwave oven with a package, a means for appropriately releasing water vapor generated with heating is required. The simplest method is to cut and open a predetermined place of the packaging bag with a scissors or the like and then heat it. In order to save such trouble and improve convenience, a part of the packaging bag is provided with a part for removing water vapor in advance and can be heated in a microwave oven without any additional work. Various bags have been proposed.

  As a means for removing water vapor from such a packaging bag, a weak portion having a reduced sealing strength at a specific location in the sealing portion of the packaging bag is provided, and when the internal pressure of the packaging bag is increased by heating, this portion of the seal is sealed. There is a known method of breaking and allowing water vapor to escape.

  However, according to such a method, depending on the heating conditions, the opening state of the opening portion is not constant, so that there is a problem, and there is a problem that the contents are ejected or spilled out depending on the case.

  In particular, it is necessary to precisely regulate the amount of water vapor released when trying to increase cooking efficiency by keeping the inside of the packaging bag at a certain level of high pressure, rather than simply releasing water vapor. It was not possible to use a water vapor escape means by the course of the seal part.

  The microwave oven bag body and the heating and pressure cooking method using the bag body described in Patent Document 1 are made from such a viewpoint, and the pressure inside the bag body rises and exceeds the atmospheric pressure. A pressure release mechanism for releasing the pressure inside the bag body to the outside by opening a part of the bag body when a predetermined value is exceeded, and the pressure release mechanism reduces the pressure inside the bag body. A microwave oven bag characterized by having a pressure maintaining function of maintaining the pressure inside the bag body at least higher than the atmospheric pressure even after escape.

  In Patent Document 1, as an example of the above-described pressure release mechanism, a method is described in which a pressure load portion (point seal portion) in which an upper surface and a lower surface sheet are bonded in a circular shape is provided inside a peripheral seal portion. . However, according to such a method, since the release of the internal pressure of the packaging bag is brought about by the material destruction of the point seal portion, a higher internal pressure is required, and there is a risk of the entire packaging bag bursting.

JP 2006-290395 A

  The problem to be solved by the present invention is to provide a microwave heating packaging bag in which an opening area is specified while a water vapor escape port for releasing water vapor generated by microwave heating is opened safely and stably. This is a proposal.

As means for solving the above-mentioned problems, the invention according to claim 1 is such that the sealant layers of the surface laminate and the back laminate each having a base material layer and a heat sealable sealant layer are opposed to each other. The peripheral edge is heat-sealed and has a point seal portion at an inner position away from the peripheral seal portion, and the surface laminate of the point seal portion includes a base material of the surface laminate. A water vapor escape port formed by a half cut penetrating the layer is provided, and an adhesive that adheres the base material layer and the sealant layer is not applied to the point seal portion and the peripheral portion of the surface laminate. A packaging bag characterized in that a portion is provided.

  In the packaging bag according to the present invention, a water vapor escape port having a fixed shape formed by half-cut is provided in the point seal part, and the point seal part and its peripheral part are bonded to bond the base material layer and the sealant layer. Since the portion where the agent is not applied is provided, when the internal pressure of the packaging bag is increased by heating, the point seal portion is surely peeled off and the water vapor escape port is opened.

  In addition, the invention according to claim 2 is characterized in that the point seal portion is provided on a center line parallel to the long side of the packaging bag and close to one of the short sides. The packaging bag according to claim 1.

  Moreover, the invention according to claim 3 is characterized in that the point seal portion has an equilateral triangle shape, and one vertex is directed toward the nearest peripheral seal portion. It is a bag.

  The invention according to claim 4 is the packaging bag according to any one of claims 1 to 3, wherein the base material layer includes a gas barrier layer.

  In the packaging bag according to the present invention, a water vapor escape port having a fixed shape formed by half-cut is provided in the point seal part, and the point seal part and its peripheral part are bonded to bond the base material layer and the sealant layer. Since the portion where the agent is not applied is provided, when the internal pressure of the packaging bag is increased by heating, the point seal portion is surely peeled off and the water vapor escape port is opened.

  Since the water vapor outlet can be formed into a shape having a specific area by half-cutting, it is possible to precisely control the amount of water vapor released. For this reason, the temperature and pressure in the packaging bag are stabilized, and stable cooking is possible.

  When the point seal portion is on the center line parallel to the long side of the packaging bag and is provided at a position close to one of the short sides as in the invention described in claim 2, the internal pressure is increased by heating. When the height increases, stress tends to concentrate on the point seal portion, and the opening of the water vapor escape port is performed more stably.

When the point seal part is an equilateral triangle shape and one apex faces the nearest peripheral seal part as in the invention described in claim 3, when the internal pressure is increased by heating, the point seal part The stress concentrated on the water vapor is further increased, and the opening of the water vapor escape port is performed more stably.

  In the case where the base material layer includes a gas barrier layer as in the invention described in claim 4, the gas barrier property of the laminate is enhanced and the permeation of oxygen and water vapor is suppressed, so that long-term storage is possible. It can be set as a package.

FIG. 1 is a schematic plan view showing an embodiment of a packaging bag according to the present invention. The contents are omitted. FIG. 2 is an enlarged view of a point seal portion of the packaging bag shown in FIG. FIG. 3 is a schematic cross-sectional explanatory view showing an A-A ′ cross section of the packaging bag shown in FIG. 1. FIG. 4 is a schematic cross-sectional view showing a state in which when the packaging bag according to the present invention is heated by a microwave oven, the sealant layer is broken by the pressure of water vapor generated from the contents, and water vapor is ejected from the water vapor outlet. It is. The contents are omitted. FIG. 5 is a schematic cross-sectional view showing a state in which water vapor generated from the contents is ejected vigorously from the water vapor escape port when the packaging bag according to the present invention is heated by the microwave oven. The contents are omitted. FIG. 6 is a schematic cross-sectional view showing a cross-sectional configuration in one embodiment of the laminate constituting the packaging bag according to the present invention. FIG. 7 is a schematic cross-sectional view showing a cross-sectional configuration in another embodiment of the laminate constituting the packaging bag according to the present invention.

  Hereinafter, the packaging bag according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic plan view showing an embodiment of a packaging bag 1 according to the present invention. The contents are omitted. FIG. 2 is an enlarged view of a point seal portion of the packaging bag shown in FIG. FIG. 3 is a cross-sectional explanatory view showing the A-A ′ cross section of the packaging bag shown in FIG. 1. FIG. 6 is a schematic cross-sectional view showing a cross-sectional configuration in one embodiment of the laminate constituting the packaging bag according to the present invention.

The packaging bag 1 according to the present invention includes a surface laminate 2 having at least a base material layer 12 and a heat-sealable sealant layer 14, and at least a base material layer 12 and a heat-sealable sealant layer 14. It is the packaging bag formed by making the sealant layers of the back surface laminate 3 to face each other and heat-sealing the periphery.
The packaging bag 1 according to the present invention has a point seal portion 4 at an inner position away from the peripheral seal portion (in this case, the top seal portion 7), and the surface laminate 2 of the point seal portion 4 includes: A water vapor escape port 5 formed by a half cut 5h penetrating the base material layer 12 of the surface laminate 2 is provided. A point seal portion 4 and a peripheral portion of the surface laminate 2 are provided with a portion 6 to which an adhesive that adheres the base material layer 12 and the sealant layer 14 is not applied.

When the water vapor pressure inside the packaging bag is increased by heating the microwave oven by providing the point seal portion 4 and the peripheral portion 6 to which the adhesive is not applied, as shown in FIG. The base material layer 12 and the sealant layer 14 are easily peeled at the portion, and the sealant layer 14 is easily broken at this boundary. As a result, destruction 17 of the sealant layer occurs, and the water vapor 16 spouts as the water vapor escape port 5 opens.

  In the embodiment shown in FIGS. 1 to 3, the shape of the point seal portion 4 is an equilateral triangle, and is parallel to the long side (in this example, the side seal portion direction) so that one vertex faces the top seal portion 7. It is arranged on the central line 11 and is provided at a position close to the short side (top seal portion 7).

  Moreover, the half cut 5h is a vertically long rectangular shape, and the steam escape port 5 is formed by the half cut 5h. The shape of the half cut 5h and the shape of the point seal portion 4 are arbitrary, but when the point seal portion 4 is an equilateral triangle as in this example, the contents are stored and heated in a microwave oven. It has been found that the sealant layer 14 around the point seal portion 4 is easily broken by the pressure of the generated water vapor.

  Moreover, the sealant layer around the point seal portion 4 is provided by the point seal portion 4 being disposed not at the center portion of the packaging bag 1 but at a position close to the short side (the top seal portion 7 in this example). 14 breaks down more smoothly.

  As a matter of course, the half cut 5h needs to have a size included inside the point seal portion 4.

  As a method of providing the half-cut 5h, a die-cut using a blade or a laser cut using a laser may be used. By using a carbon dioxide laser as the laser, the base material layer 12 is made of a material that absorbs the carbon dioxide gas laser, and the sealant layer 14 is made of a material that transmits the carbon dioxide gas laser, so that only the base material layer is efficiently half-cut. Can be cut.

  FIG. 6 is a schematic cross-sectional view showing a cross-sectional configuration in an embodiment of the laminate constituting the packaging bag 1 according to the present invention. As the base material layer 12, a synthetic resin film having higher heat resistance than the sealant layer 14 is used. Specifically, a synthetic resin film having high heat resistance such as stretched polypropylene resin (OPP), stretched polyethylene terephthalate resin (PET), stretched nylon (ONy), or the like is used.

  As the sealant layer 14, a polyolefin resin is generally used. Specifically, a low density polyethylene resin (LDPE), a medium density polyethylene resin (MDPE), a linear low density polyethylene resin (LLDPE), ethylene- Ethylene resins such as vinyl acetate copolymer (EVA), ethylene-α olefin copolymer, ethylene-methacrylic acid resin copolymer, blend resin of polyethylene and polybutene, homopolypropylene resin (CPP), propylene- Polypropylene resins such as ethylene random copolymer, propylene-ethylene block copolymer, and propylene-α olefin copolymer are used.

  As an adhesive for bonding the base material layer 12 and the sealant layer 14, an adhesive for urethane-based dry lamination is preferably used. As a coating method, since it is necessary to form the portion 6 to which no adhesive is applied, coating by a gravure printing method that is easy to synchronize with a printed pattern is suitable.

  FIG. 7 is a schematic cross-sectional view showing a cross-sectional configuration in another embodiment of the laminate constituting the packaging bag 1 according to the present invention. In this example, the base material layer 12 includes a gas barrier layer 13. The gas barrier layer 13 reduces the permeability of water vapor and oxygen, and when the base material layer 12 includes the gas barrier layer 13, the gas barrier property of the entire laminate is improved. Thereby, the preservability of the package which accommodated the contents in the packaging bag 1 can be improved.

  Examples of the gas barrier layer include: a polyvinylidene chloride film, a polyvinyl alcohol film, an ethylene vinyl alcohol copolymer film, a gas barrier nylon film, a gas barrier polyethylene terephthalate (PET) film and the like, and a PET film and other metals such as aluminum. A metal vapor-deposited film, an inorganic oxide vapor-deposited film obtained by depositing an inorganic oxide such as aluminum oxide or silicon oxide on a PET film, a polyvinylidene chloride coating, a film containing a water-soluble resin and an inorganic layered compound, A gas barrier coating layer such as a resin layer made of a film obtained by reacting a metal alkoxide or a hydrolyzate thereof and an isocyanate compound, or a metal foil such as an aluminum foil can be used.

<Example 1>
A nylon film having a thickness of 15 μm was used as the base material layer, and an LLDPE film having a thickness of 60 μm was used as the sealant layer. At the same time as gravure printing of a pattern on a nylon film, gravure printing was applied using a solid plate with a part of the urethane-based dry laminating adhesive synchronized with the pattern, and the laminate was guided to a drying oven for dry lamination.

  A carbon dioxide laser irradiation device was used to make a half cut of 2 mm in length and 1 mm in width, and then a packaging bag as shown in FIG. 1 was made. The width of the top seal part was 130 mm, the height of the side seal part was 135 mm, and the point seal part was an equilateral triangle having a side of 10 mm.

  When water was added as the contents and heated in a microwave oven, the sealant layer around the point seal part was destroyed by the pressure of the generated water vapor, and when the point seal part was peeled off, the water vapor escape port was opened. As schematically shown in FIG. 5, the generated water vapor was released from the open water vapor outlet while keeping the internal pressure of the bag constant.

DESCRIPTION OF SYMBOLS 1 ... Packaging bag 2 ... Front surface laminated body 3 ... Back surface laminated body 4 ... Point seal part 5 ... Water vapor escape port 5h ... Half cut 6 ... Adhesive is applied No part 7 ... Top seal part 8 ... Bottom seal part 9 ... Side seal part 10 ... Side seal part 11 ... Center line 12 ... Base material layer 13 ... Gas barrier layer 14 ... Sealant layer 15 ... Adhesive layer 16 ... Water vapor 17 ... Sealant layer destruction

Claims (4)

Each of the front surface laminate and the back surface laminate having a base material layer and a heat sealable sealant layer is a packaging bag formed by facing the sealant layers and heat-sealing the periphery,
It has a point seal part at the inner position away from the peripheral seal part,
The surface laminate of the point seal portion is provided with a water vapor escape port formed by a half cut that penetrates the base material layer of the surface laminate,
A packaging bag, characterized in that a portion where an adhesive for bonding the base material layer and the sealant layer is not applied is provided on the point seal portion and the peripheral portion of the surface laminate.   2. The packaging bag according to claim 1, wherein the point seal portion is provided on a center line parallel to the long side of the packaging bag, and is provided at a position close to one of the short sides.   The packaging bag according to claim 1 or 2, wherein the point seal portion has an equilateral triangle shape, and one apex faces the nearest peripheral seal portion.   The packaging bag according to claim 1, wherein the base material layer includes a gas barrier layer.

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