JPH03275475A - Composite container and using method therefor - Google Patents

Abstract

PURPOSE:To obtain a useful composite container which is applied for fillingpackaging of retort food by a method wherein an internal container which is draw-formed of a laminated body for which on both surfaces of a metal foil, a resin layer is laminated, and an external contain. er which is formed of a plastic are combined. CONSTITUTION:An internal container 1 is draw-formed of a laminated body with a constitution of a resin layer/metal foil (e.g. aluminum foil)/resin layer, and has an edge wound part 14 by caulking on the outer peripheral edge of a flange 13. An external container 2 has a similar shape with the internal container 1, and has a dimension and shape by which it can be fitted on the outside of the internal container 1 in such a manner that almost no gap generates between the two containers, and on a flange 23, an edge wound part is not formed. When sealed packaging of a cooked food is performed, a food (a) is filled in the internal container 1, and after retort sterilization is performed under a completely sealed condition by heat-sealing of a lid (b), the internal and external containers 1, 2 are fitted and unified.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a composite container comprising a metal foil molded container and a plastic container, which is particularly useful for filling and packaging retort foods, and a method for using the same.

Conventionally, one side of aluminum foil with a thickness of 90 to 120μ is coated with a heat-resistant resin, and the other side is coated with a polypropylene film (60 to 7μ).
There is an aluminum foil container made by drawing and forming sheets laminated with 0μ). However, although this container has perfect barrier properties, excellent heat resistance, and can be sterilized by retort, it may be deformed such as the corners of the container being crushed during transportation, handling, or retort sterilization. The problem is that it tends to cause Furthermore, if the corners of the container are crushed, the aluminum foil is exposed and there is a risk of sparks occurring when cooking in a microwave oven, causing problems when cooking in a microwave oven.

There are also plastic containers made by injection molding, vacuum forming, pressure forming, blow molding, and extrusion molding.

The barrier properties of these plastic containers are a problem, and improvements have been made using coextrusion techniques such as Tear, PP/EVOH/PP, and PP/PVDC/PP, but these are still insufficient.

Japanese Patent Publication No. 60-34330 discloses a composite container in which a molded plastic body is placed on the inside and a molded body made of a flexible laminate containing metal foil is placed on the outside and hermetically sealed together at a flange portion. In this composite container, the barrier properties of the inner plastic molded body are improved by the metal foil of the outer laminated molded body, but since the plastic molded body is provided on the inside, the protection of the metal foil against external impact is insufficient. It is sufficient, but there is some concern regarding barrier properties. Furthermore, since metal foil is simply covered with an extremely thin resin layer from the outside, it has poor insulation properties and is not suitable for cooking in a microwave oven. Furthermore, since the flanges of the inner and outer bottom bodies are tightly joined together before retorting, retorting must be carried out with plastic molded bodies that do not conduct heat very well, which poses problems in terms of thermal efficiency. be.

The present invention has been made with the aim of eliminating such conventional problems.

Means for Solving the Problems The present invention is formed by drawing from a laminate in which resin layers are laminated on both sides of a metal foil such as aluminum foil. A composite container consisting of a combination of an inner container having a winding portion and an outer container molded from plastic and fitted on the outside of the inner container, and a method for using the composite container, the method comprising: first inserting the container into the inner container; The present invention relates to a method of using a composite container, which is characterized in that a retort food is filled and sealed, and then heat sterilized according to a conventional method, and then an outer container is fitted and integrated on the outside of the inner container.

According to the composite container of the present invention, the following means may be used alone or in combination as means for fitting and forming the inner and outer containers.

■ Caulk the hem of the inner container to the outer periphery of the flange of the outer container.

(2) Engage the hem of the inner container with the ring-shaped groove formed along the flange of the outer container.

■ Heat seal the flange of the inner container and the flange of the outer container.

■ Adhere at least a portion of the inner container and outer container.

Embodiments Below, various embodiments of the present invention will be explained based on the accompanying drawings.

1 to 3 show an example of a caulking-type composite container of the present invention, and as shown in the exploded view of FIG. 1, the inner container (1) and the outer container (2) are individually molded.

The inner container (1) is drawn from a laminate consisting of a resin layer/metal foil (e.g. aluminum foil)/resin layer.
1) It has a side wall portion (12), a flange portion (13), and a hem wrap portion (14) on the outer peripheral edge of the flange portion (13). The surface of the flange portion (13) is preferably as smooth and wrinkle-free as possible in order to be completely sealed by heat sealing with the lid material. The edge wrapping part (14) is connected to the flange part (13
) to prevent waving during heating, and the edges of the metal foil are hidden inside, eliminating the risk of sparks occurring when cooking in a microwave oven. Edge wrapping (
14) may be wound outward as shown in the drawing, or may be wound in other ways such as inward.

The resin layer on the inner surface of the inner container (1) needs to be thermoplastic to enable heat sealing with the heat sealing agent layer of the lid material. Examples of such resins include polyolefin resins such as polypropylene and polyethylene, polystyrene resins, acrylic resins, and the second class resins are used alone or as a blend.

The resin layer on the outer surface side of the inner container (1) may be a thermosetting resin such as epoxy resin/curing agent, or a thermoplastic resin such as polypropylene. However, when integrating the inner and outer containers (1) and (2) by heat sealing the flange portion, thermoplastic resin is more suitable. The inner and outer resin layers may be formed by conventional methods, such as lamination of resin films or resin coating.

Aluminum foil is suitable for the metal foil (not shown) between the inner and outer resins of the inner container (1), and its thickness is not particularly limited as long as it can be drawn, but it is preferably about 20 to 120 μm. .

The thickness of the resin layers on both sides must be considered in balance with the thickness of the aluminum foil, but is preferably about 1 to 250 microns.

The outer container (2) is made of plastic and is made by applying general plastic molding methods such as injection molding, vacuum forming, pressure forming, blow molding, and extrusion molding. The resin used is not particularly limited as long as it can be molded by the above molding method. For example, polyolefin resins such as polypropylene and polyethylene, thermoplastic resins such as polystyrene resins, polyester resins, and acrylic resins are suitable.

The outer container (2) is similar in shape to the inner container (1);
The inner container (1
), no hemline is formed. Outer container (2)
is for increasing the rigidity of the inner container (1) and its resistance to deformation, and is normally selected from a range of about 50 to 2000 μm depending on the dimensions of the container.

Fig. 1 shows the inner and outer containers (1) and (2) in an exploded state, Fig. 2 shows them in a fitted state, and Fig. 3 shows their fitted and integrated state. In order to integrate the fitting in (2), bend the edge wrap (14) of the inner container (1) in the direction of the arrow (3) from the fitted state shown in FIG. 23) This can be easily accomplished by applying a so-called caulking means that is engaged with the lower surface of the item.

When sealing a cooked food, fill the inner container (1) with the food (a) in the disassembled state shown in Figure 1, and then heat-seal the lid (b) to completely seal it. After performing retort sterilization according to a conventional method in the state of is obtained.

The cooked food (a) and the lid (b) are shown by imaginary lines only in FIG. 1, and are omitted in FIGS. 2 and 3. As the lid material (b), materials of various known configurations used for this type of use may be used, such as materials formed by forming a heat sealing agent layer on metal foil such as aluminum foil.

According to the composite container of the present invention, as shown in FIG. 1, since the inner container (1) drawn from a laminate containing metal foil can be subjected to heat sterilization treatment such as retort sterilization alone, the outer container made of plastic Despite having a composite structure with (2), heat sterilization treatment with good thermal efficiency is possible. Furthermore, since it contains metal foil, there is no risk of deterioration of barrier properties or deformation due to heat during retort sterilization.

Inner and outer containers (1) are further removed after retort sterilization.

Since a sealed package can be obtained by fitting and integrating (2), the outer container (2) made of plastic does not require special performance such as heat resistance, and the range of selection becomes very wide.

For example, if you want to emphasize the metallic feel, you can use a transparent container made of polystyrene or polyester, and if you want to eliminate the metallic image, you can use an opaque white container made of filled polypropylene.

Furthermore, in a composite container consisting of a combination of inner and outer containers (1) and (2), the inner container (1) with metal foil has a complete barrier property and protects the contents such as cooked food. do. On the other hand, the plastic outer container (2) provides rigidity to the inner container (1) and prevents deformation of the inner container (1) during transportation and handling.
Prevent crushing etc. Furthermore, since the outer container (2) is made of plastic and can be molded into various shapes, the design effect of the composite container can be enhanced.

Furthermore, when heating containers containing metal foil in a microwave oven, there is a risk of sparks. In the composite container of the present invention, the inner container (1) containing metal foil is insulated by the plastic of the outer container (2), and the end surface of the metal foil is hidden in the hem wrapper (14), so that no sparks can be generated. can be prevented from occurring.

Figures 4 and 5 show an example of an engagement type composite container of the present invention,
Inner and outer containers (1) in the disassembled state shown in Figure 4.

(2), and fit the hemline part (14) of the inner container (1) into the ring-shaped groove (24) of the flange part (23) of the outer container (2).
) by forcibly engaging the inner and outer containers (1) using the elasticity of the plastic.

(2) can be integrated by fitting. The ring-shaped groove (24) is left open when the outer container (2) is first formed, as shown by the imaginary lines in FIGS. Bend the inner container (1) inward and press the hem (
14) may be placed in an engaged state. In this embodiment, the edge wrapping part (14) of the inner container (1) is connected to the outer container (2).
Since it is hidden within the plastic layer by engagement with the ring-shaped groove (24), spark generation can be more completely prevented. Also, the engagement method using plastic elasticity, shown in solid lines in the figure, is for the inner and outer containers (1).

(2) can be integrated simply by fitting, so fitting and integrating becomes extremely easy.

In addition, in the present invention, when the hem wrap portion (14) of the inner container (1) is roughly formed downward from the flange portion (13) (see Figs. 1 to 3), the hem wrap portion (14) is formed at the same level. (see Figures 4 and 5) and when it is formed upward (see Figure 6).
(See Figure 7).

The quality and performance of the composite container of the present invention will be clarified through the following experimental examples.

[Experimental Example 1] A laminate having the above structure (70 μ CPP film/urethane adhesive/90 μ aluminum foil/approximately 2 μ epoxy resin coating) was drawn into a shape as shown in 1 in FIG. An inner container (1) having a top out diameter of 86 mm, a top in diameter of 80 mm, and a depth of 40 mm was obtained.

A 70 μCPP film was placed on the inner surface of the inner container (1). This inner container (1) is filled with curry and has an aluminum foil lid (composition: 12μ PET/urethane adhesive/20μ aluminum foil/urethane adhesive/30μ modified PP film).
was heat sealed and sealed. Next, retort sterilization treatment was performed at 120°C for 30 minutes. Inner container by retort (
1) Deformation or puncture was not observed at all. Next, an outer container (2) made of filled polypropylene (thickness: 0.5 μm) molded by injection molding was stacked on the outer surface of the inner container (1) and fixed by caulking with the edge wrap (14).

The composite container of the present invention produced as described above had sufficient rigidity, and there was no fear of deformation or crushing during handling during transportation. Furthermore, the aluminum foil lid was removed and placed in a microwave oven to heat it, but no spark was observed.

Effects Since the composite container of the present invention has a structure in which the inner and outer containers can be fitted and integrated as appropriate, retort sterilization can be performed with the inner container containing metal foil alone, improving thermal efficiency and making it possible to The metal foil contained in the container ensures barrier properties and prevents the inner container from deforming during retort sterilization.Furthermore, the plastic outer container provides rigidity, impact resistance, and insulation, so it can withstand external influences during transportation and handling. In addition to being able to sufficiently withstand impact, it can be cooked in a microwave oven, and is particularly suitable for filling and packaging retort food.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of an exploded state showing an example of the implementation of the present invention;
2 is a longitudinal sectional view of the fitted state, FIG. 3 is a longitudinal sectional view of the fitted and integrated state, FIG. 4 is a longitudinal sectional view of an exploded state showing another embodiment of the present invention, and FIG. The figure is a vertical sectional view of the fitted and integrated state, and Figures 6 and 7 are 2 and 7 views showing still other embodiments of the present invention.
FIG. 3 is a longitudinal cross-sectional view corresponding to FIG. 3; In the figure, (1) is the inner container, and (2) is the outer container. (that's all)

Claims (6)

[Claims] (1) An inner container that is draw-molded from a laminate made of a metal foil such as aluminum foil with resin layers laminated on both sides, and has a bottom, side wall, flange, and a hem wrap around the outer periphery of the flange, and a plastic container. A composite container comprising an outer container which is molded from the above-mentioned inner container and is fitted onto the outside of the inner container. (2) The composite container according to claim 1, wherein the inner and outer containers can be integrally fitted by caulking the hem of the inner container to the outer periphery of the flange of the outer container. (3) According to claim 1, the inner and outer containers can be integrated by engaging the hem-wrapped portion of the inner container with a ring-shaped groove formed along the flange of the outer container. Composite container. (4) The composite container according to any one of claims 1 to 3, wherein the inner and outer containers can be integrated by heat-sealing the flange portion of the inner container and the flange portion of the outer container. . (5) The composite container according to any one of claims 1 to 3, wherein the inner container and the outer container are bonded together at least in part so that the inner container and the outer container can be fitted and integrated. (6) An inner container that is drawn from a laminate made by laminating resin layers on both sides of a metal foil such as aluminum foil, and has a bottom, a side wall, a flange, and a hem wrap around the outer periphery of the flange, and a plastic container. A method of using a composite container consisting of a combination of an outer container molded from the inner container and fitted to the outside of the inner container, in which the inner container is first filled with retort food and sealed, and then heated according to a conventional method. A method for using a composite container, which comprises fitting an outer container to the outside of the inner container to integrate the container after sterilization.