JPH06219464A - Plastic retort pouch - Google Patents

Abstract

PURPOSE:To prevent an inner lid from peeling off when a heating treatment is carried out by a retort sterilizing device and to facilitate a peeling off of the inner lid when content is taken out, by a method wherein an opening of a container body is sealed by the inner lid formed of plastic sheet with such an adhering strength as can peel it off easily and the inner lid is fastened to the container body by means of an outer lid. CONSTITUTION:Cooked food 9 is put in a container body 1 and an opening of the container body 1 is heat sealed with an inner lid 3 which is formed of plastic sheet. In this instance, it is designed that the heat seal has such an adhering strength as can be peeled off easily by a usual force of fingers which pick up an end of the inner lid 3. Next, an outer lid 5 is put on the inner lid 3 and turned to fasten it tightly to an upper surface of the opening of the container body 1 through a screw mechanism. In a container thus covered with lids 3 and 5, in which the inner lid 3 is fastened by the outer lid 5, when a high temperature treatment is carried out under pressure, the inner lid 3 is prevented from peeling off. In addition, if the outer lid 5 is taken off, the inner lid 3 can be peeled off easily.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention fills a plastic container with various foods, seals the opening of the container with a plastic sheet, and then uses a retort sterilizer under pressure.
The present invention relates to a plastic container for a retort that is processed at a high temperature.

[0002]

2. Description of the Related Art Conventionally, as a container for a retort, after a container body made of plastic is filled with an object to be contained,
It has been used that the opening of the container body is heat-sealed with a plastic sheet and sealed. This product is subjected to heat treatment in a retort sterilizer to be a commercial product.

[0003]

In the above prior art, the sealing and adhesion of the plastic sheet to be the lid to the opening of the container body is performed by retort treatment, that is, 100 ° C. or higher,
Preferably, the plastic sheet should have a considerably high adhesive strength so that the plastic sheet does not peel off during the treatment under a high pressure of 120 ° C. or higher. On the other hand, the end user can open the plastic sheet of the lid by pinching the end of the sheet with his fingertips and pulling it, but it is desirable that it can be easily opened especially by children, and unless the adhesive strength is relatively small. I won't. It is extremely difficult to satisfy these conflicting requirements at the same time, and in order to create a safe product, the strong adhesive strength between the plastic sheet and the container body is prioritized, which makes it difficult to open during use. Was becoming.

According to the present invention, when a retort container product is manufactured, the plastic sheet that serves as a hermetically sealed lid does not peel off, and when the end user opens the plastic sheet, the lid plastic sheet can be easily applied with normal fingertip force. An object of the present invention is to provide a peelable plastic container for a retort.

[0005]

The present invention achieves the above object, and the gist thereof is to provide a threaded portion for fitting on the outside of the opening of a retort container body made of plastic, and to provide the above opening. Part with easy-to-peel adhesive strength,
Adhesive and sealed with an inner lid made of plastic sheet,
On the inner lid of this plastic sheet, cover an outer lid having a threaded portion that fits a threaded portion provided on the periphery of the opening of the container body, and tighten the inner lid to the container body with the outer lid. The present invention resides in a plastic container for retort, which is characterized in that

The plastic container for retort according to the present invention is
In the above-mentioned conventional container, the plastic sheet that seals the opening of the container is prevented from peeling off under the severe conditions at the time of product manufacturing, and the end user of the container does not remove the plastic sheet. While it has been attempted to satisfy both of the requirements for easy opening at the same time by one adhesive point, these two requirements are satisfied by separate structures.

[0007] That is, the adhesive strength when the plastic sheet is hermetically sealed to the opening of the container main body filled with the contents is that the end of the sheet is pinched with a fingertip and the plastic sheet is easily peeled off by pulling with a normal force. Make it strong. After the sealing, with the outer lid that covers the inner lid of the plastic sheet, and that outer lid can be fitted with the container body with the screw mechanism, and the inner lid is pressed against the container body by tightening with the screw mechanism, and the retort sterilization is performed. The inner lid is prevented from peeling off during processing.

As the container body of the present invention, one made of the material conventionally used for this type of container is used. An example thereof is one in which a polypropylene layer is laminated with an adhesive on both sides of a saponified layer of an ethylene-vinyl acetate copolymer having a high gas barrier property. The inner lid made of a plastic sheet that closes off the opening of the container body is also the one that has been used as a lid of this type in the past. As a specific example, a layer of polyethylene terephthalate and a layer of polypropylene are laminated. When used as an inner lid, a polypropylene layer is laminated so as to be in contact with the opening of the container body. This bonding can be performed by heat sealing.

As the outer lid, one having good heat resistance, for example, polypropylene injection-molded is used. Further, it may be formed by using scrap generated when the container body is manufactured as a raw material. Further, a metal lid may be used, but it is not preferable when the food in the retort container is heated in a microwave oven.

[0010]

EXAMPLES The present invention will be described in more detail by way of examples, which should not be construed as limiting the invention. Example FIG. 1 is a schematic vertical sectional view of an example of the container of the present invention. In the figure,
Reference numeral 1 denotes a container body, 2 denotes a screw portion provided outside the opening of the container body 1, 3 denotes an inner lid made of a plastic sheet, 4
Is an adhesive layer between the upper surface of the opening of the container body 1 and the inner lid 3, 5 is an outer lid, 6 is a ring-shaped packing provided on the inner surface of the outer lid 5, and 7 is formed on the inner side surface of the outer lid 5. A screw portion, 8 is a ventilation hole provided in the outer lid 5, and 9 is cooked food stored in the container body 1.

The container body 1 comprises a saponified ethylene-vinyl acetate copolymer layer (thickness: 0.05 to 0.15 mm) and a polypropylene layer (each having a thickness of 0.15 to 0.15 mm).
0.7 mm) to obtain a laminated body (thickness 0.7 to 1.
5 mm) and is produced by laminating with an adhesive or thermoforming a laminated sheet obtained by a coextrusion molding method. A screw portion 2 is provided outside the opening of the container body 1. The screw part 2 (thickness including the screw thread is 1 to 3 mm) is manufactured by injection molding. The material of the screw portion 2 may be one that can be heat-sealed with the inner lid 3, but (for example, polypropylene) scraps generated when the container body 1 is molded can also be used as a material. The obtained ring-shaped screw portion 2 is welded to the outside of the opening of the container body 1 by ultrasonic welding.

The inner lid 3 is a laminated sheet (thickness: 0.3 to 0.3) of a layer of polyethylene terephthalate and a layer of polypropylene.
1 mm) and its polypropylene layer is the container body 1
It is used so as to be in contact with the opening. The outer lid 5 is made of the scrap produced when the container body 1 is manufactured, and is obtained by an injection molding method, and has a thickness of 1 to 3 mm. The packing 6 is installed inside the outer lid 5 and at a position where when the outer lid 5 is screwed into the container body, the outer lid 5 comes into contact with the upper surface portion of the opening of the container body 1. The packing 6 is made of silicone rubber.

Next, a method of using this container will be described. The cooked food 9 is stored in the container body 1, and the inner lid 3 heat-seals the opening of the container body 1. In this heat sealing, the end portion of the inner lid 3 is pinched with a fingertip so that the adhesive strength is such that it can be easily peeled off by a normal force. That is, the adhesive strength is preferably about 1.0 to 1.5 kg / 15 mm width. Next, the outer lid 5 is put on the inner lid 3, the outer lid 5 is rotated, and the inner lid 3 is strongly tightened by the screw mechanism to the upper surface of the opening of the container body 1 by the screw mechanism.

The container covered with the lid as described above is used in the retort sterilizer for the inner lid 3 even under pressure and high temperature treatment.
Since it is fastened by the outer lid 5, the inner lid 3 is not peeled off. Next, in order to use the retort container food product thus produced, first rotate the outer lid 5 to remove it from the container body 1, then sandwich the end of the inner lid 3 with a fingertip, Peel off. As described above, the inner lid 3 is not so strong in adhesive strength that it can be easily peeled off.

The contents may be taken out as they are, but if they are to be heated in a microwave oven, the outer lid 5 is used to cover them,
Just heat. The ventilation holes 8 provided in the outer lid 5 serve for ventilation at that time.

[0016]

In the container for retort according to the present invention, the inner lid of the plastic sheet for sealing the container is not peeled off during the high heat treatment under pressure in the retort sterilizer, and the end user can use the plastic sheet The lid can be pinched with fingertips and easily opened with normal force.

[Brief description of drawings]

FIG. 1 is a schematic vertical sectional view of an example of a plastic container for a retort according to the present invention.

[Explanation of symbols]

 1 container body 2 screw part 3 inner lid 5 outer lid 6 packing 7 screw part

Claims (1)

[Claims] 1. A retort container body made of plastic is provided with a fitting screw portion outside the opening, and the opening is adhesively sealed with an inner lid made of a plastic sheet with an adhesive strength for easy peeling. An inner lid of a plastic sheet is covered with an outer lid having a threaded portion that fits a threaded portion provided on the periphery of the opening of the container body, and the inner lid is fastened to the container body with the outer lid. A plastic container for a retort, which is characterized in that