JPH0242610Y2 - - Google Patents

Description

[Detailed explanation of the idea]

(Industrial Application Field) The present invention relates to a molded container that does not cause sealing defects when sealed with a sealing lid material, and in which the sealing lid material can be easily peeled off when the container is opened. (Prior art) Molded containers such as cups and trays are constructed by heat-sealing a film-like sealing material to a flange formed around the opening of a container body integrally molded from a synthetic resin material. be done. The container body is sealed with this sealing lid material after filling the container body with contents such as jelly. A tongue piece (the part that is grasped by the hand) is formed. Furthermore, in the case of conventional molded containers, the sealing surface (flange surface) of the container body and the sealing surface of the sealing lid material are constructed of a combination of materials with low adhesive strength in order to improve unsealability. There is. For example, in Japanese Patent Publication No. 53-7872, one sealing surface is made of a blend material of polypropylene and polyethylene or an ethylene-propylene copolymer, and the other sealing surface is made of an ethylene-vinyl acetate copolymer. It has been shown that (Problems to be Solved by the Invention) However, in the conventional molded container described above, when opening the container to take out the contents, the tongue of the sealing lid material is grasped by hand and the sealing lid material is peeled off from the container body. Since the width of the tongue piece is narrow, about 2 to 3 mm, and the sealing lid material is film-like and flexible, there is a problem in that the sealing lid material cannot be easily peeled off. In addition, as mentioned above, if the sealing surfaces of the container body and the sealing lid material are made of a combination of materials with low adhesive strength to improve the unsealability of the container, when filling the container with contents such as jelly, When the contents adhere to the sealing surface, there is a problem in that the sealing strength of the sealing portion is significantly reduced and the sealing performance of the container is deteriorated. The present invention was developed in view of the above problems, and its purpose is to prevent sealing defects when sealing with a sealing lid material, and to easily peel off the sealing lid material when opening the package. It is possible to provide molded containers. (Means for Solving the Problems) In order to achieve the above object, the present invention adheres a peeling flange to the sealing surface of the flange portion formed around the opening of the container body integrally molded into a cup shape,
A sealing lid material is adhered to the upper surface of the peeling flange, and the sealing surface of the flange portion of the container body and the sealing surface of the peeling flange on the container body side are made of a combination of materials with low adhesive strength. The sealing surface on the sealing lid side and the sealing surface of the sealing lid are made of a combination of materials with high adhesive strength. (Function) Therefore, if the peeling flange is adhered to the flange portion of the container body before filling the contents such as jelly into the container body, a part of the contents will be attached to the adhesive surface of both. It does not adhere and impede the sealing performance of the container, and if the sealing lid material is adhered to the peeling flange after filling the contents, the sealing surfaces of both are made of a combination of materials with high adhesive strength as described above. Because of this, the adhesive strength is strong and sealing defects do not occur when sealing with a sealing lid material. Furthermore, since the sealing surface between the container body and the peeling flange is made of a combination of materials with low adhesive strength, the adhesive force between the two is weaker than the adhesive force between the peeling flange and the sealing lid material. When the container is opened, the peeling flange and the sealing lid material are peeled off together in a state in which they are adhered to each other, and the rigidity of the sealing lid material is reinforced by the peeling flange, so that the sealing lid material can be easily peeled off. can do. (Example) An example of the present invention will be described below based on the accompanying drawings. FIG. 1 is a longitudinal sectional view of a molded container according to the present invention, and FIG. 2 is a plan view of the same molded container. The molded container 1 shown in FIG. 1 has a peeling flange 3 adhered to the upper surface (sealing surface A) of a flange portion 2a formed at the periphery of the opening of a container body 2 integrally molded into a cup shape from synthetic resin. The sealing surface of the peeling flange 3 on the container body side is designated as B), and a film-shaped sealing lid material 4 is adhered to the upper surface (sealing surface C) of the peeling flange 3. Then, the sealing surface A of the container body 2 and the container body side sealing surface B of the peeling flange 3
consists of a combination of materials with low adhesive strength,
The sealing surface C of the peeling flange 3 on the sealing lid material side and the sealing surface D of the sealing lid material 4 are made of a combination of materials with high adhesive strength. Incidentally, tongue pieces 3a and 4a are formed on a part of the peeling flange 3 and the sealing lid member 4, respectively, so that these can be peeled off by grasping the hands. The molded container 1 is filled with contents such as jelly. Next, the procedure from sealing to unsealing of the molded container 1 will be explained based on FIGS. 3a to 3f. First, the peeling flange 3 is adhered to the upper surface (sealing surface A) of the container body 2 as shown in FIGS. is composed of a combination of materials with low adhesive strength, so both seal surfaces A and B
The adhesive force is not very strong, and as will be described later, peeling occurs between the seal surfaces A and B when the seal is opened. Next, as shown in Fig. 3c, the contents 5 such as jelly are filled, but the contents 5 should not adhere to the sealing surfaces A and B during filling and impair the sealing performance of the sealing surfaces A and B. do not have. After filling the contents 5, as shown in FIGS. 3d and 3e, a film-like sealing lid material 4 is adhered to the upper surface (sealing surface C) of the peeling flange 3 to seal it. The sealing surface C of the sealing flange 3 and the sealing surface D of the sealing lid material 4 are made of a combination of materials with high adhesive strength. Even if a part of the contents 5 sometimes adheres to the sealing surface C of the peeling flange 3, the sealing properties of both sealing surfaces C and D are not impaired. Next, when unsealing the molded container 1, by grasping the tongues 3a, 4a of the peeling flange 3 and the sealing lid material 4 with your hands and lifting them, the peeling flange 3 can be opened as shown in FIG. 3f. and the sealing lid material 4 are in a bonded state and peel off at the sealing surfaces A and B where the adhesive strength is weak. Therefore, the rigidity of the seal lid material 4 is increased by the peeling flange 3, and the unsealing operation becomes extremely easy. In summary, according to the present invention, by interposing the peeling flange 3 between the container body 2 and the sealing lid material 4, the filling seal portion (sealing surface C,
D) and the peeling portions (sealing surfaces A, B) are provided separately, so there is no need to consider peelability when filling the contents 5, and the sealing conditions can be maintained at a sufficiently high level. The combination of materials for the sealing surface A of the container body flange portion 2a and the container body side sealing surface B of the peeling flange 3 is selected from known materials with low adhesive strength. Further, the sealing surface C of the peeling flange 3 on the sealing lid material side and the sealing surface D of the sealing lid material 4 are made of a combination of known materials with high adhesive strength. Examples of material combinations to be used for each sealing surface A, B, C, and D are shown in the table below.

[Table] In the above table, PP represents polypropylene, PE represents polyethylene, EVA represents ethylene acetate/vinyl copolymer, and PIB represents polyisobutylene.
In addition, the peeling flange 3 shall be constructed of a single layer or a multilayer sheet with a material composition that satisfies the material combinations shown in Table 1. If the sealing surfaces B and C are made of different materials, the peeling flange 3 shall be a multilayer sheet or the same material. Seal surfaces B and C
When they are made of the same material, they can be made into a single layer sheet. In the case of a multilayer sheet, the adhesive force between each layer is between the container body flange 2a and the peeling flange 3.
This can be achieved by known methods such as coextrusion with an adhesive resin, lamination with an adhesive, heat lamination, extrusion coating, etc. Furthermore,
The overall thickness of the peeling flange 3 is preferably about 0.1 to 1.0 mm; if the thickness is less than 0.1 mm, the peeling flange 3 will lack rigidity, and if it is more than 1.0 mm, the cost will increase and the flange of the container body will be damaged. A problem arises in that the sealing efficiency between the peeling flange 2a and the peeling flange 3 is reduced. Further, in order to seal the peeling flange 3 to the container body flange portion 2a, a known method such as hot plate sealing, high frequency sealing, ultrasonic sealing, etc. is used. Furthermore, regarding the dimensions of the peeling flange 3, it is necessary to set the inner dimension to match the container body flange portion 2a and the outer dimension to be larger than that. A piece may be provided. Next, the results of an unsealing test conducted on this molded container will be shown. <Test example> A round cup-shaped container body with a diameter of 60 mm, depth of 20 mm, and flange width of 3 mm is integrally molded from a sheet of polyethylene/polypropylene blend polymer containing 10% ethylene with a thickness of 0.6 mm using the vacuum forming method. The flange of the container body is a peeling flange punched from a 0.15 mm thick sheet of ethylene/vinyl acetate copolymer containing 10% vinyl acetate, with an outer diameter of 70 mm, an inner diameter of 60 mm, and a tongue piece in a part. were heat sealed and glued. The heat sealing was carried out using a hot plate through Teflon at a temperature of 240° C., a pressure of 1.0 Kg/cm ² and a time of 2 seconds. Next, the container body is filled with jelly, and a sealing lid material having a laminate structure of 12μ thick polyethylene terephthalate (PET) and 50μ thick polyethylene (PE) is heat-sealed to the peeling flange. The container was sealed. The heat sealing conditions at this time were a temperature of 200 to 240°C, a pressure of 1.4 kg/cm ² , and a time of 1 second. As a result of conducting an opening test on the molded container obtained as above, it was found that the container could be opened easily, and the heat seal strength and leakage rate for each heat sealing condition were as shown in the table below. can get.

[Table] Also, as a comparative example, the results of an opening test conducted on a conventional molded container without a peeling flange are shown below. <Comparative example> The molded container used in the test has a laminate structure of 12μ thick polyethylene terephthalate (PET) and 50μ thick ethylene/vinyl acetate copolymer (containing 10% vinyl acetate) on the flange of the container body. The sealing lid material was bonded by heat sealing under the same conditions as in the experimental example. According to the test results, under heat-sealing conditions at a temperature of 240°C, unsealability was somewhat poor and leakage occurred. The test results are summarized in the table below.

[Table] As evidenced by the above test results, the molded container according to the present invention has excellent sealing properties and peelability. (Effect of the invention) As is clear from the above explanation, according to the invention, the filling seal portion and the peeling portion are provided separately by interposing the peeling flange between the container body and the sealing lid material. This has the advantage that sealing failure does not occur when sealing with a sealing lid material, and the sealing member can be easily peeled off when unsealing.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of the molded container according to the present invention, FIG. 2 is a plan view of the molded container, and FIGS. 3 a to 3 f are diagrams illustrating the steps from sealing to unsealing of the molded container. Explanation of symbols, 1... Molded container, 2... Container body, 2
a...Flange portion, 3...Peeling flange, 4...Seal lid material, A, B, C, D...Seal surface.

Claims (1)

[Scope of utility model registration request] A peeling flange is adhered to the sealing surface of the flange formed around the opening of the container body integrally molded into a cup shape, and a sealing lid material is adhered to the upper surface of the peeling flange. The sealing surface and the sealing surface of the peeling flange on the container body side are made of a combination of materials with low adhesive strength.
A molded container characterized in that the sealing surface of the peeling flange on the sealing lid side and the sealing surface of the sealing lid are made of a combination of materials with high adhesive strength.