JPH0654766A - Closed container and manufacture thereof - Google Patents

Abstract

PURPOSE:To achieve a complete sealing of a lid part of a closed container made of a thermoplastic resin and a easy peeling of the lid part. CONSTITUTION:In a closed container 13, a non-weld part, a loosely weld part 14A and a weld part 14B are arranged alternately on a sealing surface 14 between a flange 11A of the body 11 of the container and the periphery of a lid part 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed container used for packaging foods containing liquids such as tofu, dark beans and pickles, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, for example, polyvinyl chloride (PV
C), polyester (PET), polyethylene (P
E), polypropylene (PP), or other thermoplastic material, and as shown in FIG. 5, a closed container (3) comprising a container body (1) and a lid (2) for sealing the container body (1). )
Is provided.

In the closed container (3), a flange (1A) is formed on the upper edge of the container body (1), and the peripheral edge of the lid (2) is defined as the flange (1A) of the container body (1). The entire surface is peelably sealed with an adhesive or by welding.

[0004]

However, in the above-mentioned prior art, the lid (2) is attached to the container body with an adhesive.
When sealing to (1), the food may be contaminated by the adhesive, and in the case of welding, the peripheral edge of the lid (2) is fixed to the flange (1A) of the container body (1) by a hot plate. In this case, when the pressing force is increased, the lid part (2) is strongly welded to the container body (1) at the sealing surface (4) and it becomes difficult to peel it off. It becomes difficult to press it uniformly, and there is a risk that the contents will leak due to the presence of an unwelded portion on the sealing surface (4). Further, there is a problem that the sealing surface (4) is deformed by heat during welding and the appearance is deteriorated. Such a problem becomes remarkable especially when PET, which is easily welded, is used as the material.

[0005]

Means for Solving the Problems As a means for solving the above-mentioned conventional problems, the present invention comprises a container body (11) made of thermoplastic material and having a flange (11A) at its upper edge, and the container body (11). ), And a sealing surface between the flange (11A) of the container body (11) and the periphery of the lid (12).
In (14), the non-bonded or loosely bonded part (14A) and the welded part (1
4B) and the closed container (13) alternately arranged, and thermoplastic resin as a material, the lid (12) is superimposed on the container body (11) with the flange (11A) at the upper edge, and pressed. surface
By pressing the peripheral edge of the lid portion (12) against the flange (11A) of the container body (11) by a hot plate (15) provided with a large number of narrow grooves (16A) in the (16), a non-attached portion or a loosely attached portion. (14A) and welded part (14A
The present invention provides a method for manufacturing a closed container (13) having a sealing surface (14) in which B and B are alternately arranged.

[0006]

In the closed container (13) of the present invention, the container body (1
Sealing surface (14) between the flange (11A) in 1) and the peripheral edge of the lid (12)
In the above, since the non-bonded or loosely bonded part (14A) and the welded part (14B) are alternately arranged, the lid part (12) can be easily peeled off even if the welded part (14B) is strongly welded. Can be done.

When the sealing surface (14) is pressed by a hot plate (15) having a large number of narrow grooves (16A) on the pressing surface (16), the narrow grooves are pressed.
The sealing surface (14) pressed by the pressing surface part (16B) divided by (16A) becomes the welded part (14B), and the narrow groove (1
The portion corresponding to 6A) becomes a loosely welded portion (14A) by heat transfer from the non-welded portion or the pressing surface (16).

In this case, the pressing surface (16) of the hot plate (15) is not entirely in contact with the sealing surface (14), but is partially covered by the pressing surface portion (16B) divided by the narrow groove (16A). On the sealing surface
Since it is in contact with (14), the sealing surface (14) can be pressed uniformly and the pressing force can be easily adjusted. In addition, the deformation of the seal surface due to heating during welding is absorbed by the non-welding portion or loosening portion (14A).

[0009]

EXAMPLES The present invention will be described with reference to one example shown in FIGS. 1 to 4. The closed container (13) comprises a container body (11) and a lid part (12). The peripheral edge is sealed by a flange (11A) formed on the upper edge of the container body (11), and the lid portion (12) is formed with an ear portion (12A). Above lid (12)
Sealing surface between the peripheral edge of the container and the flange (11A) of the container body (11)
In (14), the welded part (14B) is arranged between the non-bonded part or loosely bonded part (14A) arranged in a radial pattern.

The closed container (13) is made of PVC, PET, P
Made of a thermoplastic such as E or PP, the container body
(11) is produced, for example, by vacuum forming the thermoplastic sheet. And the container body (1
The peripheral edge of the lid (12) is overlapped with the flange (11A) of (1) and the peripheral edge of the lid (12) is covered with the flange of the container body (11) by a heating plate (15) as shown in FIG. Press on (11A).

As shown in FIG. 3, the pressing surface (16) of the hot plate (15)
Has a pressing surface part (16B) divided by a large number of radial fine grooves (16A), and the heating plate (15) has a built-in heating wire, and when the container material is PET, the pressing surface is normally pressed. (16) is usually heated to 150 to 180 ° C.

As shown in FIG. 4, the portion of the sealing surface (14) pressed by the pressing surface portion (16B) of the heat plate (15) becomes a welded portion (14B), and the portion corresponding to the narrow groove (16A) is a non-attached portion or Heat is transferred from the pressing surface (16) to form the loosely fitting portion (14A). In this case, since the pressing surface portion (16B) of the pressing surface (16) of the heat plate (15) partially abuts the sealing surface (14), the sealing surface (14)
A uniform pressing force can be exerted on, and the pressing force can be easily adjusted. Further, at the time of welding, the deformation of the seal surface (14) due to the heat from the hot plate (15) is absorbed by the non-adhesion portion or the loose attachment portion (14A), so that there is almost no deformation of the seal surface (14).

In the closed container (13), the lid portion (12) is an ear portion.
(12A) is pulled as a clue and peeled from the container body (11). At this time, since the seal surface (14) is partially welded at the welded portion (14B), the lid portion (12) can be easily peeled off.

Although the container has a cylindrical shape in this embodiment, the present invention can also be applied to a rectangular box-shaped container or the like. Further, although the narrow grooves (16A) of the heat plate (15) are radial, they may be stripe-shaped, goggles-shaped, or the like. However, if the narrow groove (16A) is radial, the container (1
The non-attached or loosely attached part (14A) of the sealing surface (14) of (3) also covers (1
The radial direction substantially coincides with the peeling direction of 2), and the lid portion (12) can be peeled off smoothly.

[0015]

According to the present invention, therefore, the lid of the closed container can be reliably sealed and the lid can be easily peeled off.

[Brief description of drawings]

 1 to 4 show an embodiment of the present invention.

FIG. 1 is a perspective view.

FIG. 2 is a sectional view.

FIG. 3 is a perspective view of a hot plate

FIG. 4 is a partial sectional view for explaining a welding state.

FIG. 5 is a perspective view of a conventional example.

[Explanation of symbols]

 11 Container body 11A Flange 12 Lid 13 Sealed container 14 Sealing surface 14A Loose fitting 14B Welding 15 Heat plate 16 Pressing surface 16A Fine groove 16B Pressing surface

Claims (2)

[Claims] 1. A container body made of a thermoplastic material and having a flange at an upper edge thereof, and a lid portion for sealing the container body, wherein a sealing surface between the flange of the container body and the periphery of the lid portion is formed. A closed container characterized in that non-bonded or loosely bonded parts and welded parts are arranged alternately. 2. A lid is placed on a container body having a flange at an upper edge and made of a thermoplastic material, and a peripheral edge of the container body is covered with a hot plate having a large number of narrow grooves on a pressing surface. A method for manufacturing a hermetically sealed container, characterized by forming a sealing surface in which non-bonded portions or loosely bonded portions and welded portions are alternately arranged by pressing against a flange.