JPS5890007A - Method of sealing vessel - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sealing method for containers, and more particularly to a sealing method suitable for use in simple containers made of synthetic resin or a laminated sheet of synthetic resin and paper.

BACKGROUND ART Laminated containers made by laminating synthetic resin or resin film and paper are used as simple disposable containers for selling various types of food products. The main body of such a container is formed, for example, in the shape of a cup, and after filling the container with contents, the container is sealed with a lid and used for distribution.

When sealing the container body with the lid, it is necessary to completely seal the joint between the two. A conventionally commonly used method for this purpose is hot plate sealing. This involves placing a lid over the container body, pressing a heated hot plate onto the lid, and melting and sealing the joint of the lid. This method has the disadvantage that the heating plate comes into direct contact with the outer surface of the lid, and irregular irregularities are formed on the outer surface of the sealed lid, impairing the appearance and reducing the product value. There is. Another method is ultrasonic sealing. Although ultrasonic seals eliminate the above-mentioned defects in appearance, the seal strength is not necessarily sufficient and the seal failure rate increases. This has disadvantages such as leakage of contents and shortened storage period or warranty period.

The present invention has been made in view of these problems, and it is an object of the present invention to provide a sealing method that does not impair the appearance of the container and has excellent seal strength.

The present invention will be explained below with reference to one embodiment. As shown in FIG. 1, the container body 1 is made of a laminated paper 2 made of laminated paper and aluminum foil, for example, and is formed into a cup shape. A resin film 3 is further laminated on the inner surface of the cup-shaped container body 1 by pressure molding (see FIG. 3). The container body 1 has an opening 4 at its upper part, and a flange 5 formed at its peripheral edge. The resin film 3 is exposed on the joint surface, ie, the upper surface, of the flange 5. On the other hand, the lid body 6 is molded from synthetic resin, has a circular disk shape, and has a stepped portion 7 projecting downward. This stepped portion 7 is fitted into the opening 4.

Next, a heating element 8 used to seal the container has a roughly semicircular shape as shown in FIG. These heating elements 8 may be composed of, for example, mica and nichrome wires wound around each other. Or use nichrome [Fig. 2 J
The heating plate may be formed directly into the shape shown in ζ. When the stepped portion 7 of the lid 6 is low or absent, or when melting is performed with a wide gap between the lid 6 and the flange 5 of the container body 1, the heating element 8 is attached to a ring. It may also be in the form of

Next, a method of sealing using this heating element 8 will be explained with reference to FIGS. 3 and 4. First, the container body 1 is placed on the receiver 9 by its flange 5. Then, the flange 51 of this container body l is held for a predetermined distance of 1!110
A lid 6 is placed on top of the container body 1 while holding the container body 1. Then, a pair of heating elements 8 are inserted into this gap lO from the outside in the radial direction as indicated by the arrows in FIG. The upper surface of the heating element 8 is made to face the lower surface of the peripheral edge of the lid 6, and the lower part of the heating element 8 is made to face the upper surface of the 7-lunge 5.

Then, the heat generated by the heating element 8 melts the surface of the resin film 3 constituting the surface of the flange 5 of the container body 1 and the lower surface of the peripheral edge of the lid 6. The degree of this melting may be sufficient for sealing, and can be adjusted by the amount of heat generated by the heating element 8, the temperature, the time for which the heating element 8 is inserted, or the length of the gap 10.

When the surface t of the flange 5 of the container body 1 and the lower surface of the periphery of the lid 6 have been melted by a tenth degree, the heating element 8 is moved radially outward, that is, in the direction opposite to the arrow in the second figure. Remove it. Immediately thereafter, the lid 6 is moved downward to eliminate the gap 10 (see FIG. 4). As a result, the step 7 of the lid 6 is fitted into the opening 4 of the container body 1, and the peripheral edge of the lid 6 and the flange 5 of the container body 1 are welded together. Then, using the press plate 11 from above the countersunk number ζ, press the loose peripheral portion of the bag lid 6 as shown in the fourth figure.

Then, the flange 5 of the container body 1 and the peripheral edge of the lid 6, which are stacked on top of each other, are sandwiched between the receiver 9 and the suppressor 11, and the surfaces of the lid 6 are fused together. The peripheral edge and the flange 5 of the container body 1 are firmly sealed.

According to the method of the above-mentioned embodiment, the hot plate does not directly contact the upper edge of the periphery of the lid body 6 to effect sealing.
Irregular unevenness is formed on the outer surface of the lid body 6 and the surface does not collapse. Therefore, the appearance or beauty of the container is not impaired, and a decrease in commercial value is also prevented. Further, according to this sealing method, the joint surfaces of the flange 5 of the container body 1 and the peripheral edge of the lid body 60 are pressed together in a pre-molten state, and the sealing is thereby performed. Therefore, a large seal strength can be obtained. Therefore, leakage of the contents due to poor sealing is prevented, and the storage period or quality guarantee period of the contents is also extended.

Next, a method according to a modification of the above embodiment will be explained with reference to FIG. In this modified heat exchanger, the mutually opposing contact surfaces of the container body l and the lid body 6 are made of a material that does not melt by itself, such as aluminum foil or paper. A bonding resin layer 14 is previously formed on each of these bonding surfaces.

The heating element 8 is heated so as to melt these bonding resin layers 14, and then melts these bonding resin layers 14.
are pressed together so that the lid 6 seals the opening 4 of the container body 1. This modification 1 also provides substantially the same effects as those of the above embodiment.

FIG. 6 shows a modification of the countersunk, in which only the lid 6 is formed of a synthetic resin molded body, and at least the front and both sides of the flange 5 of the container body 1 are made of a material that does not melt by heat itself. It was formed by And 50 flange tables? A resin layer 14 for IK bonding is formed, and a heating element 8 is formed.
The resin layer 14 and the lower part of the peripheral edge of the lid 6 are melted and sealed. Therefore, in this case as well, substantially the same effects as in the above-mentioned embodiments and modifications can be obtained.

Although the present invention has been described above with reference to embodiments and modified examples, the present invention is not limited to the above embodiments, and various changes can be made based on the technical idea of the present invention. For example, in the above embodiment, both the joint surfaces of the peripheral edge of the lid 6 and the flange 5 of the container body 1 are melted by the heating element 8. Only one of the peripheral edge and the flange 5 of the container body 1 may be sufficiently melted and sealed.

As described above, according to the present invention, since the hot plate does not come into direct contact with the outer surface of the lid, the appearance of the container will not be deteriorated and the commercial value will not be lowered. In addition, the joint surface of at least one of the opening edge of the container body and the peripheral edge of the lid body is melted, or a joining resin formed on the joint surface is melted by a heating element, and then both are sealed. Since the sealing material is made of aluminum, a large sealing strength can be obtained, and the need for sealing can also be prevented.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a container used in one embodiment of the present invention, Fig. 2 is a perspective view of a heating element used to seal this container, and Fig. 4 is a main part showing the sealing operation. FIG. 5 is an enlarged sectional view of a main part showing a sealing method of a modified example, and FIG. 6 is an enlarged sectional view of a main part showing a sealing method of another modification. In addition, in the symbols used in the drawings, 1... Container body 4... Opening 6... Lid body 8... . . . Heating element 14 . . . It is a bonding resin layer. Agent Osamu Matsuzai

Claims (1)

[Claims] In the method of joining and sealing the opening edge of the container body and the peripheral edge of the lid, the lid is spaced apart from the opening edge of the container body, and a heating element is disposed in the gap between the two. The bonding resin formed on at least one bonding surface of the opening edge of the container body and the peripheral edge of the lid body, or at least one bonding surface lζ, is melted by the heat of the heating element, and then A method for sealing a container, characterized in that the heating element is removed and the peripheral edge of the lid is joined to the opening edge of the container body for sealing.