JPS5915005A - Method of sealing plastic vessel with collar - 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 method of sealing a flanged plastic four-ring container in which the lid sheet does not become wavy or wrinkled.

Conventionally, when sealing the brim of a plastic container with the surrounding area of the lid sheet (glass stick, aluminum foil, paper, etc.),
There is a drawback that the inside of the heat-sealed portion of the lid sheet tends to become wavy or wrinkled.

As a result of the inventor's extensive research to improve this drawback,
It was discovered that when the lid sheet metal is heat-sealed to the rim of the container with the brim portion of the container tilted upward, the heat-sealed portion of the lid sheet is taut and does not become wavy or wrinkled.
The present invention was achieved based on these findings.

That is, the present invention is characterized in that a flange-shaped part formed on the outer periphery of the opening of a plastic container is tilted upward, the entire lid sheet is placed on the upper surface of the flange-shaped part, and the flange-shaped part and the surroundings of the lid sheet are bonded by heat and pressure for sealing. This is a method of sealing a plastic container with a flange.

The method of the present invention will be explained below with reference to the drawings while comparing it with the conventional method. 1 to 3 are explanatory diagrams of the heat sealing process according to the method of the present invention, and FIGS. 4 to 6 are explanatory diagrams of the heat sealing process according to the conventional method. In the figure, 1 is a glass container, 2 is a lid sheet, 3 is a pedestal, a 4Vi heating plate, and a is a flange-like part of the container l.

First, to explain the conventional method, FIG. 4 shows the entire state before heat sealing, with the flange a being horizontal. FIG. 5 shows the state of the container during heat sealing, and FIG. 6 shows the state of the container after heat sealing of the lid sheet has been completed. However, as the lid sheet becomes thinner, the inner portion of the heat-sealed portion of the lid sheet becomes wavy or wrinkled, as shown in FIG. 6, resulting in an unsightly appearance and reduced commercial value.

The method of the present invention is an improvement on this, and FIG. 1 shows the state before heat sealing, in which the flange-shaped portion a is inclined upward by an angle θ. Figure 2 shows the state of the container during heat sealing, and Figure 3 shows the state of the container after the heat sealing of the lid sheet has been completed, with the flange a becoming horizontal due to the heat sealing. As shown in Figure 2, since the flange-shaped part a is inclined upward by an angle θ, the heating plate 4 comes into contact with the outside of the flange-shaped part a (sealing part) of the container during the heat sealing process shown in Fig. 2'2. Heat sealing is performed while sequentially moving to the inside of the brim part a. Therefore, the unsealed portion of the lid sheet inside the heat-sealed portion is pulled outward, and as shown in FIG. 3, the portion of the lid sheet inside the heat-sealed portion becomes horizontal instead of wavy or wrinkled, increasing commercial value.

One of the causes of wavy or wrinkled appearance is that the unsealed portions of the lid sheet are heated during heat sealing, and this is particularly likely to occur around the outer periphery near the sealed portion.

Note that the method of the present invention can be applied to any type of plastic container, such as a round, square, or pin-shaped container, which has a flanged structure on the outer periphery of its opening.

Further, the inclination angle θ of the brim portion a of the container is preferably 15 to 201 degrees. If the angle is small, the effect will be weak, and if the angle is too large, problems such as tearing of the lid sheet may occur.

The shape of the container after the lid sheet is heat-sealed is different from the conventional one (see Fig. 6), as the brim becomes horizontal as shown in Fig. 3 due to the heat sealing by the horizontal pedestal 3 and horizontal heating plate 4. There is no place.

[Brief explanation of drawings]

1 to 3 are process explanatory diagrams according to the method of the present invention, and FIGS. 4 to 6 are process explanatory diagrams according to the conventional method. l...Glasstic container 2...Lid sheet 3...Scraper 4.・・Hot plate a・・flange-shaped part

Claims (1)

[Claims] A plastic container with a flange, characterized in that a flange-shaped part formed on the outer periphery of the opening of the plastic container is tilted entirely upward, a lid sheet is placed on the upper surface of the flange-shaped part, and the flange-shaped part and the periphery of the lid sheet are sealed by heat-pressing. Seal method.