JPH07195420A - Production of plug made of synthetic resin of bottle for carbonated beveragte - Google Patents

Abstract

PURPOSE:To obtain the plug made of a synthetic resin of a bottle for a carbonated beverage capable of reducing a gas escaping amt. by a method wherein a synthetic resin membrane having high gas barrier properties is arranged to the gap between the bottom part of a cavity and the leading end of a core in the state supported on a disc piece having the compatibility with the resin of a plug main body and a molten resin is injected into a mold from a gate. CONSTITUTION:A synthetic resin membrane 15 having high gas barrier properties is arranged to the gap 14 between the botton part of the cavity equipped with the gate 11 of an injection mold and the leading end of a core 13 in the state supported on a disc piece 16 formed from foam having compatibility with the resin forming a plug main body 7 in a molten state and having a diameter equal to or slightly smaller than the inner diameter of the cavity 12. Thereafter, a molten resin is injected into the mold from the gate 11 to mold the plug main body 7 and the disc piece 16 is melted to provide a gas barrier layer 10 to the bottom part 4 of the plug main body 7 by the membrane 15. By this constitution, the gas barrier properties of the bottom part are enhanced and the escape amt. of carbon dioxide in a bottle is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a synthetic resin plug for fitting and closing a bottle of a carbonated beverage bottle, such as sparkling wine, by using a synthetic resin product, in which carbon dioxide gas is less likely to escape. The present invention relates to a method for manufacturing a synthetic resin plug for a carbonated beverage bottle, which can prolong the service life.

In the present invention, the bottom of the plug means
Among the body parts that are fitted into the bottle mouth, not only the bottom of the tip, but also the side parts near the bottom that do not contact the inner surface of the bottle mouth when the body part is fitted are included.

[0003]

2. Description of the Related Art Generally, it is difficult to control the shape of the inner surface or the size of the inner diameter of a bottle mouth, and variations easily occur. To cope with this, the plug body has an appropriate elasticity and is different from the inner surface of the bottle mouth. It is necessary to make close contact with and secure the sealing property. Therefore, the plug body is made of an elastic soft synthetic resin selected from polyethylene, a copolymer containing ethylene as a main component, and a synthetic resin composition containing these as a main component.

The conventional method of manufacturing a plug of this type is such that a flange is provided around the upper part of a cylindrical body which is open at the top and which can be fitted into a bottle mouth having a bottom, and which is pressed against the rim of the bottle mouth. A main body and a top cap that can be fitted into an open portion of the upper portion of the plug main body are formed by injection molding the soft synthetic resin. In the injection molding,
Considering the shape of the plug body, the gate of the injection molding machine is positioned corresponding to the center of the bottom of the body.

[0005]

The synthetic resin plug obtained by the conventional method has the gas barrier property of the soft synthetic resin itself which is not so high and the center of the bottom portion corresponding to the gate of the injection molding machine. Has a property that the gas barrier property is lower than that of other portions due to the poor crystallinity of the resin, the gas escape phenomenon is increased under a predetermined condition, for example, in a high temperature atmosphere, and the product life is easily shortened.

It is an object of the present invention to further reduce the amount of gas escape from carbonated beverage bottles, and it is an object of the present invention to provide a method for producing a synthetic resin plug capable of solving the problem.

[0007]

By the way, in this type of synthetic resin plug 1, carbon dioxide gas permeates the soft synthetic resin even if there is no abnormality in the seal between the bottle mouth 2 and the plug body 7. It is generally known that it has the property of escaping to the outside, that is, it has gas permeability. The portion is mainly the bottom portion 4 of the body portion 5, the phenomenon hardly occurs from the side surface of the body portion 5, and the crystallinity of the resin at the bottom center 9 corresponding to the gate of the injection molding machine is poor. Therefore, it was found that the amount of gas escape increased extremely in this part. Therefore, it was concluded that reducing the gas escape at the bottom 4 could achieve the initial objectives.

In view of the above points, the present invention, for example, injection-molds a plug 1 having a cylindrical body portion 5 having a bottom portion 4 configured to be tightly fitted into the bottle mouth 2 with a soft synthetic resin. In the method of manufacturing according to 1., a thin film 15 of a synthetic resin having a high gas barrier property is formed by a gap 14 between a bottom of a cavity 12 provided with a gate 11 of an injection mold and a tip of a core 13.
After being placed on a disk piece 16 having a diameter equal to or slightly smaller than the inner diameter of the cavity 12 of the relevant portion, which is made of a foam material which is compatible with the resin forming the plug body 7 in a molten state, The molten resin is injected from the gate 11 into the mold, the plug body 7 is injection-molded, the disc piece 16 is melted, and the gas barrier layer 1 is formed by the thin film 15.
0 is provided in the bottom portion 4 of the plug body 7.

[0009]

In the plug 1 obtained by the above-described manufacturing method, the gas barrier layer 10 enhances the gas barrier property of the bottom portion 4, so that the escape amount of carbon dioxide gas from the bottle is small. Further, the disk piece 16 is compatible with the injected resin and disappears.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described in detail below with reference to FIGS. 1 and 2 of the accompanying drawings. Here, FIG. 1 is a vertical sectional end view of an injection molding machine showing a state before injecting resin, FIG. 2 is a partial vertical sectional front view showing a state in which a plug is attached to a bottle mouth, and FIG. 2 is a bottom view of a plug body. Is.

First, the structure of the plug 1 to be manufactured will be described. As shown in FIGS. 2 and 3, the plug 1 is a hollow having an upper portion 3 open and a bottom portion 4 which can be tightly fitted in the bottle mouth 2. Around the upper part 3 of the tubular body 5, and the bottle mouth 2
A plug body 7 having a flange 6 formed so as to abut the edge and a top cap 8 that can be fitted into the open portion of the upper portion 3 are formed by injection molding of soft synthetic resin. A gas barrier layer 10 made of a synthetic resin thin film is provided in the bottom portion 4. The soft synthetic resin is made of a material capable of making close contact with the inner surface of the bottle mouth 2 and ensuring sealing property. Specifically, polyethylene or a copolymer containing ethylene as a main component or a main component thereof is used. It is selected from among synthetic resin compositions.

Further, the center of the flange 6 is integrally opened with the open portion of the upper portion 3 of the body portion 5, and the top cap 8 separately manufactured by injection molding is fitted into the open portion. By doing so, the plug 1 is configured.

Next, a method of manufacturing the plug body 7 by injection molding will be described. As shown in FIG. 1, first, a mold (not shown) of an injection molding machine corresponds to the bottom center 9. In the space 14 between the bottom of the cavity 12 having the gate 11 and the tip of the core 13, a thin film 15 of a synthetic resin having a high gas barrier property is provided with a disc having a diameter equal to or slightly smaller than the inner diameter of the cavity 12 of the portion. The piece 16 is supported and arranged on the surface on the core 13 side. The disc piece 16 is made of foam that is compatible with the resin forming the plug body 7 in a molten state. Then, gate 11
When the molten resin is injected from the inside, the plug body 7 is injection-molded and the disc piece 16 is melted into the molten resin and disappears. When the resin has solidified, the cavity 12
From the core 13 and the tip of the gate 11, that is, the outside of the portion corresponding to the center 9 of the bottom, is sheared, and the plug body 7
Is removed from the injection mold. As shown in FIG. 1, the plug body 7 thus obtained has the gas barrier layer 10 provided inside the bottom portion 4 toward the inside.

Table 1 shows the measurement results of the amount of carbon dioxide gas escaped from the bottles closed with the plugs of the conventional example and the first example.

[Table 1] As is clear from these values, it was proved that the escape amount of the first embodiment is significantly smaller than that of the conventional example.

As described above, the plug body 7 provided with the gas barrier layer 10 according to the first embodiment has the gas barrier layer 10
As a result, the gas barrier property of the bottom portion 4 is improved, so that the escape amount of carbon dioxide gas from the bottle is small and the life of the product can be extended.

Next, a second embodiment of the present invention will be described with reference to FIGS. Here, FIG. 4 is a partially enlarged vertical sectional end view of the main part of the injection molding machine showing a state before injecting the resin, and FIG. 5 is an enlarged partial vertical sectional front view of the main part of the plug body obtained in the second embodiment. It is a figure, and among the reference numerals described therein, the same reference numerals are used to indicate the parts configured in the same manner as in the first embodiment, and the detailed description thereof will be omitted.

In the second embodiment, the same die as in the first method is used, and the same disc piece 16 and thin film 15 are used, and the thin film 15 is formed on the surface of the disc piece 16 on the gate 11 side.
Is carried and disposed, and the gas barrier layer 20 is provided on the outer side of the bottom portion 4 through the same steps as in the first embodiment.

Further, a third embodiment of the present invention will be described with reference to FIGS. Here, FIG. 6 is a partially enlarged vertical sectional end view of the main part of the injection molding machine showing a state before injecting the resin, and FIG. 7 is an enlarged partial vertical sectional front view of the main part of the plug body obtained in the third embodiment. Among the reference numerals described in these, the same reference numerals are used for the parts that have the same configurations as those of the first embodiment or the second embodiment, and the detailed description thereof will be omitted.

The third embodiment is the same mold as the first embodiment or the second embodiment, and the same disc piece 16 is used.
And the thin film 15, the thin film 15 is arranged on both sides of the disk piece 16, and the gas barrier layers 30a and 30b are provided in the bottom portion 4 in the same process as in each of the embodiments.

As described above, the plug bodies 7 and 7 obtained by the second and third embodiments have the gas barrier layers 2 respectively.
0 or the gas barrier layers 30a and 30b improve the gas barrier property of the bottom portion 4 or the bottom portion 4, so that the escape amount of carbon dioxide gas from the bottle is small and the life of the product can be extended.

The disc piece 16 used in the present invention is
The present invention is not limited to the foams and may be made of any material that is compatible with the resin in the molten state.

[0022]

As described above, the synthetic resin plug of the bottle for carbonated beverages according to the present invention can improve the gas barrier property at the bottom, particularly at the center of the bottom corresponding to the gate of the injection molding machine. In addition to being able to reduce the amount of carbon dioxide gas that escapes, the thin film is placed on a disk piece during injection molding, so that a gas barrier layer can be reliably formed at a prescribed site on the bottom, and the disk can also be reliably formed. Since the piece is made of a material that is compatible with the resin in a molten state, it has the effect of obtaining a plug free of unnecessary disk pieces after injection molding.

When the disc piece is made of a foamed material, it has an effect that the melting property is enhanced and the extinction during injection molding becomes more reliable.

[Brief description of drawings]

FIG. 1 is a vertical sectional end view of an injection molding machine showing a state before a resin is injected in a first embodiment.

FIG. 2 is a partially longitudinal front view showing a state in which the plug obtained in the first embodiment is attached to a bottle mouth.

FIG. 3 is a bottom view of the plug body.

FIG. 4 is a partially enlarged vertical sectional view of a main part of an injection molding machine showing a state before injecting a resin in a second embodiment.

FIG. 5 is an enlarged partial vertical sectional front view of the main part of the plug body obtained in the second embodiment.

FIG. 6 is a partially enlarged vertical sectional end view of a main part of an injection molding machine showing a state before injecting resin in a third embodiment.

FIG. 7 is an enlarged vertical sectional front view of a main part of the plug body obtained in the third embodiment.

[Explanation of symbols]

 1 Synthetic Resin Plug 2 Bottle 4 Bottom 5 Body 7 Plug Body 9 Bottom Center 10, 20, 30a, 30b Gas Barrier Layer 11 Gate 12 Cavity 13 Core 14 Void 15 Thin Film 16 Disc Piece

Claims (4)

[Claims] 1. A method for producing a synthetic resin plug of a carbonated beverage bottle having a cylindrical body portion having a bottom portion adapted to be tightly fitted into a bottle by injection molding a soft synthetic resin. So, a thin film of synthetic resin with high gas barrier properties,
In the gap between the bottom of the cavity with the gate of the injection mold and the tip of the core, made of a material that is compatible with the resin that forms the plug body in the molten state, equal to the cavity inner diameter of that part, After placing it on a disc piece with a slightly smaller diameter, inject molten resin from the gate to injection-mold the plug body and melt the disc piece to provide a gas barrier layer at the bottom of the plug body. A method for manufacturing a synthetic resin plug of a bottle for carbonated drinks, which comprises: 2. A synthetic resin plug for a carbonated beverage bottle according to claim 1, wherein a thin film of a synthetic resin having a high gas barrier property is carried and arranged on one surface of the disc piece on the gate side. Manufacturing method. 3. The method for producing a synthetic resin plug for a carbonated beverage bottle according to claim 1, wherein a thin film of a synthetic resin having a high gas barrier property is placed on both sides of the disc piece. . 4. The method for producing a synthetic resin plug for a carbonated beverage bottle according to claim 1, 2, or 3, wherein the disc piece is made of foam.