JPH10180853A - Molding of bottle body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and certainly form the air introducing part to the gap between outer and inner layers without requiring post-treatment. SOLUTION: This parison is constituted so as to be formed by fitting an outer cylinder 2 made of a synthetic resin having a thread 4 provided in the outer peripheral surface of the mouth part 11 thereof and molded into a closed- end cylindrical shape and an inner cylinder 3 made of a flexible synthetic resin freely relaeasable with respect to the outer cylinder 2 molded into a closed-end cylindrical shape wherein an outer flange 5 is provided in the upper end of the mouth part 11. In the case, the groove 7 being the air introducing part 6 to the gap between the outer and inner layers 12, 13 is preliminarily formed to at least one of the mouth part 11 of the outer cylinder 12 and the mouth part 11a of the inner cylinder 3 and the lower parts of the mouth parts 11, 11a of this parison 1 are subjected to biaxial stretch/blow molding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outer layer forming a fixed outer shell, and an inner layer forming a deformable inner bag is laminated on the outer layer so as to be releasable. The present invention relates to a method for molding a synthetic resin bottle, which allows a liquid content to be poured out and used without allowing outside air to enter a storage section.

[0002]

2. Description of the Related Art In a synthetic resin blow-molded bottle body in which an inner layer forming a deformable inner bag is releasably laminated on an outer layer forming a fixed outer shell, the inner layer is housed in the inner layer. When the content liquid is used to be poured out and the inner bag formed by the inner layer is deformed to reduce the volume, by allowing outside air to enter between the outer layer and the inner layer, the inner layer can be smoothly separated from the outer layer. In addition, the volume of the inner layer is reduced and deformed by the use of the content liquid.

As a means for allowing outside air to enter between the outer layer and the inner layer, Japanese Patent Application No. Hei 6-1433 has been filed by the present applicant.
No. 26 has been proposed.

In the above-mentioned prior art, an outer layer made of a synthetic resin having a relatively low melting point, such as polyethylene, and an inner layer made of a flexible synthetic resin having a higher melting point, such as nylon, are laminated by co-extrusion molding means. After blow molding a bottle from a parison extruded into a cylindrical shape, a perforation jig heated to a temperature equal to or higher than the melting point of the outer layer material and lower than the melting point of the inner layer material is applied to the outer layer portion of the body including the mouth of the bottle. And an air intake hole between the outer layer and the inner layer is melt-formed.

[0005]

However, in the above prior art, after the bottle is formed by blow molding, the outer layer is formed while using a dedicated piercing jig and controlling the temperature and the pressing force to predetermined set conditions. However, since the air intake hole is formed by melting, a drilling step as post-processing is required, and the number of steps is increased, and the drilling operation is technically difficult.

Accordingly, the present invention has been made to solve the above-mentioned problems in the prior art, and the air introducing portion between the outer layer and the inner layer can be easily and reliably provided without the need for post-processing. The purpose is to form.

[0007]

Means of the present invention to achieve the above-mentioned object is to form a synthetic resin outer layer forming a fixed outer shell by blow molding, and to be releasably laminated on the outer layer,
A method for molding a bottle comprising a flexible synthetic resin inner layer forming an inner bag, and a synthetic cylinder formed by injection molding into a bottomed cylindrical shape provided with a thread on an outer peripheral surface of a mouth. An outer cylinder made of a resin, and an inner cylinder made of a flexible synthetic resin which is formed into a bottomed cylinder having an outer flange provided at the upper end of the mouth by injection molding and which can be separated from the outer cylinder. At least one of the mouth of the outer cylinder and the mouth of the inner cylinder of the fitted parison is formed in advance with an air introduction portion between the outer layer and the inner layer at the time of injection molding. Biaxial stretch blow molding of the portion below the mouth.

The air introducing portion may be at least one groove provided from the lower surface of the outer flange of the inner cylinder to the outer peripheral surface of the mouth portion.
Alternatively, at least one groove provided from the upper end surface of the outer cylinder to the inner peripheral surface of the mouth portion, or at least one through hole provided at a lower portion of the mouth portion of the outer cylinder. Is good.

[0009]

In the molding of the bottle, the lower portion of the parison is formed by biaxial stretching blow molding, so that the mouth retains the original shape of the parison and does not deform. Of the air between the outer layer and the inner layer can be smoothly achieved.

[0010]

1 and 2 show a first embodiment of the present invention. Parison 1 is, as shown in the left half of FIG.
Outer cylinders 2 each formed into a cylindrical shape with a bottom by injection molding
And the inner cylinder 3 are fitted together.

The outer cylinder 2 is made of polyethylene or the like, and a thread 4 to which a cap with a pump or the like is screwed is formed on the outer peripheral surface of the upper end which is the mouth portion 11.

The inner cylinder 3 is made of a flexible synthetic resin such as nylon. An outer flange 5 is provided at the upper end of the inner cylinder 3 so as to overlap the upper end surface of the outer cylinder 2. A groove 7 serving as the air introduction portion 6 is formed from the outer peripheral surface of the opening 11a to the opening 11a (see FIG. 2).

Then, the parison 1 is set in a blow molding die, and the portion below the mouth portions 11 and 11a is biaxially stretched and blow-molded, as shown in the right half of FIG.
A bottle body 10 is formed which comprises an outer layer 12 made of a synthetic resin forming a fixed outer shell, and an inner layer 13 made of a flexible synthetic resin laminated releasably on the outer layer 12 to form an inner bag. You.

In this molding, since the mouth portions 11 and 11a are portions not blow-molded and retain the original shape of the parison 10, the groove 7 is formed between the outer layer 12 and the inner layer 13 of the bottle 10. It works effectively as an air introduction passage.

In the second embodiment shown in FIG. 3, the air introducing portion 6 is constituted by a groove 8 provided from the upper end surface of the outer cylinder 2 to the inner peripheral surface of the mouth portion 11.

In the third embodiment shown in FIG. 4, the air inlet 6 is a through hole 9 provided below the mouth 11 of the outer cylinder 2.

[0017]

Since the present invention has the above-described structure, the following effects can be obtained. Since an air introduction portion between the outer layer and the inner layer is formed beforehand at the mouth of the parison, which is a portion that is not biaxially stretch-blown at the time of molding the bottle, at the time of injection molding of the parison, the air introduction portion is used for post-processing. Without need
It can be formed easily and reliably.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a first embodiment of the present invention, in which a left half is a parison and a right half is a molded bottle.

FIG. 2 is a perspective view of a main part of the inner cylinder, showing the first embodiment.

FIG. 3 is a perspective view of a main part of an outer cylinder, showing a second embodiment.

FIG. 4 is a perspective view of a main part of an outer cylinder, showing a third embodiment.

[Explanation of symbols]

 1; parison 2; outer cylinder 3; inner cylinder 4; screw thread 5; outer flange 6; air inlet 7; groove 8; groove 9; through hole 10; bottle 11, 11a; mouth 12; outer layer 13;

Claims (4)

[Claims] 1. An outer layer (12) made of a synthetic resin that forms a fixed outer shell by blow molding, and a flexible synthetic resin layer that is peelably laminated on the outer layer (12) to form an inner bag. A method for molding a bottle (10) composed of an inner layer (13) and a synthetic resin molded by injection molding into a bottomed cylindrical shape provided with a screw (4) on the outer peripheral surface of a mouth (11). By resin outer cylinder (2) and injection molding,
An inner cylinder (3) made of a flexible synthetic resin, which is formed into a bottomed cylinder provided with an outer flange (5) at the upper end of the mouth (11a) and which can be peeled off from the outer cylinder (2). Of the parison (1)
At least one of the mouth (11) of the outer cylinder (2) and the mouth (11a) of the inner cylinder (3) has an air inlet (6) between the outer layer (12) and the inner layer (13). ) Is formed beforehand at the time of injection molding, and a portion below the mouths (11) and (11a) of the parison (1) is biaxially stretch blow-molded. 2. The air inlet part (6) is at least one groove (7) provided from the lower surface of the outer flange (5) of the inner cylinder (3) to the outer peripheral surface of the mouth part (11a). Item 10. A method for molding a bottle according to Item 1. 3. An air inlet (6) having at least one groove provided from the upper end surface of the outer cylinder (2) to the inner peripheral surface of the mouth (11).
The method for molding a bottle according to claim 1, wherein (8) is used. 4. An air inlet (6) is connected to an opening (11) of an outer cylinder (2).
At least one through-hole (9) provided in the lower part of the body.
A method for molding the bottle according to the above.