JPH1058482A - Manufacture of cup-like composite container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve moldability without necessity of a high injection pressure. SOLUTION: In the method for manufacturing a cup-like composite container comprising the steps of mounting a cup-like paper container made of a laminated material primarily consisting of a paper layer in an injection mold in advance, injecting hot-melt synthetic resin in the mold, and integrally forming a reinforcing frame having an opening peripheral edge, a columnar portion, and a bottom annular portion with the paper container, the molten resin is injected substantially from a center of a columnar portion 220 of a reinforcing frame 200 of a paper container 100 in a height direction of the columnar portion of a fusion bonded position with the portion 220.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite container in which a cup-shaped paper container is mounted in a mold in advance, and a reinforcing frame is integrally formed on the peripheral edge of the opening, the bonding end surface and the bottom annular portion of the paper container. The present invention relates to a method for producing a cup-shaped composite container.

[0002]

2. Description of the Related Art Conventionally, cup-shaped containers used for yogurt, pudding, margarine, alcoholic beverages, fruit juice drinks, and the like are made of a laminated sheet mainly composed of a paper layer, and a fan-shaped body member is wound into a cylindrical shape. With the body, an opening is formed above the body, and a circular bottom member is combined below the body,
Cup-shaped paper containers have been used in which the lower peripheral edge of the trunk and the peripheral edge of the bottom are tightly wound in a heated state to integrate the trunk with the bottom. However, depending on the application, the cup-shaped paper container is apt to have insufficient rigidity as a whole and to protect the bonding end face portion of the body portion.
There is a cup-shaped composite container disclosed in Japanese Patent No. 3411. As shown in FIG. 2, this cup-shaped composite container has an opening peripheral portion (21) at the opening periphery of the cup-shaped paper container (100).
0), a pillar portion (220) is formed on the bonding end surface portion of the body portion, and a bottom annular portion (230) is formed at a position along the seam between the body portion and the bottom portion on the inner surface of the container body. A reinforcing frame (200) composed of a pillar portion and a bottom annular portion is formed by molding with a synthetic resin and is simultaneously fused to the inner surface of a cup-shaped paper container to be integrated. Recently, such a cup-shaped composite container (10)
However, in a conventional mold for a cup-shaped composite container for producing the cup-shaped composite container, generally, as shown in FIG.
A gate (g) is provided on one side of the opening peripheral portion (210) of (0).
(Gate for injecting the molten resin).

[0003]

However, in the above-described conventional mold for a cup-shaped composite container, the molten metal injected from the gate into the cavity (the space between the female mold and the male mold in which the molded product is molded) is provided. Since the resin must flow at a high pressure from the peripheral edge of the opening to the pillar portion and further from the pillar portion to the bottom annular portion at a high pressure, a high injection pressure is required, and the production cost of the mold is increased. In some cases, defective products such as burrs were generated in the products.

The present invention solves the above-mentioned problem in the conventional mold for a cup-shaped composite container, and provides a method for producing a cup-shaped composite container having good moldability without requiring a high injection pressure. Things.

[0005]

SUMMARY OF THE INVENTION According to the present invention, a cup-shaped paper container made of a laminated material mainly composed of a paper layer is mounted in an injection mold in advance, and a synthetic resin melted by heat is placed in the mold. FIG. 1 (a) and FIG. 1 (b) show a mold for a cup-shaped composite container which is injected to integrally form a reinforcing frame composed of an opening peripheral portion, a column portion and a bottom annular portion in the cup-shaped paper container. As described above, the reinforcing frame (20) of the cup-shaped paper container (100)
A method for manufacturing a cup-shaped composite container, characterized in that molten resin is injection-molded from substantially the center in the height direction of the column at the fusion position with the column (220).

The method for producing a cup-shaped composite container of the present invention comprises:
At the approximate center of the height of the pillar portion of the reinforcing frame, the molten resin injected from the gate to the cavity flows from the pillar portion to the opening peripheral portion, at the same time, at a high speed from the pillar portion to the bottom annular portion, The flow distance of the molten resin from the gate to the farthest end is shorter than in the conventional cup-shaped composite container mold.
Therefore, the injection pressure can be reduced as compared with the conventional method for manufacturing a cup-shaped composite container, and the moldability of the product is also stabilized.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS When a molten resin is supplied from the outside in the method of manufacturing a cup-shaped composite container according to the present invention, a mold is previously formed of a laminated material mainly composed of a paper layer in an injection mold. Inserting a paper container, injecting the hot-melt synthetic resin into the mold, and using insert injection molding to integrally form a reinforcing frame consisting of an opening peripheral part, a pillar, and a bottom annular part in the cup-shaped paper container 1 (a) and 1 (b).
As shown in the figure, the reinforcing frame (2) of the cup-shaped paper container (100)
A window (111), which is narrower than the width of the pillar, is opened substantially at the center in the height direction of the fusion position with the pillar (220).
This is a mold in which a gate (g) is formed at this window position. The window provided in the cup-shaped paper container is formed at a position that does not protrude from the pillar of the reinforcing frame.

The above-mentioned cup-shaped paper container is made of a laminated material mainly composed of a paper layer and having a synthetic resin layer on the inner surface side or inner / outer surface of the container. The part is opened upward and an opening is formed at the upper end, a circular bottom member is combined below the trunk, and the lower periphery of the trunk and the periphery of the bottom are tightened in a heated state and the trunk and the bottom are joined together. Are integrated. The laminated material is formed by laminating various synthetic resin layers, metal layers, metal vapor deposited layers, and the like, mainly through a paper layer, via heat fusion or an adhesive, in accordance with the intended use of the container.

A method of integrally forming a reinforcing frame at a predetermined position of a cup-shaped paper container is based on an insert injection molding method, and a cup-shaped paper container having a gate window in a body portion is previously formed in a mold. After being inserted and arranged inside, the hot-melt synthetic resin is injected into the cavity from the gate to form a reinforcing frame consisting of an opening peripheral portion, a pillar portion and a bottom annular portion, and at the same time, a predetermined shape of the inner surface of the cup-shaped paper container. It is formed by heat fusion at a position. Therefore, the synthetic resin forming the reinforcing frame, and the synthetic resin layer on the inner surface side or the inner and outer surfaces of the container of the laminated material of the cup-shaped paper container, it is necessary to use a material that can be mutually heat-sealed, It is preferable to use the same resin or the same resin. And, as the injection molding resin for forming the reinforcing frame, usually, high density polyethylene, polypropylene or the like is used. When the molten resin is injected from the inside of the reinforcing frame, it is not necessary to provide a window in the cup-shaped paper container as described above, and the resin is supplied from almost the center of the reinforcing frame, and the other parts are manufactured in the above-described steps. Good.

[0010]

According to the method for producing a cup-shaped composite container of the present invention, the gate position is devised, the flow distance of the molten resin is shorter than that of the conventional mold, and as a result, the injection pressure can be reduced. As a result, it is possible to reduce the manufacturing cost of the mold, stabilize the moldability, and reduce the defective rate of the product.

[Brief description of the drawings]

FIG. 1 (a) is a front view of a cup-shaped composite container produced by a mold used in the production method of the present invention, and FIG. 1 (b) is a cross-sectional view showing a gate position of the cup-shaped composite container. .

FIG. 2 is a perspective view of an example of a cup-shaped composite container.

FIG. 3 is a cross-sectional view of an example of a cup-shaped composite container showing a conventional gate position.

[Explanation of symbols]

 10 cup-shaped composite container 100 cup-shaped paper container 110 body part 111 gate window part 120 bottom part 200 reinforcing frame 210 opening peripheral part 220 column part 230 bottom Annular part g …… Gate

Continued on the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B29L 9:00 22:00

Claims (1)

[Claims] 1. A cup-shaped paper container made of a laminated material mainly composed of a paper layer is mounted in an injection mold in advance, and a hot-melt synthetic resin is injected into the mold to form the cup-shaped paper container. In a method for manufacturing a cup-shaped composite container, in which a reinforcing frame composed of an opening peripheral portion, a column portion, and a bottom annular portion is integrally formed in a container, the column at the fusion position with the column portion of the reinforcing frame of the cup-shaped paper container A method for manufacturing a cup-shaped composite container, comprising injecting molten resin from substantially the center in the height direction of the portion.