JPH031918A - Container having barrier properties and production thereof - Google Patents

Abstract

PURPOSE:To obtain a container more excellent in barrier properties by a method wherein a projection protruding outwardly in a radius direction is provided to the leading end opening molding part of the rising part of a preparatory molded body and a resin is cast in such a direction that the barrier film wound around a male mold is pressed to the barrier film on the outer peripheral surface of the preparatory molded body when the resin is injected in a cavity. CONSTITUTION:Cut pieces 24, 24 corresponding to the shape of a preparatory molded body 1 is punched from a barrier film sheet 2 to be sucked to the leading end surface of a male mold 25 and the male mold 25 is combined with a female mold 28 to inject a resin from an injection hole 26 and, at the same time, air is injected from aperatures 27 to press the cut pieces 24 to the inner wall 28a of the female mold 28 to cover the rising part 2 of the preparatory molded body 1. This preparatory molded body 1 is sucked to the lower end surface 60a of the male mold 60 under vacuum using a vacuum drawing port 60b and the lower end part 61a of a cut piece 61 is brought into contact with the end part 2a of the barrier film covering the rising part 3 of the preparatory molded body 1. In this state, the male mold 60 is combined with a female mold 62 to form a cavity 63 and a resin is injected from a plurality of the injection holes 63b, 63b provided to the bottom surface 63a of the cavity 63 so as to extend in the circumferential direction at an appropriate interval.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a container having barrier properties and a method for producing a container having barrier properties.

[Conventional technology]

In recent years, containers made of injection resin that are inexpensive, lightweight, and have high barrier properties against oxygen, water vapor, etc. have appeared, replacing metal cans such as tin cans and aluminum cans.

As a manufacturing method for such a container, the present applicant has disclosed in another application a barrier 1! having gas barrier properties, as shown in FIG. ! [Preformed body 11 partially containing 110
1 is prepared in advance, and the preformed body 111 is placed in the cavity 114 formed by the male die 112 and the female die 113, and the barrier film 115 is wrapped around the male die 112 so that the wrapped end 115a A method of injection molding is disclosed in which the resin is overlapped with the barrier film 110 on the outer peripheral surface of the preform and injected into the cavity 114 from the female mold part 113 so as to be integrated with the preform 111. .

[Problem to be solved by the invention]

However, according to the above method, the resin is poured into the cavity 11.
4, the resin flows between the wrapped end 115a of the barrier film 115 wrapped around the male die 112 and the barrier film 110 on the outer peripheral surface of the preform 111,
The barrier film 115 wrapped around the male die 112 is attached to the wrapped end 11 of the barrier film 115 on the outer peripheral surface of the female die 112.
It may peel off from 5a. For this reason, the wrapped end 1 of the barrier film 115 wrapped around the male mold 112
15a and the barrier film 110 on the outer circumferential surface of the preform 111 becomes insufficient, resulting in a disadvantage that defective products with poor barrier properties are likely to be produced.

In view of the above-mentioned points, an object of the present invention is to provide a barrier container having high barrier properties and a method for manufacturing the same.

[Means to solve the problem]

Therefore, the barrier container according to the present invention is made of a resin material having a relatively shallow rising part, having a protruding part protruding outward in the radial direction on the tip opening molded part of the rising part, and having the outer wall covered with a barrier film. The barrier film of this preform and the end of the barrier film of the other part of the container were overlapped and integrally molded with the preform using injection resin.

In addition, in the method for manufacturing a barrier container according to the present invention, a resin preform having a relatively shallow rising portion and a protruding portion protruding radially outward at the tip opening forming portion of the rising portion is prepared in advance. Prepare the preform, cover this preform with a barrier film, place the preform covered with the barrier film in the cavity formed between the male mold and the female mold, and wrap the barrier film around the male mold. , the winding end overlaps the barrier film on the outer peripheral surface of the preform, and the resin is injected into the cavity from the female part of the preform on the protrusion formation side to integrate with the preform. I configured it as follows.

[Effect]

By providing a protrusion that protrudes radially outward in the tip opening molding part of the rising part of the preform, when the resin is injected into the cavity, the barrier film wrapped around the male mold can be applied to the outer peripheral surface of the preform. Since it flows in the direction in which it is pressed against the barrier film of the mold, it is possible to ensure adhesion between the overlapping part of the barrier film around the male mold and the barrier film on the outer peripheral surface of the preform, making it possible to provide a container with even better barrier properties. becomes.

[Embodiment J] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a preformed body 1 that is injection molded in advance, and this preformed body 1 constitutes, for example, the bottom of a container, and in the case of a container with unevenness, forms the uneven portion. It is. The exterior surface of this preformed body 1 is covered with a barrier film 2, and the end H2a of this barrier film is connected to the preformed body 1.
It covers the rising part 3 of . This barrier film 2 is made of aluminum foil 21 with a thickness of 40 μm as shown in FIG.
For example, a multilayer film covered on both sides with an unstretched propylene layer 22 with a thickness of 40 μm and an unstretched propylene layer 23 with a thickness of 80 μm, a multilayer film with iron foil treated in the same way, or a vinylidene chloride layer, a polyamide layer, and an ethylene-vinyl acetate layer. Resin films such as a saponified polymer resin layer, a vapor-deposited polyester film, a vapor-deposited polyamide film, a composite film of these films, and a multilayer film of a composite film of the above-mentioned metal film and resin film are used.

Furthermore, a flange-shaped protrusion 3b is formed near the opening of the rising portion 3 and protrudes outward in the radial direction.

This preformed body 1 is formed, for example, as shown in FIGS. 3 to 5.

First, sheets 1 and 2 of the barrier film having the structure shown in FIG.
A cut piece 24, 24 having a shape corresponding to the shape of the preform 1 is punched out using a cutter. This cut piece 24 is
As shown in the figure, it is attached to the tip end surface of the male die 25. The male die 25 is provided with an injection hole 26 for injecting the resin and vacuum and air ejection holes 27 and 27 located radially outward from the injection hole 26, and this hole 27 can be opened to vacuum by switching a valve. connected to a source of compressed air or connected to a source of compressed air. When the cut piece 24 is suctioned and fixed to the tip wall of the male mold 25, vacuum is drawn through the hole 27. At this time, the outer peripheral end 24a of the cut piece 24 is
It protrudes outward from the tip of the.

Next, a cavity 29 is formed by combining the male mold 25 and the female mold 28, and a cavity 29 is formed by combining polypropylene (PP), polyethylene (PE), polyester, polycarbonate (PC).
, polystyrene (PS) or other resin is injected from the injection hole 26 of the male die 25. At the same time, the valve is switched and air is ejected from the hole 27 to create a cut piece 2 due to the injection pressure of the resin.
Help 4 move. That is, the air allows the cut pieces 24 to move evenly due to the injection pressure.

As a result, the cut piece 24 is pressed against the inner wall 28a of the female mold 28, and the outer peripheral end 20a of the cut piece 20 also rises on the inner wall 22a of the female mold 22 and covers the rising portion 2 of the molded body 1. (Figure 4). Although this method has a limit on the thickness of the molded product, it is possible to mold products with a wall thickness of 5 mm or more. Note that the female die 28 is provided with a notch 28b for forming the protrusion 3a of the rising portion 3 of the preform 1.

Such a preform 1 is formed into a male mold 6 as shown in FIG.
0 by being vacuumed by the vacuum suction hole 60b. Thereafter, a rectangular cut piece 61 obtained by cutting the barrier film 2 is tightly wrapped around the cylindrical male die 60. That is, as shown in FIG. 7, both ends of the cut piece 61 are brought together and the mating surfaces are bent. At this time, the lower end 61a of the cut piece 61 is brought into contact with the end 2a of the barrier film covering the rising part 3 of the preform 1 that is being attracted.

In this state, as shown in FIG. 8(a), the male mold 60 is assembled into the female mold 62 to form a cavity 63. Said female mold 6
2 is provided with a plurality of injection holes 63b, 63b extending at appropriate intervals in the circumferential direction on the bottom surface 63a of the cavity 63, and from these injection holes 63b, polypropylene (pp),
Resins such as polyethylene (PE), polyester, polycarbonate (PC), and polystyrene (PS) are injected. In this case, as shown in FIG. 8(b), the protrusion 3b of the rising portion 3 of the preform 1 and the cavity 63
The bottom part of the barrier container to be molded may be molded with an injected resin so that a certain distance is left between the bottom surface 63a and the bottom surface 63a of the molded barrier container.

At this time, by providing a protrusion 3a protruding radially outward at the end of the rising part 3 of the preform 1, when the resin is injected into the cavity, the barrier film 61 wrapped around the male mold can be used as a preform. Barrier film 2 on the outer peripheral surface of the molded body
Since it flows in the direction in which it is pressed against a, the overlapping portion of the barrier film 61 around the male die and the barrier film 2a on the outer peripheral surface of the preform is securely bonded, making it possible to provide a container with even better barrier properties. becomes.

In this case, the end portion 2a of the preform 1 extending to the vicinity of the rising portion of the barrier film 2 and the cut piece 61 made of the barrier film
The lower end portion 61a of the container melts and adheres to the lower end portion 61a of the container, thereby ensuring the barrier properties of the bottom of the container. Then, instead of the cut piece 61, a tape-shaped barrier film may be spirally wound to form the body barrier film of the container.

The preformed body 1 was adsorbed to the tip end surface of the male die 60, but the preformed body 1 was fixed to the bottom of the female die 60 and the male die 6
0 may be inserted.

Finally, the molded product is removed from the mold, and the molding of the barrier container 100 shown in FIG. 1-0 is completed.

〔Effect of the invention〕

Since the present invention is configured as described above, when the resin is injected into the cavity, the barrier film wrapped around the male mold flows in the direction of being pressed against the barrier film on the outer peripheral surface of the preform, so that the male mold is injected into the cavity. Adhesion between the overlapping portions of the barrier film around the mold and the barrier film on the outer peripheral surface of the preform is ensured, making it possible to provide a container with even better barrier properties.

[Brief explanation of drawings]

Fig. 1 is a sectional view of the preform, Fig. 2 is a sectional view of the structure of the barrier film, Fig. 3 is a perspective view showing the state in which cut pieces are cut from the barrier film, and Fig. 4 is the preform before injection. A sectional view of the manufacturing device, FIG. 5 is a sectional view of the preform manufacturing device after injection,
FIG. 6 is a cross-sectional view of the state in which the preform is adsorbed to the male mold and the cut piece is wound around the male mold body, FIG. 7 is a cross-sectional view of the state in which the cut piece is wound around the male mold body, FIG. 8(a) is a sectional view of the injection molding apparatus, FIG. 8(b) is a sectional view showing another embodiment of the injection molding apparatus, and FIG. 9 is the preform manufacturing apparatus of FIG. 8(a). FIG. 10 is a sectional view of a barrier container according to the present invention, and FIG. 11 is a sectional view of a conventional injection molding apparatus. DESCRIPTION OF SYMBOLS 1... Preformed body, 2... Barrier film, 3... Standing part, 3b... Protrusion part, 60... Male mold, 62...
-Female type, e...Cavity 0...Barrier container.

Claims (1)

[Claims] 1. A spare made of resin, which has a relatively shallow rising part, has a protruding part protruding radially outward in the tip opening molded part of the rising part, and whose outer wall is covered with a barrier film. A part of the container includes a molded body, and the barrier film of this preform and the end of the barrier film of the other part of the container are overlapped and integrally molded with the preform by injection resin. Barrier container. 2. Prepare in advance a resin preformed body having a relatively shallow rising portion and a protruding portion protruding radially outward at the tip opening forming portion of the rising portion, and coat this preformed body with a barrier film. The preform covered with this barrier film is placed in the cavity formed between the male mold and the female mold, and the barrier film is wrapped around the male mold, so that the wrapped end is attached to the preform. The barrier property is characterized in that the resin is overlapped with the barrier film on the outer peripheral surface, and is injected into the cavity from the female part of the protrusion forming side of the preform to be integrated with the preform. Method of manufacturing containers.