JPH05154868A - Vessel molding device - Google Patents

Abstract

PURPOSE:To enable high-precision molding by a method wherein after a vessel- like blank is molded between a cavity and core by an insert injection molding method, synthetic resin is injected onto the surface of the vessel-like blank between the cavity and core, and a vessel main body is molded. CONSTITUTION:After a preheated laminated sheet 23 is carried between a cavity 21 and core 25, the cavity 21 is raised and the laminated sheet 23 is pressed into the cavity 21 by the core 25. Then after the laminated sheet 23 is held by placing between a cavity side pressing part 22 and core side pressing part 26, the laminated sheet 23 is vacuum-drawn and the laminated sheet 23 is stuck close to the inside 21a of the cavity. The cavity 21 is raised after that, the fringe part of the laminated sheet 23 is cut off by a cutting part 27 and a vessel- like blank 17 is obtained. Then the core 25 and core side pressing part 26 are raised a little, synthetic resin 18 is injected into an injection space 19 between the cavity 21 and core 25 and a vessel main body 14 is completed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container molding device for molding a plastic container body.

[0002]

2. Description of the Related Art In recent years, as an alternative to a conventional metal can, a container with a metal lid has been considered in which a metal lid is attached to a container body of a plastic container. When a metal lid is attached to a plastic container body, the peripheral edge of the metal lid is double wound around the flange of the container body.

Regarding this plastic container body,
There is a demand for the flange to have sufficient accuracy to withstand double winding and to have a gas barrier property in consideration of the storage stability of the contents.

Generally, in a plastic container body, a laminated sheet having a gas barrier property is thermoformed in advance by thermoforming or the like to prepare a container-shaped blank, and then this container-shaped blank is inserted into an injection mold to form a container. It is formed by injecting a synthetic resin along the surface of the blank. This molding method is
It is called the insert injection method.

[0005]

In the conventional insert injection method, a container blank is prepared in advance in another molding die as described above, and then this container blank is inserted into the injection die. Therefore, the dimension between the container-shaped blank 35 and the injection mold 30 may deviate as shown in FIG. As shown in FIG. 3, when such dimensional deviation occurs, the injection female mold 31 of the injection mold 30
The container blank 35 may not be welded to the inner surface (A
part). Further, the container blank 35 may bend with respect to the inner surface of the injection female die 31 (B portion).

[0006] Such dimensional deviation between the container-shaped blank 35 and the injection mold 30 mainly occurs because the molding mold for molding the container-shaped blank 35 and the injection mold 30 are separate bodies. As a result, as shown in FIG. 3, when the container body is molded by injecting the synthetic resin into the injection space 36 between the injection female die 31 and the injection male die 32, the precision of the container body may be deteriorated. ..

In addition, when the container-shaped blank 35 formed by the molding die is inserted into the injection mold 30, the container-shaped blank 35 can be easily handled (to improve the handling property). It is necessary to increase the thickness of 35. However, increasing the thickness of the container-shaped blank 35 leads to an increase in cost.

The present invention has been made in view of the above points, and an object of the present invention is to provide a container forming apparatus capable of surely forming an accurate container body without increasing the cost. ..

[0009]

SUMMARY OF THE INVENTION According to the present invention, a cavity side pressing portion is provided at a peripheral edge of an upper end opening, and a cavity for adsorbing a plastic laminated sheet on an inner surface of the cavity and the cavity side pressing portion are provided with the lamination sheet. A core-side pressing portion for pressing is provided, and a core forming an injection space with the cavity is provided, and the laminate is provided on either the outer periphery of the core-side pressing portion or the outer periphery of the cavity-side pressing portion. A container molding apparatus, wherein a cutting portion for cutting a sheet is slidably provided, and an injection port for injecting a synthetic resin into the injection space is provided in either the core or the cavity. ..

[0010]

[Function] The preheated laminated sheet is conveyed between the cavity and the core, and then the cavity moves to the core side,
The core pushes the laminated sheet into the cavity. Then, the laminated sheet is adsorbed on the inner surface of the cavity while the laminated sheet is being pressed between the cavity side pressing portion and the core side pressing portion, and the cavity is further moved to the core side so that the space between the cavity side pressing portion and the cutting portion is increased. Then, the laminated sheet is cut to form a container-like blank. Next, the synthetic resin is injected from the injection port of the core into the injection space between the cavity and the core.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

First, an outline of a container with a metal lid will be described with reference to FIG. As shown in FIG. 2, the container 10 with a metal lid is
Perimeter 1 of metal lid 11 made of aluminum or tin
2 is wound around the flange portion 15 of the plastic container body 14 to be configured.

Next, referring to FIG. 1, an embodiment of a container molding apparatus for molding the plastic container body 14 will be described.

As shown in FIG. 1, the container forming apparatus 20 is
A cavity 21 having a cavity-side pressing portion 22 on the periphery of the opening and a core 25 for pushing the plastic laminated sheet 23 into the cavity 21 are provided.

On the outer periphery of the core 25, a core side pressing portion 26 for pressing the laminated sheet 23 with the cavity side pressing portion 22 is provided. Further, a cutting portion 27 is provided on the outer periphery of the core side pressing portion 26 so as to be vertically slidable. The cutting portion 27 is fitted on the outer periphery of the cavity side pressing portion 22 and cuts the laminated sheet 23 between the cavity side pressing portion 22 and the cavity side pressing portion 22.

The core-side pressing portion 26 is fixed to the core 25, and the core-side pressing portion 26 has an opening 28 penetrating the core-side pressing portion 26 and extending into the core 25. Further, the cutting portion 27 is formed with an insertion opening 27a into which the lock 29 is inserted. The lock 29 inserted into the insertion opening 27a is then inserted into the opening 28 and has a function of fixing the cutting portion 27 and the core 25.

On the other hand, on the inner surface 21a of the cavity 21,
A large number of suction ports (not shown) for sucking the laminated sheet 23 are provided. Further, when the cutting portion 27 is fitted into the outer periphery of the cavity side pressing portion 22, the cavity 21 and the core 2 are
An injection space 19 is formed between the space and the space 5 (FIG. 1 (d)). Furthermore, an injection port 25 a for injecting the synthetic resin 18 into the injection space 19 is formed in the center of the core 25.

Next, the operation of this embodiment having such a configuration will be described. First, as shown in FIG. 1A, the preheated laminated sheet 23 is conveyed between the cavity 21 and the core 25.

As the laminated sheet 23, for example, polypropylene (PP) 150 μ / adhesive layer 20 μ / ethylene / vinyl alcohol copolymer (EVOH) 20 μ / adhesive layer 2
A coextrusion laminated sheet having a layer structure of 0 μ / polypropylene (PP) 150 μ is used.

Instead of this, PP 150 μ / EVO
It is also possible to use a laminated sheet in which layers having a layer structure of H20μ / PP150μ are attached to each other by a dry lamination method.

Further, among the above-mentioned layer constitutions, EVOH functions as a gas barrier layer, but it may be replaced with polyvinylidene chloride (PVDC) instead of EVOH.

Next, as shown in FIG. 1B, the cavity 21 rises with respect to the core 25, and the laminated sheet 23 is pushed into the cavity 21 by the core 25. afterwards,
Between the cavity side pressing portion 22 and the core side pressing portion 26,
The laminated sheet 23 is pressed and pinched, and the cavity 21
Stops rising. Next, the laminated sheet 23 is evacuated by the suction port provided on the inner surface 21 a of the cavity 21 and is brought into close contact with the inner surface 21 a of the cavity 21.

After that, as shown in FIG. 1C, the cavity 21 further rises, for example, about twice the thickness of the laminated sheet 23. In this case, the cutting part 27 on the core 25 side is stopped, and the core 25 and the core side pressing part 26 are pushed by the rise of the cavity 21 and move upward. When the cavity 21 rises and the cutting portion 27 fits into the outer periphery of the cavity side pressing portion 22, the laminated sheet 23 is cut between the outer periphery of the cavity side pressing portion 22 and the inner periphery of the cutting portion 27 to form a container shape. A blank 17 is obtained.

Next, as shown in FIG. 1D, the core 25
And the core side pressing part 26 rises slightly. When the openings 28 of the core 25 and the core-side pressing portion 26 are aligned with the insertion openings 27a of the cutting portion 27, the core 25 and the core-side pressing portion 2
The ascending of 6 stops, and the lock 29 is inserted into the insertion opening 27a and the opening 28.

In this manner, with the cutting portion 27 fixed to the core 25 and the core side pressing portion 26, the injection port 25 of the core 25 is placed in the injection space 19 between the cavity 21 and the core 25.
The synthetic resin 18 is injected from a (FIG. 1E). PP can be considered as the synthetic resin 18. The reason why the cut portion 27 is fixed (mold clamped) by the lock 29 is to prevent the cavity 21 and the core 25 from being opened by the injection pressure (10 t / cavity) of the synthetic resin 18.

In this way, the container-shaped sheet blank 1
A plastic container body 14 having a synthetic resin 18 injected on the surface of 7 is obtained.

According to this embodiment, the laminated sheet 23 is thermoformed between the cavity 21 and the core 25, and the laminated sheet 23 is cut between the cavity side pressing portion 22 and the cutting portion 27 to form a container-shaped blank. After molding 17, the cavity 21
Since the synthetic resin 18 is injected into the injection space 19 between the core 25 and the core 25 to mold the container body 14, there is no dimensional deviation between the injection space 19 and the container blank 17. Therefore, the container body 14 can be accurately molded. Further, since it is not necessary to bring the container-shaped blank 17 into the injection space 19 from another mold, it is not necessary to make the container-shaped blank 17 thick in consideration of handleability.

Next, specific examples of the present invention will be described.

As the laminated sheet 23, PP 150 μ / adhesive layer 20 μ / EVOH 20 μ / adhesive layer 20 μ / PP15
A coextrusion laminated sheet having a layer constitution of 0 μ was used. Of these, P
PY220 manufactured by Mitsubishi Petrochemical was used as P, Admer QF500 manufactured by Mitsui Petrochemical was used as the adhesive layer, and Eval T-102B manufactured by Kuraray was used as EVOH.

The laminated sheet 23 having such a layer structure is used as the 12
After preheating to 0 to 170 ° C., the container blank 17 is thermoformed by the container forming device 20 according to the present invention, and PP is injected onto the surface of the container blank 17 to calibrate φ80 and depth 4.
A 5 mm container body 14 was obtained. As the injection PP, K1008 manufactured by Chisso Petrochemical was used.

An oxygen barrier performance test was conducted on the container body thus obtained. As a comparative example, injection PP (K10 made by Chisso Petrochemical Co.
Performance tests were also conducted on the container body consisting of only 08). The results of the performance test are shown in the table below.

Table Target container body Oxygen barrier property (CC / ke · 24 hrs · atm) Container body of the present invention 0.03 Container body of comparative example 4.3 As is apparent from Table, the container body of the present invention is large It can be seen that it has an oxygen barrier property.

Next, another embodiment of the container forming apparatus according to the present invention will be described with reference to FIG.

The same parts as those of the embodiment shown in FIG. 1 are designated by the same reference numerals and detailed description thereof will be omitted. In FIG. 4, the core 2
Reference numeral 5 has a core side pressing portion 26 that presses the laminated sheet 23 between the cavity side pressing portion 22 of the cavity 21 and the cavity side pressing portion 22. Further, a cutting portion 41 is provided on the outer periphery of the cavity 21 so as to be vertically slidable. This cutting part 41 is
It fits into the outer periphery of the core 25 and cuts the laminated sheet 23 with the outer periphery of the core side pressing portion 26.

An opening 43 is formed in the cavity 21, and a lock 49 is inserted in the cutting portion 41.
2 is formed. The lock 49 inserted into the insertion port 42 is then inserted into the opening 43 and serves to fix the cutting portion 41 and the cavity 21. Further, on the lower surface 25 a of the core 25, the laminated sheet 2
A large number of suction ports (not shown) for sucking 3 are provided. An injection port 40 is formed in the center of the cavity 21.

Next, the operation of this embodiment having such a configuration will be described. First, as shown in FIG. 4A, the preheated laminated sheet 23 is conveyed between the cavity 21 and the core 25.

Next, as shown in FIG. 4B, the cavity 21 rises with respect to the core 25, and the core 25 pushes the laminated sheet 23 into the cavity 21. afterwards,
Between the cavity side pressing portion 22 and the core side pressing portion 26,
The laminated sheet 23 is pressed and pinched, and the cavity 21
Stops rising. Next, the laminated sheet 23 is evacuated by the suction port provided on the lower surface 25 a of the core 25, and adheres to the lower surface 25 a of the core 25.

Thereafter, as shown in FIG. 4 (c), when the cutting portion 41 rises and fits into the outer periphery of the core side pressing portion 26,
The laminated sheet 23 is cut between the outer circumference of the core-side pressing portion 26 and the inner circumference of the cutting portion 41 to obtain the container-shaped blank 17.

Next, as shown in FIG. 4 (d), the cavity 21 is slightly lowered. Opening 43 of cavity 21
And the insertion opening 42 of the cutting portion 41 coincide with each other, the descent of the cavity 21 is stopped, and the insertion opening 42a and the opening 43
The lock 49 is inserted therein.

With the cutting portion 41 fixed to the cavity 21 as described above, the synthetic resin 18 is injected from the injection port 40 of the cavity 21 into the injection space 19 between the cavity 21 and the core 25. The plastic container body 14 in which the synthetic resin 18 is injected onto the surface of the container-shaped sheet blank 17 is obtained.

In addition to the above, in the embodiment shown in FIG. 1, instead of the injection port 25a provided on the core 25 side, an injection port is provided on the cavity 21 side and a suction port is provided on the core 25 side to form a container. The sheet blank 17 may be closely attached to the core 25 side.

Further, in the embodiment shown in FIG. 4, the core 25 is used instead of the injection port 40 provided on the cavity 21 side.
The container-shaped sheet blank 17 may be closely attached to the cavity 21 side by providing an injection port on the side and an adsorption port on the side of the cavity 21.

[0043]

As described above, according to the present invention,
Since the container blank was molded between the cavity and the core, and then the synthetic resin was injected onto the surface of the container blank in the injection space between the cavity and the core to mold the container body, the injection space and the container blank There is no dimensional deviation between and. Therefore, the container body can be accurately molded.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of a container forming apparatus according to the present invention.

FIG. 2 is a side sectional view of a container with a metal lid, which includes a container body and a metal lid.

FIG. 3 is a side sectional view showing a conventional container molding device.

FIG. 4 is a side sectional view showing another embodiment of the container forming apparatus according to the present invention.

[Explanation of symbols]

 20 Container Molding Device 21 Cavity 22 Cavity Side Pressing Section 23 Laminated Sheet 25 Core 25a Injection Port 26 Core Side Pressing Section 27 Cutting Section

Claims (1)

[Claims] 1. A cavity-side pressing portion is provided at a peripheral edge of an upper end opening, and a cavity for adsorbing a plastic laminated sheet is provided on an inner surface thereof, and a core-side pressing portion for pressing the laminated sheet between the cavity-side pressing portion. And a core forming an injection space with the cavity, and a cutting part for cutting the laminated sheet is slid on either the outer periphery of the core side pressing part or the outer periphery of the cavity side pressing part. A container molding device, which is movably provided and is provided with an injection port for injecting a synthetic resin into the injection space in one of the core and the cavity.