JPH06246778A - Method and apparatus for producing composite container - Google Patents

Abstract

PURPOSE:To prevent the generation of a gate mark on the surface of a composite container by arranging a blank plate in the cavity formed between a fixed template and a core and injecting a thermoplastic resin into the cavity from an injection gate through the runner formed on the core. CONSTITUTION:Split molds 21a, 21b for forming a screw thread are provided above the fixed template 12 possible to separate and contact with respect to a fixed attaching plate 11 equipped with an injection gate 41. Further, a core 31 is provided to a movable attaching plate 34 through a receiving plate 35 and a plurality of runners 32 are provided to the upper part of the core 31 by drilling. A cavity 51 is formed by the fixed template 12, the split molds 21a, 21b and the core 31 and a molten resin can be injected into the cavity from the injection gate 41 through the runner 32. Therefore, the gate mark generated in a molded composite container becomes the inside of the container and the composite container having no gate mark on the surface thereof is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a composite container integrally formed with a blank plate and a thermoplastic resin, and more particularly to a method and an apparatus for manufacturing a composite container having no gate mark on the container surface. .

[0002]

2. Description of the Related Art Conventionally, a so-called pillar container in which a blank plate and a thermoplastic resin are integrally molded is used.

Generally, in a pillared container, a blank plate made of a laminated sheet material in which paper and a resin are laminated is arranged in a cylindrical shape in an injection molding die, and the end portion of the blank plate is abutted with each other. In addition, the blank container is a composite container integrally molded in a state where the blank plate is held in a container shape by a holding frame made of resin by injecting a thermoplastic resin into the open end and the like. Then, the resin layer on the innermost surface of the blank plate is integrated with the injected thermoplastic resin by heat fusion, and the strength of the molded container is high.

Such a pillared container has both advantages as an injection molded product and as a paper container,
For example, it is widely used as a container for storing various products such as soft drinks, sake, powder detergents, fragrances, and liquid foods.

[0005]

By the way, in recent years, there is an increasing demand for a container having an opening with a screw at its upper end and a cap with a pump attached to the opening, such as a shampoo or liquid soap container. ing. When molding such a container with a pillared container as described above, via a runner provided on the fixed-side template of the injection mold,
Thermoplastic resin is injected into the cavity.

However, in this case, there has been a problem that a gate mark is formed on the outer surface of the container to impair the appearance. on the other hand,
By injecting a thermoplastic resin into the cavity from a location corresponding to the threaded opening located at the upper end of the container, even if there is a gate mark on the upper end surface of the opening or the screw molding part, it is concealed by the pump cap Therefore, the appearance of the container is not spoiled. However, there are problems that it becomes difficult to seal with a cap with a pump due to the traces of the gate, and that the process of removing the traces of the gate is required after the container is molded, which complicates the process.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a manufacturing method and a manufacturing apparatus in which no gate mark is formed on the surface of a composite container.

[0008]

In order to achieve such an object, the manufacturing method of the present invention is such that a blank plate is provided in a cavity formed between a stationary mold plate and a core, and an injection gate is provided. The thermoplastic resin is injected into the cavity through the runner formed on the core.

Further, in the manufacturing apparatus of the present invention, a blank plate is arranged in a cavity formed between the stationary mold plate and the core, and a thermoplastic resin is injected from the injection gate into the cavity to form a composite container. In the apparatus for manufacturing, the core has a runner communicating from the injection gate to a predetermined position of the cavity.

[0010]

The thermoplastic resin injected from the injection gate into the cavity formed between the stationary mold plate and the core passes through the runner drilled in the core so as to reach the predetermined position of the cavity from the injection gate. Since it reaches the inside of the cavity, the gate mark generated in the manufactured composite container is limited to the inside of the container.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing an example of an apparatus for manufacturing a composite container of the present invention, and FIG. 2 is a partially enlarged perspective view of an upper portion of a core of the apparatus for manufacturing the present invention. 1 and 2, the manufacturing apparatus 1 of the present invention includes a fixed-side mounting plate 11 having an injection gate 41, a fixed-side template 12 that can be attached to and detached from the fixed-side mounting plate 11, and a fixed-side template 12 above the fixed-side template 12. Split dies 21a, 21b provided on the (fixed side mounting plate 11 side) and provided with groove portions for thread formation, a core 31 disposed on a movable side mounting plate 34 via a receiving plate 35, and a guide pin 4
2 is provided with a stripper plate 36.
A plurality of runners 32 are formed on the core 31 as described later. Further, the fixed side mounting plate 11 is provided with an angular pin 13 projecting obliquely downward so as to be separated from the core 31, and a guide member 14 is arranged on the outer side thereof. Angular Pin 13
Penetrates the split mold 21a and reaches the inside of the concave portion 15 formed in the fixed-side mold plate 12. The guide member 14 has a surface 14 having an inclination corresponding to the inclination angle of the angular pin 13.
a is provided on the split mold 21a side. The surface of the split mold 21a opposite to the split mold 21b constitutes a surface having an inclination corresponding to the inclination angle of the angular pin 13, and this surface is in contact with the surface 14a of the guide member. Further, a biasing member 16 is installed inside a storage hole 17 formed between the fixed-side mounting plate 11 and the fixed-side template 12. With such a configuration, the biasing member 16 allows the fixed-side mounting plate 11, the fixed-side mold plate 12, and the split mold 21.
When a and 21b are separated from each other, the split mold 21a is slidable on the peripheral surface of the angular pin 13 and the surface 14a of the guide member and is movable in a direction away from the core 31 (rightward in the illustrated example). .

On the other hand, the injection gate 4 is provided on the core 31.
1 and a plurality of runners 32 that connect the cavity 51 described later. Therefore, the injection gate 4
The thermoplastic resin injected from No. 1 passes through the runner 32 and is injected into the cavity 51 from the pores 32a at the tip thereof. That is, in the manufacturing apparatus 1 of the present invention, the core 31
Since the thermoplastic resin is supplied into the cavity 51 from the side, the trace of the gate generated in the molded container is limited to the inside of the container.

An ejector pin 33 is vertically movable in the center of the core 31, and a flange portion 33a is provided below the ejector pin 33. And
The flange portion 33a is slidably positioned in a cylinder portion 35a formed in the receiving plate 35, and the cylinder portion 35a is connected to the outside through a communication hole 35b. In addition, the cylinder portion 35a includes a movable side mounting plate 34
It is also connected to the communication hole 34a formed inside.
Then, the cylinder portion 35a is formed by the flange portion 33a.
Is airtightly divided into a communication hole 35b side and a communication hole 34a side. Therefore, by feeding air or the like into the cylinder portion 35a from the outside through the communication hole 34a, the flange portion 33a rises in the cylinder 35a, whereby the protrusion pin 33 protrudes upward from the upper flat surface of the core 31. .

In the illustrated example, the fixed-side mounting plate 11, the fixed-side mold plate 12 and the split molds 21a and 21b are in contact with each other, and the core 31 is inserted into the fixed-side mold plate 12. . In this state, the fixed mold plate 12 and the split mold 2
The cavity 5 is provided in the gap between the core 31 and the cores 1a and 21b.
1, the molten thermoplastic resin can be injected into the cavity 51 from the injection gate 41 via the runner 32.

Next, a method of manufacturing the composite container of the present invention using the manufacturing apparatus 1 of the present invention as described above will be described. Prior to that, an example of a composite container that can be formed using the manufacturing apparatus 1 of the present invention will be described first with reference to FIGS.

FIG. 3 is a perspective view showing an example of the composite container, and FIG. 4 is a sectional view taken along line IV-IV of the composite container shown in FIG. 3 and 4, the composite container 10
Reference numeral 0 denotes a main body 101 including a thermoplastic resin molding portion 102 and a blank plate 103 held in a tubular shape, and a bottom portion 111.
It is a so-called Pillard container composed of and.

The thermoplastic resin molding portion 102 of the main body 101
Is a pillar portion 102 formed at a joint portion where the end portions 103a and 103b of the blank plate 103 are butted.
a, a flange portion 102b formed at the lower open end 103b of the blank plate 103 held in a tubular shape, and a shoulder portion 1 formed at the upper open end 103c of the blank plate 103.
02c and a threaded opening 102d that is provided at a substantially central portion of the shoulder 102c. Then, for example, a cap, a cap with a pump (shown by an imaginary line in FIG. 1), or the like is screwed into the threaded opening 102d to seal the inside of the composite container 100.

The main body 101 composed of the thermoplastic resin molding portion 102 and the blank plate 103 can be manufactured by the above-described manufacturing apparatus. Here, the blank plate is, for example, polyethylene (PE) / paper / polyethylene (P).
E) 3-layer structure, polypropylene (PP) / PE / paper /
5-layer structure of PE / polypropylene (PP), PE / paper /
It has a five-layer structure such as an adhesive layer / aluminum (Al) layer / PE.

The bottom portion 111 is composed of a flange portion 112 formed of a thermoplastic resin around the bottom blank plate 113 and is formed separately from the main body 101. Then, the flange portion 112 is integrated with the main body 102 by being fixed to the flange portion 102b of the main body 101. Flange portion 102b and flange portion 1
As for the fixation with 12, a threaded portion may be formed on both of them and screwed, or various methods such as a heat sealing method and an ultrasonic sealing method may be used.

As a means for integrating the flange portion 102b and the bottom portion 111 of the main body 101, the ultrasonic sealing method can be used as described above. In this case, the flange portion 102b of the main body 101 is projected on the lower end surface thereof. Parts can be provided. Since such a convex portion is selectively melted by ultrasonic waves, quick and reliable heat sealing can be performed. Further, an L-shaped edge portion may be provided on the outer edge portion of the flange portion 102b so that the melted resin does not flow out from between the flange portion 102b and the bottom portion 111. The shape of the convex portion may be any shape such as a ring shape or a protrusion shape such as a cone, and the height of the convex portion is about 0.1 to 0.5 mm,
The angle of the top is preferably in the range of 60 to 120 °. Also,
The convex portion may be provided on the flange portion 112 side of the bottom portion 111, and in this case, the lower end surface of the flange portion 102b is flat.

Next, the manufacturing method of the present invention will be described by taking the body 101 of the composite container 100 as described above as an example. First, as shown in FIG. 5, the blank plate 103, which has been wound around the core 31 in advance and bent in a fold, is arranged at a predetermined position in the cavity 51. Next, as shown in FIG. 6, the injection gate 4
The molten thermoplastic resin is injected into the cavity 51 from 1 through the runner 32. As a result, the pillar portion 102a, the flange portion 102b, the shoulder portion 102c, and the threaded opening portion 102d are formed. At this time, the blank plate 103 held in the cylindrical shape has the end portions 103a, 103.
a, the lower open end 103b, and the upper open end 103c, the pillar portion 102a and the flange portion 102, respectively.
b, it is fused and integrated with the thermoplastic resin forming the shoulder portion 102c.

The appearance of the pillar portion 102a formed by injection of the thermoplastic resin is difficult to be confirmed from the outside of the composite container 100 because it is preferable from the appearance. Therefore, for example, the amount of resin in the pillar portion 102a should be as small as possible. May be less. Further, as shown in FIG. 4, ribs 105 may be provided so as to project inside the container of the pillar portion 102a. By thus projecting the ribs 105, stacking between the main bodies 101 is prevented and the subsequent separation is facilitated when the main bodies 101 before the bottom portion 111 are integrated are stacked and stored or transported. .

Next, as shown in FIG. 7, the fixed-side mounting plate 11 and the fixed-side mold plate 12 which are engaged and abutted by an engagement member (not shown) are released from the engagement, and urged. The fixed-side mounting plate 11 and the fixed-side template 1 by the member 16
2 and the split molds 21a and 21b are separated. At this time,
Since the angular pin 13 moves upward relative to the split mold 21a together with the fixed-side mounting plate 11, the split mold 21a
a is the peripheral surface of the angular pin 13 and the surface 14 of the guide member
It slides a and moves in a direction away from the core 31 (rightward in the illustrated example). Although not shown in the drawing, the split mold 21b is also provided with a mechanism similar to that of the split mold 21a, and the split mold 21b moves away from the core 31 at the same time as the split mold 21a moves. Moving. Therefore, the engagement between the threaded opening 102d and the split dies 21a and 21b is released. As a result, as shown in FIG.
Body 101 of composite container having threaded opening 102d
At the same time, the core 31 can be easily pulled out from the fixed-side template 12. At this time, the stripper plate 36
Is separated from the stationary mold plate 12 integrally with the core 31.

After the core 31 is pulled out from the fixed-side mold plate 12 to a predetermined position, air is supplied into the communication hole 34a from an external compressed air supply device (not shown) as shown in FIG. The flange portion 33a located in the lower portion of the cylinder 35a is lifted upward in the cylinder 35a. As a result, the protrusion pin 33 rises in the core 31, and the thermoplastic resin 61 remaining in the upper portion of the core 31 and the runner 32 can be removed. At this time, since the thermoplastic resin in the runner 32 is separated from the threaded opening 102d at the pores 32a connecting the runner 32 and the cavity 51, the main body 10
The trace of the gate generated inside 1 is minute.

Finally, as shown in FIG. 10, the stripper plate 36 is guided to the core 3 by using the guide pins 42 as guides.
1, the molded composite container main body 101 is taken out from the core 31.

In the example of the manufacturing apparatus 1 described above, the core 31
The number of runners drilled on the upper part of the above is three, but the present invention is not limited to this, and the number of runners can be appropriately determined.

Further, it is preferable for the appearance of the pillar portion 102a formed by injection of the thermoplastic resin that the presence of the pillar portion 102a is difficult to be confirmed from the outside of the composite container 100. Therefore, the amount of resin in the pillar portion 102a should be minimized. It is preferable to design the core 31 so that Further, as shown in FIG. 4, ribs 105 may be provided so as to project inside the container of the pillar portion 102a. By thus projecting the ribs 105, stacking between the main bodies 101 is prevented and the subsequent separation is facilitated when the main bodies 101 before the bottom portion 111 are integrated are stacked and stored or transported.

Further, in the present invention, the body 10 of the composite container is provided.
A recess 31a as shown in FIG. 11A may be provided on the outer peripheral portion of the core 31 corresponding to the position where the first flange portion 102b is formed. In this case, as shown in FIG. 11B, when the thermoplastic resin is injected in the state where the blank plate 103 is arranged in the cavity 51, the flange portion 102b is formed and the concave portion 31a is also heated. It is filled with a plastic resin. Then, as shown in FIG.
When the core 31 is pulled out from the fixed-side template 12, the main body 101 of the composite container is engaged with the core 31 in the recess 31a, so that the main body 101 of the composite container together with the core 31 can be reliably removed from the fixed-side template 12. It is possible to withdraw.
The main body 101 of the composite container 100 shown in FIG. 4 is molded using such a core.

[0029]

As described in detail above, according to the present invention, the thermoplastic resin injected into the cavity formed between the stationary mold plate and the core passes through the runner drilled in the core. Then, since it reaches the inside of the cavity from the core side, the gate mark generated in the molded composite container is limited to the inside of the container, and it becomes possible to manufacture a composite container having no gate mark on the container surface.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of an apparatus for manufacturing a composite container of the present invention.

FIG. 2 is an enlarged perspective view of an upper portion of the core of the manufacturing apparatus shown in FIG.

FIG. 3 is a perspective view showing an example of a composite container.

4 is a sectional view taken along line IV-IV of the composite container shown in FIG.

FIG. 5 is a perspective view showing an example of a blank plate used for the composite container.

FIG. 6 is a view showing a state in which a molten thermoplastic resin is injected into a cavity in which a blank plate is arranged in advance.

FIG. 7 is a diagram showing a state in which the fixed side mounting plate and the fixed side template are separated and the split mold is opened.

FIG. 8 is a view showing a state in which the core is pulled out from the fixed-side template along with the main body of the composite container.

FIG. 9 is a diagram showing a state in which compressed air is supplied into the air cylinder to remove the thermoplastic resin remaining in the core and the runner.

FIG. 10 is a diagram showing a state where the stripper plate is moved upward along the core and the main body of the molded composite container is taken out from the core.

FIG. 11 is a partially enlarged cross-sectional view of a core of the composite container manufacturing apparatus of the present invention, FIG. 11 (A) shows a state before injection molding, and FIG. 11 (B) shows a blank plate disposed in a cavity. It is a figure which shows the state in which the thermoplastic resin was injected.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Composite container manufacturing apparatus 11 ... Fixed side attachment plate 12 ... Fixed side mold plate 21a, 21b ... Split mold 31 ... Core 32 ... Runner 51 ... Cavity 100 ... Composite container 103 ... Blank plate

Front page continuation (72) Inventor Kazuko Yamase 1-1-1, Ichigaya-Kagacho, Shinjuku-ku, Tokyo Dai Nippon Printing Co., Ltd. Nakayama Kogyo Co., Ltd. (72) Inventor Tetsuya Oshiro Shinka 402, Takemazawa, Miyoshi-cho, Iruma-gun, Saitama Prefecture Nakayama Kogyo Co., Ltd.

Claims (3)

[Claims] 1. A blank plate is arranged in a cavity formed between a stationary mold plate and a core, and a thermoplastic resin is injected into the cavity from an injection gate through a runner formed in the core. A method of manufacturing a composite container, comprising: 2. An apparatus for manufacturing a composite container, in which a blank plate is disposed in a cavity formed between a stationary mold plate and a core, and a thermoplastic resin is injected from the injection gate into the cavity, The said core is equipped with the runner which leads from the said injection gate to the predetermined position of the said cavity, The manufacturing apparatus of the composite container characterized by the above-mentioned. 3. The composite container comprises a threaded opening,
The fixed-side template has a split mold at a portion corresponding to the threaded opening of the composite container, and the cavity has a space formed between the split mold and the core and the fixed-side template. 3. The apparatus for manufacturing a composite container according to claim 2, wherein the runner comprises a space formed between the core and the core, and the runner communicates with a space formed between the split mold and the core. .