JPH05162174A - Tube container manufacturing method and tube container - Google Patents

Abstract

(57) [Abstract] [Purpose] To equalize the material distribution in the tube neck integrally formed at the upper end of the tubular tube body and the subsequent shoulder, and to equalize the pressure during molding. .. [Structure] The tubular tube body is provided with a cavity 4, a core 5,
6. Inserted in the injection molding die 1 composed of the split mold 3, and at least two or more sprues 12 on the inner peripheral surface of the tube neck portion 8.
The molten resin is evenly injected from the runner 11 through the sprue 12 to integrally form the tube neck 8 and the subsequent shoulder 10 on the upper end of the tube body. [Effect] Since the molten resin can be turned from two or more sprues, uniform pressure and material flow can be obtained, and the tube neck and the shoulder that follow the tube are integrally formed on the upper end of the tubular body. It is possible to provide a high-quality tube container by achieving equalization of the material distribution in the above and equalization of pressure during molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a tube container and a tube container, and more specifically, to an injection molding metal having a tubular tube body manufactured in advance and having a cavity, a core and a split mold. The present invention relates to a tube container manufacturing method and a tube container in which a synthetic resin is inserted into a mold and a synthetic resin is injected into a cavity to integrally form a tube neck portion and a shoulder portion subsequent to the tube neck portion.

[0002]

2. Description of the Related Art Conventionally, in this type of tube container, a tube container as disclosed in JP-A-62-238722 is generally used. As shown in FIG. 8, this tube container includes a cylindrical tube body portion 20, a tube neck portion 21 formed and fixed to one end side thereof, and a shoulder portion 22 following the tube neck portion 21. One spout 24 of the runner 23 for injecting the synthetic resin is provided on the inner surface of the.

A tube neck portion 21 is attached to the tube body portion 20.
In order to mold the shoulder portion 22 and the subsequent shoulder portion 22, first, the core is inserted into the tube body portion 20 which is fixed in advance, and the tube body portion 20 is inserted into the nest having the split structure.
Then, the space formed by the cavity of this nest and the tip of the core tip member becomes the tube neck portion 21 of the tube container.
And a space for injection molding of the shoulder portion 22. Then, when the molten resin is injected from the injection device after the tube body portion 20 is held under pressure, the space inside the cavity is filled with the molten resin from the runner 23 through the sprue 24. Then, after cooling, the mold is opened, and when the core is pulled out from the split mold, the sprue 24 is automatically cut from the molded product, leaving one sprue mark on the inner surface of the tube neck.

[0004]

However, in the above-mentioned tube container, since there is only one spout 24, the synthetic resin, which is the material, must flow from one direction to the entire cavity internal space. There was a problem that the pressure was uneven and the material flow was non-uniform.
As a result, as shown in FIG. 9, the material excessively flows into the neck portion 21 and the shoulder portion 22 in the mold on the side where the sprue 24 is formed. There was a problem that occurred.

On the other hand, in the mold on the opposite side, a material shortage occurs and the thickness of that portion becomes insufficient, resulting in a problem that the welding strength between the shoulder portion and the body portion is significantly reduced.

Further, when the tube shape becomes elliptical, the material does not flow to the shoulder opening in the mold on the opposite side as shown in FIG. 10, and in some cases, the hole remains open. There was a problem.

The present invention has been made in view of the above prior art, and an object thereof is a material for a tube neck portion integrally formed at an upper end of a tubular tube body manufactured in advance and a shoulder portion following the tube neck portion. It is to equalize the distribution of and the pressure during molding.

[0008]

In order to achieve the above object, according to the present invention, a pre-manufactured tubular tube body is inserted into an injection molding die including a cavity, a core and a split mold. In a method of manufacturing a tube container in which a synthetic resin is injected into a cavity to integrally form a tube neck portion and a shoulder portion subsequent to the tube neck portion on an upper end of the tube body portion, at least two gates are provided on an inner peripheral surface of the tube neck portion. To form
The synthetic resin is injected through the sprue to integrally form a tube neck and a shoulder following the tube on the upper end of the tube body.

Further, in a tube container in which a tube neck portion and a shoulder portion following the tube neck portion are integrally formed on the upper end of the tube body portion, at least two or more spout marks for injection of synthetic resin are provided on the inner peripheral surface of the tube neck portion. It is characterized by

Further, the present invention is characterized in that at least two vertical ribs are formed on the inner peripheral surface of the tube neck portion of the tube container, and the vertical rib has a spout mark.

Further, the present invention is characterized in that the tube neck portion of the tube container and the shoulder portion subsequent to the tube neck portion have a narrowed portion on the inner peripheral surface thereof.

Further, the tube container is characterized by having a narrowed portion on the outer peripheral surface of the tube shoulder portion.

[0013]

In order to solve the above-mentioned problems, in the present invention, the molten resin injected is evenly filled into the space at the upper end of the body from two or more sprues, and the upper end of the body and the shoulder are inserted in advance. It can be welded at the part to form a tube container. Further, after the molten resin is solidified, an injection molding die including a cavity, a core and a split mold is opened, and the molded product is separated from the core. At this time, the sprue at two or more locations is automatically cut by the core coming out of the molded product, and the sprue marks remain on the inner surface of the neck of the container.

Further, the vertical rib formed on the inner peripheral surface of the tube neck secures the rigidity of the neck, and the vertical rib is used to inject the molten resin by providing the sprue rib with the sprue rib.

Further, a narrowed portion is formed on either the tube neck portion or the shoulder portion following the neck portion, and the melted resin uniformly filled from at least two gates provided on the inner circumference of the tube neck portion is squeezed. By squeezing at the portion, the flow speed and pressure of the resin flowing in the integrally molded portion of the shoulder portion and the tube body portion can be adjusted, and the occurrence of burrs can be prevented.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the drawings. 1 to 3 are a sectional view and a top view of a tube container manufacturing method and a tube container according to a first embodiment of the present invention.

In FIG. 2, reference numeral 1 indicates an injection mold for carrying out the method of the present invention. The mold 1 is composed of a first core 5, a split mold 3, a cavity 4, a split mold retainer 2, a second core 6, and ejector pins 7, 7. Further, a runner 11 for injection-molding the neck portion 8 of the tube container and the shoulder portion 10 following the neck portion 8 is provided in the central portion of the first core 5 so as to vertically pass therethrough. Further, a runner 11 is also provided in the central portion of the upper surface of the second core 6, and the runner 11 is further branched to open a spout 12 on the outer peripheral surface of the second core 6. Spout 1
As shown in FIGS. 1 (a), 1 (b), 1 (c) and 1 (d), 2 are provided at two or more positions at the opposite positions on the upper outer peripheral surface of the second core 6. 1 (b) is a top view when the sprue 12 has two openings, and FIG. 1 (c) is a top view when the sprue 12 has four openings. (D)
[Fig. 6] is a top view when the tube shape is an ellipse.

To carry out the method of the present invention using such an injection molding die 1, first, the second core 6 and the ejector pins 7, 7 are inserted into the body portion 9 of the tube container, and the tube container The body 9 is inserted from below the cavity 4 of the mold 1 and fixed. Next, the split die 3 is closed, the split die presser 2 is closed, the cavity 4 and the split die 3 are fixed, and when compressed by the first core 5 from above, the tip surface of the tip member of the second core 6 and the split die 3 are fixed. And the space 13 formed by the first core 5 becomes a space for injection molding of the container neck of the tube container, and the space 14 formed by the tip member of the second core 6 and the cavity 4 is injected by the container shoulder of the tube container. It becomes a space for molding.

The molten resin injected through the runner 11 is evenly filled in the spaces 13 and 14 from the above-mentioned two or more sprues 12, and the upper end and the shoulder of the body 9 inserted in advance. It is welded at the part 10, where the neck 8 and the shoulder 10 are formed, which can constitute a tube container. At this time, the sprue 12 is in contact with the inner peripheral surface of the neck portion 8 and opens. Furthermore, after the molten resin is solidified,
The mold 1 is divided, and the ejector pins 7 and 7 are projected to separate the molded product from the core 6. At this time, the runner 11 provided on the core 6 is automatically cut by the sprue 12 when the core 6 comes out of the molded product, and the sprue mark remains on the inner surface of the neck of the container.

FIG. 3 shows a modification of the above embodiment. In this embodiment, the ejector pin 7 is provided at the center of the second core 6a.
a is provided. A runner 11 is provided at the upper end of the ejector pin 7a, and the runner 11 is further branched to form a sprue 12 on the outer peripheral surface of the ejector pin 7a. The spout 12 is shown in FIGS. 1 (a) (b) (c).
As shown in (d), two or more locations are provided at opposite positions on the outer peripheral surface of the ejector pin 7a. Others
It is similar to the above-described first embodiment and has the same operation.

FIG. 4 shows a second embodiment of the present invention. In this embodiment, four vertical ribs 15 are provided on the inner peripheral surface of the neck 8a.
15 is provided, and the sprue 12 is passed through each vertical rib 15. This is used when the diameter of the tube container is smaller than the screw diameter of the neck. When the diameter of the mouth is small, the rigidity of the neck is reinforced and the sprue 12 is easily formed. Others are the same as those of the above-described first embodiment and have the same operation.

5 to 7 show a third embodiment of the present invention. In the embodiment of FIG. 5, a wide-diameter throttle portion 16 that can throttle the flow of the injection resin is formed on the inner peripheral portion of the upper portion of the shoulder portion 10. Further, in the embodiment of FIG. 6, a narrowed portion 17 is formed on the outer peripheral portion of the root of the neck portion 8 so that the diameter of the outer periphery thereof is smaller than the thread valley. Further, in the embodiment of FIG. 7, the diameter of the inner peripheral portion of the lower portion of the neck portion 8 is increased to form the throttle portion 18. The molten resin injected through the runner 11 by these squeezing portions has a more uniform speed and pressure when being filled from the spout 12 into the spaces 13 and 14 for injection molding of the container neck and shoulder. You can get it. Others are the same as those of the above-described first embodiment and have the same operation.

[0023]

As described above, according to the present invention, a pre-manufactured tubular tube body is inserted into an injection molding die including a cavity, a core and a split mold, and the synthetic resin is placed in the cavity. A tube container manufacturing method in which a tube neck and a shoulder following the tube are integrally formed on the upper end of the tube body by injecting
It is characterized by forming gates at more than one place, injecting synthetic resin through the gates, and integrally molding the tube neck and the shoulders following it at the upper end of the tube body. Since it can be turned from more than one pouring gate, a uniform pressure and material flow can be obtained, so that problems such as uneven pressure and uneven material flow can be solved.

Further, the problem that the material excessively flows into the mouth portion and the shoulder portion in the mold on the side where the sprue is formed, and burrs are generated due to this excessive material inflow during molding of the mold, is solved. ..

Furthermore, since the material is evenly circulated in the mold on the opposite side, a material shortage occurs, resulting in a lack of wall thickness, resulting in a marked decrease in the welding strength between the shoulder and the body. The points are also eliminated.

Furthermore, even when the tube shape is elliptical, the material is spread, so in the mold on the opposite side,
The problem that the material does not flow to the shoulder area and the hole remains open is also solved.

In the present invention, the distribution of the material in the tube neck integrally formed at the upper end of the tubular body of the tube and the subsequent shoulder portion is equalized, and the pressure during molding is equalized. It is possible to provide a high quality tube container. .

Further, since at least two vertical ribs are formed on the inner peripheral surface of the tube neck portion of the tube container, and the vertical rib has a spout mark for injecting a synthetic resin, the sprue can be easily formed, and the neck portion can be easily formed. The rigidity of can be secured.

Furthermore, since the tube neck portion of the tube container and the subsequent shoulder portion are provided with the squeezing portions, the flow velocity and pressure of the resin flowing in the welded portions of the shoulder portion and the body portion can be adjusted, and burr formation is prevented. It can be prevented.

[Brief description of drawings]

FIG. 1 (a) is a cross-sectional view of a first embodiment of a tube container according to the present invention. (B) It is a top view of 1st Example of the tube container which concerns on this invention. (C) It is a top view of the modification of 1st Example of the tube container which concerns on this invention. (D) It is a top view when the shape of the first embodiment of the tube container according to the present invention is different.

FIG. 2 is a cross-sectional view showing the method of manufacturing the tube container according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing another method of manufacturing the tube container according to the first embodiment of the present invention.

FIG. 4 (a) is a sectional view of a second embodiment of the tube container according to the present invention. (B) It is a top view of 2nd Example of the tube container which concerns on this invention.

FIG. 5 is a sectional view of a tube container according to a third embodiment of the present invention.

FIG. 6 is a sectional view of a tube container according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a third embodiment of the tube container according to the present invention.

FIG. 8 is a cross-sectional view showing a conventional technique.

FIG. 9A is a top view showing a conventional technique. (B) It is sectional drawing which shows a prior art.

FIG. 10A is a top view showing a conventional technique. (B)
It is sectional drawing which shows a prior art.

[Explanation of symbols]

1 Injection Mold 2 Split Mold Presser 3 Split Mold 4 Cavity 5 First Core 6,6a Second Core 7,7a Ejector Pin 8,8a Neck 9 Body 10 Shoulder 11 Runway 12 Gate 13 Space 14 Space 15 Vertical Ribs 16, 17, 18
Aperture

Claims (5)

[Claims] 1. A prefabricated tubular tube body is inserted into an injection molding die including a cavity, a core, and a split mold, and a synthetic resin is injected into the cavity to upper end of the tube body. In a method of manufacturing a tube container in which a tube neck portion and a shoulder portion following the tube neck are integrally formed, at least two or more gates are formed on an inner peripheral surface of the tube neck portion,
A method for producing a tube container, comprising injecting a synthetic resin through the gate to integrally form a tube neck and a shoulder following the tube on an upper end of the tube body. 2. A tube container in which a tube neck portion and a shoulder portion following the tube neck portion are integrally formed on the upper end of the tube body portion, and at least two or more spout marks for injection of synthetic resin are formed on the inner peripheral surface of the tube neck portion. A tube container having. 3. The tube container according to claim 2, wherein at least two or more vertical ribs are formed on the inner peripheral surface of the tube neck portion of the tube container, and the spout marks are formed on the vertical ribs. 4. The tube container according to claim 2, wherein the tube neck portion of the tube container and a shoulder portion subsequent to the tube neck portion have a narrowed portion on an inner peripheral surface thereof. 5. The tube container according to claim 2, wherein the tube container has a narrowed portion on the outer peripheral surface of the tube shoulder portion.