JPH0462843B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for making plastic injection containers.

Traditionally, injector containers have a diameter of 50 mm.
mm, length 250mm, it is made of a relatively thin container cylinder with a wall thickness of about 1mm, and has the same inner diameter and the same outer diameter. The content to be hardened is pressed by an inner lid fitted in a piston-like manner to the rear opening of the container cylinder, and is discharged from a small-diameter injector opening provided at the tip of the container cylinder via a constriction plate. It is.

Conventionally, this type of injection extraction container was made by cutting a plastic pipe and selecting parts with a constant inner diameter to make the container cylinder, and then joining a separately molded aperture plate and injection exit mouth to this. Not only did this require time and effort to manufacture, but there was also a problem that the inner lid did not move smoothly due to a large amount of variation in the product.

In addition, when an injection container is integrally molded from plastic, if you try to blow-mold it like a normal container, the inner diameter will not be constant.
In addition, there was a problem in that the thickness was uneven, making it difficult to mold accurately.

Furthermore, in injection molding, molten plastic is injected between the core and the outer mold, and the core is removed after solidification. Because it has the property of shrinking and coming into close contact with the core when it solidifies, it is possible to use a container at one end of a long, thin container cylinder with the same inner diameter and the same outer diameter, as in the injection container according to the present invention. If a small-diameter injector opening is provided through a diaphragm plate, the injector outlet is supported by the outer threaded part of the outer mold, and the container cylinder contracts and attempts to pull out the tightly stuck core. The problem is that tensile force concentrates on the diaphragm plate, which has no supporting force, resulting in the injector opening becoming detached or cracking or deforming the cylindrical part, making it impossible to obtain a satisfactory plastic injector ejection container. It was hot.

Japanese Unexamined Patent Publication No. 53-8248 discloses that elongated cylindrical containers for mascara, eye color, etc. are made thicker to prevent cracking or deformation of the cylindrical portion, and a flange is attached to the outer periphery of the container body. A method has been proposed in which the outer circumference of the container cylindrical body is supported by the outer mold material during the injection molding process by providing a protrusion, and a core without a draft angle can be extracted. Not only does the weight and volume of the entire container increase relative to its capacity, as does the cost of materials, but the flange that protrudes from the outer periphery of the container and is obstructive requires a great deal of effort to remove after solidification, resulting in wasted material. Moreover, there were problems in that the appearance was impaired and the advantages of integral molding were lost.

Therefore, the present invention provides a threaded portion 4 provided on the outer periphery of a small-diameter injection exit opening 3 and a gripper provided on the outer periphery of a large-diameter container cylindrical body 1 connected to the injection exit opening 3 via an aperture plate portion 2. Molten plastic is injected between the outer mold material for forming the threaded part 4 and the gripping recess 5 of the container cylinder 1 having the recess 5 and a core with no draft provided inside the container cylinder 1. ,
After solidification of the molten plastic, the core with no draft provided in the container body 1 is removed while the threaded part 4 and gripping recess 5 of the container cylinder 1 are supported by the outer mold material. The purpose of the present invention is to provide a method for manufacturing an injector container.

The present invention will be described in detail with reference to the embodiments shown below. Reference numeral 1 denotes a container cylinder, which is shaped like a relatively thin pipe with the same inner diameter and the same outer diameter. 2
is a diaphragm plate integrally provided at one end thereof, and an injection exit opening 3 is integrally provided in the center thereof. A threaded portion 4 for attaching a cap is formed on the outer periphery of the injection opening portion 3. Reference numeral 5 denotes a gripping recess according to the present invention, which is provided in two strips on the outer periphery of the container cylindrical body 1 near the end on the injection opening 3 side. Therefore, the middle of the two gripping recesses 5 and the end of the container cylindrical body form a gripping protrusion 6 having the same outer diameter as the container cylindrical body 1. In addition, the container cylindrical body 1
The other end is open for fitting an inner lid for pressing.

Incidentally, the gripping recesses 5 may be provided in a single strip, or they may be provided intermittently at three locations spaced 120 degrees apart from each other, without continuing around the outer periphery of the container cylindrical body.
It goes without saying that it belongs to the gripping recess of the present invention.

In the embodiment having the above configuration, during plastic processing, a threaded portion 4 provided on the outer periphery of the small diameter injection exit opening 3 and a large diameter container cylinder 1 connected to the injection exit opening 3 via the aperture plate 2 are used. The threaded part 4 and the gripping recess 5 of the container cylindrical body 1 having a gripping recess 5 provided on the outer periphery of the container cylindrical body 1 are molded with an outer mold material, and a core with no draft provided inside the container cylindrical body 1 is formed. During this period, molten plastic is injected, and after the molten plastic solidifies, the threaded portion 4 of the container cylinder 1 is
When removing a core with no draft provided in the container cylinder 1 with the gripping recess 5 supported by the outer mold, the container cylinder 1 has its outer periphery supported by the outer mold. Since the threaded part 4 of the mouth part 3 and the gripping recess 5 of the container cylinder 1 are supported, even if the core without draft is removed from the container cylinder 1, there will be no tension in the aperture plate part 2. The core can be pulled out smoothly and easily to the right in FIG. It will never occur. Therefore, according to the container cylindrical body 1 according to the method for producing an injector container of the present invention, by inserting and pressing the inner lid into the container cylindrical body 1 from the right end in the figure, the contents such as silicone can be smoothly removed from the injector opening 3. It will be possible to pour it out.

As described above, according to the method for manufacturing a plastic injection container according to the present invention, the threaded portion 4 provided on the outer periphery of the small diameter injection exit portion 3 and the large diameter screw portion 4 connected to the injection exit portion 3 via the aperture plate portion 2 are provided. an outer mold material for shaping the threaded portion 4 and the gripping recess 5 of the container cylinder 1, and a draft provided in the container cylinder 1; A molten plastic is injected between the core and the core, and after the molten plastic is solidified, the threaded part 4 and the gripping recess 5 of the container cylindrical body 1 are installed in the container cylindrical body 1 while being supported by the outer mold material. Since the core is extracted without a draft angle, the gripping recess 5 that does not protrude to the outer periphery of the container cylindrical body 1, and conversely reduces the wall thickness of the cylindrical body 1, can be formed. During processing, the container cylindrical body is reliably supported against the tensile force along the length of the cylindrical body, and the core can be extracted without a draft angle, so the tensile force is concentrated on the drawing plate unlike in the conventional case. Because I can't join it,
This has the effect of making it possible to integrally injection mold a plastic injection container without the injection opening opening coming off or cracking or deforming the cylinder.Also, since the gripping recess does not protrude from the container cylinder, it is easy to handle and handle. Not only does it not interfere with processing, but it also has the effect of giving the container a beautiful design and distinctiveness as a trademark.

[Brief explanation of the drawing]

FIG. 1 is a partially longitudinally sectional front view of an embodiment of a plastic injection container to be molded according to the present invention, FIG. 2 is a left side view thereof, and FIG. 3 is a right side view thereof. DESCRIPTION OF SYMBOLS 1...Container cylindrical body, 2...Aperture plate part, 3...Injection opening part, 4...Threaded part, 5...Recessed part for gripping.

Claims (1)

[Claims] 1. It has a threaded part 4 provided on the outer periphery of the small-diameter injection exit opening 3, and a gripping recess 5 provided on the outer periphery of the large-diameter container cylindrical body 1 that is connected to the injection exit opening 3 via the aperture plate part 2. Molten plastic is injected between the outer molding material for forming the threaded part 4 and gripping recess 5 of the container cylinder 1 and a core with no draft provided inside the container cylinder 1. After solidification, the container cylinder 1 is held in a state where the threaded part 4 and the gripping recess 5 of the container cylinder 1 are supported by the outer mold material.
A method for manufacturing a plastic injection container characterized by extracting a core with no draft angle provided therein.