JPH11227033A - Production of container made of synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively mass-produce a container formed into an arbitrary shape having excellent quality and strength, especially, a container with a lid which is formed attachably and detachably by using a preform of a standard product. SOLUTION: In a method for producing a container made of a synthetic resin, the fitting part 4 with a lid member is preformed in the body part 3 of the container at the time of stretch blow molding using a preform and, after molding, the part above the fitting part 4 of the container is cut. This fitting part 4 may be formed by employing any structure such as a screw (screw cap) type one, a capping type one or the like. The caliber of the fitting part 4 is affected by a preform to be used but the arbitrary size/shape can be fundamentally set from the small caliber of the preform to the large caliber thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention is capable of mounting a separately detachable lid using PET (polyethylene terephthalate), PEN (polyethylene naphthalate) or a mixture thereof or PP (polypropylene) as a raw material. The present invention relates to a method for manufacturing a synthetic resin container formed in the above.

[0002]

2. Description of the Related Art In general, the container portion of a synthetic resin container with a cover, such as a laver container, is formed by so-called direct blow molding in consideration of production costs. As is well known, in the direct blow molding, since a molded product is obtained by blowing air into a parison extruded in a predetermined mold in a hanging state, there is an advantage that a lightweight and inexpensive hollow container can be mass-produced to a considerable extent.

However, the direct blow-molded container is inferior in quality, strength, and mass productivity such as transparency as compared with a uniaxial or biaxial stretch blow-molded container using a preform. can not deny. On the other hand, in stretch blow molding using a preform, a large amount of equipment and cost are required for molding a preform corresponding to a synthetic resin container having a desired shape, regardless of the case where a standard preform widely used is used. There are drawbacks. for that reason,
Conventionally, for example, in the case of shampoo containers, etc., a direct blow-molded container was used at the beginning of the launch of a new product, and a special preform was used after a considerable amount of sales could be predicted based on market reactions. Measures have been taken in consideration of the production cost of containers, such as switching to uniaxial or biaxial stretch blow molded containers.

[0004]

As described above, in order to mass-produce containers of the same shape having excellent quality and strength, stretch blow molding using a preform is optimal, but cost is high. In terms of quality and equipment, at the beginning of shipping new products, direct blow molded products with inferior quality and strength were inevitably used. The present invention provides a method for mass-producing low-cost mass production of a synthetic resin container having an arbitrary shape excellent in quality and strength, particularly a synthetic resin container having a detachable lid, using a standard preform. Is what you do.

[0005]

According to the present invention, at the time of stretch blow molding using a preform, a fitting portion with a lid is formed in a body of a container, and after molding, the fitting portion is formed above the fitting portion. This is a method for producing a synthetic resin container characterized by cutting.

That is, according to the present invention, a fitting portion with a separately manufactured lid is formed in the body of a molding die for a synthetic resin container such as PET which is generally used.
After uniaxial or biaxial stretch blow molding using a preform, cut and separate up and down above the fitting part, adopt only the lower side including the bottom as a product, while discarding or reusing the upper side. did. Therefore, if a molding die is replaced, a synthetic resin container with an arbitrary diameter, depth, and shape can be stretched, which is a high-quality, high-strength, and low-cost container manufacturing method compared to direct blow molding. It became possible to manufacture using blow molding.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a synthetic resin container according to the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front view of a standard preform 1 for a PET bottle having a capacity of 2 liters which is commonly used. In the present invention, as described above, a variety of raw materials such as PET or PEN or a mixture thereof or PP can be used, and any preform having various shapes can be used. In particular, when a deep-bottom container, which is difficult to form with a uniform thickness by direct blow molding, is to be used, a particularly excellent effect can be exhibited.

FIG. 2 is a front view showing a state in which the preform of FIG. 1 is formed into a bottle by performing biaxial stretch blow molding. In the method for manufacturing a synthetic resin container according to the present invention, a fitting portion 4 for fitting to a lid used for a completed container is formed in a body 3 below the shoulder 2 of the synthetic resin container formed into a bottle shape. deep. The fitting portion 4 may have any structure, such as a screw (screw cap) type shown in FIG. 2 or a stopper type. Although the diameter of the fitting portion 4 depends on the preform to be used, the diameter of the fitting portion 4 basically ranges from a small diameter of about the same as the diameter of the preform to a large one shown in FIGS. It is possible to set the height and shape.

When performing blow molding, it is desirable to form a guide portion 5 of the cutter above the fitting portion 4 in order to facilitate the cutting operation after molding. By cutting the bottle-shaped container up and down by applying a blade to the gutter guide portion 5, the lower bottomed container 7 is commercialized as a desired synthetic resin container. The cutting may be performed by an automatic robot. FIG. 3 is a front view showing a state in which the molded synthetic resin container is cut and separated vertically. The upper remnants 6 that have not been adopted as a product can be discarded or dissolved, re-formed into a standard preform or the like, and reused.

According to the method for producing a synthetic resin container of the present invention, although it depends on the capacity of the molding machine, for example,
Approximately 1,500 pieces can be produced per hour using individual molding dies. This corresponds to about 4 to 5 times the production capacity of a normal direct blow molded product.

[0012]

According to the present invention, a container made of a synthetic resin having an arbitrary diameter, depth and shape can be formed with higher quality and higher strength than a direct blow molding simply by changing a molding die. It can be manufactured using uniaxial or biaxial stretch blow molding, which is a low-cost container manufacturing method.

That is, if a desired synthetic resin container is to be obtained only by stretch blow molding using a preform, it is necessary to use a preform suitable for the diameter and structure, which is a great deal of work for molding the preform itself. Although equipment and costs are required, according to the method for manufacturing a synthetic resin container according to the present invention, only a low-cost blow molding die is prepared as compared to a preform molding die, and a standard preform is used. Thus, synthetic resin containers of various shapes can be obtained.

[Brief description of the drawings]

FIG. 1 is a front view of a standard preform for PET bottles.

FIG. 2 is a front view of a container in which a standard preform is biaxially stretch blow-molded by a molding die.

FIG. 3 is a front view showing a state where a molded container is cut and separated vertically.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Preform 2 Shoulder part 3 Body part 4 Fitting part 5 Gutter guide part

Claims (1)

[Claims] 1. A stretch-molding method using a preform, wherein a fitting portion with a lid is formed in a body of a container, and cutting is performed above the fitting portion after molding. A method for manufacturing a resin container.