JPS581527A - Method for molding container made of polyethylene terephthalate resin - Google Patents

Abstract

PURPOSE:To obtain the titled container of which an opening part is uniformly whitened and crystallized without irregularity, by a method wherein only the epening part of a biaxially oriented container made of polyethylene terephthalate or the intermediate material thereof is uniformly heated and temp. control is carried out thereafter. CONSTITUTION:After only the opening part 11 of a container 10 obtained by biaxially orienting and blow molding a polyethylene terephthalate resin or an intermediate material having a bottomed cylindrical form which is a primary molded product is uniformly heated from the periphery thereof by radiant heat, temp control is carried out to whiten and crystallize said opening part 11. In order to carry out this process, it is pref. that a heater 23 is arranged around the opening part 11 so as to encircle the same in an appropriate interval and said opening part is heated by radiant heat therefrom. In addition, it is pref. that a hold 22 is inserted into the inside of the opening part 11 to prevent the deformation thereof and a shield plate is arranged directly under the opening part 11 to prevent the transmission of heat to the lower part below the opening part 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding polyethylene terephthalate resin containers by biaxial stretch blow molding, and particularly relates to a method for forming polyethylene terephthalate resin containers in which the mouth portion is whitened and crystallized and the body portion is transparent. This paper relates to a method for whitening and crystallizing a container made of polyethylene terephthalate resin, in which the mouth part is whitened and crystallized evenly and uniformly. The present invention has the configuration described in the claims,
The present invention provides a method for molding a container made of polyethylene terephthalate resin in which the mouth part is evenly whitened and crystallized.

The molding method of the present invention will be described in detail below based on explanatory drawings showing raw materials.

What is not shown is a case in which the opening of a container formed by biaxial stretching is whitened and crystallized, and the main body 10 is formed by biaxial stretching.
is placed on a base 21, and a hold 22 is inserted into the opening 11 to prevent it from deforming inward due to heating.

Annular heaters 23 are arranged around the mouth portion 11 at appropriate intervals. The mouth portion 11 is heat treated by radiant heat from the heater, and further whitened and crystallized by temperature control. In addition, a shielding plate 2 is provided directly below the mouth portion 11, that is, at the shoulder portion.
4 is arranged to prevent the radiant heat of the heater 23 from affecting the torso including the shoulders. Note that if the base 21 is rotated, the radiant heat to the first part 11 will be further averaged, and uniform heat treatment can be performed. Alternatively, the portion 11 may be heat-treated by placing a metal cap over the mouth instead of the hold 22 and applying radiant heat to the metal gap.

In the above explanation, the mouth is heat-treated after the container is formed by biaxial stretching, but the mouth is heat-treated when the intermediate material in the shape of a cylinder with a bottom is the primary molded product before the container is formed to prevent whitening crystals. It may be made into

The method for molding a polyethylene terephthalate resin container of the present invention is carried out based on the above-mentioned apparatus, and is a method for molding a polyethylene terephthalate resin container by biaxial stretch blow molding or a bottomed cylinder that is a primary molded product of the container. The opening of the intermediate plan 4'A of shape is uniformly heated by radiant heat generated from an annular heater placed around the outer periphery of the opening at appropriate intervals, and then the temperature is controlled to cause whitening and crystallization.
Furthermore, in the molding method of the present invention, a hold is placed inside the part [ ] to perform heat treatment using radiant heat while preventing deformation of the mouth part by heating, and a shielding plate is further placed directly under the mouth part. , the mouth part is heat-treated while preventing radiant heat from being transmitted below the mouth part.

The method of molding the polyethylene terephthalate 4 liter container of the present invention is a two-step method, which allows only one part of the container to be reliably and easily heat-treated, furthermore uniform heating can be carried out, and the mouth part can be heated more uniformly. It has the special effect of being able to whiten and crystallize evenly and uniformly.

[Brief explanation of the drawing]

FIG. 1 is an overall view of a container whose mouth portion has been whitened and crystallized by the molding method of the present invention, and FIG. 2 is a partial cross-sectional view for explaining the molding method. 10: Container body, 11: Mouth, 23: Heater. Patent Applicant Yoshino Kogyo Co., Ltd. Agent Osamu Kawa Yoshito Tatsuya Fuji Fig. 1 Fig. 2 No. 1

Claims (1)

[Claims] 1. Only the opening of a polyethylene terephthalate resin container formed by biaxial stretch blow molding, or a bottomed cylindrical intermediate material that is the primary molded product of the polyethylene terephthalate resin container, is uniformly heated by radiant heat from the surroundings. A method for molding polyethylene terephthalate resin, which is characterized by heating it to a temperature and then controlling the temperature to whiten and crystallize it. 2. The method for molding a polyethylene terephthalate resin container according to claim 1, wherein the radiant heat is generated by a heater placed around the opening at appropriate intervals. 3. The method for molding a polyethylene terephthalate resin container according to claim 1, wherein the mouth is heat-treated by radiant heat while a hold is inserted inside the mouth to prevent deformation of the mouth due to heating. 4. Molding of the polyethylene terephthalate resin container according to claim 1, wherein a shielding plate is disposed directly below the mouth to heat the mouth while preventing radiant heat from being transmitted below the mouth. Method.