초록 ▼

A method of producing a form retaining container made of synthetic plastic material comprising feeding a plastic material in liquid state onto a male member to provide a layer on the male member constituting a blank for the container. The layer is cooled to prevent crystallization of the material. T

A method of producing a form retaining container made of synthetic plastic material comprising feeding a plastic material in liquid state onto a male member to provide a layer on the male member constituting a blank for the container. The layer is cooled to prevent crystallization of the material. The thus cooled blank is placed into a mold cavity having an interior configuration corresponding to the desired outer shape of the container to be produced. The layer is inflated into conformity with the mold cavity. The configuration of the mold cavity is such that the blank undergoes biaxial stretching in a middle region of the container by at least 1.5 times while the mouth and part of the bottom of the container will be formed by biaxially stretching the blank less than 1.5 times. The inflated blank is then heated until curing is completed and then the blank is removed from the mold.

대표청구항 ▼

A method of producing a form-retaining container made of a thermoplastic polymer which is capable of being crystallized, the container having regions constituted by a first region inclusive of the mouth and part of the neck of the container, a second region inclusive of the remainder of the neck, a

A method of producing a form-retaining container made of a thermoplastic polymer which is capable of being crystallized, the container having regions constituted by a first region inclusive of the mouth and part of the neck of the container, a second region inclusive of the remainder of the neck, a main body portion and the peripheral portion of the bottom of the container, and a third region constituted by a central portion of the bottom of the container, said method comprising the steps of: placing a parison of amorphous material into a mold cavity having an interior configuration corresponding to the desired outer shape of the container to be produced; said material being a thermoplastic polymer selected from the group consisting of polyethylene terephthalate, polyhexamethylene adipamide, polycaprolactam, polyhexamethylene sebacamide, polyethylene 2,6 and 1,5 naphthalate, polytetramethylene- 1,2-dioxybenzoate, and copolymers of ethylene terephthalate and ethylene isophthalate; inflating the parison at a temperature between the glass transition temperature and the crystallization temperature to expand the parison into conformity with the mold cavity to form the configuration of the container; said mold cavity having a configuration related to the configuration of the parison so that the second region of the container will be obtained by stretching the material of the parison in said second region in more than one direction to achieve biaxial stretching and orientation of the material by at least 1.5 times while the material of the parison in the first and third regions will be biaxially stretched less than 1.5 times; heating the inflated parison to a temperature above the crystallization temperature, while maintaining internal pressure in the parison during the heating to prevent shrinking, to effect selective crystallization of said regions such that the first and third regions obtain a crystallization forming opaque regions while the second region obtains only a small crystallization forming a transparent region, whereby a container is obtained which is form-stable when reheated to a temperature slightly above the crystallization temperature of the material, and removing the container from the mold.