The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 23, 1996
Filed:
Jun. 07, 1995
Yoshino Kogyosho Co., Ltd., Tokyo, JP;
Abstract
A method of blow-molding a biaxially-oriented polyethylene terephthalate resin bottle-shaped container having high heat resistance and substantially no residual stress is disclosed. The method comprises the steps of: providing a preform with a neck and a body; heating the preform to an orienting temperature; first biaxial-orientation blow-molding the preform in a first mold which is at a first temperature to biaxially stretch the preform to form a primary intermediate molded bottle-shaped piece that is larger than the bottle-shaped container and having an area magnification of at least 5 times the preform, the biaxial stretching creating residual stress in the primary intermediate molded bottle-shaped piece; causing thermal contraction of the primary intermediate molded bottle-shaped piece by heating the primary intermediate molded bottle-shaped piece to a temperature higher than the first temperature to form a secondary intermediate molded bottle-shaped piece and to eliminate residual stress caused by the first blow-molding; and second blow-molding the secondary intermediate molded bottle-shaped piece in a second mold to form the bottle-shaped container, wherein orientation magnification of the secondary intermediate molded bottle-shaped piece is small compared to orientation magnification of the primary intermediate molded bottle-shaped piece and substantially no stress is created during the second blow-molding.