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:
Mar. 29, 1988
Filed:
Jan. 29, 1986
Applicant:
Inventors:
Assignee:
Idemitsu Petrochemical Co., Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B29C / ;
U.S. Cl.
CPC ...
264564 ; 2642093 ; 264569 ;
Abstract
A method of biaxially stretching a tubular thermoplastic resin to provide a film, wherein air is blown against a starting point for heating and stretching the tube, from the upstream side of the starting point, at a predetermined angle relative to the feeding direction of the film. An apparatus for achieving this method includes: two pairs of nip rolls being different in circumferential speed between the pairs; a heating-stretching section interposed between the pairs of nip rolls, for heating the tube to a temperature where the tube can be stretched; and an air ring device for blowing air in the feeding direction of the film.