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:
May. 25, 1982
Filed:
Oct. 10, 1980
Masahide Yazawa, Kunitachi, JP;
Hiroshi Yazawa, Kunitachi, JP;
Haruhisa Tani, Tokyo, JP;
Kazuhiko Kurihara, Tokyo, JP;
Nippon Petrochemicals Co., Ltd., Tokyo, JP;
Polymer Processing Research Institute Ltd., Tokyo, JP;
Abstract
Longitudinal and transverse stretching of a tubular film is effected by gripping opposite selvages of the tubular film between a pair of substantially coplanar pulleys and a pair of endless belt means trained arcuately around the pulleys, respectively, and by rotating the pulleys at a peripheral speed greater than a speed of feed of the tubular film. As the film selvages progress along a pair of arcuate divergent paths, respectively, around the pulleys, the film is heated, reversed in direction of travel, and cut along the selvages into a pair of biaxially stretched sheets. Before stretching of the film, live steam is introduced into the tubular film for heating the same.