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:
Aug. 08, 1978
Filed:
Mar. 12, 1976
Stanley B Levy, Wilmington, DE (US);
William D Garlington, Wilmington, DE (US);
E. I. Du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
An apparatus for stretching polymeric film is disclosed wherein a heating unit is located slightly above and between the parallel tracks of a tenter frame and wherein the heating unit includes an air duct with an air entrance opening and a series of apertures directed between the tenter frame tracks wherein the air duct is separated, by internal intermediate walls, into adjacent isolated zones extending parallel with the tracks of the tenter frame and wherein each isolated zone includes a heater. Air introduced into the duct is conducted through the zones where it is heated and directed through the apertures onto a web of polymeric film moving in the tenter frame prior to stretching.