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:
Dec. 12, 1978
Filed:
Mar. 29, 1976
Teijin Limited, Osaka, JP;
Abstract
A process for producing a film of reduced thickness unevenness which comprises extruding a thermoplastic resin from an extrusion die into a film form, exposing the extrudate to an electric field induced by an electrostaticity applying electrode, and then pinning it to the surface of a cooling drum, wherein a shielding object is disposed between the extrusion surface of the die and the electrostaticity applying electrode thereby to maintain the applied voltage constant in the widthwise direction of the extrudate and to enable the extrudate to adhere intimately to the surface of the cooling drum, and an apparatus for producing a film of reduced thickness unevenness comprising an extrusion die equipped with means for adjusting the thickness unevenness of the film by temperature control, an electrode for applying electrostaticity, a cooling drum and a shielding object, said shielding object being a conductive object, a non-conductive object or a combination of these, and being disposed between the extrusion surface of the die and the electrostaticity applying electrode.