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:
Jul. 31, 1990
Filed:
Sep. 30, 1985
Clinton D Felton, Charlotte, NC (US);
Baylor D Gibson, Waxhaw, NC (US);
Charles E Jamison, Charlotte, NC (US);
William O McWhorter, Monroe, NC (US);
George A Serad, Charlotte, NC (US);
Celanese Corporation, New York, NY (US);
Abstract
Continuous processes for the preparation of electrets and the products produced thereby, including filter fabrics, are disclosed. The process employs a continuous film or continuous filaments in the form of a tightly packed warp having a warp density as determined by light transmission of not more than 40%. The continuous film or continuous filament in the form of a tightly packed warp are continuously fed one or more times through a corona charging station having electrodes disposed on both sides of the material being treated, the material being treated being simultaneously heated while being subjected to a corona discharge of from 6 KV to 20 KV direct current.