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. 22, 1994
Filed:
Jul. 31, 1992
Michael C Davis, Richmond, VA (US);
Michael A Bryner, Midlothian, VA (US);
E. I. du Pont de Nemours and Company, Wilmington, DE (US);
Abstract
Process and apparatus for improving web pinning and uniformity in a fibrous web forming operation. The improvements are achieved by imposing an auxiliary electrostatic field above the fibrous web as it is pinned along a moving collection surface. An auxiliary electrostatic field enhancing plate is positioned above the web and collection surface and downstream of the laydown position where the web initially is deposited on the collection surface. The plate enhances the electrostatic field in the region above the collection surface and thereby increases the web pinning forces. When the invention is applied to a flash-spinning process where trifluorochloromethane is used as the fluid medium, an auxiliary electrostatic field of between about 2 and 80 kV/cm, preferably between about 10 and 60 kV/cm, is applied by the plate.