Method and apparatus for making a nonwoven fibrous electret web from free-fiber and polar liquid
Assignee3M Innovative Properties Company
InventorsSeyed A. Angadjivand, Michael G. Schwartz, Philip D. Eitzman, Marvin E. Jones
Life of this patent
Estimating the term…
Abstract
A method and apparatus for charging fibers that contain a nonconductive polymer. A polar liquid 32, 34 is sprayed onto free-fibers 24, and the free-fibers 24 are then collected to form an entangled nonwoven fibrous web 25 that may contain a portion of the polar liquid. The nonwoven web 25 is then dried 38. By applying an effective amount of polar liquid 32, 34 onto the nonconductive free-fibers 24 before forming the nonwoven web 25, followed by drying 38, the individual fibers 24 become charged. The method and apparatus enable the fibers 24 to be charged during web manufacture without subsequent processing.
Claims46
A method of making a nonwoven fibrous electret web, which method comprises the steps of:
- (a) forming one or more free-fibers from a nonconductive polymeric fiber-forming material;
- (b) spraying an elective amount of polar liquid onto the free-fibers;
- (c) collecting the free-fibers to form a nonwoven fibrous web;
- and
- (d) drying the fibers or the nonwoven web to form a nonwoven fibrous electret web.
Dependencies are inferred from the claim text.