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:
Jun. 01, 2004
Filed:
Apr. 13, 2000
Applicant:
Inventors:
Thomas I. Insley, West Lakeland Township, MN (US);
Randall L. Knoll, Grant, MN (US);
Assignee:
3M Innovative Properties Company, St. Paul, MN (US);
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B03C 3/28 ; B05D 5/12 ; B05D 3/02 ;
U.S. Cl.
CPC ...
B03C 3/28 ; B05D 5/12 ; B05D 3/02 ;
Abstract
A method of making an electret includes condensing vapor from the atmosphere of a controlled environment onto a dielectric article and then drying the article to remove the condensate. The dielectric article may be a nonconductive polymeric material, and the condensate may include a polar liquid. The method is particularly useful for forming an electret from a porous material such as a nonwoven fibrous web. The method can enable individual fibers in the web to exhibit at least quasi-permanent electrical charge.