Back to results
US 6,119,691 AGranted
Electret filter media
AssigneeMinnesota Mining and Manufacturing Company
InventorsSeyed A. Angadjivand, Marvin E. Jones, Daniel E. Meyer
Life of this patent
Estimating the term…
Abstract
An electret filter media, and mask, that is made of a nonwoven web of thermoplastic microfibers. The thermoplastic microfibers are of substantially the same composition, are nonconductive, and have an effective fiber diameter less than about 15 micrometers. The nonwoven web also has sufficient unpolarized trapped charge to exhibit an initial filtration quality factor of at least 0.31 when measured under the DOP Penetration and Pressure Drop Test.
Claims18
Electret filter media that comprises:
- a nonwoven web that contains thermoplastic microfibers that are of substantially the same composition, that are nonconductive, and that have an effective fiber diameter less than about 15 micrometers,
- the web also has sufficient unpolarized trapped charge such that the web exhibits an initial filtration quality factor of at least 0.31 under the DOP Penetration and Pressure Drop Test.
Dependencies are inferred from the claim text.