Patent · US Expired

Electret filter media

US6119691A · kind A · utility

75Cited by
35References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 29, 1997
Grant dateSep 19, 2000
Priority date
Expiry dateMay 29, 2017

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T442/626
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.