Electret filter media and filtering masks that contain electret filter media
US6783574B1 · kind B1 · utility
50Cited by
41References
6Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 2, 1997 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Sep 2, 2017 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T442/626
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
Electret filter media comprising a nonwoven web of thermoplastic nonconductive microfibers having trapped charge, said charge provided by (1) subjecting the nonwoven web to a corona treatment, followed by (2) impingement of jets of water or a stream of water droplets on the web at a pressure sufficient to provide the web with filtration enhancing electret charge and (3) drying the web. This electret filter media may be used in a respiratory mask to provide extraordinarily good filtration properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.