Gerald M Brostrom, David C Byram: Drop-down face mask assembly. 3M Innovative Properties Company, Karl G Hanson, Kevin W Raasch, James A Rogers, October 1, 2002: US06457473 (50 worldwide citation)

An improved face mask that is retained by a carriage and harness assembly, thereby allowing the face mask to drop down from the face of the wearer.


Marvin E Jones, Christopher S Lyons, David B Redmond, Jeffrey L Solomon, Seyed Abolhassan Angadjivand: Fluorinated electret. 3M Innovative Properties Company, Karl G Hanson, Allison Johnson, June 25, 2002: US06409806 (49 worldwide citation)

An electret is described that includes a surface modified polymeric article having surface fluorination produced by fluorinating the polymeric article.

Alan D Rousseau, Marvin E Jones, Seyed A Angadjivand: Electret filter media containing filtration enhancing additives. Minnesota Mining and Manufacturing Company, Karl G Hanson, Carole Truesdale, November 2, 1999: US05976208 (47 worldwide citation)

Electret filter media comprising a fibrous web of a blend of a thermoplastic resin and at least one compound or oligomer that enhances the web's electret properties.

David L Braun, James E Steffen: Fibrous filtration face mask having corrugated polymeric microfiber filter layer. Minnesota Mining and Manufacturing Company, Gary L Griswold, Walter N Kirn, Karl G Hanson, August 12, 1997: US05656368 (47 worldwide citation)

A composite structure contains a lofty corrugated nonwoven web of polymeric microfiber that is maintained in a corrugated condition by securing a fabric to the corrugated web at the valleys of the corrugations. The composite structure is made without substantially effecting web loft by (i) introduci ...

Seyed A Angadjivand, Marvin E Jones, Daniel E Meyer: Electret filter media. Minnesota Mining and Manufacturing Company, Carole Truesdale, Karl G Schwappach, Karl G Hanson, September 19, 2000: US06119691 (46 worldwide citation)

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 unpol ...

David M Castiglione: Respirator nose clip. Minnesota Mining and Manufacturing Company, Gary L Griswold, Walter N Kirn, Karl G Hanson, September 24, 1996: US05558089 (46 worldwide citation)

A nose clip 12 useful for fitting a respirator 10 over a person's nose. The nose clip 12 includes a non-linear strip 18 that has first and second wings 20 and 22 and a midsection 24. There are first, second, and third inflections 26, 28, and 30 disposed, respectively, between the first wing 20 and t ...


Gregory Yuschak, Peter O Rekow, Thomas W Holmquist Brown: Respirator having snap-fit filter cartridge. Minnesota Mining and Manufacturing Company, Gary L Griswold, Walter N Kirn, Karl G Hanson, December 3, 1996: US05579761 (43 worldwide citation)

A respirator (10) that includes a face piece (14) and a cartridge receiving structure (22) located on the face piece (14). The face piece (14) is sized to fit snugly over the nose and mouth of a person, and the filter cartridge (12) is capable of being manually snapped into engagement with the cartr ...