1
James F Dyrud, Harvey J Berg, Alice C Murray: Resilient shape-retaining fibrous filtration face mask. Minnesota Mining and Manufacturing Company, Donald M Sell, Roger R Tamte, February 28, 1989: US04807619 (136 worldwide citation)

New molded fibrous filtration face masks that are highly resilient and shape-retaining are provided using one or more molded fibrous shaping layers, with a fibrous filtration layer disposed on one side of or between the molded fibrous shaping layers; the molded fibrous shaping layers having a total ...


2
Minnesota Mining And Manufactu: Resilient shape-retaining fibrous filtration face mask.. Minnesota Mining & Mfg, October 14, 1987: EP0241221-A1 (12 worldwide citation)

Resilient shape-retaining face mask (10) comprising molded, bonded, high-basis-weight, lofty fibrous shaping layers (15, 17) and a fibrous filtration layer (16).


3
Murray Alice C, Dyrud James F, Berg Harvey J: Masque filtrant fibreux souple a memoire de forme, Resilient shape-retaining fibrous filtration face mask. Minnesota Mining And Manufacturing Company, SMART & BIGGAR, December 17, 1991: CA1293094

Abstract Resilient shape-retaining face mask comprisingmolded, bonded, high-basis-weight, lofty fibrous shapinglayers and a fibrous filtration layer.