3613678 is referenced by 36 patents and cites 7 patents.

A face mask having high and prolonged filtering efficiency specially adapted for surgical use formed from a filtering web composed entirely of synthetic organic fibers including filtering fibers 0.5 to 6 microns in diameter and a nonfuzzy face contacting layer formed from a porous smooth-surfaced thermoplastic film.

Title
Filtration mask
Application Number
05/014,210
Publication Number
3613678
Application Date
February 24, 1970
Publication Date
October 19, 1971
Inventor
Mayhew Delbert J
Assignee
Minnesota Mining and Manufacturing Company
IPC
A62b 23/06
A41D 13/11
A41D 13/05
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