Molded respirators containing an air-permeable, sorbent-particle-containing layer between air-permeable particle-retaining layers. The particle-containing layer is stretchable during shaping without tearing or significant loss of particles. At least some of the fibers in the particle-containing layer...http://www.google.com.au/patents/US6102039?utm_source=gb-gplus-sharePatent US6102039 - Molded respirator containing sorbent particles
