摘要 |
<p>A respirator is sealed at its sides to the face of a wearer by seals comprising a multiplicity of bristles. The length of the bristles is chosen so that they are deflected to lie at their free ends against the wearer's face. The length resilience and packing density of the bristles is selected to provide a required resistance to air flow. The bristles are of horse hair, camel hair, nylon, polypropylene, or other noninjurious material. Preferred bristle diameters are 0.03 to 0.25 mm and lengths 10 to 30 mm.</p> |