Abstract: A method of making a filtering face piece respirator, which method includes: providing a cup shaped mold 30; providing a forming chamber 24 where the mold 30 is located and where loose fibers 22 are introduced into air in the forming chamber 24; causing the loose fibers 22 to be accumulated 10 on the mold 30 in the forming chamber 24; and bonding 12 the accumulated fibers to each other at points of fiber intersection. The inventive method thus is beneficial in that it eliminates steps in the manufacturing process. The fibers also are uniformly distributed throughout the mask body, and because the webs do not have to be cut during respirator manufacture, less web waste is generated.

Abstract: Nonwoven electret fibrous webs including randomly oriented discrete fibers comprising electret fibers, the webs including a multiplicity of non-hollow projections extending from a major surface of the nonwoven electret fibrous web, and a multiplicity of substantially planar land areas formed between each adjoining projection in a plane defined by and substantially parallel with the major surface. In some exemplary embodiments, the randomly oriented discrete fibers include multi-component fibers having at least a first region having a first melting temperature and a second region having a second melting temperature, wherein the first melting temperature is less than the second melting temperature. At least a portion of the oriented discrete fibers are bonded together at a plurality of intersection points with the first region of the multi-component fibers. In certain embodiments, the patterned air-laid nonwoven electret fibrous webs include particulates.

Abstract: Nonwoven fibrous webs including randomly oriented discrete fibers defining a multiplicity of non-hollow projections extending from a major surface of the nonwoven fibrous web (as considered without the projections), and a plurality of substantially planar land areas formed between each adjoining projection in a plane defined by and substantially parallel with the major surface. In some exemplary embodiments, the randomly oriented discrete fibers include multi-component fibers having at least a first region having a first melting temperature and a second region having a second melting temperature, wherein the first melting temperature is less than the second melting temperature. At least a portion of the oriented discrete fibers are bonded together at a plurality of intersection points with the first region of the multi-component fibers. In certain embodiments, the patterned air-laid nonwoven fibrous webs include particulates.

Abstract: Nonwoven fibrous webs including a multiplicity of discrete fibers, a population of sub-micrometer fibers having a population median diameter less than one micrometer adjoining the discrete fibers, and a multiplicity of chemically active particulates secured to the nonwoven fibrous web. In some embodiments, more than 0% and less than 10% wt. of the nonwoven fibrous web is made of discrete fibers that are thermoplastic polymeric fibers, and which optionally at least partially melt and coalesce to secure the discrete polymeric fibers to each other. In certain embodiments, at least some of the particulates are bonded to the thermoplastic polymeric fibers. In other embodiments, at least some of the particulates are secured within interstices of the fibrous web, without substantial bonding to the discrete fibers. Methods of making and using such nonwoven fibrous webs are also described.