Patent ID: 6602311
Filing Date: 2003-08-05
Classification: A24D,D01D,D04H,Y10S

Abstract:
A coalescing element formed from a homogeneous web of mixed fibers, some of which comprise a material selected from the group consisting of homopolymers and copolymers of fluorocarbon polymers and chlorinated fluorocarbon polymers, and the remainder of which comprise a bonding polymer, said fibers comprising said material being bonded to each other at spaced points of contact by said bonding polymer to form a porous matrix, wherein said fibers comprising said material are bicomponent fibers comprising a core of said bonding polymer and a sheath of said material, said web of mixed fibers being produced by a fiber spinning process comprising the steps ofproviding at least two independent sources of polymer materials, feeding said polymer materials from each of said independent sources into a spinning device including at least one element defining a plurality of spinneret orifices, maintaining said polymer materials in mutually separated distribution paths in said spinning device at least until said polymer materials approach the inlets to the spinneret orifices in said element, flowing at least some polymer material from one of said independent sources into selected ones of the spinneret orifices in said element and flowing at least some polymer material from another of said independent sources into different selected spinneret orifices in said element under conditions causing extrusion from the spinneret orifices of said element of a homogeneous web of fibers, at least some of said fibers formed from said web of fibers having different characteristics from other fibers formed from said web of fibers, wherein said polymer materials from said independent sources comprise different polymers whereby individual fibers in said web of fibers comprise different polymers from other fibers in said web of fibers, wherein portions of at least two of said polymer materials are combined as they enter said selected ones of the spinneret orifices so as to be extruded therefrom as multiple-component fibers, whereby said web of fibers comprises a mixture of multiple-component fibers and single component fibers, and wherein said multiple-component fibers each comprise a core of the same polymer material forming said single component fibers, and a sheath of a different polymer material, and the ratio of said multiple-component fibers and said single component fibers being substantially uniform throughout said web of mixed fibers.