Patent ID: 7431869
Filing Date: 2008-10-07
Classification: D01D,D01F,D04H,Y10T

Abstract:
1. A method of forming fibers, comprising: delivering at least first and second polymer components in a molten state from a spin pack to a spinneret, wherein the first polymer component comprises at least one polymer that is at least partially dissolvable in a dissolving medium and the second polymer component comprises at least one of polyacrylonitrile and pitch; and extruding fibers including the first and second polymer components from the spinneret, wherein at least some of the fibers include islands-in-the-sea fibers, each islands-in-the-sea fiber includes island segments disposed within a sea section, the sea sections of the islands-in-the-sea fibers comprise the first polymer component, and at least some of the island segments comprise sheath-core segments including a sheath section comprising the second polymer component surrounding a core section.