Process of making multiple mono-component fiber

Abstract

An apparatus for extruding a wide variety of plural-component and mixed monocomponent fiber configurations in a spin pack which utilizes one or more disposable distributor plates in which distribution flow paths are formed on one or both sides to distribute the polymer components to appropriate spinneret inlet hole locations. The etching process, itself inexpensive as compared to drilling, milling, reaming, etc., permits very thin metal plates to be employed, rendering the fabrication expense for the plates small, relative to the remainder of the spin pack, as to justify discarding or disposing of the plates rather than periodically cleaning them. The etching process also permits the etched distribution paths to be small and densely packed, whereby the spinneret orifices can be more densely packed in the spinneret and staggered as between rows and columns so as to increase the fiber yield per given spinneret surface area. The etching process also permits the distribution paths to be sufficiently small to facilitate issuing multiple discrete polymer component streams axially into each spinneret orifice inlet hole, whereby the resulting extruded fiber can be made up of at least one hundred side-by-side sub-fibers. If the adjacent sub-fibers are weakly bonded, they can be readily separated by agitation or dissolution to significantly increase the effective yield from the spin pack and provide very fine and uniform fibers. Importantly, these product advantages are achieved because of the etched disposable distribution plate which reduces initial and maintenance costs and is selectively replaceable to permit differently configured fibers to be fabricated from the same spin pack assembly.