Production of high strength polyethylene filaments
 Production of polyethylene filaments of tenacity at least 30 g/d from a hot, supersaturated solution of high viscosity polyethylene having intrinsic viscosity of at least 11 dl/g, by contacting a length of such filament (functioning as a seed) simultaneously with a stationary arcuate surface and with such polyethylene solution, and withdrawing the filament through the solution in sliding contact around the surface at a rate reaching at least 30 cm per minute thereby producing tension and inducing crystal growth from the solution onto the filament, with increase of tension up to a steady state tension of at least 70 grams. More particularly the polyethylene has intrinsic viscosity of 17-28 dl/g, the solvent is xylene, the surface is composed of PTFE, the polyethylene concentration is 0.1 to 0.5 wgt. percent, the rate of withdrawing the filament is at least 200 cm per minute, and the polyethylene seed filament is initially led around the arcuate surface by attaching the filament to an endless loop which is drawn through the solution and around the surface; and then the seed filament is passed to a takeup reel; and afterward (when the tension has reached at least 70 g) the seed filament is severed from its supply source while growth of the product filament on the seed filament and from the end thereof proceeds. 
Allied Corporation
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D01F D01D
inventional inventional
Dusan C. Sheldon Donald G.
Prevorsek Kavesh Wang