SPINNING HEAT-TREATED POLYURETHANE AND HARD POLYMER INTO CONJUGATE FILAMENT

摘要

In a process for melt-spinning a conjugate fiber from a hard polymer and a solid melt-spinnable fiber-forming polyurethane obtained by reacting together a polymeric glycol having a molecular weight between 800 and 3000, between 4.6 and 8.8 mols of an aromatic diisocyanate per mol of said polymeric glycol, and sufficient low molecular weight polyol to provide an NCO/OH ratio between 0.96 and 1.04 to 1; characterized by heating said polyurethane immediately prior to being melt-spun to a temperature within the range from at least and less than 255.degree.C. to form a molten stream. In the process, the denier uniformity can be improved and the shape of the interface between the two polymers can be controlled.