PROCESS FOR PREPARING BICOMPONENT FIBERS COMPRISING POLY(TRIMETHYLENE TEREPHTHALATE)

摘要

Disclosed is a process for preparing crimpable bicomponent fibers from two poly(trimethylene terephthalate) starting materials that differ from one another in intrinsic viscosity. One starting material is characterized by an intrinsic viscosity ≦0.7 dL/g. The relatively low intrinsic viscosity allows the employment of a low melt temperature, with concomitant reduction in the evolution of acrolein, and without significant degradation in the properties or processibility of the bicomponent fiber.

主权项

1. A process comprising melting a first poly(trimethylene terephthalate) starting material characterized by an intrinsic viscosity of ≦0.7 dL/g to form a first melt stream characterized by a melt temperature less than 250° C., said first melt stream being characterized by an intrinsic viscosity that is no more than 0.03 dL/g lower than the intrinsic viscosity of said first starting material;
melting a second poly(trimethylene terephthalate) starting material characterized by an intrinsic viscosity >0.7 dL/g to form a second melt stream, with the proviso that the difference between the intrinsic viscosity of said first and second melt streams is >0.1 dL/g; providing said first and second melt streams to a spinneret therein contacting said first melt stream with said second melt stream; extruding a molten fiber from said spinneret; and, quenching said molten fiber to form a solid bicomponent fiber characterized by a first component and a second component disposed with respect to one another in a configuration suitable for the formation of crimp.