Composite fibres of partially crosslinked polyesters - offering a wool like feel from short spun fibres

摘要

Conjugated filaments made of two materials extruded in parallel and used as chopped fibres to make yarns which handle like wool and have a shrinkage of 60, , pref. 40% and 7, pref. 7-10 semi-undulations/cm. Component resins are (I) polyethylene terephthalate of intrinsic viscosity 0.45-0.60 and crosslinked with 0.20-0.70 mole % of a trior tetrafunctional reagent, pref. trimethylopropane (II) polybutylene terephthalate incorporating 0.20-0.60 mole % crosslinking agent and having melt viscosity 4000 poises at 260 degrees C. Yarns incorporating 50-80% wt. I/50-20% wt II, made by coextrusion followed by drawing (x 2.6 - x 3.3) in steam at 80-100 degrees C and crimping at 100-150 degrees C.