Abstract
The changes in the structure of commercial polyethylene terephthalate yam, when it is textured on a spindle false- twist machine, have been studied over a range of heater temperatures and heater contact times. Compared to the un textured yarn, crystalline content increases on texturing, but crystallite orientation, birefringence, and amorphous orien tation decrease. The changes in these structural parameters with temperature and time of texturing are discussed.