Properties and Structures of Polyethylene Terephthalate Yarns in Conventional and Simultaneous Draw-Texturing

Abstract

This study was conducted on sets of yarns produced by two different texturing processes. One set was generated via conventional technology with predrawn feeder yarn, whereas the second set was produced by simultaneous drawing and twisting of an undrawn feed yarn. “Grab samples” obtained from zones throughout the processes permitted discernment, to a degree not previously reported, of intraprocess changes in yarn structural and physical attributes. To correlate changes in fine structure with specific properties of the textured yarn, comparisons of output from each of the two contrasted processes (and in some instances within each process) were obtained by the following techniques: stress-strain, density, rates of chain scission during aminolysis, wide-angle x-ray diffraction, and electron microscope studies. Details about process parameters for yarn systems are also presented, along with twist levels and twist contractions in the preheater, heater, and output zones.