Effects of Commercial Heat Setting on the Structure and Properties of Polyester Carpet Yarn

Abstract

Polyester carpet yarn is heat set during the production process in order to impart structural stability. Although batch (autoclave) and continuous (Superba TVP and Suessen GVA ) heat setting methods are used, the continuous processes are prevalent and constitute a greater part of this study. Commercial heat setting equipment and settings are used here because previous works were the results of laboratory studies. The primary technique applied in this study to determine the microstructural features of polyester is x-ray diffraction. Crystallization and crystallite melting temperatures from differential thermal analysis ( DTA ) and colorimetric determinations of initial rates of dyeing are also measured to provide additional data for interpreting the results, and tensile properties of the yarns are reported as well. X-ray and DTA results indicate no significant increases in the degree of crystallinity of yarns heat set by the Superba TVP method, while crystallinity increases with in creasing temperature for samples heat set by the Suessen GVA method. Crystal size increases for samples heat set by either of the continuous methods. Although x-ray determined crystallinity measures are significantly different at different levels of tem perature and dwell time, there are no significant differences in heat of fusion values obtained from DTA with changes in heat setting temperatures and dwell times. Te nacity, percent elongation, and work to break increase as a result of heat setting for samples set using the Superba TVP, autoclave, or Suessen GVA equipment, while the initial modulus decreases compared to a non-heat set sample.