The effect of first heater temperature on the properties of poly (ethylene terapthalate) filaments was characterized through measurements of tenacity, breaking elongation, boiling shrinkage, crimp stability, crimp contraction and crystallinity. It was found that crystallinity reached a maximum at a temperature around 200 C, and then started to decrease. A similar behavior was observed in crimp stability. Tenacity and crimp contraction increased and boiling water shrinkage decrn the heater temperature increased.
