Flow Drawing Behavior of Poly (ethylene terephthalate) Fiber Heated by CO2 Laser Irradiation

Poly (ethylene terephthalate) fiber was continuously flow drawn with heating by CO, laser irradiation. The flow drawing behavior was discussed with the view point of the irradiated laser energy and draw ratio. The drawing behavior can be classified into 4 categories; (1) only stable neck drawing can be observed, (2) both neck and flow drawing can be observed, (3) only stable flow drawing can be observed, and (4) melt down or break. The fiber temperature and the fiber speed profile on the flow drawing process were measured. As the results, it revealed that the maximum fiber temperature on the drawing process was the range of 210 to 225 degrees C, and the length of deformation region increase with the draw ratio. The apparent elongational viscosity of the flow drawing process was also estimated by the measured fiber speed profiles, and was compared with the reported values of the neck drawing process and the melt-spinning process. The minimum value of the apparent elongational viscosity was about 10 - 20 kPa.s regardless of the draw ratio. (Received 30 September 2010; Accepted 28 October 2010)