Primary Heater and Heat Setting Systems
topic
False twist texturing primary heaters maintain yarn at 180 to 220 degrees Celsius for polyester and 160 to 195 degrees Celsius for nylon through contact with a heated plate or non-contact convection heater over 1 to 2 metres length, thermally setting the twisted filament crimp geometry through polymer crystallisation at the heater temperature that determines crimp amplitude, frequency, and permanence in the finished textured yarn.
Role
Sets the helical crimp geometry thermally in the highly twisted yarn configuration that will partially unfold to provide bulk and stretch in the finished textured yarn, with heater temperature being the most critical false twist texturing process variable that determines crimp stability, yarn elasticity, and bulk through its effect on the degree of polymer crystallisation achieved during the heat setting dwell time in the primary heater zone.