False-Twist Texturing (DTY Process)
topic
False-twist texturing (FTT) draws POY through a heater (180–220°C, H1), a false-twist spindle (friction disc or pin type, twist multiplier 60–90°/cm), a second heater (H2, 120–180°C for set), and winds as DTY. Simultaneously draws (DR 1.5–1.9×), twists (S or Z), and heat-sets the helical configuration. Output: bulk (high CB crimp elongation 20–50%), stretch (elastic recovery >80%), and cover.
Role
False-twist texturing converts flat POY into the bulked, stretchy DTY that constitutes the majority of polyester yarn used in apparel. Understanding its machine mechanics, heater dynamics, and quality parameters is essential for textile process engineering.