Partially oriented yarn POY

PTT polymer pellets must be dried to a moisture level of <30 ppm, preferably in a close-loop hot air dryer, to avoid hydrolytic degradation during melt processing. Drying is canied out widi 130°C hot air witli a dew point of <—40°C for at least 4h. Because of tire faster ciystallization rate, PTT pellets are already semicrystalline after pelletizing, and do not require pre-crystallization prior to drying as with PET. The dried polymer is extruded at 250-270 °C into bulk continuous filaments (BCFs), partially oriented yarn (POY), spin-draw yarn (SDY) and staple fiber. 

Brown and Chuah [84] and Oppermann et al. [36] studied tire spinning of partially oriented yarn (POY) as a function of take-up speed from 500 to 5000 m/min. Figures 11.18 and 11.19 show, respectively, development of tire tenacity and elongation as a function of spinning speed. Tenacity increases witli increasing... 

The dried polymer is extruded at 250-265° C into fibers using conventional processing machines for bulk continuous filaments (BCF), partially oriented yarn (POY), spin-draw yarn (SDY), and staple fiber. 

POY-DTY partially oriented yarn-drawn textured yarn... 

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