Thermodynamic Equilibrium Shifts of Cyclic Oligomers during High Temperature Yarn Texturing
High heater temperatures mobilize PET cyclic trimers, driving surface crystallization that glazes texturing discs and requires strict HPLC wash thresholds.
False Twist Texturing
Mechanical Principle
Filament crimping machinery generates permanent bulk in synthetic yarns by imparting temporary twist and setting the geometry with heat before untwisting the running yarn downstream. Industrial false twist texturing converts flat partially oriented yarn into elastic textured filament through continuous friction disc assemblies. The process leaves zero net twist in the final package while permanently fixing three-dimensional crimp structure in single filaments.
Kinematic Control
Friction disc geometry and surface friction coefficients govern twist density within the primary heater zone. In false twist texturing, ratio adjustments between disc surface speed and yarn delivery speed adjust crimp rigidity. Overfeed rates control tension inside the second heater to regulate residual torque.
Defect Profile
Surges in running yarn tension produce localized structural defects in the wound bobbin. Insufficient twisting torque during false twist texturing creates untextured filament segments that appear as dark streaks in dyed knitted fabrics. Heat fluctuations cause uneven dye uptake across dye lots.
Testing Protocol
Quality control laboratories verify crimp properties using standardized skein contraction test methods. Mill technicians evaluate false twist texturing consistency by measuring crimp rigidity and crimp stability on sample skeins after hot water immersion. Automated tension sensors detect process deviations in real time.