Twist

Twisting is the process of combining filaments into yarn by twisting them together or combining two or more parallel singles yarns (spun or filament) into plied yarns or cords. Twisting increases strength,smoothness and uniformity.

Many high performance yarns benefit from the improved load sharing that twisting allows. Optimum twist level varies with the material, fiber size, yarn size, end use, etc. Table 19 illustrates Vectran’s tenacity response to varying twist level, suggesting tenacity optimums of 2.5 TPI for 400 denier and 1.5TPI for 1500 denier yarns. Similar tests determine ideal cord and cable pick levels (Figures 25, 26).