false twisting

False twisting is a texturizing process used in man-made fiber manufacturing to create crimp, loops, or coils in filaments. This process significantly affects the feel and behavior of fabrics made from these fibers.

In false twisting, a heated multifilament yarn is twisted at high speed. It is then cooled in this twisted state, setting the twist geometry. Subsequently, the yarn is untwisted, but the filaments retain a convoluted structure. This results in a textured yarn with greater volume compared to its untextured state. This technique is often combined with drawing, particularly for partially oriented nylon and polyester yarns.1

Twisting itself is a fundamental process in yarn and rope production, binding fibers or yarns into a continuous strand. The direction of the twist (Z or S) and the number of turns per unit length influence the fabric's appearance and durability.23