The frictional force between fibers determines the strength of staple yarns, which reflects the fiber surface properties and the transverse pressure in the fiber assembly. The conventional method of creating transverse forces of coherence between fibers during the spinning of staple yarn is twisting, either by rotating the output package (traditional spinning) or rotating the forming yarn end (open end spinning). The strength of the yarn depends on the configuration uniformity and tightness of the wrapping fibers. Air jet spun yarns are considered superior to ring spun yarns in most properties, with the notable exception of single yarn strength. Air jet spinning uses false twist technology in which only a small percentage of fibers is actually wrapped around the core yarn. Tenacity is created by tightening the wrapping fibers under elongation. Thus, the fibers most suitable for air jet spinning are those with high elongation, high tenacity, and greater strength.