Effect of Twist on Yarn Strength
Short chief yarn
Twist is communicated into a chief yarn to bind the filaments together and give consonance to give strength to the yarn. originally, with the proliferation of twist, the side force holding the filaments also increases, which allows further filaments to contribute to the yarn strength. But secondly, when twist increases from the optimum position, the angle of filaments made with the axis of the yarn also increases, which makes the filaments contribute lower to the yarn strength. The influence of adding twist on the strength of a chief spun yarn is shown in Figure- 1.

nonstop hair yarns
In the case of hair yarns, a small quantum of twist is demanded to hold the hair filaments together. thus increase in twist will drop the strength of hair yarn. This is due to the fact that the fibers are stronger than short chief filaments, so lower twist is demanded to conduct strength in the case of hair yarns. Theoretically the maximum strength of a nonstop hair yarn is possible when the fibers are acquainted parallel to the axis of the yarn. Since the fibers are of variable strength, so the primary function of twist is to give support to weaker fibers therefore performing in an increase in the yarn strength. The influence of adding twist on a nonstop hair yarn is shown in Figure- 2.