twisting

In the case of yarns which are spun by intermittent methods, for example the drop spindle, spinning wheel or Indian charkha, the twist is inserted into the yarn by rotation of the spindle, one turn of the spindle per one turn of twist in the yarn.  Yarns spun by the continuous methods twist is inserted into the yarn if one end is held and the other swung round in a circular path and simultaneously wound onto a bobbin or other type of collector. Testing the twist (T.P.I. or T.P.M.) of yarn can be done using a simple twist testing device.