Amount of Twist | Importance of Twist

Amount of twist

The amount of twist means the number of turns in unit length in a twisted yarn. If “n” be the number of turns in “L” length of yarn, then amount of twist will be n/L. Amount of twist is expressed in –

• Twist per inch (TPI)
• Twist per meter (TPM)
• Twist per centemeter (T.P.C.m) 

Here, twist per inch means the number of turns in unit inch and in the same way twist per meter and twist per centimeter is the number of turns in unit meter & unit centimeter. TPI of a yarn is 40 means the number of turns in 1 inch length of yarn is 40.

Amount of twist depends on the yarn count, for which purpose the yarn will be used and on the  length of yarn. Without these the amount of twist depends on the types of fabric i.e. for soft surfaced fabrics slack twist is given and such kind of yarn is called soft twisted yarn.

Importance of twist

1. Twist increase the tensile strength of yarn as well as the strength of yarn.
2. The yarn shape becomes round i.e. shape factor goes near 1 due to twist.
3. The inter-cohesion affinity of fibres increases due to twist and do not open easily.
4. The more twist increased under the constant value, the yarn become so strength.