YARN TWIST, DEGREE OF TWIST , S - TWIST, Z - TWIST

Yarn twist (Degree of twist):

The yarn twist is a very important parameter. The amount of twist required to hold the fibers and yarns together depends on the diameter or size of yarns. The coarse yarn needs less amount of twist to hold the fibres together in the yarn and fine yarn needs more amount of twist to hold the fibres together in the yarn. The amount of twist or degree of twist seriously affects the performance of yarn. If the yarn has less twist than standard then fibre slippage may occur. The yarn having low twist posses low strength. There may be the chance of pilling formation due to low twist. It will give soft feel and touch. If the yarn has more twist than standard. The yarn will show good strength but it will give rough feel and touch. There may be a chance of snarling too. The amount of twist is expressed in turns/inch.

·       T.P.I. – turns per inch In the yarn.

Type of twist: it shows the direction of twist. There are two types of twist direction possible which are:

·       S-twist:

The clockwise twist of yarn is called s-twist. The inclination of fibres in yarn looks similar to the middle part of the English letter “S”.

·       Z-twist:

The anticlockwise twist of yarn is called z-twist. The inclination of fibres in the yarn looks similar to the middle part of English letter Z.