Direction of twist (S or Z): That means the inclination direction of spiral when the vertical yarn rotate around the axis. S direction is the right direction or clockwise direction, Z direction is the left direction or anti-clockwise direction.
Twisting and strength : Twisting of yarn is proportional to the strength, however, when twisting reaches a certain level, higher twisting will lead to lower strength. Excess twisting will make the threads matt and rough. And insufficient twisting will make the threads hairy and loose.
In short, there is great relationship between strength and twisting. Twisting degree and direction depends on processing demand, generally we adopt “Z” direction.
Jan 302013
