Twist Setting

Twist is what finally gives the power to the yarn. It brings out drape, feel, strength for weaving and crease qualities.

Higher the twist, higher is the torque in the yarn and this torque is a mess in warping and weaving. In warping, the yarns would slough off the package and in weaving, the weft would pop up incrementally and give trough to the fabric. It is for this very reason that twisted yarns are very rarely used in weft.

Twisted yarns need to be twist stabilized, but the way the system is designed is a disaster. The yarns are shoved into a steaming oven, wherein after a certain time and certain temperatures are pulled out and put to use.

How can steam or hot air ever penetrate the inner layers of yarn and even with conductivity, yarns inside layers to outside layers and middle layers have differential heat exposure and hence differential shrinkage. One of the effects of this shrinkage is a twist CV% going out of range and hence a differential dyeing result.

Interestingly , the fabric dyer believes that it is a dyeing problem and keeps trying to change recipes to take care of streaks and deep dyeing etc, but can never imagine for his life that the problem is with the twist of the yarn in the fabric. Same applies to yarn dyeing.

The whole know how in good stabilized twisted package is with optimizing the density of the package in twisting machines. Unless, one makes soft packages to allow the steam to easily enter the package and stabilize all layers of package, the twist setting would remain sub optimal.

As a hint, the density of polyester textured yarns should be around 450 gms per litre as maximum and for FDY yarns should be around 220 gms per litre. But to get such levels of density, the twisting machines need to be tweaked.

Secondly, the package centre has to be a spring bobbin only. Mantex Dyesprings are the best option.

All textured and FDY yarns, which go for high twist should be with zero residual lubricant, otherwise,it would give yellow color with steam. Secondly, the steamer should have water purifiers lest the hardness of water would give yellow color as compliment.

Timing in a steamer depends upon the torque in the yarn and hardness of the package.