Crimp behavior of DTY

The curling performance includes the curling rate KE, curling stability KB, and boiling water shrinkage rate. Generally, only the first two items or boiling water shrinkage rate need to be measured. The curl rate and curl stability can be obtained by the following equation:

In the formula: Lg is the length when the load is increased; Lz is the length when adding a light load; Lb is the length when removing heavy loads and adding light loads.

High shrinkage rate, DTY has a full hand feel, beautiful appearance, and good elasticity. Curling stability refers to the degree of gradual loss of curling rate during weaving and wearing, which is inversely proportional to the curling rate. So in actual production, these two indicators must be taken into account. DTY with higher shrinkage rate can mask some uneven dyeing, so the shrinkage rate is often controlled slightly higher during the production process. But if DTY uses tube dyeing in post-processing, due to the high shrinkage rate of DTY in boiling water, the tube is not easy to unwind after dyeing. If DTY yarn is used or dyed after weaving into fabric, there is no restriction, and the shrinkage rate can be controlled higher.

The process factors that affect the curling performance include stretching ratio, winding tension, and the temperature and temperature difference of the first and second heat boxes.