It is mainly silk and cotton yarn singeing.
Silk is a product of silk spinning. Because of its long hairs and adherent coarse grains and chips, it has to be burned. After singeing, these hairs and coarse grains of ashes form spherical hardening, which is not easy to remove from the surface of silk. Therefore, there are a number of nail caps on the silk singeing machine. The silk is wound on the rotating nail cap with a certain tension, and the ash is removed by the friction between the nail cap and the yarn through the flame mouth five to nine times, then the silk is wound on the cylinder. The main technological conditions of singeing are flame temperature, speed of silk passing through flame, distance between silk and flame core, number of nail caps, tension and number of times of singeing. These conditions are generally determined according to the quality requirements of finished products. Sintering cleanliness is one of the evaluation indexes of silk appearance quality.
Cotton yarn singeing is mostly used in the production of cotton yarn, sewing yarn and embroidery yarn for sweater weaving. Its technological conditions are similar to that of silk singeing, but because the ash of cotton fibers is easily removed after burning, no nail cap device is needed for singing. Sintering loss should be considered in process design to ensure that yarn count meets the requirements. The heat source of yarn singeing machine is usually gas, but there are other heat sources.