- Secondary carding
Secondary carding of colour spinning is mainly aimed at cotton fibers. Some of the cotton fibers in raw materials need to be carding twice. That is, after the first carding (or combing) and then the second carding.
For medium and high-grade color spinning products, the dyed cotton in the raw materials is mostly combed twice. The first combing is before the dyeing of raw materials, and the second combing is after the dyeing of fibers.
Raw materials need to be combed twice for the purpose of:
(1) Remove the colour spots formed by the fine neps. In colour spinning, fine neps may not form harmful defects, but neps in colour spinning become colour neps, because there are colour differences, even very small may highlight harmful defects.
(2) Ensure even mixing. Carding (carding and combing) stage in spinning process is an important link to achieve full blending (single fiber blending) of multi-mark raw materials. Of course, blending of multi-color fibers in color spinning can not give up the blending effect of carding stage. However, the noil in carding stage is not conducive to ensuring the multi-component color mixing ratio in color spinning, because the noil ratio of various colored raw materials can not be controlled, which will lead to the color ratio out of control, resulting in the final yarn produced color difference from the original design, which is a big taboo in color spinning. The noil rate of cotton fibers after one carding is very small after the second carding. The risk of color ratio runaway caused by noil can be reduced by multi-component mixing with the second carding.
It can be seen that the characteristics of carding objects are: colored fibers (cotton, chemical fibers dyeing or chemical fibers source liquid dyeing); heterosexual mixed fibers (heterochromatic mixing, cotton and chemical fibers mixing); carding cotton fibers (dyeing or natural color).