Study On Color Difference Of Cashmere Hank Dyeing

Color difference in dyeing is the most common quality problem in dyeing enterprises. It is also a complex and unsolved quality problem to the colorists in the long term. With the expansion of China's textile exports, participating in an increasingly competitive international, color grading requirements were becoming more stringent. Therefore, it is increasingly important that how to improve accuracy and stability of the dyeing fabric color light and adapt to the demands of clients. It is not only related to the economic efficiency of enterprises, but also more related to the enterprise's reputation.Color difference range is very wide. It includes color difference between customer's sample and laboratory sample, laboratory sample(or duplicate sample) recipes are used for large production what be come into being color difference between bulk and laboratory sample, color differences between vats in same batch and color differences between batches and so on.Controlling every link of dying seriously could minimize the color difference. The color difference could come out not only just in the dying procession. Factors lead to color difference which is wide range. It involves not only in the dying process and technology, but also is closely related to management, equipment and operating factors, dyes chemicals etc. The whole process is complex. Any links is mistake which will touch an outbreak influencing the whole of its quality. Used suitable dyestuff of dyeing and managed assistant well can prevent the fluctuation of assistant which can generate colour differeance minimizing. The consolidation of procession of dying, such as accurately measure, strictly control ratio of bath, pH, up and down of temperature can prevent the influence of after treatment to color differeance. Improvement quality of water and reaching a certain target is the basic work of the normal and little flow of process of dying.This paper takes cashmere hank dyeing as an example, some experiments and testing are operated in dongxu dyeing company and technique center of Erdos group from the view of pH value of dye bath, salt dosage, levelling agent dosage, bath ratio, the first heat preservation temperature, the final heat preservation time, yarn whiteness and yarn count etc which influence color difference. This paper analyzes the main factors influencing color difference between customer's sample and laboratory sample, color difference between bulk and laboratory sample, color differences between vats in same batch and color differences between batches can be found out through orthogonal experiment design, the reasonable process parameters be adjusted and enterprise production optimization technology curve be developed, and using the optimization process parameters and optimize the technology curve for cashmere hank dyeing, the results of which showed these methods can increase dyeing"one accuracy"(RFT), and ultimately reduce the color difference."The 30 percent technique, the 70 percent management"which means improving production operation of on-site technical management is the key to reducing color difference.