Dye application
1.According to the nature of the fiber selection of dyestuff various fibers due to their different properties, when dyeing need to choose the appropriate dyestuff. For example, when dyeing cotton fiber, because its molecular structure contains many hydrophilic hydroxyl groups, easy to absorb moisture expansion, can react with reactive groups, and more resistant to alkali, so you can choose direct, reduction, sulfur, ice dyes and reactive dyes dyeing. Polyester is hydrophobic and not resistant to alkali at high temperature, so it is generally not suitable to use the above dyes, but should choose disperse dyes for dyeing.
2. Select dyestuff according to the use of the dyed material Because the dyed material is used for different purposes, the fastness requirements of the dyed products are also different. For example, the cloth used for curtains is not often washed, but it is often exposed to sunlight, so when dyeing, we should choose dyes with higher fastness to sunlight. When dyeing underwear and light-colored fabrics worn in summer, dyes with higher fastness to washing, sunlight and sweat should be chosen because they are washed and sun-dried frequently.
3. Choose dyestuff according to the cost of dyestuff When choosing dyestuff, we should not only think about the color light and fastness, but also consider the cost and source of dyestuff and additives used. If the price of dyestuff is higher, we should try to consider using other dyestuff that can dye the same effect to reduce the production cost.
4. Selection of dyestuff for color matching When color matching is needed, attention should be paid to their composition, solubility, color fastness, dyeing rate and other properties when choosing dyestuff. Since the dyeing properties of various dyes are different, the dyeing effect is often affected by the difference in temperature, solubility and dyeing rate. Therefore, when color matching, it is necessary to choose dyestuffs with similar properties, and the more similar the better, so as to facilitate the control of process conditions and the stability of dyeing quality.
5 Select dyestuff according to the performance of dyeing machinery Because of the different dyeing machinery, the nature and requirements of the dyestuff are different. If used for roll dyeing, the dyestuff with higher directness should be chosen; for rolling dyeing, the dyestuff with lower directness should be chosen, otherwise it will produce products that do not meet the requirements such as deep before and light after, uneven color.
