The application of the dyeing agent

1.Dyeing agent are selected according to the fiber properties. Due to the different properties of various fibers, appropriate dyeing agent need to be selected when dyeing. For example, when dyeing cotton fiber, because its molecular structure contains many hydrophilic hydroxyl groups, it is easy to absorb moisture and expand, can react with reactive groups, and is more alkali resistant, so direct, reduction, vulcanization, ice dyes and reactive dyes can be selected for dyeing. Polyester has strong hydrophobicity and is not alkali resistant at high temperature. Generally, the above dyes should not be selected, but disperse dyes should be selected for dyeing.

2. Select dyeing agent according to the use of the dyed objects. Due to the different uses of the dyed objects, the requirements for the fastness of the dyed products are also different. For example, the cloth used for curtains is not often washed, but it should be often exposed to sunlight. Therefore, when dyeing, dyes with high light fastness should be selected. As light colored fabrics for underwear and summer wear, dyes with high washing, sun resistance and sweat fastness should be selected because they should be washed and exposed to the sun frequently.

3. Select dyeing agent according to the cost of dyes. When selecting dyes, we should not only consider the color light and fastness, but also consider the cost and supply of dyeing agent and additives. If the price of dyes is high, try to replace them with other dyeing agent that can get the same effect, so as to reduce the production cost.

4. Selection of dyeing agent during color matching. When color matching is required, pay attention to their composition, solubility, color fastness, dye uptake and other properties. Because the dyeing properties of various dyes are different, the dyeing effect is often affected by the difference of temperature, solubility and dye uptake. Therefore, when color matching, dyes with similar properties must be selected, and the closer the better, which can be conducive to the control of process conditions and the stability of dyeing quality.

5 select dyeing agent according to the dyeing mechanical properties. Due to different dyeing machines, the properties and requirements of dyes are also different. If it is used for roll dyeing, dyes with high directness shall be selected; For pad dyeing, dyes with low directness should be selected, otherwise products that do not meet the requirements such as deep in the front and light in the back, uneven color and so on will be produced.