Views: 342 Author: Site Editor Publish Time: 2021-03-26 Origin: Site
Because of the different properties of various fibers, it is necessary to select suitable dyes when dyeing. For example, when cotton fiber is dyed, because its molecular structure contains many hydrophilic hydroxyl groups, it is easy to absorb moisture and expand, can react chemically with reactive groups, and is more alkali-resistant, so you can choose direct, reduced, vulcanized, and ice dyes. And reactive dyes. Polyester has strong hydrophobicity and is not alkali-resistant at high temperatures. Under normal circumstances, the above dyes should not be used, but disperse dyes should be used for dyeing.
Due to the different purposes of the dyed materials, the requirements for the fastness of the dyed finished products are also different. For example, the cloth used as curtains is not often washed, but it is often exposed to sunlight. Therefore, when dyeing, choose dyes with higher light fastness. As the dyeing of underwear and light-colored fabrics worn in summer, because it needs to be washed and exposed frequently, dyes with high fastness to washing, light and sweat should be selected.
When choosing dyes, we should not only consider the shade and fastness, but also consider the cost and supply of dyes and auxiliaries. For higher-priced dyes, other dyes that can be dyed with the same effect should be considered as substitutes to reduce production costs.
When color matching is required, when selecting dyes, attention should be paid to their composition, solubility, color fastness, dye uptake and other properties. As the dyeing properties of various dyes are different, the dyeing effect is often affected by the difference in temperature, solubility, and dye uptake during dyeing. Therefore, when performing color matching, dyes with similar properties must be selected, and the closer the better, which can help control the process conditions and stabilize the dyeing quality.
Due to different dyeing machinery, the properties and requirements of dyes are also different. If it is used for jig dyeing, the dye with higher directness should be selected; for pad dyeing, the dye with lower directness should be selected, otherwise it will produce products that do not meet the requirements such as dark front and light back, uneven color and luster.