1. Selection of dyes according to fiber properties due to the different properties of various fibers, it is necessary to choose suitable dyes when dyeing. For example, when dyeing cotton fiber, because it contains many hydrophilic hydroxyl groups in its molecular structure, is easy to absorb moisture and expand, can react with reactive groups, and is relatively alkali resistant, so it can choose direct, reduction, vulcanization, ice dyes and reactive dyes for dyeing. Polyester hydrophobic, high temperature does not alkali resistance, generally should not choose the above dye, and should choose disperse dye dyeing.
2. Dye selection according to the use of the dye, due to different USES of the dye, the requirements for the fastness of the dyed products are also different. For example the cloth that USES as a curtain is infrequent wash, but want to often get sunlight illuminate, when accordingly dyeing, should choose fast fastness fastness is taller dye. As underwear and summer wear light color fabric dyeing, because to often wash, sun, so should choose fastness to wash, light, sweat fastness is higher.
3. According to the cost of the selection of dyes in the selection of dyes, not only from the color and fastness, but also to consider the cost of dyes and additives, supply, etc. If the higher price of dyes, should be considered to be able to dye the same effect of other dyes to replace, in order to reduce production costs.
4. Selection of dyes for matching colors when matching colors, attention should be paid to their composition, solubility, color fastness, dyeing rate and other properties. Due to the different dyeing properties of various dyes, the dyeing effect is often affected by the different temperature, solubility, dyeing rate, etc. Therefore, when matching colors, dyes with similar properties must be selected, and the closer the better, which is conducive to the control of process conditions and the stability of dyeing quality.
Dye selection according to dyeing mechanical properties due to different dyeing machinery, dye properties and requirements are not the same. If used for coil dyeing, should choose direct dye; For pad dyeing, you should choose a less direct dye, otherwise it will produce before dark after light, uneven color and other products do not meet the requirements.