1. Choose dyes according to the mechanical properties of dyeing: Due to different dyeing machinery, the properties and requirements of dyes are different. If it is used for jelly dyeing, a dye with higher directness should be selected; for pad dyeing, a dye with lower directness should be selected; otherwise, products that do not meet the requirements such as front deep and light back, uneven color and luster will be produced.
2. Choose dyes according to fiber properties: Due to the different properties of various fibers, you need to choose a suitable dye 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. It can react with reactive groups and is more resistant to alkali. Therefore, direct, reduction, vulcanization, and ice dyes can be selected. And reactive dyes. Polyester has strong hydrophobicity and is not resistant to alkali at high temperatures. Generally, the above dyes should not be used, but disperse dyes should be selected for dyeing.
3. Selection of dyes when color-matching: When color-matching is needed, when choosing dyes, 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 temperature, solubility, and dyeing rate during dyeing. Therefore, when color matching is performed, dyes with similar properties must be selected, and the closer the better, the better the control of process conditions and the stability of dyeing quality.
4. Select dyes according to the use of the dyed object: Because the use of the dyed object is different, the fastness requirements of the dyed product are also different. For example, the cloth used as curtains is not often washed, but it is often exposed to sunlight, so when dyeing, you should choose a dye with high light fastness. As the dyeing of light-colored fabrics for underwear and summer wear, since it is often washed with water and sun, you should choose a dye that has high washing fastness, lightfastness and sweat fastness.
5. Choose dyes according to the cost of dyes: When choosing dyes, we must not only consider the light and fastness, but also consider the cost of dyes and auxiliary agents and the source of supplies. For example, dyes with higher prices should be replaced with other dyes that can achieve the same effect as far as possible to reduce production costs.
So everyone masters the above five points, and then you can choose the dye that suits you according to your actual situation!