1、 Direct dyes:
The heat-resistant stability of direct dyes is relatively good. Direct dyes can be dissolved with soda ash soft water. When chemical materials are used, first mix the dyes into slurry with cold soft water, then stir and dissolve them with boiling soft water, dilute them with heating water, and then add water to the specified amount after cooling.
2、 Reactive dyes:
Such dyes are not heat-resistant and easy to be hydrolyzed at high temperature. It is advisable to use cold soft water to make a slurry. Then, according to the hydrolysis stability of different dyes, use soft water at appropriate temperature to dissolve, heat soft water to dilute, and add soft water to the specified amount after cooling.
Low temperature type (type X): use cold water or 30-35 ℃ warm water (basically eliminated)
70-80 ℃ hot water is used for high temperature type (K type, he type, etc.)
60-70 ℃ hot water for medium temperature type (KN, M type)
For those with low solubility, use hot water at 90 ℃
3、 Vat dyes:
The dissolution process of vat dyes is a reduction reaction process. When dissolving, the dissolution temperature should be determined according to the reduction conditions of the reducing agent used. For example, the common reducing agent of vat dyes is insurance powder, and the best use temperature in the solution is 60 ℃. Too high temperature will lead to a large amount of decomposition of insurance powder.
(1) Full bath method:
Put the dye into the dyeing cup, add red oil and a small amount of warm and soft water successively, mix well, then add the specified amount of caustic soda and insurance powder, add soft water to the required bath amount, and reduce it at 55 ℃.
(2) Dry cylinder method:
Put the dye into the dye cup, add red oil and a small amount of warm and soft water successively, and then add two-thirds of the amount of caustic soda and insurance powder to make the amount of dye solution one-third of the total amount. The dissolution temperature shall be determined according to the reduction conditions of the reducing agent used. Add the remaining caustic soda and insurance powder into the dyeing cup and add soft water to the required bath volume.
4、 Sulfur dyes:
Accurately weigh the required amount of dye into a beaker, mix it into a slurry with cold soft water, then add the dissolved sodium sulfide dye solution and boil for 10 minutes. Heat soft water for dilution, and add soft water to the specified amount after cooling.
5、 Disperse dyes:
When the temperature is too high, disperse dyes are easy to crystallize and precipitate. It is advisable to mix the slurry with cold soft water first, then use cold soft water below 40 ℃ to melt the material, and add soft water to the specified liquid volume
6、 Acid dyes:
The heat-resistant stability of acid dyes is relatively good. When converting acid dyes, first mix the dyes into slurry with cold soft water, then boil the soft water, stir and dissolve, heat the soft water to dilute, and add soft water to the specified amount after cooling
7、 Cationic dyes:
The heat-resistant stability of cationic dyes is relatively good. When chemical materials are used, first mix the dyes into slurry with concentrated acetic acid (solution aid), then stir and dissolve them with boiling soft water, dilute them with heating water, and add soft water to the specified amount after cooling
