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Chemical Method For Various Dyes

Date:Sep 21, 2019

First, direct dye:

Direct dyes have relatively good heat resistance stability. Direct dyes can be added with soda ash soft water to help dissolve. When the materials are used, the dyes are firstly slurried with cold and soft water, then stirred and dissolved in boiling soft water, diluted with heating water, and water is added after cooling. Liquid volume.


Second, reactive dyes:

The dyes are not heat-resistant, and are easily hydrolyzed at high temperature. They should be prepared into a slurry by using cold and soft water. Then, according to the hydrolytic stability of different dyes, they are dissolved in soft water of suitable temperature, diluted with soft water, and softened to a prescribed amount after cooling.

Low temperature type (X type): use cold water or warm water of 30-35 ° C (already eliminated)

High temperature type (K type, HE type, etc.) with 70-80 ° C hot water

Medium temperature type (KN, M type) with 60-70 ° C hot water

Low solubility with 90 °C hot water


Third, vat dye:

The dissolution process of the vat dye is a reduction reaction process, and when dissolved, the dissolution temperature is determined according to the reduction conditions of the reducing agent used. For example, the reducing agent commonly used for vat dyes is a powder. The optimum temperature for use in the solution is 60 ° C. If the temperature is too high, the powder will be decomposed in large quantities.

(1) Full bath method:

Put the dye into the dyeing cup, add red oil and a small amount of warm water and mix thoroughly. Then add the specified amount of caustic soda and insurance powder, add soft water to the required bath volume, and reduce at 55 °C.

(2) Dry cylinder method:

Put the dye into the dyeing cup, add red oil and a small amount of warm water and mix thoroughly, then add two-thirds of the amount of caustic soda and insurance powder, so that the amount of dyeing liquid is one-third of the total amount, depending on the reducing conditions of the reducing agent used. To determine the temperature of the dissolution. Add the remaining caustic soda and powder to the dyeing cup and add soft water to the desired amount of bath.


Fourth, sulfur dyes:

Accurately weigh the required amount of dye in a beaker, mix it with cold soft water, then add the previously dissolved sodium sulfide solution and boil for 10 minutes. Dilute with warm water and add soft water to the specified amount after cooling.


5. Disperse dyes:

When the temperature is too high, the disperse dye is easily crystallized. When making the material, it is best to use cold and soft water to adjust the slurry, then use cold and soft water to make the material below 40 °C, add soft water to the specified amount.


6. Acid dyes:

The acid dye has relatively good heat resistance stability. When the acid dyeing material is used, the dye is firstly slurried with cold soft water, then stirred and dissolved in boiling soft water, diluted with soft water, and softened to a prescribed amount after cooling.


Seven, cationic dyes:

The heat resistance stability of the cationic dye is relatively good. When the chemical is used, the dye is firstly pulverized with concentrated acetic acid (cosolvent), then stirred and dissolved in boiling soft water, diluted with heating water, and soft water is added to the prescribed amount after cooling.