1. Strengthen the pre-treatment, especially the process of boil-out bleaching

Using a mild non-caustic oxygen bleaching process(such as oxygen bleach accelerator + H2O2) to avoid the wet rubbing fastness affected by fiber brittleness, the rough surface of the fabric and the large friction coefficient of the fabric yarn surface in the process of oxygen bleaching.

Strict control of water hardness to prevent the formation of surface lakes, causing the rough feel of the dye, increasing the friction coefficient and decreasing the wet rubbing fastness. The chelating agent, Ca2 +, Mg2 + and other metal ions can be added in the water to decrease the wet rubbing fastness.

2. Fabric can not be boiled with alkali soap after dyeing.

Whether use mixed alkali fixation or single Na2CO3 fixation, the fabric must be fully washed with acetic acid 1 ~ 2mL / L in order to achieve fully hydrolysis of flooding, otherwise it will affect the effect of soap washing.

3. Control the quality of soap boiling water

The workshop usually uses hard water with dispersing chelating agent and anti-staining cleaning agent added to it. The metal ions in chelate water can improve the effectiveness of soap cooking agent and prevent the floating color and impurities back to the fiber. So that the wet rubbing fastness of dye-Sub fabric will be better.

4. Strengthen the overflow wash

Add cold water the jet overflow dyeing machine, and open the door so that residual liquid can overflow, and finally open the discharge valve. 

5. Choices of additives and dye

If the measured wet rubbing fastness is still 0.5 level less, 2 ~ 3 g / L cationic fixing agent can be used for fixing. The dye-Sub fabric treated with dye fixing agent need to be washed fully to achieve the better effect of solid color. The dye with the double-active and multi-active group, high fixation rate, and high lifting power are suggested.