The work of various helpers of direct dye:
Various helpers are used for direct dye. E.g. https://bdfabric.com/how-do-you-dye-wool-and-silk-by-direct-dye/
(B) Soda ash
(C) Wetting agent
1) NaCl – It is used for deep shade.
2) Na2 SO4 – It is used for a medium shade.
3) Na2 SO4,10H2O – It is used for light shade.
The above three assists are called electrolytes.
The following is the ratio of NaCl (electrolyte) for different shades of Dye:
For light shade:
For medium shade:
For dark shade:
(B) The work of various helpers-Soda ash:
Soda ash solution is added to the dye bath for the following reasons.
1. It eliminates water hardness.
2. It increases the solubility of dye.
3. It destroys the presence of acid in the dye bath.
4. It increases the action of salt.
5. It increases the brightness of colored objects.
(C) The work of various helpers-Wetting agent:
The work of various helpers of direct dye. They act as surface-active agents. This means that it reduces the surface tension of the solution so that the solution can penetrate the material well. For example- T.R oil, monopol, lissapol, etc. act as the wetting agent.