How do you improve the colour fastness of reactive dyes on cotton?
In many ways the most important of the dyeing of cotton and cellusic fibres is the subsequent washing and fixing processes.
Reactive dyes besides reacting with the cotton also reacts with water. It forms what is called hydrolysed dye. This needs to be removed to ensure good colour fastness.
So how do you do it?
1) Do a cold rinse. This removes a significant amount of the hydrolysed and unfixed dye.
2) Neutralise the alkali. This will stop any futher chemical reactions
3) Soaping off at the boil. Or if you can’t, at the highest possible temperature. We recommend the use of Itoscour LJ350. This the perfect product to help remove unfixed dye. For very deep shades, it may be necessary to do ut again but at the lower temperature. The full method is shown by clicking on the Itoscour LJ350 link.
4) Use a Fixing agent. We recommend the use of Ifofix EZF. This binds any unfixed dye to the fibre. It significantly improves the fatsness to cold water bleeding. Click on Itofix EZF link to find out more.
If you need help, please contact the company.