What is direct dye & how to use direct dye :
The dye which have direct affinity to textile fiber is called as direct dye . It is also called as Substantive dye . This dye mostly have affinity to cellulose fiber . Cellulose fiber are : Cotton , jute , linen , viscos rayon . We can dye all of these by direct dye . This types of dye if we use with water , salt and soda then heat at a certain temperature then this dye will enter into the fiber . This dye fastness quality is not good so without after treatment if we sunk in water then it will soluble in water .
Direct dye recipe to color cotton fabric :
Color : 1-4% based on the weight of the fabric
Wetting agent : 1% based on the weight of the fabric
Soda Ash : 1-3% based on the weight of the fabric
Sodium Chloride : 10-20% based on the weight of the fabric
Water : 20 times than fabric weight
Scouring temperature : 100°C
Time : 45-60 minutes
Working procedure :
We need to take 1-4% dye based on weight of the fabric then we add some normal water and mix with dye and make paste . Then we use wetting agent with dyes paste and pour boiled water 20 times than dyes weight to make dye solution . Then we need to filter the solution .
We take one pot and take soda ash 1-3% based on the weight of the fabric another one pot take salt 10-20% based on the weight of the fabric and make solution . Then we take another pot and take 20 times water than cotton material and give soda ash and salt solution .
Salt solution can be use below as per fabric required shade :
Light shade : 5%
Medium shade : 10%
Dark shade : 20%
Then we take scoured fabric and give it to dye bath and treat at temperature 40°C-60°C . After that we rise temperature at boiling and process for 30-40 minutes . After that we continue dyeing up to one hour . Then we unload the fabric and first wash by hot water then wash by cold water .
After treatment :
We need to fix up color by after treatment . Generally 1-2% sodium di chromate , 1-2% copper sulphate , 2-4% acetic acid we make the all a solution and treatment at 60-80°C for 20-30 minutes . Then light and washing fastness be good.
