White Patches in Soft Flow Dyed Cotton Knitted Fabric
In the knitted industry there are two types of dyeing techniques .
1- Exhaution Based Dyeing
2- Cold Pad batch Based Dyeing .
Exhaustion based dyeing is done in the Winch, Soft Flow, Air Flow type of machine. As now We are proceeding for the low liquor ratio dyeing techniques , So the salt formation during exhaust dyeing increases .
If a salt is formed during dyeing process , it will be deposited on the textilefabric and gives the White patches, In general these salts are of Calcium and Magnesium . Hence it is due to hardness of the fabric or the water or the Chemicals used in the dyeing , may be Dyes, Salt, Soda, etc.
Hence a strong demineralising agent is needed in the dye bath, But the concentration of the Demin agent should be very minimal . Other wise it will effect dyeing process.
By this we can avoid the white patches in the fabric, It is geerally visualise in the black, navy shades.