Properties Of vat Dyes: Explained Completely
by : Rahul Sharma
PROPERTIES OF VAT DYES:
- INSOLUBLE IN WATER
- CAN NOT BE USED DIRECTLY FOR DYEING
- CAN BE CONVERTED TO WATER SOLUBLE FORM
- POSSESS AFFINITY TO CELLULOSIC FIBRES
- PROCESS OF CONVERTING WATER INSOLUBLE FORM TO
- WATER SOLUBLE FORM KNOWN AS VATTING
- INVOLVES TWO STEPS
- REDUCTION OF VAT DYE INTO WEAKLY ACIDIC LEUCO FORM
- SALT FORMATION BY NaOH
- REDUCING AGENT USED IS SODIUM HYDROSULPHITE Na2S2O4 + 2H2O 2NaHSO3 + 2H
