Sequence of operation for dying with azoic dye | Factors affecting Naptholation

Sequence of operation for dying with azoic dye: The color producing sequence of azoic dye is mentioned below:

1. Naptholation (Napthol is dissolved in water)
2. Impregnation (Impregnation of fabric with napthol)
3. Diazotization(Diazo component is prepared at 0-50C)
4. Naptholated fabric is treated with diazo component solution
5. Reaction and color production by couplingRemoval of excess color form fabric surface
6. After treatment.

Factors affecting Naptholation: The concentration of napthol and their take up by material depends on the following factors:

1. Absorption of napthol by material
2. Impregnation time (should be 30 minutes)
3. Type of material impregnated
4. Material to liquor ratio (should be low)
5. Inherent substantivity of napthols
6. Addition of additives (increases absorption)