Brief Process Of Rapid Fast (Azoic) Dyes On Cotton/ Viscose Textiles.

The Rapid Fast are stabilized Azoic Dyestuffs specially prepared for printing. They are applied to the fiber in one operations. When developed under acid condition bright full shades are obtained which possess very good fastness properties. Due to cross coupling which may occur between certain Rapid Fasts, proper care should be taken when using mixtures of Rapid Fast as resultant shade obtained is un-predictable. Dyestuffs of others groups may be used to supplement the color range, particularly for greens and blues. As the Rapid Fast can be developed by either neutral or Acid ageing colors of Rapid Fast vat or Rapid Sols may be printed alongside. In some cases Rapid Sols can also be printed in admixture with Rapid Fast eg., For producing Green shade, Rapid Fasts are largely used in block and screen printing, some printers prefer particularly for Rapid Fast L.Y. 3 GH, RED RH, G.Y. 2 RA, G.Y. IGK, to expose undeveloped print to sunlight and then acid developed.

Rapid Fast Dyestuffs (Powder)	50 Parts	40 parts
Caustic Soda Solution (1:2) 33% W/W	30 Parts	30 Parts
Methylated Spirit	20 Parts	20 Parts
Boiling Water	200 Parts	200 Parts
Thickening (Neutral)	695 Parts	700 Parts
Wetting Agent	5 Parts	5 Parts
	1000 Parts	1000 Parts