Reactive Dyes

Reactive Dyes are the most versatile and popular class of Organic Dyes for importing color on cellulosic fibres. As the name suggests, these dyes chemically react with cellulose to form a covalent bond between dye molecule and cellulose. Reactive site on dye reacts with functional group on the fibre to bind dye covalently under influence of heat and proper pH. Reactive dyes are unique as they are the only class of dyes that actually form a chemical bond with the textile fiber and this bond gives them their excellent wash fastness properties. Reactive dyes are used to cotton Rayon wool silk & Nylon.

Print Paste Recipe
10 parts Titanium Dioxide (1.1)
10 parts Citric Acid
1 part Optical Whitening Agent
20 parts Water
  Balance Thickening
100 parts

Print with resist paste-overprint with Kevizol print paste containing alkali. Dry-steam either in Rapid Ager or in Star Ager at atmospheric pressure for 5-7 minutes or 15-20 minutes respectively. Wash off in neutral detergent at boil

Cold Pad - Batch Dyeing

Pad at 20-30°C
Dyes Titanium Dioxide (1.1)
Urea Citric Acid
Sodium Sillicate Optical Whitening Agent
Caustic Soda Water
Glauber's Salt  
Wash off Balance Thickening
Pick up
Cotton Woven 65-80%, Knit 80-110%
Viscose Rayon 70-90%

Behaviour of Keviactive using Sodium Silicate

Solubility in Presence of Alkali Stability at 30°C
With Urea With Urea
  g/I 100g/I 200g/I Minutes
Yellow FG 100 - - 30
Yellow GR 100 - - 60
Red 58 60 - - 120
Rubine CB 100 - - 30
Violet 5R 75 - - 60
Blue 3R 100     60
Blue R 100 150 150 60
Turq. Blue PG 75     120
Brown GR 100 - - 120
Black B 100 - - 45


Drop Dyebath
10 Rinse cold
10 Rinse cold
15-30 Soap at the boil
10 For heavy shades rinse warm (50°C)
15 Rinse cold until clear and soften if required drop bath and unload

Thorough wash and efficient soapping is very vital to get optimium fastness

General Properties

Light fastness (Day Light) ISO 103-B01-1998 1 to 8 increasing order
Washing and other fastness 1 to 5 increasing order
  • A - White Discharge
  • B -Moderaterly Dischargeable
  • C -Non Dischargeable
Stain Staining on adjacent White fabric

Key to Abbreviations

Y - Yellow L - Low Substantivity or Reactivity
on unmercerised cotton
G - Greener M - Medium
R  -  Redder H - High
Br - Brighter B1 - Blackish  
D - Duller LS - Less Suitable  
Sr - Stronger NS - Not Suitable  
W - Weaker S - Suitable  

(On bleached mercerised cotton) Kevizol dyes applied by Cold Pad Batch method

Got a specific Requirement ? Request for a sample.