Direct Dyes

A water soluble dye usually of the Azo class that is used in alkaline or neutral solution especially for dyeing cellulosic material directly such as cotton or paper is know as direct dyes.

Use of Direct Dyes:

Direct dyes are used for dyeing cellulosic fibres including viscose rayon and also it can dye wool & silk. Direct dyes also used for denim washing and paper mills. Direct dyes are applied in low temperature for that reason it can be used to dye tie and batik work. Generally these dyes are used where high wash fastness is not required.

Dyeing Process of Direct Dyes:

Make dye paste with mixing dye with normal water. Then pour hot water to dissolve the dye properly and ensure bath concentration.

Set dyebath at 40°C with required substrate and water
Add wetting agent, sequestering agent, leveling agent and other auxiliaries and run for 5 min.
Add dye solution linear dosing at 40°C and run for 10 min
Add soda ash by curve or progressive dosing and run for 10 min
Raise temperature 100°C within 30 min
Dye will be continued for 60 mins at 100°C
Cool down at 70°C
Drop the bath rinse and carry out after treatment process to improve wet fastness.

Dyeing Curve

Recipe of Direct Dyes:

Wetting Agent	1-2g/L
Sequestering Agent	1-2g/L
Leveling Agent	0.5-1g/L
Direct Dyes	X%
Soda Ash	1-5g/L
Glauber Salt	5-20g/L
Temperature	95±5°C
Time	30-50 Mins
pH	Neutral to Alkaline
M:L	1:5-1:10
Lubricant	1-3g/L

Direct Dyes

Use of Direct Dyes:

Dyeing Process of Direct Dyes:

Dyeing Curve

Recipe of Direct Dyes:

SHADE CARD