Direct
Dyes are following groups:-
(a)
Non - Benzidine and Sunfast Direct Dyes (Shade Card)
(b)
Direct Dyes (Shade Card)
Our Direct Dyes are used in following industries
- Textile
- Leather
- Paper
Sunfast And Non Benzidine Direct Dyes
Direct Dyes are used in wide range of dyeing applications
such as on Cotton, Silk and Viscose Fabrics. Direct dyes are Famous
for their easy application, leveling property, good brightness and
fastness. These dyes can be safely applied on Textiles and Leather.
PRE - TREATMENT
Good pre-treatment is essential if satisfactory
dyeing is to be obtained. To get better depth and fair brightness,
Grey Fabrics must be free from impurities like sizing materials
and spinning oil by boiling the Grey with alkline or some times
bleaching also carried out in case of pale shades.
METHOD OF DYEING
(1) DISSOLVING THE DYESTUFF
The dyestuff is pasted with cold water and dissolved
by pouring 50 to 100 times its weight of Boiling water while stirring.
The solution may be boiled to ensure complete dissolution. For Certain
dyes, which are dyes from and alkline dye bath, it is preferable
to add half its weight of soda ash while pasting with water.
(2) YARN DYEING
Set the Dye Bath at 50°-60° C temperature
with dyes solution, salt and soda ash. Run for 15 Minutes. Gradually
raise Temperature to 90°-95° C. Run for 30 to 45 minutes.
In order to Overcome un level dyeing salt may be added in installments
after about 15 minutes of initial dyeing prior to raising the dye
bath temperature.
In the case of dyestuff which possess maximum affinity
at temperature below boil, it is preferable to start dyeing at boil,
dye for 15 to 20 minutes and then add salt in two installments to
exhaust the bath abd continue dyeing in a cooling bath (60°
c) for 15 to 20 minutes.
chrysophinine G, Blue 2B, Green B and Yellow 5GLL
can be dyed in this manner.
JIGGER DYEING
The dyeing on the Jigger is carried out as follows:-
First End : 1/2 quantity of Dyes solution, soda ash and 1/4 quantity
of Salt at room Temperature.
Second End : 1/2 quantity of Dyes solution, 1/4 quantity of Salt
at 60°)c, raised to 80°c.
Third End : 1/4 quantity of Salt.
Fourth End : 1/4 quantity of Salt.
The temperature is raised to raised to boil and
four ends are given at boil. Finally the dye-liquor is Drained and
further two ends are given in cold water.
AFTER TREATMENT
Fastness to wet treatments can be improved by after
treatment with 1-2% Cationic Dye Fixing Agents at 40-50° c for
minutes.
In case of some selected dyes, light fastness can be improved by
after treatment with:-
1-2% Copper Sulphate
1-2% Actic (30%) at 80° c Temparature. |