|
5、Discharge
printing process
Dyeing
→
Discharging → Drying →
Streaming → Washing(2sec)
→ Soaping（3-5g/L
Sodium carbonate，90-100℃，10sec）→
Finishing
|
Vat dyes |
X |
|
Sodium formaldehyde
sulfoxylate |
10％ |
|
Urea |
6％ |
|
Sodium carbonate |
6％ |
|
Starch paste |
Y |
6、Vat
dyes stripping
Vat dyes could strip colors from fabric or strip
it into light color for dyeing again. General stripping
materials contain the sodium hydrosulfite 5 g / L,
peregal O 2-4g and 30% caustic soda 12-15 g / L. It
should be operated in the temperature of 60-70
℃
for 30 minutes.
7、Shade
rehandling methods
7.1 Warshing method
It is the easiest way to amend the color light, which is
suitable for the medium and dark varieties. If the
fabric products are dark colored with more color
floating or not fully washed, poor soaping effect, they
can be amended by washing or soaping.
7.2 Reduction steaming
If the cloth is dyed to dark by vat dyes which need to
be reduced to a light color, use the caustic soda and
sodium hydrosulfite for 25 g / L each while in steaming
washing, over 1/10 color light can be reduced.
7.3 Whitening agent rehandling method
It can be used to reduce the red color of the fabric
dyed by the reduction vat dyes and improve the
brightness of cloth, especially for the medium or
light. General dosage of brightener is 0.3-1.2 g / L. |
