Effect of Pretreatment Process on Dyeing of Viscose Fabric with Reactive Dyestuff
Mohammod Habibur Rahman & Ataur Rahman
Department of Textile Engineering
Dhaka University of Engineering & Technology (DUET)
- To increase quality of dyed fabric.
- Cost minimization
- Best process selection
- Observation of different pretreatment process
- Compare various pretreatment process
1. Scouring & bleaching:
- Different amount of wetting agent use.
- Different amount of detergent use.
- Different types of detergent use.
- Different amount of caustic soda (NaOH) and soda ash (Na2CO3) apply.
- Different amount of Hydrogen peroxide (H2O2) use.
- Various liquor ratio use.
Note: When one parameter change then others parameter will remain constant.
Our main object is to observation of different pretreatment process effect for same dyeing recipe. Which process gives us better result.
The methodology is as follows-
Planning & budgeting
Collection of viscose fabric
Collection of chemicals & dyes
Various pretreatment & dyeing procedure
Observation of results
Compare of results
Select best alternative
Chemicals and Dyes:
- 1.Wetting agent
- Sequestering agent
- Caustic soda (NaOH)
- Soda ash (Na2CO3)
- Anti creasing agent
- Antifoaming agent
- Hydrogen per oxide (H2O2)
- Acetic acid
- Leveling agent
- Peroxide killer
- Bicromate or fitcary
- Copper sulphate
Modal fabric dyeing (Deep Shade):
Fabric construction: 40/s Modal cotton S/J & 20D Lycra, GSM =150, 3424, SL = 2.9 mm Dia = 75″ (open)
|Chemicals/ mlt||Recipe||Process||Dozing /inject||Running & pH|
|Materials||Batch||Heat setting||190°c to 200°c through stentering|
|Material||Batch||Loading||Take water before start m/c at 1:10|
|Detergent (NOPS)||1 g/l||Cold wash||Normal temp.||40˚C – 10´|
|Stabilizer & sequestering (CONL)||0.5 g/l|
|Anti creasing (NC)||0.5 g/l|
|Anti forming||0.5 g / l|
|Viscose color||3 g/l||Scouring & bleaching||Dozing 40˚C – 7´||70˚C – 60´|
|BD||Before BD absorbency check|
|Per oxide killer (Biokil)||0.3 g/l||Inject||40˚C – 10´|
|Acetic acid||0.5 g/l||Neutralization||Inject||50˚C – 10´ for pH = 6.00 ~ 7.00|
|Leveling ( REB)||1 g/l||Leveling||Temperature Increase at 60˚c||60°C – 10 ´|
|Sequestering (CONL)||0.5 g/l|
|Anti creasing ( NC )||0.5 g/l|
|Salt||80 g/l||Migration||5 % dozing 60˚c – 10´95% doz. 10´||60˚C – 10´ 60˚C – 10´ pH below 7|
|R/T orange ME – 2RL||3.46%||Color||Dozing 60˚C – 20´||60˚C – 10´|
|EVR. Red 3BS||2.76 %|
|Soda ash||20 g/l||Fixation||1% dozing 60˚C – 20´5% – 20´94% – 20´||60˚C – 10´ 60˚C – 10´ pH 10.5 60˚C – 10´|
|BD||Before BD sample check (Shade)|
|Acetic acid||0.5 g/l||Neutralization||Inject||40˚C – 10´|
|BD||Before BD/rinse sample check (Shade)|
|RSK||1 g/l||Soaping||Inject||80˚C – 10´|
|BD||Before BD /rinse sample check (Shade & soft)|
|Fixer||1 g/l||Fixing||Inject||40˚C -10´|
Table: Modal fabric dyeing process with Reactive dye
N.B: Viscose fabric dyeing process is same as to Model fabric dyeing process. Do not use caustic & peroxide, viscose color is a multifunctional chemical which perform scouring & bleaching. Viscose fiber has more absorbency than cotton so liquor ratio uses 1:10. So possibility to uneven dye to prevent it used high liquor ratio & carefully dozing salt and soda.
A= Cold water loading
B= Fabric, Detergent, Stabilizer, sequestering, Anti creasing, Anti forming Inject.
C= Viscose color (Scouring & Bleaching Agent) dozing then temperature increase at 3ºc/min.
D= Scouring and bleaching running
E = Scouring and bleaching bath drain
F= Peroxide killer Inject
G= Temperature Increase 3ºc/min
H= Hot wash
J= Neutralization to remove residual alkali
K= Fresh water taken for dyeing then temperature Increase
L= Leveling, Sequestering, Anti creasing, dozing.
I= Salt dozing,
V= Color dozing
W= Soda ash dozing
M= Color bath drain
N= Fresh water taken and Neutralization
O= Acid Bath drain
P= Fresh water taken for soaping
Q= Soaping agent Inject then temperature increase 3ºc/min
R= RSK (soaping) running
S= Soap bath drain
T= Fixer Inject
U= Fabric Unloading
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