Effect of Pretreatment Process on Dyeing of Viscose Fabric with Reactive Dyestuff

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)
Gazipur-1700, Bangladesh



  1. To increase quality of dyed fabric.
  2. Cost minimization
  3. Best process selection
  4. Observation of different pretreatment process
  5. Compare various pretreatment process

Operational activities:

1. Scouring & bleaching:

  1. Different amount of wetting agent use.
  2. Different amount of detergent use.
  3. Different types of detergent use.
  4. Different amount of caustic soda (NaOH) and soda ash (Na2CO3) apply.
  5. Different amount of Hydrogen peroxide (H2O2) use.
  6. Various liquor ratio use.

Note: When one parameter change then others parameter will remain constant.

2. Dyeing:
Our main object is to observation of different pretreatment process effect for same dyeing recipe. Which process gives us better result.

3. Finishing

Dyeing of Viscose Fabric

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. 1.Wetting agent
  2. Detergent
  3. Sequestering agent
  4. Caustic soda (NaOH)
  5. Soda ash (Na2CO3)
  6. Stabilizer
  7. Anti creasing agent
  8. Antifoaming agent
  9. Salt
  10. Hydrogen per oxide (H2O2)
  11. Acetic acid
  12. Leveling agent
  13. Softener
  14. Enzyme
  15. Peroxide killer
  16. Lubricant
  17. Dyes
  18. Bicromate or fitcary
  19. 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/ mltRecipeProcessDozing /injectRunning & pH
MaterialsBatchHeat setting190°c to 200°c through stentering
MaterialBatchLoadingTake water before start m/c at 1:10
Detergent  (NOPS)1  g/lCold washNormal temp.40˚C – 10´
Stabilizer & sequestering (CONL)0.5  g/l
Anti creasing (NC)0.5 g/l
Anti forming0.5 g / l
Viscose color3 g/lScouring & bleachingDozing  40˚C – 7´70˚C – 60´
BDBefore BD absorbency check
Per oxide killer (Biokil)0.3 g/lInject40˚C – 10´
HotWashing80˚C -10´
Acetic acid0.5 g/lNeutralizationInject50˚C – 10´ for pH = 6.00 ~ 7.00
Leveling ( REB)1 g/lLevelingTemperature Increase at 60˚c60°C – 10 ´
Sequestering (CONL)0.5 g/l
Anti creasing ( NC )0.5 g/l
Salt80 g/lMigration5 % dozing 60˚c – 10´95% doz. 10´60˚C – 10´ 60˚C – 10´ pH below 7
R/T orange ME – 2RL3.46%ColorDozing 60˚C – 20´60˚C – 10´
EVR. Red 3BS2.76  %
Cotton blue0.0044%
Soda ash20 g/lFixation1% dozing 60˚C – 20´5% – 20´94% – 20´60˚C – 10´ 60˚C – 10´ pH 10.5 60˚C – 10´
Soda ash
Soda ash
BDBefore BD sample check  (Shade)
Acetic acid0.5 g/lNeutralizationInject40˚C – 10´
BDBefore BD/rinse sample check (Shade)
RSK1 g/lSoapingInject80˚C – 10´
BDBefore BD /rinse sample check (Shade & soft)
Fixer1 g/lFixingInject40˚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.

Graphical representation of Modal or viscose fabric dyeing process
Graph: Graphical representation of Modal or viscose fabric dyeing process


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

You may also like: General Dyeing Procedure of Cotton Fabric with Recipe

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