Wet Processing Technology

1. MD.MEHEDI HASAN RIMAN
ID : 12132107012
Intake : 8th
Section : 01
BUBT
Department of Textile
Engineering
Presentation
on
reactive Dye &
DisPerseDye

2. Reactive Dye and Disperse Dye

6. 6
Textile Auxilaries
1 Salt- reduce negative charges on the fibers
2. Water - dyeing media
3. Soda Ash - excite the dye to link with the fibers with covalent bonding.
Therefore, it enhances wet fastness
4. Fixing Agent - enhance wet fastness for heavy shade but usually reduce light
fastness.
5. Levelling agent - for levelness dyeing
6. Retarding agent - for inhibiting the dye not attach to fibbers too fast
7. Acid - adjust the dyeing condition and make the fibbers to show negative
charges
8. Water - dyeing media

7. Reactive Dyes
 water-soluble compounds
 give excellent wet-fastness
 easy to hydrolyzed
 Enough simple dyeing proses
 Choice of more complete available color
 Good color resilience
General Properties of Reactive dyes

8.  Permanency of the color
 Easy washing
 Chemical Binding
Types of reactive dyes
 Vinylsulphone Dye (VS)
 Monochlorotriazine Dye (MCT)
 Bi-functional Dye
Advantages of the Reactive Dyes

9. 1. Hot reactive dyes
Reactive dyes which have low reactivity ( monochlorotriazin
faction )
Example of : Procion HE type ( ICI ) , Negative HE type
( Colorindo )
2. Cool reactive dyes
Reactive dyes which have high reactivity ( dichlorotriazin faction )
Example : Procion MX type ( ICI )
Based on its reactivity , reactive dye divided 2 faction :

10. Illustrating reaction which happened by at dyeing process
between reactive dye with cellulose fiber

14. Side Reaction
•Hydrolysis of dichlorotriazine
1.Results in wasted dye
2.Economic and environmental concern
•Typically fixation of around 60% is obtained

15. Dyeing Conditions
Time allowed for diffusion of dye into substrate
‰ Concentration of dye in fiber is up to 500 times greater than in solution
Acidity difference creates ~25-fold excess cellulose anion

16. Leaving Groups
Variation of substituents = variations in fixation
‰ “Cold” dyes = fixation temperature of 30-40°C
‰ “Warm” dyes = fixation temperature of 50-80°C
‰ “Hot” dyes = fixation temperature of >80°C

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REACTIVE DYES
This is an entirely class of dye
introduced to the market in 1956.
They react chemically with the fiber
being dyed & if correctly applied,
cannot be removed by washing or
boiling.

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REACTIVE DYES
The main feature of
the dyestuff is its low
affinity to cellulose;
therefore large
amounts of salt are
required to force its
deposition on he
fabric.

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REACTIVE DYES
After this has been
achieved, addition of
alkali causes the
deposited dyes to react
with the fiber.
Only a successfully
concluded reaction
guarantees a fast
dyeing.
Basically there are two
types of reactive dyes:
the cold dyeing & hot
dyeing types.

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REACTIVE DYES - USE:
 Reactive dyes are used where
bright dyeing with high light &
wash fastness is required.
 Cold dyeing is used extensively
in batik work.
 Although some reactive
dyestuffs have been specially
modified to dye wool, their main
usage is in dyeing cotton linen &
viscose rayon.

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REACTIVE DYES Cold water fiber reactive
dyes, suitable for dyeing on
cotton, silk, jute, rayon &
hessian.
 Cannot be used on
synthetics or fabric that
has been coated with resin
or drip-dry finish.
Yellow 2GL
Golden Yellow 2RL
Orange 2R
Scarlet
Red BG (primary)
Red 4B (bluish red)
Red 8B (magenta)
Rubinole 5B
Brilliant Blue 2R
Brilliant Blue BL
Violet 2R
Turquoise 2G
Navy GRL
Brown 2R
Brilliant Green BL
Black B (blue base)
Black 2B (green base)

22. DYES for SYINTHETIC FIBERS
Popular Dyes For Synthetic Fibers
Name of fibers Name of common dyes that are used
Polyester Disperse Dyes
Acetate (Cellulose acetate)
Doesn't take dyes ordinarily. It requires
cross dyeing.
Acrylic Disperse dyes
Mod acrylic Fiber Reactive Dyes
Modal Fiber Reactive Dyes
Nylon Cationic Dyes, Acid Dyes, Disperse Dyes
Orlon Disperse Dye
Rayon Acetate Rayon Dyes
Saron RIT Dyes
Spandex Disperse Dyes
Vinalon Doesn't take Dyes (in normal condition)
Vinyon Doesn't take Dyes (in normal condition)

23. Disperse Dyes
DISPERSE DYES FOR DYEING IS DIVIDED BY 3 FACTION :
1. Disperse dyes of the size molecule small
Example : Dispersol B ( ICI )
2. Disperse dyes of the size molecule medium
Example : Dispersol C ( ICI )
3. Disperse dyes of the size molecule big
Example : Dispersol D ( ICI )

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Dye for Other Fibres:
Disperse
Dyes for
Polyester,
Acetate
Cationic
Dyes for
Acrylic

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Introduction to Coloration &
Finishing
25
Classification of dyes
Dye
Class
General description
Main
application
Disperse Require skill in application (either
by carrier or under high
temperature); moderate price;
complete color range; limited
solubility in water (normally
dispersed in water for
application); good fastness
after reduction clearing treatment;
sublimation property.
Mostly used
for polyester
& acetate; can
also be applied
on nylon &
Acrylic.

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DISPERSE DYES
 The introduction of a new regenerated
cellulose acetate fiber in 1920 led to the
necessity to develop an entirely new range of
dyes.
 It was found that acetate (or Celanese) fiber
had hardly any affinity for water-soluble dyes.
 A new dyeing principle was introduced: dyeing
with water dispersed coloured organic
substances.
 These finely coloured particles are applied in
aqueous dispersion to the acetate material &
actually dissolved in the fibres.

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DISPERSE DYES - USE:
Basically developed for dyeing of
acetate fibres, Disperse dyes are also
used for dyeing of polyamide (Nylon)
& acrylic (Orlon & Acrylan) fibres.
With the addition of 'carriers' or
swelling agents these dyes are also
used in dyeing of Polyester (Terylene,
Dacron, etc.)

30. Advantage and disanvantage:
1. Disperse dyes of the size molecule small
- Dyeing levelness very good
- Hot resilience low
- Temperature dyeing low ( economical energy )
- Usable for dyeing 130 0C with very by good level

31. 2. Disperse dyes of the size molecule medium
- Dyeing levelness good
- Good color resilience
- Absorbtion dye into maximum fiber
- Not sensitive to temperature and time
- Accessible dye at characteristic temperature 130 C in a
short time

32. 3. Disperse dye of the size molecule big
- Resilience color to temperature very good
- Sensitive to time and temperature
- Need to process reduction clearing ( RC )

33. Disperse Dyes for Polyester Dyeing Method
1. High temperature high pressure dyeing
 dyeing at atmospheric pressure
 Fixation 45 to 60 minutes at 120°C t0 130°C

34. 2. Carrier dyeing
 carried out under atmosphere pressure by an addition of carrier
 Fixation  90-120 min at 100°C.
3. Thermosol dyeing
 continuous dyeing method
 fixation  dry heating for 60-120 sec. at 180- 210°C (depending on
the form of the material and type of disperse dyes)

35. Dyeing of polyester/cotton blend
Three well known exhaust dyeing procedures :
(1) a conventional two bath procedure
(2) a reverse two bath procedure
(3) a one bath, multi step procedure

36. (1) The conventional two bath procedure
1. first dyed with a disperse dye at pH 5-7 at 120°-140° C to dye the
polyester.
2. removed from this first dye bath and transferred to a second dye
bath containing a fiber reactive dye, electrolyte and alkali.
(2)The reverse two bath procedure
1.first dyeing the cotton with the fiber reactive dye
2. dyed the polyester with the disperse dye in separate dye baths.

37. (3) In the one bath multi-step procedure
1. a single dye bath is prepared and the cotton portion of the blend is
dyed alkaline conditions low temperature the presence of
electrolyte.
2.The dye bath is then acidified to lower the pH and a disperse dye is
added
 the polyester portion of the blend is dyed at 120° C. to 130° C.