The document discusses salt-free dyeing of cotton with reactive dyes. It examines pretreating cotton with cationic agents via exhaust and pad-dry methods, and then dyeing without salt. Experiments compare exhaustion and fixation of representative reactive dyes on cotton pretreated with cationic agents and dyed with or without salt. The objectives are to study the effect of cationic agents on wash/light fastness and dye-fiber bonding, and suggest a mechanism for reactive dye exhaustion without salt using cationic agents. Methods involve pretreatment with various cationic agents, dyeing representative dyes, and analyzing exhaustion, color yield, and fastness properties. Results show cationic agents can increase exhaustion and color yield compared to dye

1. Salt F ree Dyeing
of
Cotton with Reactive Dyes
Presented by
Dinesh Chand Sharma
2002TTF 018
Under the Guidance of
Prof. R. B. Chavan

2. • Use of cationc agents for salt free dyeing of cotton with reactive dyes
• Pretreatment of cotton with cationic agent
• Exhaust method
• Pad-dry method
• Comparison of exhaustion and fixation of representatives of procion M, H and Rmazol dyes on
• Cotton pretreated with cationic agent and dyeing with salt
 To study the effect of cationic agent on the wash fastness and light fastness of reactive dyes.
 To investigate the interference of cationic agent on dye fibre covalent bond formation
 To suggest the tentative mechanism of reactive dye exhaustion in presence of cationic agent but
in absence of salt.

3. Objective
 To study the feasibility of the use of cationic dye
fixing agent and cationising agent (use for exhaust
dyeing of pigment colour) for the dyeing of cotton
with reactive dyes in absence of salt.
 Compare the exhaustion and fixation of a
representative of reactive dyes belonging to Procion
M, Procion H and Ramazol on cotton when the
dyeing were carried out in the absence of salt in
presence of 60 g/l salt and in presence of various
cationic agent.

4. Objective
 To study the dyeing behavior of cotton pretreated
with cationic agent by pad dry application followed
exhaust dyeing with selected reactive dyes.
 To study the effect of cationic agent on the wash
fastness and light fastness of reactive dyes.
 To investigate the interference of cationic agent on
dye fibre covalent bond formation
 To suggest the tentative mechanism of reactive dye
exhaustion in presence of cationic agent but in
absence of salt.

5. I
N Reactive dye
T
R
O  Discovered in 1956-57 by I. D. Rattee
D and W. E. Stephen
U
C  Characteristic structure
T
I S C B X
O
N S- Solubilising group C- Chromophor
B- Bridging group X- Reactive group

6. I
N Expected dye consumption in 2004
T
R
Sulphur (19%)
O Reactive dyes (49%)
D
Direct dyes (19%)
U
C
T
I Vat dyes (6%)
O Azoic dyes ( 4%) Indigo (3%)
N

7. I
N
T Classification of reactive dyes
R
O
D
U  Monofunctional reactive dyes
C
T  Bifunctional reactive dyes
I
O
N

8. L
I
T
E
R Problems with Reactive dyes….
A
T
U  Requirement of salt in dyeing process
R
E
 Hydrolysis of dye during dyeing
R
E
V
I
E
W

9. L
I
T
E
R Role of salt in dyeing with Reactive dyes
A
T
U
R  Reduces the Zeta potential
E
 Reduction in dye solubility
R
E
V
I
E
W

10. L
I
T
E
R
A
T
U Environmental and ecological
R problems
E
R
E
V Make points
I
E
W

11. L
I
T
E Cationization of fiber
R
A
T  Aminated epoxy derivatives
U
 Glycidyl-tri-methyl-ammonium-chloride (Glytac-A)
R
E
 Polyamide epichlorohydrin (PAE) type polymers
R
 Chlorotriazine type quaternary compounds
E
V
I
E
W

12. L
I
T
E Cationization of fiber
R
A
T  N-Methylol acrylamide
U
R  2,4–dichloro–6(2 pyridino ethyl-amino) s-triazine
E
(DCPEAT)
R  Polyepichlorohydrin (PECH) – Di-methyl-amine
E
V
I
E
W

13. Deficiency of most of the techniques
 Not economically viable.
 It is so complex that it cannot be incorporated
in dyeing procedure.
 Surface modification may lead to ring dyeing.
 Probability of uneven pretreatment with
Cationization agent.
 Inconsistency, reproducibility in compound shades.

14. • Existing methods
• Approach
• Conditions of treatment
• Practical problem
• How your approach will eliminate the problems of existing methods..
• Simultaneous pretreatment and dyeing would have been the simplest
approach but not possible because of dye precipitation
• Simple pretreatment by exhaust and pad dry application
• No special equipments required
• Commercially readily available cationic agents

15. Materials
• Cotton fabric
• Commercially available cationic agents
• Give names
• Other chemicals as required
• Details in thesis

16. Experimental Methods
Dyeing of cotton with reactive dyes
Three sets of experiments were used for dyeing of cotton with
reactive dye –
1. Dyeing of cotton in presence of 60 g/l
2. Pretreatment of cotton with 2.5%, 5%, 7.5% and 10% owf
with selected cationic agents by exhaust method followed
by exhaust dyeing in the absence of salt.
3. Pretreatment of cotton with cationic agent ( 1.25, 2.5, 3.75
and 5 g/l ) by pad dry application followed by exhaust
dyeing with reactive dyes in the absence of salt.

17. Pretreatment of cotton with cationic agent
• Exhaust Method
• Pad dry Method
– Padding
– Drying
• Dyeing
• Washing and soaping
• Dyeing on laboratory jigger

18.  Determination of dye exhaustion
 Determination of colour yield on fabric
 Stripping with dimethylsulphoxide (DMSO)
 Determination of fastness properties
– Wash fastness (IS 764 : 1979)
– Rubbing fastness ( IS 766 : 1988)
– Light fastness (IS 2454 : 1985)

19. Result and Discussion
Effect of Pidicron RMG concentration on Dye
bath exhaustion
(Pidicron RMG exhaust application)
With
Dye Salt 60 g/ 2.5% 5% 7.5% 10%
l
Procion Red
65.5 73.3 77.4 78.0 81.4
M8B
Ramazol
39.6 34.8 38.3 31.7 46.0
Orange 3R
Procion Blue
46.0 56.9 70.0 76.8 78.1
H7G

20. Effect of Pidicron RMG concentration on Dye
bath exhaustion
(Pidicron RMG pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
65.5 65.2 68.8 75.2 82.0
M8B
Ramazol
39.6 35.0 33.0 34.8 50.2
Orange 3R
Procion Blue
46.0 44.2 62.8 72.5 81.8
H7G

21. Effect of Sandofix WEI concentration on Dye
bath exhaustion
(Sandofix WEI exhaust application)
With
Dye Salt 60 g/ 2.5% 5% 7.5% 10%
l
Ramazol
39.6 76.3 80.7 84.9 89.0
Orange 3R
Procion Blue
46.0 41.1 54.1 54.7 69.2
H7G

22. Effect of Sandofix WEI concentration on Dye
bath exhaustion
(Sandofix WEI pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
65.5 71.7 73.9 79.2 76.1
M8B
Ramazol
39.6 50.4 66.9 76.9 71.6
Orange 3R
Procion Blue
46.0 31.2 35.8 46.3 60.9
H7G

23. Effect of Tinofix ECO concentration on Dye
bath exhaustion
(Tinofix ECO exhaust application)
With
Dye Salt 60 g/ 2.5% 5% 7.5% 10%
l
Procion Red
65.5 78.8 81.4 82.1 83.2
M8B
Ramazol
39.6 53.4 78.4 81.3 86.2
Orange 3R
Procion Blue
46.0 47.2 54.7 71.7 74.0
H7G

24. Effect of Tinofix ECO concentration on Dye
bath exhaustion
(Tinofix ECO pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Ramazol
39.6 50.7 68.3 76.2 77.7
Orange 3R
Procion Blue
46.0 44.1 51.7 60.0 65.8
H7G

25. Comparison of effectiveness of the Cationic Agent on
Dye bath exhaustion at single concentration
(5% owf for exhaust and 2.5 g/l for pad dry application)
Exhaust Pidicron RMG Sandofix WEI Tinofix ECO
Dye Dyeing
60 g/l salt
Exhaust Pad dry Exhaust Pad dry Exhaust Pad dry
Procion Red
100 118 105 - 113 124 -
M8B
Ramazol
100 97 83 203 169 198 172
Orange 3R
Procion Blue
100 152 137 118 - 119 112
H7G

26. Effect of Pidicron RMG concentration on colour yield
(Pidicron RMG exhaust application)
With
Dye Salt 60 g/ 2.5% 5% 7.5% 10%
l
Procion Red
6.2 5.5 5.2 5.9 5.9
M8B
Ramazol
4.4 3.3 3.3 3.4 3.5
Orange 3R
Procion Blue
6.9 8.6 9.5 9.4 9.7
H7G

27. Effect of Pidicron RMG concentration on colour yield
(Pidicron RMG pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
6.2 5.4 6.3 5.3 5.2
M8B
Ramazol
4.4 3.3 3.2 3.3 3.4
Orange 3R
Procion Blue
6.9 9.9 10.8 11.3 10.8
H7G

28. Effect of Sandofix WEI concentration on colour yield
(Sandofix WEI exhaust application)
With
Dye Salt 60 g/ 2.5% 5% 7.5% 10%
l
Procion Red
6.2 6.2 5.5 5.3 6.4
M8B
Ramazol
4.4 5.9 6.5 6.5 6.9
Orange 3R
Procion Blue
6.9 8.0 8.3 8.3 8.8
H7G

29. Effect of Sandofix WEI concentration on colour yield
(Sandofix WEI pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
6.2 6.6 7.4 6.1 5.7
M8B
Ramazol
4.4 8.1 7.8 7.7 7.9
Orange 3R
Procion Blue
6.9 9.7 9.6 9.2 10.2
H7G

30. Effect of Tinofix ECO concentration on colour yield
(Tinofix ECO exhaust application)
With
Dye Salt 60 g/ 2.5% 5% 7.5% 10%
l
Procion Red
6.2 6.1 6.8 6.9 6.4
M8B
Ramazol
4.4 5.2 5.3 5.9 5.6
Orange 3R
Procion Blue
6.9 8.1 8.3 9.4 9.5
H7G

31. Effect of Tinofix ECO concentration on colour yield
(Tinofix ECO pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
6.2 5.8 6.8 6.5 7.5
M8B
Ramazol
4.4 5.7 5.4 6.2 7.5
Orange 3R
Procion Blue
6.9 9.9 11.1 10.9 11.0
H7G

32. Comparison of effectiveness of the Cationic Agent on
colour yield at single concentration
(5% owf for exhaust and 2.5 g/l for pad dry application)
Exhaust Pidicron RMG Sandofix WEI Tinofix ECO
Dye Dyeing
60 g/l salt
Exhaust Pad dry Exhaust Pad dry Exhaust Pad dry
Procion Red
100 87 100 96 117 90 107
M8B
Ramazol
100 70 72 145 177 132 123
Orange 3R
Procion Blue
100 148 168 126 150 127 173
H7G

33. Effect of cationic agent on the colour yield at single
concentration on Jigger
(Solidozon NRL, 5% owf for exhaust method)
Colour yield of jigger dyed sample pretreated with NRL and
in presence of salt in terms of k/s value obtained are –
With salt (60 g/l) = 5.2
With 5% NRL = 9.1
Delete show only sample without mentioning the name of
cationic agent

34. Comparison of effectiveness of cationic agent on dye
bath exhaustion and colour yield
• % exhaustion and colour yield % dye bath exhaustion increases as
compare to dyeing carried out in presence of salt.
• % exhaustion (exception Procion Blue H7G) is not directly
proportional to colour yield is less.?
• Possible reason for this the covalent bond formation of dye of
exhausted dye is hindered to some extent by the presence of
cationic agent on the fabric.
• The possible reason for such hindrance by cationic agent may be
due to –
– Blocking part of - OH group due to electrostatic bond formation
between negatively charged -OH groups of cellulose and positively
charge of cationic agent. Resulting in reduced number of -OH groups
available for covalent bond formation with cellulose.
– The complex formation between cationic agent and the dye. The
complexed dye having reduced reactivity towards cellulose.

35. Effect of cationic agent on loss in depth of shade on
stripping with DMSO
(Pidicron RMG exhaust application)
With
Dye Salt 60 g/ 2.5 % 5% 7.5 % 10 %
l
Procion Red
9.0 46.0 34.3 48.6 43.7
M8B
Ramazol
14.7 7.2 12.5 16.3 11.8
Orange 3R
Procion Blue
59.0 19.9 16.1 11.1 12.7
H7G

36. Effect of cationic agent on loss in depth of shade on
stripping with DMSO
(Pidicron RMG pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
9.0 21.6 41.4 60.1 48.4
M8B
Ramazol
14.7 9.7 10.4 15.6 11.5
Orange 3R
Procion Blue
59.0 24.7 21.7 24.3 16.5
H7G

37. Effect of cationic agent on loss in depth of shade on
stripping with DMSO
(Sandofix WEI exhaust application)
With
Dye Salt 60 g/ 2.5 % 5% 7.5 % 10 %
l
Procion Red
9.0 6.1 16.8 28.6 13.5
M8B
Ramazol
14.7 72.9 74.1 72.8 69.7
Orange 3R
Procion Blue
59.0 29.2 26.6 32.8 22.8
H7G

38. Effect of cationic agent on loss in depth of shade on
stripping with DMSO
(Sandofix WEI pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
9.0 21.8 28.6 16.4 28.9
M8B
Ramazol
14.7 85.4 89.7 92.1 91.6
Orange 3R
Procion Blue
59.0 44.8 29.2 20.5 33.6
H7G

39. Effect of cationic agent on loss in depth of shade on
stripping with DMSO
(Tinofix ECO exhaust application)
With
Dye Salt 60 g/ 2.5 % 5% 7.5 % 10 %
l
Procion Red
9.0 10.3 13.8 3.7 8.7
M8B
Ramazol
14.7 37.4 53.6 46.4 42.4
Orange 3R
Procion Blue
59.0 18.9 8.9 9.0 12.6
H7G

40. Effect of cationic agent on loss in depth of shade on
stripping with DMSO
(Tinofix ECO pad dry application)
With
Dye Salt 60 g/ 1.25 g/l 2.5 g/l 3.75 g/l 5 g/l
l
Procion Red
9.0 4.8 4.1 17.8 24.4
M8B
Ramazol
14.7 35.7 30.3 45.4 47.8
Orange 3R
Procion Blue
59.0 13.8 23.2 25.1 16.0
H7G

41. Effect of cationising agent and covalent bond
formation between dye and fibre
The order of loss in depth and shade in following order –
Sandofix WEI > Tinofix ECO > Pidicron RMG
Following general conclusions may be drawn from the DMSO stripping test
1. Procion Red M8B: The loss in depth was more for cotton treated with
three cationic agents compared to salt dyeing.
2. Ramazol Orange 3R: The loss in depth in case of pretreatment with
Pidicron RMG was equivalent to salt dyeing. In case of Sandofix WEI
almost complete stripping took place-indicating deactivation of Ramazol
Orange 3R. Whereas in case of Tinofix ECO the loss in depth was higher
compared to salt dyeing.
3. Procion Blue H7G: The loss in depth was higher for salt dyeing compared
to cotton pretreated with cationic agents.
4. No general trend in terms of loss in depth was observed. Therefore it is
necessary to study the effect of cationic agents on individual dyes.

42. Mechanism of dye fibre exhaustion and fixation
 Interaction of dye fixating agent with cellulose
The extent of dye bath exhaustion was also higher than the dyeing
carried out in presence of salt there could be two possibility for this
observation.
1. The reduction in surface potential of cationic agent pretreated
cotton is higher than that is achieved by using 60 g/l salt.
2. In addition to reduction in surface potential the presence of
cationic agent attracts the dye by electrostatic force of attraction.
 Interaction of dye fixing agent with dye

43. Wash Fastness
Effect of Pidicron RMG on wash fastness (change of colour)
With
Dye Salt 60 g/ 2.5 % 5% 7.5 % 10 %
l
Procion Red
4-5 3 3 3 3
M8B
Ramazol
5 5 4-5 4-5 4-5
Orange 3R
Procion Blue
3-4 3-4 3-4 3-4 3-4
H7G

44. Wash Fastness
Effect of Sandofix WEI on wash fastness (change of colour)
With
Dye Salt 60 g/ 2.5 % 5% 7.5 % 10 %
l
Procion Red
5 5 5 5 5
M8B
Ramazol
4 4 4 4-5 4-5
Orange 3R
Procion Blue
4 4 5 4-5 4-5
H7G

45. Wash Fastness
Effect of Tinofix ECO on wash fastness (change of colour)
With
Dye Salt 60 g/ 2.5 % 5% 7.5 % 10 %
l
Procion Red
5 5 5 5 4-5
M8B
Ramazol
5 5 4-5 5 5
Orange 3R
Procion Blue
4 4 4 4 4
H7G

46. Rubbing Fastness
Effect of Pidicron RMG on Rubbing fastness
With salt
Dye Fastness 2.5 % 5% 7.5 % 10 %
60 g/l
Dry rubbing fastness 5 4-5 4-5 4-5 4-5
Procion red
M8B
Wet rubbing fastness 4-5 3 3 3 3
Dry rubbing fastness 5 5 5 5 5
Ramazol
Orange 3R
Wet rubbing fastness 5 5 4-5 4-5 4-5
Dry rubbing fastness 5 3-4 3-4 3-4 3-4
Procion
Blue H7G
Wet rubbing fastness 5 3 2-3 3-4 2-3

47. Rubbing Fastness
Effect of Sandofix WEI on Rubbing fastness
With salt
Dye Fastness 2.5 % 5% 7.5 % 10 %
60 g/l
Dry rubbing fastness 5 4-5 4-5 4-5 4-5
Procion red
M8B
Wet rubbing fastness 4-5 3 3 3 3
Dry rubbing fastness 5 4-5 4-5 4-5 4-5
Ramazol
Orange 3R
Wet rubbing fastness 5 3 3 3 3
Dry rubbing fastness 5 4-5 4-5 4-5 4-5
Procion
Blue H7G
Wet rubbing fastness 4-5 3 3 3 3

48. Rubbing Fastness
Effect of Tinofix ECO on Rubbing fastness
With salt
Dye Fastness 2.5 % 5% 7.5 % 10 %
60 g/l
Dry rubbing fastness 5 5 5 5 5
Procion red
M8B
Wet rubbing fastness 5 4-5 3-4 3-4 3-4
Dry rubbing fastness 5 5 4-5 4-5 4-5
Ramazol
Orange 3R
Wet rubbing fastness 4-5 3-4 3 3 3
Dry rubbing fastness 5 4-5 4-5 4-5 4-5
Procion
Blue H7G
Wet rubbing fastness 4-5 3-4 3 3 3

49. Light fastness
Effect on cationic agent on light fastness
(Cationic agent concentration 5% owf)
With salt 60 Pidicron Sandofix
Dye Tinofix ECO
g/l RMG WEI
Procion Red
4-5 3 3 3
M8B
Ramazol
4-5 3 1 1-2
Orange 3R
Procion
5 4-5 4-5 4-5
Blue H7G

50. Conclusion
 Pretreatment of cotton with three selected dye fixing agents
applied by exhaust method and pad dry application gave dye
bath exhaustion higher or equivalent to dye bath exhaustion
in presence of 60 g/l salt.
 In general there was increased in dye bath exhaustion with
increase in cationic agent concentration for both exhaust
application and pad dry application. However, pretreatment
with 2.5 to 5% owf. by exhaust method and 2.5 g/l
concentration by pad dry application are good enough to give
the dye bath exhaustion equivalent or better than salt dyeing.
 Exhaust method of pretreatment of cotton was more effective
compared to pad dry application.

51. Conclusion
 Pretreatment of cotton with cationic agent both by exhaust
method and pad dry method gave colour yield (k/s). as good as
salt dyeing.
 The extent of stripping of dyed sample with DMSO in general
was higher for cotton pretreated with cationic agent compare to
salt dyeing. Exception to this was the stripping of blue H7G,
which was higher in case of salt dyeing.
 A tentative mechanism of dye bath exhaustion on cotton
pretreatment with cationic agent is suggested.

52. Conclusion
 In general the wash fastness and dry rubbing fastness was not affected
for dyeing carried out on cotton pretreated with cationic agent.
Pretreatment of cationic agent lower the wet rubbing fastness
compared to salt dyeing.
 The pretreatment with cationic agent of cotton lower the light fastness
of all the three dyes. The maximum reduction in light fastness was in
case of Orange 3R and marginal reduction in case of Procion Blue
H7G.
 A remarkably simple method is suggested for salt free dyeing of
cotton with reactive dyes. This subject has been investigated for long
by many researchers. It will essential to analyse the environmental
merits/demerits of this method.

53. Scope of Future Work
1. Analysis of environmental merits/benefit of salt free
dyeing reported in the present thesis.
3. Quantitative estimation of cationic agent on cotton.
5. To investigate the salt free dyeing of cotton with direct
dyes and effect on fastness properties.
7. To establish the exact mechanism of dye bath
exhaustion on cotton pretreated with cationic agent.

54. Thank you !!!