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The Ultimate Chemistry of Color
 
  Reactive Dyes  
 
Reactive ME Brand Dyes (Bifunctional)

Properties | Shade Card | Dyeing Procedur
Properties:

REACTIVE ME BRAND DYES are mixed Bifunctional reactive dyes where Vinyl Sulfone group is linked to chromophore through a mono chloro triazine group as a bridge link. They are applicable on cellulosic material at lower dyeing temperature 60oC. The main features of these 'Bifunctional' dyes are as under:

  • The dye-fibre bond between Vinylsulfone group and cellulose is stable to acid hydrolysis, so that stability of dyed goods in industrial acidic atmosphere is very good with the time lapse.

  • The dyes which are not fixed during the dyeing process can be washed off easily because the hydrolyzed dye has low substantivity and thus there is a little risk of staining of adjacent whites.

  • Excellent leveling properties.

  • Better reproducibility in dyeing.
  • High exhaustion and high fixation efficiency.
  • Good all round fastness properties.

Bi-functional dyes are applicable on cellulosic materials by dyeing as well as printing methods.

Shade Card:

 0.5%   DYEING  4.0%

  

REACTIVE
ME Brand Dyes
(Bifunctional)

  

C.I. No.

  

General Properties

  

Fastness Properties

  

Suitability
 

Sub-
stanti-
vity

  

Solubi
lity at 500C

  

Dis
charge
ability

  

Day Light 1/1

 

Wash
ing
ISO4

  

Perspiration

  

Hypo-
chlorite
Bleach

  

Pero-
xide
Bleach

  

Exha-
ust 40oC
& 60oC

  

One Bath Pad Batch

 

One Bath Pad-Dry Stream

  

Printing
 

Alka-
line

  

Acidic

  

Steam

  

Sili-
cate

 

Yellow ME7GL

  

Y.185

  

H

  

120

  

F

  

6

  

4

  

4-5

  

4-5

  

1

  

4

  

+

  

(+)

  

-

  

(+)

  

(+)
 

 

Yellow ME4G 150%

  

Y.186

  

M

  

120

  

G

  

6

  

4

  

4-5

  

4-5

  

1

  

4

  

+

  

(+)

  

-

  

+

  

+
 

 

Yellow MERL 150%

  

Y.145

  

M

  

100

  

G

  

5

  

3-4

  

4

  

4

  

1

  

3-4

  

+

  

(+)

  

+

  

+

  

+
 

 

Orange ME2RL150%

  

O.122

  

H

  

75

  

P

  

5

  

4-5

  

4-5

  

4-5

  

3

  

4

  

+

  

+

  

+

  

+

  

+
 

 

Red ME3G

  

R.194

  

H

  

100

  

P

  

5-6

  

4-5

  

4-5

  

4-5

  

3

  

4

  

+

  

+

  

+

  

+

  

+
 

 

Red ME4BL 150%

  

R.195

  

H

  

100

  

P

  

5

  

4-5

  

5

  

5

  

1

  

4

  

+

  

+

  

+

  

+

  

+
 

 

Red MERB 150%

  

R.198

  

H

  

100

  

P

  

5-6

  

5

  

5

  

5

  

1

  

3

  

+

  

+

  

+

  

+

  

+
 

 

Red ME3B

 

R.227

  

H

  

100

  

P

  

4

  

5

  

4-5

  

5

  

1

  

4

  

+

  

+

  

+

  

+

  

+
 

 

Red ME46BL 150%

  

R.250

  

H

  

80

  

P

  

5

  

4-5

  

5

  

5

  

1

  

4

  

+

  

+

  

+

  

+

  

+
 

 

Violet ME4BL

 

-

  

H

  

100

  

P

  

5-6

  

5

  

5

  

5

  

1

  

3

  

+

  

+

  

+

  

+

  

+
 

 

Blue ME2R

  

B.248

  

H

  

100

  

P

  

4

  

5

  

5

  

5

  

1

  

3

  

+

  

+

  

+

  

+

  

+
 

 

N.Blue ME2G 150%

  

B.194

  

H

  

120

  

F

  

6

  

5

  

5

  

5

  

1

  

3

  

+

  

+

  

+

  

(+)

  

(+)
 

 

Blue MERF 150%

  

B.221

  

H

  

100

  

G

  

5

  

5

  

5

  

5

  

1

  

3

  

+

  

+

  

+

  

(+)

  

(+)
 

 

N. Blue MEGR

 

B.222

  

H

  

80

  

G

  

3-4

  

4-5

  

5

  

5

  

1

  

3

  

+

  

+

  

+

  

(+)

  

(+)
 
Key to Abbreviations
Affinity or Substantivity on cotton  
L =     Low + =     Suitable
M =     Medium (+) =     Fairly Suitable
H =     High - =     Not Suitable
V =     Very High    

Dischargeability :     G     =     Good;      F     =     Fair;      P     =     Poor     
Light :     1 to 8 in increasing order
Washing & other :     1 to 5 in increasing order

Y =     Yellow O =     Orange
R =     Red V =     Violet
B =     Blue Br =     Brown
Bl =     Black G =     Green

 
Top
Dyeing Procedure:

DYEING METHOD WITH BI-FUNCTIONAL DYES

Bi-functional dyes are applicable by both exhaust dyeing method as well as pad-dyeing method.

i) Exhaust dyeing methods

Bi-functional dyes are applicable by exhaust dyeing methods in following different ways.

(a) Increase temperature method

Procedure:

Set the dye-bath 25 deg c with dye solution and carry out dyeing for 10 minutes. Then add half amount of salt and continue dyeing by raising temperature to 45 deg c in 10 minutes. Add remaining half the amount of salt at 45 deg c and raise the temperature to 60 deg. C in 10 minutes with continued dyeing. Continue dyeing 60 deg. C for further 5 minutes and then add half amount of soda ash and dyeing is continued for further 50 minutes at 60 deg. C. The goods are then washed off.

Salt & Alkali Requirements:  

% Shade * Glaubers Salt gms/l Soda Ash gms/l
1.0 to 2.0
2.0 to above		 35 to 50
50		 15
15-20

* For light shades of less than 1%, quantity of Glauber's salt and soda ash to be reduced appropriately.

Temperature increasing method.


This method gives better levelness when it is difficult to obtain level dyeing.

(b) Constant temperature method.

Procedure

Set the dye-bath at 60 deg. C with the dye solution. Carry out dyeing at 60 deg. C for 10 minutes. Then add salt at 60 deg. C and continue dyeing for 25 minutes. Add half the amount of soda ash and continue dyeing for 10 minutes. Then add remaining half amount of soda ash and continue dyeing for further 50 minutes at 60 deg. C. the goods are then washed off.

Salt & Alkali requirements: same as (8)

(c) All-in Method

This method is particularly suitable for unmercerised cotton produce deep shades. Moreover this method is applicable to vinylsulfone dyes and hence combination of vinylsulfone dyes is possible.

Process

Set the dye-bath at 20-30 deg. C. Add salt and continue dyeing for 5 to 10 minutes. Then dye solution and continue for 15-20 minutes. Now add half amount of alkali and dye for 5-10 minutes. Add remaining 1/2 amount of alkali and continue for further 5 to 10 minutes. Then raise temperature to 50 - 60 deg. C in 20 minutes.(1.5 deg. C rise/minute) and continue dyeing at 50 - 60 deg. C for 45 - 60 minutes.

"New all-in" Method


 The "new all-in" method with Bi-functional dyes gives an ideal rate of dyeing in terms of levelness and reproducibility even after the addition of alkali, but it is necessary to take into account the type of dyeing machines and the form of materials to be dyed.

Suitability for cheese dyeing

The suitability for cheese dyeing was measured as follows:

Dyeing depth
Glauber's salt anhydrous
Soda ash
Goods : Liquor ratio
Temperature and time
 

:   3.0% o.w.f.
:   50 g/l
:   20 g/l
:   1:20
:   60oC, 60 minutes
 



ii) Pad dyeing method

(a) Pad batch method

Padding liquor

Dyestuff

x parts

 

Urea

50 parts

 

Water
Sodium Silicate
(134-142oTw
Na2O : SiO2 1:2.1

remaining
85 parts

 

Caustic Soda 33%

4 parts

 

Total

1000 parts

Procedure

The goods are padded in the above padding liquor and batched on a plastic sheet and kept for about 20 hours and then washed. However, all dyes are not suitable by this method. Hence proper selection is to be carried out.

It is also applicable by using Caustic Soda plus Glauber's salt in place of Sodium Silicate + caustic soda as alkali agent in above padding liquor. This is particularly important when dyeing thick fabric such as corduroy because removal of silicate is very difficult.

Caustic Soda (40oBe)
       +
Glauber's Salt 		- 12 cc/litre

- 30 gms/litre 		Alkali Agent
 

(b) Printing Methods

Bi-functional dyes are applicable by various printing methods on cellulosic material with the following advantages:

  1. Suitable for various method of printing with a high fixation degree.

  2. Print paste containing alkali has superior storage stability.

  3. A smaller amount of alkali is sufficient for dye fixation.

(a) Print - Dry - Steam - Wash - Dry (Bi-functional dye + alkali).

Printing recipe Dyestuff 20 parts
Urea 50 parts
Water
 		 300 parts