Cotfix Vinylsulphone Dyes - dyeing methods & Tips

Cotfix Vinylsulphone Dyes

These reactive groups are normally transients, and are masked by water solubilizing leaving groups and their name is abbreviated to VS. The Vinyl sulfone groups are actually written as -SO₂-CH=CH₂, but we cannot find this group in actual dye-bath. What we may see is: -SO₂-CH₂-CH₂-OSO₃-(H⁺ or Na^+), depending up on the pH.

• Reactive dyes for dyeing natural and regenerated cellulose fibers by the exhaust, pad-batch and pad-dry-pad-steam
• Good stability of the dye-cellulosic fiber bond and a high fastness level.
• Cotfix Vinylsulphone dyes can be dyed at 60°C in any one of the following exhaust dyeing methods:
• All–in-one method
• Iso-thermal-dyeing method
• Cooling method
• Migration method
• Preconditioning method

The brilliant blue, turquoise dyes are an exception; for full fixation they must be applied at 80°C.

For optimum dyeing results the correct choice of the best suited dyeing method is influenced by the type, form and pretreatment of the material and the type and performance of the dyeing machine used. The Cotfix Vinylsuplhone dyes permit dyeings covering the entire shade spectrum according to their specific application area or purpose.

 

Scouring and Bleaching Process for Yarn in package form:

 The following process sequence may be used for Scouring and Bleaching of yarn in package form:

Recipe:

Demineralization:

Demineralizing Agent = 0.5 %

Non-ionic & anionic admixtures = 0.5 %

Scouring & Bleaching:                                                        

Sequestering Agent = 0.5%

Organic Stabilizer = 0.6 % (0.4 gpl)

Soda Ash =2.4% (3 gpl)

Hydrogen Peroxide (50%) = 1.6% (2 gpl)

Peroxide Killer Treatment:

Organic Peroxide killer =0.4%

Acetic Acid = 2 gpl

After the above pretreatment check the pH (6) and residual peroxide using proper indicators. (Merk Paper)

Note:

The yarn package should be wound on perforated stainless steel or specially made dye-springs with uniform package density.

   Salt and Alkali Requirements

Depth of Shade % (o.w.f.)	Salt (g / l)	Soda Ash (g / l)
up to 0.5	20	10
0.5 ~ 1.0	35	15
1.0 ~ 2.0	50	15
2.0 ~ 4.0	60	20
Above 4.0	80	20

Washing off Treatment: After dyeing to remove the unfixed / hydrolyzed dye the following sequence recommended.

Cold Rinse	-	Hot Rinse	-	Neutral	-	Soap
(1-3 times)	-	Hot Rinse	-	Cold Rinse

Turquoise Blue Dyeing:

Reactive Blue R spl and Turquoise Blue H2GP or Turq Blue G 133% Combinations.

Do’s and Don’ts.

1. Water hardness should be below 10 ppm. As these dyes are tend to precipitate in the presence of Ca, Mg and Fe ions.
2. Iron salts in water – even traces will result in dull shades, due to the complexes it will develop with Copper salts in the dyestuff.
3. Remember strictly that you should not use any non-ionic wetting or scouring or rewetting or leveling agent while preparing the fabric for turq blue dyeing. The presence of non-ionic component (ethoxylates) will form lumps and oily precipitation over the fabric. Avoid using any non-ionic product before and during dyeing operation.
4. Avoid using common salt or un-purified salts in these dyeing. Use only Glaubers salt.
5. Use TSP (Tri Sodium Phosphate) instead of Soda Ash for better results.
6. Residual Peroxide on the fabric is detrimental to Turquoise and Blue R shades. There should not be any trace of Residual Peroxide. Check using Merk Paper.

 

The above chart shows a dyeing method, where you are using Turquoise Blue G or H2GP along with HE dyes in combination. Since both the dyestuffs can be applied at 80°C, mostly the combination you are selecting would be a compatible one. The following dyestuffs we suggest you to select for combination with Turquoise Blue:

·         Cotfix Blue HERD

·         Cotfix N.Blue HER

·         Cotfix Red HE3B

·         Cotfix Yellow HE4G

·         Cotfix Yellow HE6G

The suggested combinations with Turquoise Blue dyestuff are:

·         Cotfix Yellow 5GL

·         Cotfix Yellow ME4GL

·         Cotfix Blue BB (for <0.5%)

·         Cotfix Blue BFN (for >0.5%)

·         Cotfix Red F3B

Dye Bath Setup and Dyeing Method: [Hardness of water should be less than 50 ppm]

·         RECIPE:

o   Resist Salt = 1 g/l                                                            Run at 50°C for 10

o   Sodium-hexa-meta-phosphate = 1 g/l                        minutes

o   Add 2 grams/liter of Soda Ash – run 10 minutes       

·         Add Pre-dissolved and filtered dyestuff in two portions. – run 10 minutes     

·         Raise Temperature to 85°C and run for 10 minutes.                                         

·         Add 1/10 portion of Glaubers Salt  - run 10 minutes

·         Add 2/10 portion of Glaubers Salt – run 10 minutes.

·         Add 7/10 portion of Glaubers Salt – run 20 minutes

o   Note: (if the dyestuff combination contain V.S or Bi-functional dyes   reduce temperature to 60°C)

·         Add ½ the quantity of Soda Ash – run  10 minutes

·         Add ½ the quantity of Soda Ash – run 10 minutes.

o   Note: (if the dyestuff combination contain V.S or Bi-functional dyes

continue dyeing at 60°C for 30 minutes, then raise temperature to 85°C and dye the Turquoise dyestuff for another 30 to 45 minutes.)

·         If the combination is only HE dyes continue dyeing for another 30 to 45 minutes.

                       (Do tonal corrections if necessary at this point.)

·         Drain – Over flow cold wash – 10 minutes

·         Acetic Acid Neutralization with 2 g/l Acetic Acid at cold. – 10 minutes.

·         Hot Wash at 70°C for 2 cycles. ( 10 minutes)

·         Hot wash at 70°C for 2 cycles. ( 10 minutes)

·         soaping :

o   RECIPE:

§  Sandopur RSK Liq or Cobapon R or Alcosperse AD = 2 g/l (1^st soaping)

·         At 95°C for 20 minutes.

§  Sandopur RSK Liq or Cobapon R or Alcosperse AD = 1 g/l (2^nd soaping)

·         At 95°C for 20 minutes.

§  Sandopur RSK Liq or Cobapon R or Alcosperse AD = 1 g/l (3^rd soaping)

·         At 95°C for 20 minutes.

§  Hot Wash – 10 minutes

§  Hot Wash – 10 minutes

§  Cold wash – cold wash (10 minutes each).

§  Acetic Acid = 1 gpl at room temp. = 10 minutes.

§  Softening agent (cationic) = 10 minutes in the same bath at 50°C.

§  Drain

§  Unload.

·         Generally we do not suggest for any cationic dye fixing treatment. However shades like Turquoise Blue may tend to bleed even after all these processes; in that case a suitable dye fixing agent like Sandofix WEI may be used up to 1 to 2 gpl along with the acetic acid and softening agent.

Continuous dyeing of Vinylsulphone dyes

Vinyl Sulphone Based Dyes : 'VS' dyes are based on B-Sulfatonethysulphone reactive system. These dyes have low to medium substantivity / reactivity for cotton and therefore better recommended for padding and printing application also.

  COLD PAD - BATCH DYEING

Pad at 20-30° C
Dyes	x g / l
Urea	50 - 200 g / l
Sodium Silicate	48° Be (Na2 O: Sio2 Ratio 1:2.6)
Caustic Soda	38° Be 10-25 ml / l
Glauber's Salt	30 g / l
Temperature	20 - 30° C
Batching	24 Hrs.
Pick up %
Cotton	Woven 65-80%, Knit 80-110%
Viscose Rayon	70 -90%

 After Treatment Washing off : Cold Rinsing --> Hot Rinse (70° C) --> Soaping (95° C)
Hot Rinsing (70° C) --> Cold Rinsing  

Behavior of Vinylsulphone dyes while using Sodium Silicate

V. S. Based Dyestuff	Solubility in Presence of alkali	Stability at 30°C
	Without urea g/l	minutes
Yellow FG	100	30
Yellow GR	100	60
Brill Red 5B	60	120
Red BS	80	60
Red RB	100	30
Violet 5R	75	60
Blue 3R	100	60
Blue R	100	60
T. Blue G	75	120
Black B	100	45

  Note: Reactive Brill. Orange 3R is not suitable for this purpose due to insufficient solubility in alkali at the padding liquor.

COLD PAD/DRY/CURE METHOD:

Cold Padding with:

1. Dyestuff               = x grams
2. Sodium Alginate = 2 grams/liter
3. Urea                     = 50 grams/liter
4. Glauber’s Salt      = 100 grams/liter
5. Sodium Bicarbonate = 60 grams/liter

Dry:

      Dry the fabric in a stenter at 110 to 120 °C

Cure:

       Curing at 140°C for 5 minutes or 150°C for 4 minutes

Washing:

·         Cold wash in washer or jigger = 10 minutes

·         Hot wash at 60°C for 10 minutes

·         Neutralization with Acetic Acid 2 grams/liter at cold – 10 minutes.

·         Cold wash

·         1^st Soaping

o   Sandopur RSK Liquid or Dekol SN = 2 g/l at 95° for 10 minutes

·         2^nd Soaping

o   Sandopur RSK Liquid or Dekol SN = 1 g/l at 95° for 10 minutes

·         Hot wash at 50°C for 10 minutes

·         Cold wash 10 minutes

·         Acetic acid 1 g/l – check pH to be 6.

·         Unload.

   

Another method:

Cold Padding:

1. Dyestuff (only VS) = x grams
2. Urea                        = 30 grams/liter
3. Soda Ash                = 20 grams/liter
4. Caustic Soda(flakes)= 5 grams/liter

• Cold padding with the above solution with 80~90% pick up (expression).
• Batched in an A-Frame trolley and allowed to rotate 8-12 hours.
• Loaded in Jiggers
• Over-flow cold wash
• Neutralization with Acetic acid – 2 grams/liter
• Hot wash – 50°C for 10 minutes.
•  1^st Soaping

                                                              i.      Sandopur RSK Liquid or Dekol SN = 2 g/l at 95° for 10 minutes

•  2^nd Soaping

                                                              i.      Sandopur RSK Liquid or Dekol SN = 1 g/l at 95° for 10 minutes

•  Hot wash at 50°C for 10 minutes
•  Cold wash 10 minutes
•  Acetic acid 1 g/l – check pH to be 6.
•  Unload.