System setting in pretreatment and dyeing in reactive dyeing for cotton

A practical approach for Tripur/Erode/Coimbatore area

According to latest survey in India 60% reactive dyeconsumption is in Tripur only.

For winch/soft flow machine famous cotton quality runningfor ex-single jersey, interlock, double jersey, fleece, pickipolo etc.

For cabinet dyeing famous cotton count running forex-2,10,2/40,2/20,2/17,2/10 count etc.

(I) Pretreatment process for winch/soft flow/cabinet dyeingmachine where auto steam controller is available (boiler is available)

As mentioned bottom side:-

First check water hardness if less than 30 ppm follows this process. IF hardness is more than 100 ppm used sequestering agent to be used (for Ex- waterhardness 200-500m ppm used Levacol SQ 0.1-0.5 g/l(colourtex)

1. wetting agent(non-ionic)=0.5-1% owf +caustic soda=3-4% owf
   Run at 50-55 degree Celsius, holding time-20 minute)
   Then add stabilizer (organic based silicate free) =0.3-0.5% owf (first) +hydrogen peroxide (50%) =1-3% owf (second)
   (Increase temp to 85-90 degree Celsius, rise in temp-3-3.5 degree per minute, holding time 60 minute)
   Check absorbency if less than 3 second drain the bath.
2. peroxide killer (enzyme based)=0.5-1% owf
   Acetic acid=0.3-0.8% owf
   (50-55 degree celcius, holding time-30 minute)
   Or
   Peroxide neutralizer=0.5-1 gpl (75-85 degree celcius, 20-25 minute)
   (Check residual peroxide by peroxide test indicator or spotting the fabric directly with titanyl chloride reagent.)
   Advantage: - washing can be avoided if peroxide neutralizer is used.
3. Washing or rinsing
4. Check PH and absorbency (PH should be 6-7 range absorbency less than 3 second. For RFD (ready for dyeing) Fabric).If fabric PH is alkaline used HCL (hydrochoric acid) for neutralizing in cold condition. Why HCL used instead of acetic acid because of cost factor otherwise acetic acid is best for neutralizing .
5. Continue dyeing process
6. (Mostly place in Tripur /Erode /Coimbatore area 60 degree Celsius reactive dyes is used for example-colourtex co lour series (corazol RFT (medium shade), corazol seies, corafix ME series, corafix GD (for dark shade) Series), ciba series (ciba FN series (for light shade) etc).

Dyeing Process (Continue--)

Salt dye soda exhaust process.

For winch machine machine no need for leveling agent andlubricating agent.

For soft flow machine leveling agent (0.5% to 1% owf) andlubricating agent (0.5-1% owf) is must to avoid unevenness and crease mark andcrow feet mark.

Before dyeing water hardness and PH to be check (if hardness is more) used sequestering agent

1. Vacuum salt (for maximum shade), (glauber salt for turquoise blue shade) + lubricating agent leveling agent.
   (Run for 15-20 minute in cold, PH should be 5.5-6.5)
2. Add dissolved dyes solution in two installments.
   (Run for 15-20 minute in cold, dye addition gap should be 15-20 minute)
   Then Increase temp to 60 degree celcius in 1.5 to 2 degree celcius rise in temperature. Hold for 10 minute.
3. Added dissolved soda ash in two installment in 15-20 minute at 60 degree celcius holding time 90 minute (for light shade-45-60 minute , medium shade-60 -90 minute (ex-corazol RFT series (Colourtex)),for dark shade caustic soda to be added in installment base after 60 minute (1.25 gpl-2.5 gpl)ex-Cora fix GD series (Colourtex)) If shade ok drain
4. Cold wash
5. Neturalizing
6. Soaping (fastness checking, for light shade only hot wash sufficient, for medium shade, for dark shade if required second soaping)------hot wash----cold wash----check sample if ok---fixer ---unloaded.

NOTE: - IF soft flow/Cabinet dyeing machine with above mentioned process we can go for 80 degree celcius dyeing colour (for ex-coracion HE, Coracion CTXLE (COLOURTEX) ETC).Dyeing process will be same but instead of 60 degree go for 80 degree celcius dyeing.

(II) For Dark shade like black shade direct by wetting agent dyeing done for local order in liquid soda also in most of Tripur company (for ex-corazol Black GR,corafix Black GDN colour(colourtex)) giving good result as compared to conventanional process:

1. wetting agent(non-ionic)=1-2% owf
   (Run at 50 -55 degree celcius, holding time 20-30 minute)
2. dye-vacuum salt-liquid soda +caustic soda exhaust process
   Dyeing temp 60 degree celcius.mostly vinyl sulphone base is used).

Comparison of liquid soda available in local market done with soda ash running powder sample

Conclusion:

Liquid soda is not 100 % pure soda it is mixed with some other cheaper alkali also

(III) For some company if boiler is not available then cold beach process is running in winch machine (for local quality) for 100% cotton knitted fabric.

Pretreatment:-

1. Wetting agent (local):-0.3-0.5 % owf
   Bleaching liquor=2 GPL (AVAILABLE CHORLINE)
   (Cold, 1 hour holding)
2. Cold wash
3. Liquor killer or neutralizer=1% owf
   (Cold, 30 minute holding time)
4. Check PH and absorbency of RFD (Ready for dyeing) fabric

Dyeing process:-

Coricion cold brand colour (colourtex) and corazol series (in most of company smoothly running for local order)

Dye---vacuum salt---soda ash (for light and medium shade and for dark shade mixed alkali is used in cold dyeing) cold process-------cold wash----neturalizing(with hydrochoric acid for local order)---soaping(low foaming anionic soap)(for light shade only cold wash)---cold wash---cold wash ---check fastness at 40 or 60 degree celcius---if ok go for fixer---unloded.

Wetting agent popular in Tripur/erode/Coimbatore

1. ALPHOX-200 (INDIAN GLYCOL LTD, Delhi) ---Non-ionic wetting and detergent also (based on aryl polyglycol ether). It is mostly shows cloudy point after 55-60 degree celcius in 70 ppm water hardness.
2. It is always advisable for more than 50 ppm hardness water sequestering agent to be added in the bath because cloudiness causes reduction of wetting power.
3. Lenatol PBX-(CRODA) ----Non-ionic wetting agent and detergent also (based on alcohol ethoxylates).
4. Kieralon JET (BASF)
5. Ultraven GM (HUNTSMAN).
6. Local wetting agent also running.

STABILIZER popular in pretreatment for cotton in erode/tripur/coimbatore.

1. Stabilizer NS (CRODA) ----Non silicate stabilizer for peroxide bleaching liquor. Its cationic in nature.
2. Clarite G-100(HUNTSMAN)Non silicate stabilizer.
3. Stabilizer AWNI (Clariante)
4. Local stabilizer

Residual Peroxide killer or neutralizer popular for cotton in erode/tripur/Coimbatore.

1. METAXIL NZPN (CRODA)peroxide neutralizer for removal of residual peroxide in fabric because lot of reactive dye is very sensitivity towards peroxide. It is anionic in nature (based on Enzyme, 50-55 degree celcius, PH=5.5, Holding time=20-25 minute).
2. LUZYME PK (BASF)Enzyme for the-Catalytic removal of residual peroxide (active ingredient:-Fungal catalyses).it decomposes residual peroxide into oxygen and water. It is totally bio-degardable.
3. INVAZYME CAT-I (HUNTSMAN) ----enzyme based catalytic removal of residual peroxide available.
4. METAXIL BAPK(CRODA):-Peroxide neturaller.it is anionic in nature(alkaline solution of organic sodium salt)(55-60 degree celcius,holding time 15-20 minute)
5. Local peroxide killer or neutralizer also running.

Leveling agent, lubricating agent and sequestering agent popular for reactive dyeing (FOR SOFT FLOW/winch machine).

1. Drimagen E2R (CLARIANT):-leveling agent with better electrolyte stability for reactive dyeing. It is smoothly running in Tripur and erode area(soft flow machine)
2. Local leveling agent also running.
3. IMACOL C2G.IN LIQUID (clariant):-Non foaming lubricant for cellulose fibre. It is smoothly running in soft flow machine
4. Local lubricating agent also running.
5. Metaxil ADW (Croda):-For cabinet dyeing it performance is good it act as a powerful dispersing agent to remove unfixed and hydrolysis reactive dye and side by side acts a chelating agent also( it work as a protective colloid for elimination of problem caused by redeposit ion of insoluble calcium and magnesium salt without any demetalizing effect on dyestuff) .it is also good washing off agent for reactive dyeing .it is anionic in nature(based on sodium salt polyacrylic acid).
6. Some local sequesting agent also running successfully.
7. Levacol SQ (COLOURTEX)-High performance excellent sequestering agent side by side act as a chelating agent also. It is blend of chelating agent even small quantity also good result it can be used in dye bath also if water hardness is more.
   Water hardness:-200-500 ppm apporex dosage :-( 0.1-0.5 gpl)
   
   

Trail taken:-

In garment dyeing (drumming machine) sometime RFD (Ready for dyeing) garment wetting power is poor and water hardness was more than 200 ppm . One trial taken in 200 kg machine with levacol SQ=0.3 GPL before dyeing in khakhi shade with carazol RFT Series (colourtex) given excellent result.

SOAP:-

1) Maximum anionic soap is used (based on sulphate alcohol)for ex-lissapol D paste, local soap etc

Fixer:-

1) Maximum free formaldehyde based cationic and non-ionic based fixer is used.

This above recipe is running smoothly in some well reputed company smoothly.

System set up can be according to the following variable factor;-

1. Water hardness and PH.
2. Substrate ex-fabric, hank etc
3. Machine available: - ex-cabinet dyeing,soft flow, winch machine.
4. Chemical auxiliaries:-
5. M;L(material/liquor)ratio:- ex-cabinet dyeing m/c (M:L=1:18-1:20), garment drumming m/c (M;L=1:13-1:15), Soft flow machine (M:L=1:6-1:10), Winch machine (M:l=1:13-1:15) etc.
6. Electrolyte:-free flow vacuum salt smoothly running in Tripur /erode and Coimbatore area. Sometime glauber salt is used for turquoise blue shade.
7. lab to bulk dyeing recipe correlation:-for ex-corafix GD Series(colourtex) for dark shade(for ex-black,maroon,navy etc) in mixed alkali system bulk sample is 15-20% plus depth as compared to lab recipe.

Lab to bulk dyeing recipe correlation has to be done by dyeing expert only.

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