1. Function of
Dying Chemical and Auxiliary

2. Name : MAZADUL HASAN SHESHIR
ID: 2010000400008
Batch: 13th Batch (Session 2009-2013)
Department: Wet Processing Technology
Email: mazadulhasan@yahoo.com
Blog: www. Textilelab.blogspot.com
Southeast University
Department of Textile Engineering
PREPARED BY ©right

3. Pre-treatment
Chemical

4. Criteria : Combination of Anionic & Non-ionic Detergent with strong wetting power is
recommended.
Dosage : Depending on the presence of fat, oil, dirt & G.S.M of the fabric ranging from
0.5to 1g/l.
Run Time : Within 10min chemical addition to be made and then running for 30 mins
Temperature : These chemicals addition to be made at 400C and then temp to be
raised at 950C for 30mins
Remarks : Addition of chemicals for 10 mins then loading of fabrics Then increasing of
Temperature to 950 to 1050C
Wetting Agent

5. Criteria : Sequestering Agent to be used as per the necessity of both fabric and
water hardness.
Dosage : Dosage should be optimized and should not be more than the need to
remove hardness.
Run Time : Within 10min chemical addition to be made and then running for 30
mins
Temperature : These chemicals addition to be made at 400C and then temp to be
raised at 950C for 30mins
Remarks : Addition of chemicals for 10 mins then loading of fabrics Then
increasing of Temperature to 950 to 1050C
Sequestering Agent

6. Criteria :Should be colourless and stable in high pH & temp.
Dosage :Lower GSM fabrics need more Anti-creasant
Run Time : Within 10min chemical addition to be made and then
running for 30 mins
Temperature :These chemicals addition to be made at 40C and then
temp to be raised at 95C for 30mins
Remarks :Addition of chemicals for 10 mins then loading of fabrics Then
increasing of Temperature to 950 to 1050C
Anti-creasing Agent

7. Criteria : Improves wetting property of fabrics but more care needed
forneutralizing. Fabric GSM can also be decreased.
Dosage : 3 g/l (38 Be'), Over dosing may cause oxycellulosic damage.
Run Time : Within 10min chemical addition to be made and then
running for 30 mins
Temperature : These chemicals addition to be made at 400C and then
temp to be raised at 950C for 30mins
Remarks : ++++
Caustic Soda (38Be)

8. Criteria :Conventional process and risk free
Dosage : ++++
Run Time : Within 10min chemical addition to be made and then
running for 30 mins
Temperature : These chemicals addition to be made at 40C and then
temp to be raised at 95C for 30mins
Remarks : Raising temp. to 950C & running it for 600 then cooling down
to 300& over flow wash for 10 min.
Soda Ash

9. Criteria : Should be silicate free & organic based to avoid harshiness
Dosage : Usually 1/8 to 1/10 of peroxide dosing
Run Time : Within 10min chemical addition to be made and then
running for 30 mins
Temperature : These chemicals addition to be made at 40C and then
temp to be raised at 95C for 30mins
Remarks : Raising temp. to 950C & running it for 600 then cooling down
to 300& over flow wash for 10 min.
Peroxide Stabilizer

10. •Name of Chemicals : Hydrogen Peroxide
Criteria :Strength test should be done properly. Usualy 50% Peroxide is
used in Textile Processing.
Dosage :For Pre-scouring 2-3 g/L and for Bleaching 4.00 to 5.00 g/L
Run Time :Within 10min chemical addition to be made and then
running for 30 mins
Temperature :These chemicals addition to be made at 400C and then
temp to be raised at 950C for 30mins
Remarks :++++

11. Criteria : Both enzymetic and non-enzymetic(Thio-sulphate based) ( 60C
for Enzymetic and 80 for non-enzymetic)
Dosage : Depending on the presence of Peroxide, thedosing should be
within 0.25 to 0.5 g/L
Run Time : 15 min.
Temperature : 650C/800C
Remarks : Presence of Peroxide to be tested by Peroxide stripe.
Peroxide Killer

12. Criteria : Glacial Acetic Acid(99%) & no Inorganic Acid to be present
Dosage : To get pH 5-6
Run Time : 15min
Temperature : 80C
Remarks : To be chechedatleast after 10 mins
Acetic Acid

13. Finally over flow wash for 10 mins and Fabrics pH (to be
kept between 5.5-6) and Temperature (to be kept below dyeing
temperature) checking is very important.

14. Bio polishing
Chemical

15. Criteria: Glacial Acetic Acid(99%) & no Inorganic Acid to be present
Dosage Qty: To decrease pH to 4-5
Run Time : +++++
Temperature: 600C
Remarks: ++++++
Acetic Acid

16. •
Criteria: For better performance, Bio-polishing to be done after scouring
Dosage Qty : Excessive dosing may reduce tensile strength
Run Time : 30-45 min
Temperature: 600C
Remarks: ++++
Finally over flow wash for 5 mins and fabrics Temperature checking is
important. Fabrics temp. should be less than dyeing temperature.
Cellulose Enzyme & GSM of fabrics

17. Dyeing
Chemical

18. •
Criteria: It should not have any proton treatment property & should
have both Iron,Magnesium and Calcium binding power
Dosage Qty: Usually 0.5 g/L to 1 g/L but for metal complex dyes, the
dosing should be higher.
Run Time: ++++
Temperature: Normal temp.
Remarks: Dyestuffs can be dissolved with some dispersing agent. Salt
dosing should be done at linear method.
Dispersing Agent

19. Criteria: It's a kind of retarding agent and acts as stabilizing the
exhaustion of dyestuffs for maximum dye-levelness.
Dosage Qty: Usually 0.5 g/L but for light shades higher dosing should
be needed for betterlevelness.
Run Time: ++++
Temperature: ++++
Remarks: ++++
Leveling Agent

20. Criteria: Should be colorless and stable in high pH & temp
Dosage Qty: Lower GSM fabrics need more Anti-creasant
Run Time: ++++
Temperature: ++++
Remarks: ++++
Anti-creasing Agent.

21. Criteria: To be dissolved and filtrated properly. It it better to dissolve with some
dispersing agent and Acetic Acid.
Dosage Qty: According to the fabric (ready for dyeing) qty.
Run Time: ++++
Temperature: ++++
Remarks: ++++
Dyestuffs

22. Criteria : pH should not be more than 8.5 and should be hardness andbi-carbonate
free. Purity test to be done prior to use (amount needed to gain expected
concentration)
Dosage Qty:
•To gain recommended concentration
•To gain recommended concentration
(Optimum fixation pH is 10.8-11.5)
Run Time: ++++
Temperature : 600C
Remarks: During soda dosing maximum care to be taken and dosing should be done as
slow as possible Progressive Dosing System can be introduced.
Electrolyte Soda Ash

23. Criteria :Purity test to be done prior to use.(amount needed to gain expected
concentration)
Dosage Qty: To gain recommended concentration (Optimum fixation pH is 10.8-
11.5)
Run Time: ++++
Temperature: ++++
Remarks : ++++
Running the bath at 60C until shade matching …..
Caustic Soda

24. Washing off
Chemical

25. Criteria: Glacial Acetic Acid (99%)& no Inorganic Acid to be present
Dosage Qty : To gain pH 6-7(to be checked after 10-15 min)
Run Time : 10 min
Temperature: 500C
Remarks: Wash fastness of fabrics mostly depends on the washing off
process.
Acetic Acid

26. Criteria : It's pH should be neutral with moderate dispersing & anionic detergency
effect.
Dosage Qty : Dosage to be made as per the shade%
Run Time : 10-15 min
Temperature : 980C
Remarks : Wash fastness of fabrics mostly depend on the washing off process.
For VinylSulphone dyes Acidifying for neutralization needed, otherwise can be omitted . Firstly
cooling and overflowing then three washes at 70C for 10 min each, then at 980C (with
sequestrant) for 10-15 min and for 10 min at 700C and at 500C for 10min
Washing off Agent

27. Finishing
Chemical

28. Criteria : It makes coating on the fabrics and color change is inevitable
Dosage Qty : As per the depth of shade
Run Time : 15-20 min
Temperature : 30-40C
Remarks : All most all the the finishing chemicals to be applied
Fixing Agent

29. •
Criteria : Cationic finish reduces wash & light fastness of the fabrics
Dosage Qty : As per the quality requirement
Run Time : 15-20 min
Temperature : +++++
Remarks : in acetic medium.
Other Finishing Agent