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Presentation about 'Function of dying chemical and auxiliary es'
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Function of Dying Chemical and Auxiliary
PREPARED BY ©right 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
Pre-treatment Chemical
Wetting Agent 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 950to 1050C
Sequestering Agent 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 950to 1050C
Anti-creasing Agent 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 950to 1050C
Caustic Soda (38Be) 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 : ++++
Soda Ash 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 600then cooling down to 300& over flow wash for 10 min.
Peroxide Stabilizer 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 600then cooling down to 300& over flow wash for 10 min.
•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 :++++
Peroxide Killer 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.
Acetic Acid 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
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.
Bio polishing Chemical
Acetic Acid Criteria: Glacial Acetic Acid(99%) & no Inorganic Acid to be present Dosage Qty: To decrease pH to 4-5 Run Time : +++++ Temperature: 600C Remarks: ++++++
Cellulose Enzyme & GSM of fabrics • 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.
Dyeing Chemical
Dispersing Agent • 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.
Leveling Agent 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: ++++
Anti-creasing Agent. Criteria: Should be colorless and stable in high pH & temp Dosage Qty: Lower GSM fabrics need more Anti-creasant Run Time: ++++ Temperature: ++++ Remarks: ++++
Dyestuffs 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: ++++
Electrolyte Soda Ash 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: ++++ : 600C Temperature Remarks: During soda dosing maximum care to be taken and dosing should be done as slow as possible Progressive Dosing System can be introduced.
Caustic Soda 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 …..
Washing off Chemical
Acetic Acid 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.
Washing off Agent 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 VinylSulphonedyes 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
Finishing Chemical
Fixing Agent 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
Other Finishing Agent • 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.