Function of dying chemical and auxiliary es

Function of Dying Chemical and

Auxiliary

Name : MAZADUL HASAN SHESHIRID: 2010000400008Batch: 13th Batch (Session 2009-2013)Department: Wet Processing Technology Email: [email protected]: www. Textilelab.blogspot.com Southeast UniversityDepartment of Textile Engineering

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Pre-treatmentChemical

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

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.



Remarks : Addition of chemicals for 10 mins then loading of fabrics Then increasing of Temperature to 950 to 1050C

Sequestering Agent

Criteria :Should be colourless and stable in high pH & temp.

Dosage :Lower GSM fabrics need more Anti-creasant


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

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.



Remarks : ++++

Caustic Soda (38Be)

Criteria :Conventional process and risk free

Dosage : ++++



Remarks : Raising temp. to 950C & running it for 600 then cooling down to 300& over flow wash for 10 min.

Soda Ash

Criteria : Should be silicate free & organic based to avoid harshiness

Dosage : Usually 1/8 to 1/10 of peroxide dosing



Remarks : Raising temp. to 950C & running it for 600 then cooling down to 300& over flow wash for 10 min.

Peroxide Stabilizer

•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 :++++

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

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

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 polishingChemical

Criteria: Glacial Acetic Acid(99%) & no Inorganic Acid to be present

Dosage Qty: To decrease pH to 4-5Run Time : +++++Temperature: 600CRemarks: ++++++

Acetic Acid

•

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

DyeingChemical

•Criteria: It should not have any proton treatment property & should have both Iron,Magnesium and Calcium binding powerDosage 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

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

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.

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

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

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

Washing offChemical

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

Criteria : It's pH should be neutral with moderate dispersing & anionic detergency effect.

Dosage Qty : Dosage to be made as per the shade%


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

FinishingChemical

Criteria : It makes coating on the fabrics and color change is inevitable

Dosage Qty : As per the depth of shade


Temperature : 30-40C

Remarks : All most all the the finishing chemicals to be applied

Fixing Agent

•Criteria : Cationic finish reduces wash & light fastness of the fabrics

Dosage Qty : As per the quality requirement


Temperature : +++++

Remarks : in acetic medium.

Other Finishing Agent

Function of dying chemical and auxiliary es

Engineering

Transcript of Function of dying chemical and auxiliary es