Dyeing of acrylic fibre

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Dyeing of acrylic fibre

  1. 1. DYEING OF ACRYLIC FIBRE <ul><li>PRODUCED BY ADDITION POLYMERIZATION OF ACRYLONITRILE (CH2=CHCN) </li></ul><ul><li>INITIATERS: REDOX SYSTEM </li></ul><ul><li>SODIUM BISULPHITE/SODIUM PERSULPHATE </li></ul><ul><li>HOMO POLYMER IS DIFFICULT TO DYE </li></ul><ul><li>CO-MONOMER SUCH AS ACRYLIC ACID OR VINYL ACETATE USED TO AN EXTENT OF 15% </li></ul><ul><li>COMMERCIAL ACRYLIC FIBRE IS CO-POLYMER OF ACRYLONITRILE (85%) AND ACID CO-MONOMER (15%) </li></ul><ul><li>FIBRE IS –veLY CHARGED DUE TO </li></ul><ul><li>PRESENCE OF ACID CO-MONOMER </li></ul><ul><li>PRESENCE OF SO3 – FROM RESIDUES OF REDOX INITIATERS </li></ul>
  2. 2. SUITABLE DYE CLASSES <ul><li>DISPERSE DYES </li></ul><ul><li>LOW AFFINITY </li></ul><ul><li>SUITABLE ONLY FOR PALE TO MEDIUM SHADES </li></ul><ul><li>CATIONIC OR BASIC DYES </li></ul><ul><li>MOST SUITABLE DYE CLASS </li></ul><ul><li>CAN PRODUCE DEEP SHADES WITH GOOD FASTNESS PROPERTIES </li></ul><ul><li>WIDELY USED </li></ul>
  3. 3. CATIONIC DYE STRUCTURE <ul><li>COLOURED SALT OF ORGANIC BASE </li></ul><ul><li>ABSENCE OF WATER SOLUBILIZING GROUP </li></ul><ul><li>LOW WATER SOLUBILITY </li></ul><ul><li>SOLUBILITY IMPROVED IN PRESENCE OF ORGANIC ACID LIKE ACETIC ACID </li></ul>
  4. 4. DYEING MECHANISM <ul><li>FIBRE </li></ul><ul><li>FIBRE IS –Ve LY CHARGED DUE TO PRESENCE OF </li></ul><ul><li>ACID CO-MONOMER </li></ul><ul><li>RESIDUES OF REDOX INITIATERS </li></ul><ul><li>DYE </li></ul><ul><li>+ Ve CHARGE </li></ul><ul><li>DYE-FIBRE INTERACTION </li></ul><ul><li>ELECTROSTATIC OR IONIC INTERACTION </li></ul><ul><li>ABSORPTION OF DYE ON FIBRE SURFACE </li></ul><ul><li>NEUTRALIZATION OF FIBRE CHARGE </li></ul><ul><li>AT HIGH TEMP. DYE PENETRATION INSIDE FIBRE </li></ul><ul><li>INTERACTION WITH ACID GROUPS OF COMONOMER AND RESIDUES OF REDOX INITIATERS </li></ul><ul><li>DYE IMMOBILIZATION </li></ul>
  5. 5. DYEING WITH DISPESE DYES <ul><li>LOW DYE AFFINITY </li></ul><ul><li>ONLY PALE TO MEDIUM DEPTH OF SHADES CAN BE PRODUCED </li></ul><ul><li>USED ON LIMITED SCALE </li></ul><ul><li>DYE X% </li></ul><ul><li>ACETIC ACID 1g/l </li></ul><ul><li>NON-IONIC WETTING AGENT 1g/l </li></ul><ul><li>pH 4.5-5.5 </li></ul><ul><li>START DYEING AT 40 0 c, </li></ul><ul><li>RAISE TEMP. TO BOIL IN 30 MIN. </li></ul><ul><li>DYE AT BOIL FOR 1 hr </li></ul><ul><li>RINSE WITH COLD WATER </li></ul><ul><li>WASH WITH HOT WATER 60 0 c USING NON-IONIC DETERGENT </li></ul><ul><li>RINSE WITH COLD WATER </li></ul><ul><li>DRY </li></ul>
  6. 6. DYEING WITH CATIONIC DYES <ul><li>MOST WIDELY USED DYE CLASS </li></ul><ul><li>GOOD FASTNESS PROPERTIES </li></ul><ul><li>POSSIBLE TO DYE DEEP SHADES </li></ul>
  7. 7. DYEING WITH CATIONIC DYES <ul><li>DUE TO RAPID DYE UPTAKE ABOVE 85 0 C, CHANCES OF UNEVEN DYEING </li></ul><ul><li>UNIFORM DYEING OBTAINED BY </li></ul><ul><li>VERY SLOW RATE OF RISE OF TEMP ABOVE 85 0 C </li></ul><ul><li>THE USE OF RETARDER TO PREVENT RAPID DYE UPTAKE BY FIBRE </li></ul><ul><li>RETARDER </li></ul><ul><li>CATIONIC COLOURLESS AUXILIARY </li></ul><ul><li>COMPETE WITH ANIONIC DYE SITES IN FIBRE </li></ul><ul><li>RETARD THE DYE EXHAUSTION </li></ul><ul><li>RETARDER CONCENTRATION 2-4% owf </li></ul>
  8. 8. DYEING WITH CATIONIC DYES <ul><li>DYE DISSOLUTION </li></ul><ul><li>PASTE THE DYE WITH ACETIC ACID </li></ul><ul><li>ADD HOT WATER </li></ul><ul><li>BOIL TILL DYE IS DISSOLVED </li></ul><ul><li>FILTER TO REMOVE UNDISSOLVED DYE </li></ul><ul><li>DYE BATH </li></ul><ul><li>PREPARE THE DYE BATH WITH </li></ul><ul><li>RETARDER 2-4% owf </li></ul><ul><li>ACETIC ACID 4% owf </li></ul><ul><li>SOD. ACETATE 1% owf </li></ul><ul><li>GLAUBER’S SALT 20% owf ALSO ACT AS RETARDER </li></ul>
  9. 9. DYEING WITH CATIONIC DYES <ul><li>START DYEING AT 40 0 C </li></ul><ul><li>TREAT THE FABRIC WITH BLANK DYE BATH CONTAINIG RETARDER FOR 10-15 MIN. </li></ul><ul><li>ADD PREDISSOLVED DYE IN TWO INSTALMENTS </li></ul><ul><li>RAISE THE TEMP. SLOWLY TO BOIL </li></ul><ul><li>CARRY OUT DYEING AT BOIL FOR 1 hr </li></ul><ul><li>COOL THE DYE BATH </li></ul><ul><li>DRAIN </li></ul><ul><li>WASH WITH COLD WATER </li></ul><ul><li>SOAP AT 60 0 C NON IONIC DETERGENT </li></ul><ul><li>WASH WITH COLD WATER </li></ul><ul><li>DRY </li></ul><ul><li>DYEING MUST BE CARRIED OUT WITHOUT TENSION </li></ul><ul><li>JIGGER DYEING MACHINE NOT SUITABLE </li></ul><ul><li>JET DYEING MACHINE MOST SUITABLE </li></ul>

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