Eco friendly in textile processing

Eco Friendly In Textile Wet Processing By Aravin Prince Periyasamy aravinprince@gmail.com 1 Supercritical Carbon Dioxide 2aravinprince@gmail.com What is supercritical carbon dioxide?  A supercritical fluid is a substance above its critical temperature and critical pressure. Under these conditions the distinction between gases and liquids does not apply and the substance can only be described as a fluid. 3aravinprince@gmail.com Supercritical Fluid of CO 2 4aravinprince@gmail.com Above 31.1 0 C and 73 atm carbon dioxide behaves as a supercritical fluid and shows properties of both a liquid and a gas It fills the container, like a gas, and dissolves substances like a liquid. 5aravinprince@gmail.com Supercritical fluid of CO 2  With an increase in temperature the meniscus begins to diminish.  The liquid density falls due to expansion and the gas density rises as more of the substance evaporates. 6aravinprince@gmail.com Supercritical fluid of CO 2  Once the critical temperature and pressure have been reached the two distinct phases of liquid and gas are no longer visible. The meniscus can no longer be seen. One homogenous phase called the "supercritical fluid" phase occurs. 7aravinprince@gmail.com Industrial extraction with supercritical CO 2  Decaffeinating coffee and tea  Extracting bitterness to make beer  Defatting cocoa powder  Extracting spices and aromatic plants 8aravinprince@gmail.com Significant properties of supercritical fluids Diffusivity gas > supercritical fluid > liquid Viscosity gas < supercritical fluid < liquid Surface tension gas = supercritical fluid < liquid Density gas < supercritical fluid < or = liquid 9aravinprince@gmail.com Benefits of using supercritical CO 2 for extraction  It is having the penetration power of a gas and the extraction power of a liquid.  It acts as a solvent to extract organic compounds with a low molecular weight.  It leaves no residual trace on treated material  It respects the environment. 10aravinprince@gmail.com [...]... solvent in coatings industry (replacing 40 - 90% of volatile solvents)  Degreasing and dry cleaning applications  Increasingly applied as a solvents in synthetic industrial processes aravinprince@gmail.com 11 Use of supercritical CO2 in dyeing processes aravinprince@gmail.com 12 Use of supercritical CO2 in dyeing processes aravinprince@gmail.com 13 Enzymes aravinprince@gmail.com 14 aravinprince@gmail.com... also the depth to which the penetration takes place in the fabric This makes microwave superior to conventional dyeing techniques aravinprince@gmail.com 18 Ultrasonic Treatments aravinprince@gmail.com 19 Electrochemical dyeing Vat and sulphur dyeing involves both a reducing and an oxidising step, which are carried out with chemical oxidants and reducing agents The environmental concerns associated with... reduced by indirect aravinprince@gmail.com 20 electrolysis Plasma Treatment aravinprince@gmail.com 21 4th State of Matter Plasma Electrically neutral +ve, -ve Charges, Radicals, Electrons, Excited molecules, atoms Highly Reactive & Energetic aravinprince@gmail.com 22 Sun Lightening bolt Hydrogen Bomb Fire aravinprince@gmail.com 23 Thermal Plasma Cold Plasma Hybrid Plasma RT to Over 50,000°C aravinprince@gmail.com... Particles > 50,000°c aravinprince@gmail.com 25 Principle Potential Difference > Dielectric Strength 13.56MHz RF Power aravinprince@gmail.com 26 Gases Used Non-polymerizing Gases He, Ar, Air, Oxygen, Nitrogen, And Mixture Of Gases Polymerizing Gases Cf4, C3f6 aravinprince@gmail.com 27 Major Applications Synthetic Fibres/films Wettability Water Repellency Dyeability aravinprince@gmail.com 28 … Major... treatment aravinprince@gmail.com 16 Microwaves Microwaves are electromagnetic waves whose frequency ranges from 1000MHz to10,00,000 MHz Microwave dyeing takes into account only the dielectric and the thermal properties The dielectric property refers to the intrinsic electrical properties that affect the dyeing by dipolar rotation of the dye and influences the microwave field upon the dipoles aravinprince@gmail.com... the cathode In indirect electrolysis the reducing power of the cathode is transferred to the solution by a soluble reversible redox system (e.g based on antraquinone chemistry or iron complexes) With this reversible redox system the reducing agent is continuously regenerated at the cathode, which thus allows full recycling of the dye bath and the reducing agent Direct cathodic reduction in an electrochemical... solution of dye has two components which are polar, in the high frequency microwave field oscillating at 2450MHz It influences the vibrational energy in the water molecules and the dye molecules  The heating mechanism is through ionic conduction, which is a type of resistance heating Depending on the acceleration of the ions through the dye solution, it results in collision of dye molecules with the molecules... aravinprince@gmail.com 28 … Major Applications ….Synthetic Fibres/films Deep Shades •Soil Release Properties •Composite Applications aravinprince@gmail.com 29 … Major Applications ….Natural Fibres •Shrinkage resistance •Dyeability •Fastness properties aravinprince@gmail.com 30 aravinprince@gmail.com 31 . Eco Friendly In Textile Wet Processing By Aravin Prince Periyasamy aravinprince@gmail.com 1 Supercritical Carbon Dioxide 2aravinprince@gmail.com What is supercritical. Degreasing and dry cleaning applications  Increasingly applied as a solvents in synthetic industrial processes 11aravinprince@gmail.com Use of supercritical CO 2 in dyeing processes 12aravinprince@gmail.com Use. processes 12aravinprince@gmail.com Use of supercritical CO 2 in dyeing processes 13aravinprince@gmail.com Enzymes 14aravinprince@gmail.com 15aravinprince@gmail.com Electron-ray treatment 16aravinprince@gmail.com Microwaves Microwaves