(Textile Knowledge) Dyeing of Polyester/Cotton Fibers with Disperse/Reactive Dyes
For satisfactory dispersion in the dye batch, the dyes were initially finished by mortar milling in the presence of a specially selected dispersing agent. Cotton/Polyester fabrics were dyed in Atlas dyeing machine at a liquor ratio of 40:1 using distilled water. The dye batch was prepared with the dye at range of dye concentrations (0.5 %, 1%, 1.5%, 2% and 3% owf) and with 1.5 g/l anionic dispersing agent (Avolan IS Bayer Co.). The pH was then adjusted to 4, 6, 7, 8, 9 and 10 using 10% acetic acid and 0.2 mol sodium carbonate solution. Dyeing was started at 450C for 15 minutes, then the dye batch temperature was raised at a rate of 1.5-2 C/min to 90, 100, 110, 120 and 130 0C and the dyeing continued at the desired temperature for a further 60 minutes unless otherwise specified. Dyeing was commenced at 700C. The dye batch temperature was raised by 1 C/min to 1300C, maintained at this temperature for 60 minutes and cooled to 600C. After 30 minutes at 600C, 20g/l of alkali (Na2Co3) was added to effect fixation of the dye on cotton and maintained at 600C for further 30 minutes. The dyeing were rinsed and soaped at 950C for 15 minutes with 1.5 g/l soaping agent.