The dyeing of poly(lactic acid) fibres with disperse dyes using ultrasound: Part 1 – Initial studies

Six disperse dyes were applied at 0.5%, 1% and 2% omf depths of shade to poly(lactic acid) fabric at 30–80 °C for 20, 50 and 90 min in both the presence and absence of ultrasound. Whilst ultrasound enhanced the colour strength obtained for three of the six disperse dyes used at temperatures upto 70 °C, ultrasound did not always result in enhanced colour strength being achieved in the case of the three other dyes. The observed intensification of colour strength was attributed to dye disaggregation. Dyeing at 80 °C in the presence of ultrasound resulted in pale, dull dyeings of reduced colour strength, which was attributed to breakdown of the dye dispersions at this particular temperature.

► Six disperse dyes were applied to poly(lactic acid) fabric in the absence and presence of ultrasound at 30–80 °C. ► Ultrasound enhanced dye uptake for three of the dyes at temperatures upto 70 °C but reduced dye uptake at 80 °C. ► The intensification in shade was attributed to dye disaggregation.