Dyeing cotton with reactive dyes: a comparison between conventional water-based and solvent-assisted PEG-based reverse micellar dyeing systems

Use of reactive dyes of red, blue and yellow colours for exhaustion dyeing of cotton conventional water-based dyeing method and PEG-based solvent-assisted reverse micelle dyeing method was investigated. Calibration curves of both dyeing approaches were established. The calibration results show that red dye can achieve higher absorbance value than yellow and blue dyes and the R-square of the curves can reach a value above 0.99 which indicates the curves are linear in structure and suitable for subsequent measurement. The values of substantivity factor (S), exhaustion factor (E), rate of fixation (R) and fixation factor (F) (SERF) are measured in percentage. The results reveal that using reverse micelle method can achieve higher dye absorption in both exhaustion and fixation processes, resulting in higher final exhaustion of dye in fibre than with the conventional water-based method. Therefore, the reverse micellar dyed samples generally can obtain higher dye absorption, lower reflectance percentage and darker shade in appearance than conventional water-based dyeing.