| Abstract: | Cotton ha been dyed with reactive dyes by both wet-on-wet (WOW) and wet-on-dry (WOD) cold pad-batch processes, and by conventional exhaust methods. The colour yields, in terms of the Kubelka-Munk values as a function of the amount of fixed dye, showed that the WOW method required less fixed dye to produce a given depth of shade than the other methods. It is proposed that the higher colour yields are a consequence of limited dye penetration into the cotton fibre. Compared with exhaust dyeings, WOW and WOD dyeings were clearly ring dyed but, unfortunately, no definitive difference in the degree of dye penetration into the cotton fibres was found despite their colour yield differences. Although ring dyeings often have inferior fastness properties, the WOW dyeings were of equal or slightly superior fastness to repeated washing and to normal daylight in comparison with the other dyeings |
