The wash-off of reactive dyes on cellulosic fibres .3. Dichlorotriazinyl dyes on lyocell

Lyocell fabric was dyed using six concentrations of three commercial dichlorotriazinyl reactive dyes using the dyeing method recommended by the dye maker. One surfactant-based and three sodium carbonate-based wash-off methods were used to remove unfixed dye from the dyeings and the fastness of the resulting dyed samples to the ISO CO6/C2 wash test was determined. The results suggest that the use of the surfactant may be unnecessary in washing-off the dyeings and that an adequate level of both wash-off and wash fastness can be achieved using 2 g litre(-1) Na2CO3. The findings agree very closely with those previously secured using commercial monochloro-, dichloro- and bismonochlorotriazinyl reactive dyes on cotton fabric. (C) 1997 Elsevier Science Ltd.