Dyeing Properties of Bifunctional Monofluoro-s-triazine Reactive Dyes

Abstract

As monofunctional reactive dyes have a low level of fixation, a number of bifunctional dyes are offered by the producers, becoming more and more acceptable, both from environmental and from the economic point of view. Dyeing properties of a new group of bifunctional monofluoro-s-triazine reactive dyes, compared to monofunctional dyes of the same reactive system, are investigated. Dyeing procedures were organised with the dyestuffs chosen following the recommendations of the producer. Spectrophotometric method was used to determine, after dyeing and rinsing, the content of residual reactive dyestuff in the dyeing bath, as well as the content of the dyestuff exhausted and fixed on a viscose woven fabric. The content of the fixed dyestuff was determined simultaneously on the dyed samples, before and after rinsing, employing remission spectrophotometer. Relative strength of bifunctional reactive dyes compared to monofunctional ones was also determined. Results indicate that bifunctional monofluoro-s-triazine reactive dyes, compared to monofunctional of the same reactive system, have 10 to 20 % higher rate of fixation, and are both economically and ecologically much more acceptable.