Solvent Assisted Low Temperature Dyeing. Part I: Results for Mohair (Angora Goat) Fibres

Abstract

It is generally known that mohair tends to lose its luster when dyed for prolonged periods at the boil, and to preserve its luster it is generally necessary to use short dyeing cycles and low dyeing temperatures. Beyond preserving fibre luster, the dyeing of fibres at low temperature does have some advantages from an industrial point of view, namely saving energy, environmental control and fibre protection during dyeing. However, the problem of low temperature dyeing is that it hinders dye diffusion into the fibre, thus decreasing the colour yield of dyed samples. In this study, by using benzyl alcohol as a dyeing auxiliary at lower temperatures, it was possible to dye fibres at both at 90 degrees C and 80 degrees C for all dye classes without causing any decrease in colour yield. Dyeing kinetics were also studied, and it was demonstrated that in the presence of benzyl alcohol, the rate constant and Standard affinity increased.