Dyeing of N-modified viscose rayon fibres with reactive dyes

Modified viscose rayon fibres were produced by incorporation of different doses of a polydiallyldimethyl ammonium chloride based additive in the viscose dope prior to spinning. On dyeing the modified fibres with different reactive dyes, excellent dye exhaustion and total dye fixation above 90% were obtained without the use of electrolyte and with low salt concentration. Exhaustion and total dye fixation showed an exponential relationship. The wash fastness properties of the dyed fibres were excellent and the light fastness showed a slight drop in the modified fibres, The presence of the amino groups along with low density and crystallinity of the modified fibres may be responsible for the enhanced dyeability.