Combination dyeing of sea-island nylon superfine fiber PU synthetic leather

Combination dyeing with disperse and acid dyestuff was employed to improve the dyeing effect on sea-island nylon superfine fiber PU synthetic leather with single dyestuff.A few critical parameters were ascertained and the effects of dyeing sequence and fixing agents were also discussed by investigating dyeing penetration,rubbing color fastness,washing color fastness,K/S value and uptake rates.The results show that the optimum effect occurred when the dyeing with disperse dyestuff is performed after that with acid dyestuff.The amount of acid and disperse dyestuff is 4% and 2%,respectively.APA has the best fixing effect.The color is more uniform when APA is added before dyeing.And there are no colored spots.However,dry rubbing fastness can be enhanced to 4.0 and wet rubbing fastness and washing fastness can be enhanced to above 3.0 when APA is added after dyeing.Furthermore,K/S value can also be improved slightly.