Cationization of cotton and its reactive dyeing without salt

Cotton fabric is pretreated with cationic modifier,and then dyed with reactive dyes without salt.The optimum modification process is: modifier 4%(omf),NaOH 4 g/L,treating at 40 ℃ for 30 min.The dyeing process of the modified fabric is: Reactive Black RWN 4%(omf),dyeing temperature 40 ℃,dyeing time 5 min,liquor ratio 1∶30,soda ash 10 g/L,fixation time 60 min.Compared with the unmodified fabric,the color fastness to rubbing and washing of the modified cotton fabric declines 0.5 grade.The modified dyeings have similar color depth(K/S value) with those of the conventional dyeings,and the levelness is good.