Dyeing process of undried poly( p-phenyleneterephthamide) fibers

Undried poly( p-phenyleneterephthamide)( PPTA) fibers were dyed with cationic dyes and disperse dyes. The influences of fiber moisture content,dyeing temperature,dye type and dye dosage on the dyeing properties were studied. Compared with dried PPTA fibers,dyeing of undried fibers can obviously improve the dyeing rate and K / S value of PPTA fibers. With the increase of the moisture content of fiber and the dosage of dye,the K / S value of the dyeing fiber increases,the dyeing effect of cationic dye is better than that disperse dye. Moreover,the color fastnesses of dyed fibers to soaping and rubbing are both above 4 grade,and dyeing does not affect the original mechanical properties of PPTA fibers. The reasonable process parameters are as follows: liquor ratio of 1∶ 20,fiber moisture content of50%,dyeing temperature of 110- 120 ℃,and cationic dyes in use.