Effect Of Cationic Dyes
Affinity of cationic dyes for acrylic, dye diffusion due to adsorption is slow, prone to dyeing unevenness, and unlevel dyeing, it is difficult to extend the time to correct. When cationic dyes, for uniform staining, should lower uptake rates. Influence factors of cationic dyes dyeing rate among acrylic type things, there are the following aspects:
Temperature is an important factor control leveling. When the Acrylic fibre with cationic dyes, at 75 ℃ dyeing rarely, when dyeing temperature reaches the glass transition temperature (75-85), dye dyeing rate increases rapidly. Therefore, when dyeing temperature fiber glass transition temperature is reached, slowly heating up, every 2~4 min warming l c. Insulation in 85~90℃ stained after a period of time, then continue to heat up to boiling.
2. dye bath pH value
Acid dye bath, inhibit dissociation of acrylic acid groups, reduce the amount of anionic groups on the fiber, dyes and fibers of the coulombic force decreases, stain decreased. Effect of pH value on the exhaustion rate to carboxylate-containing acrylic is more significant, sulfonic acid group-containing acrylic fiber dyeing rate less affected by dye bath pH values. Stain should be reasonably control the dye bath pH values. Cationic dyes are generally not alkali, staining the optimum pH value typically is 4-4.5, dyed dark dye bath pH value can be higher when dyed light should be carried out at lower pH values. Dye bath pH value adjustment of acetic acid, acetic acid dye bath pH value can be reduced, but also improve the solubility of dyes. Adding sodium acetate in dyeing bath can stabilize the dyebath pH values in the required range.