Firstly, we should choose a suitable acrylic retarding agent . At the same time, to ensure the dyeing, in a same bath, it is unnecessary to add two kinds of surfactants for using as retarding agent or leveling agent. Strictly speaking, it will achieve much better leveling effect to add one surfactant (Dosage: 0.5~1% o.w.f.) and one anhydrous sodium sulphate, as Na2SO4 (Dosage: 5~10 g/ L).
Secondly, it is not suitable to adopt temperature-gradient method. Generally, please add dyes at room temperature. After beginning to dye, please raise the temperature to 100℃ at a rate of 1.5℃/min, and then keep dyeing at 100℃ for 40~60 min (from light color to dark color). During heat preservation stage, the temperature should be relatively stable, but not go up and down, which is to avoid ring dyeing.
Lastly, after dyeing , please decrease the temperature to 65~70℃ at a rate of 1℃/min, and then add cold clear water while drain off the dye until it is cooled. Next, please thoroughly discharge the residual liquor in the bath and wash off the surface dyeing and auxiliary residue with clear water. It will avoid fiber or yarns shape changing and impart them soft and fluffy hand feeling.
Post time: Sep-19-2022