Low-temperature ultrasonic dyeing of silk

Silk was dyed with cationic, acid and metal-complex dyes at low temperatures in the presence of ultrasonic energy for relatively short durations. The results in terms of dye uptake were compared with those obtained by conventional processes run at higher temperatures and for longer dyeing times. It was found that the ultrasonic energy helps in obtaining good fast dyeings, simultaneously conserving energy and reducing the time required for the dyeing process. In some cases the dye uptake was even higher than that obtained by the conventional dyeing procedures.