Development of a novel method for natural dyeing of cotton fabrics using ultrasonic radiations and acacia bark

Natural dyeing has been the focus of many previous researches as a substitute for synthetic dyeing, which is a known hazardous process. However, the limitations in the color range and poor fastness properties are the main obstacles in the further development of natural dyeing processes. This work corresponds to the inclusion of ultrasonic energy to enhance the color yield and color fastness properties of fabrics dyed with natural dyes. Cotton fabrics were dyed with acacia dye using conventional infrared exhaust and ultrasonic assisted procedures. Moreover, the effects of different processing factors like temperature, time, and liquor ratio were also investigated, in order to optimize the process. The ultrasonic assisted dyeing shows promising results in terms of both shade depth and washing fastness.