Application of Ultrasonics in Dyeing of Cotton Fabrics with Direct Dyes: Part I-Kinetics of Dyeing

133-139<span style="font-size:11.0pt;line-height:115%; font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" calibri;mso-fareast-theme-font:minor-latin;mso-hansi-theme-font:minor-latin;="" mso-bidi-font-family:arial;mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="">The effect of ultrasonic cavitations on dyeing of cotton fabrics with direct dyes has been studied under the influence of kinetic variables. Six barium titanate crystal transducers were used to generate ultrasonic waves of 40 kHz frequency. The ultrasonic cavitation accelerates the rate of dyeing and increases the adsorption of dye on fabric. The magnitude of the effect, however, depends on cavitation intensity and increases as the intensity is increased. By the use of ultrasonics the same amount of dye can be obtained on the fabric either by reducing the dye and electrolyte concentrations in the bath or by reducing the dyeing time or dyeing temperature.