A Study on Optimization of Irradiation Frequency for Ultrasonic Laundry of Textile

Research into the industrial practice of ultrasonic aqueous textile cleaning is still underway despite success in the technology being used in other cleaning industry. This study uses ultrasonic frequencies of 40 kHz, 60 kHz and 80 kHz to examine frequency dependence of ultrasonic textile laundry. Results showed that fabric washing efficiency is not proportional to the ultrasonic frequency. Ultrasonics at a lower (40 kHz) or higher frequency (80 kHz) showed a better washing efficiency than that at 60 kHz, especially for the removal of stubborn stain and for natural textile materials such as wool and silk. The reason lies in the mechanism of cavitation implosion, micro-streaming induced changes in surface boundary layer, as well as the intricate micro-structure of the fibre surface. These were analyzed and discussed in detail in the paper.