Cavitation energy mapping for ultrasound application in dyeing processes

In recent years the textile industry has focused its attention both on the research of environmentally friendly processes and on the necessity of increasing the product quality. Recently, the use of ultrasounds (US) in dyeing has brought to valuable results, especially with natural fibres, where it was shown that dyeing at lower temperatures with an overall better quality of the final product is possible. The new process can be considered ready for an industrial application transfer. In the frame of the Regional Project INTEXUSA (INnovation in TEXtile productions by UltraSound Application) the study of the ultrasonic field in a water medium, inside a dyeing prototype equipment, was carried out by using a cavitometer (Ultrasonic Energy Meter, by PPB Megasonics) to measure the local cavitation energy and its spatial distribution. The tests were aimed at evaluating the influence of the operative conditions, typical of dyeing (such as temperature, internal liquor circulation, liquor ratio, distance from the US emitting device), on the US field. The same apparatus, where several dyeing processes are studied, was used for this investigation. The graphical visualization of the US field was carried out by integrating the measured data by means of Matlab software.