Cleaning of solid rigid materials is one of the best known power ultrasonic applications. Nevertheless, the use of ultrasonic energy for washing textiles has been tried several times without achieving practical development. In fact, the flexibility of the fibres makes the cavitation to produce small erosion effect and the reticulate structure of the fabric favours the formation of air bubble layers which obstruct wave penetration. During several years an investigation about the use of ultrasonic technologies for cleaning textiles in domestic washing machines was carried out. It was found out that by diminishing the amount of dissolved air in the wash liquor the application of ultrasonic energy improved wash results in comparison to conventional methods. Nevertheless, practical requirements hindered the commercial development of the ultrasonic washing system. Specifically, the requirements of high water level and small wash load needed to ensure efficiency and homogeneity in the wash performance. To overcome these problems for industrial applications, a new process was developed in which textiles are exposed to the ultrasonic field in a flat format and within a thin layer of liquid. Such process has been implemented at laboratory and at semi-industrial stage. The textile items are transported in a continuous way passing them underneath the radiators of specially designed power ultrasonic transducers. A series of devices select and adjust different parameters of the process. This paper deals with the structure and performance of the system.
J.A. Gallego-Juárez, E. Riera, V.M. Acosta, G. Rodríguez, A. Pinto, A. Blanco
Proceedings of the International Congress on Ultrasonics, Viena, April 9-13, Paper ID 1406 Session R12; High power ultrasonic processing.
