Comparison of ultrasonic devices for the pretreatment of textiles before washing and analysis of action

Abstract

Up to now, when measuring the cleaning effect of ultrasound, it has generally been only possible to record combinations of different influencing variables corresponding to the parameters of Sinner’s circle. These parameters are temperature, chemistry, mechanics, and time. In order to evaluate the ultrasonic effect, a new experimental design was developed making it possible to separately measure the influence of these parameters. This approach was used to determine the cleaning of three hand-held ultrasonic devices intended for the pretreatment of stains on textiles before washing in household washing machines. For six difficult to remove stains, the contributions of soaking, friction, and ultrasound were experimentally investigated separately. The cleaning effect was measured as increased brightness. In case of all stains, the contribution of ultrasound was the maximum, followed by friction and soaking. Since it was observed that the temperature of the transducer increased during ultrasonic operation, the ultrasonic effect was further divided into an effect of temperature and ultrasound. This was done with one device and one sebum stain as an example. Analysis of the temperature influence showed that the soaking process in particular was temperature dependent, while the influence of temperature on the ultrasonic action and friction was negligible. The experiments showed that the experimental design could be used to separate the effects according to Sinner’s circle. This information enables a better understanding of the effect of devices using ultrasound and opens up new possibilities for optimizing such processes.