Now that we have covered “Time” and “Temperature”, we continue our venture through the seven major concerns related to a successful ultrasonic cleaning. Next up we will explore the essential variable: Chemistry.
Since UPC serves a broad range of industries including aerospace, automotive, firearms, medical, food/beverage and music, we provide a line of incredibly versatile detergents and degreasers designed for optimal use within the specific range of temperatures and chemistry. Whether you are cleaning anything from car engines to surgical instruments, our specialized cleaners are formulated to get the job done! You can check out our powerful line of cleaning solutions and choose the formula that is right for you here.
In ultrasonic cleaning, chemistry or detergent serves two purposes. The first purpose is to promote the formation of cavitation. The detergent should contain a surfactant. The surfactant lowers the surface tension of the liquid which lowers the cavitation threshold allowing cavitation bubbles to form more freely. Pure water has a relatively high surface tension making cavitation more difficult to reach. Adding a surfactant dramatically enhances the cavitation activity. This is easily verified by an experiment adding a small amount of dishwashing liquid to plain water in an ultrasonic tank and watching it “come alive”. One must be careful when choosing a detergent, not to use one designed for spray parts washers as they tend to contain de-foaming agents. De-foaming agents have the opposite effect and will significantly reduce the cavitation activity.
The second purpose of the detergent is to promote the removal of the contaminant by either breaking it down or helping separate it from the substrate. It is helpful to keep in mind that just like washing dishes by hand, the detergent serves to remove the contaminant from the dish, and will over time by simply soaking, but adding a scrubbing action (brush or rag) reduces the cleaning time. Ultrasonics is the scrubbing action in an industrial application.
With aqueous cleaning the general rule of thumb is to use an alkaline detergent for removing machining oils, lubricants, carbon, coolants, fat and buffing compounds. Specific formulas are designed for peak performance. A phosphoric based detergent is commonly used for removing rust, calcium, minerals, lime and oxidation.
Every detergent that UPC supplies has specific instructions as to mixture rate and temperature range. It is important to follow these in order to save cost and maximize performance.
Need assistance regarding your specific application? E-mail or call one of our experts today! We also do on site parts testing to help determine the best ultrasonic cleaning process for you!