Ultrasonic cleaning machine

The modern production facility is very likely to have an ultrasonic cleaning machine as a part of its manufacturing processes. Therefore, it is essential to ensure components are cleaned to a satisfactory standard, reliably and consistently. But what is ultrasonic cleaning, and what makes it necessary for parts cleaning?

What is the definition of “cavitation”?

The fast production and collapse of millions of small bubbles (or cavities) in a liquid constitutes “cavitation.” Cavitation is caused by the oscillation of high and low-pressure waves created by ultrasonic (high frequency) sound. During the low-pressure phase, these bubbles expand from tiny size until they are squeezed and collapse during the high-pressure phase.

What is “degassing”, and why is it necessary?

Degassing is the initial process of removing gases from a solution. After removing the gas from the cleaning solution, leaving a vacuum in the created bubble, useful cavitation develops. When the high-pressure wave collides with the bubble wall, the bubble collapses, and it is the energy produced by this collapse helps a detergent dissolve the bindings between components and their soils. Due to the low pressures found in contemporary solvent systems, degassing has already occurred because these systems are permanently under vacuum—approximately 800mbar for chlorinated systems and 100mbar for hydrocarbon and modified alcohol-based systems.

Is rinsing necessary following cleaning cycles?

Rinsing is advised to eliminate any chemical residue that might be hazardous to the component. In an ultrasonic cleaner, parts can be washed in a clean water bath or in a separate bath using tap, distilled, or deionised water.

How can I get optimal ultrasonic cleaning?

There are several factors to consider while performing ultrasonic cleaning. These factors must be optimised for the most significant cleaning results. The most crucial consideration are choosing the optimal cleaning solution. As a general rule your clean like-with-like. For example, oils are hydrocarbons so cleaning with a chlorinated hydrocarbon or straight hydrocarbon can be more effective than other solutions, however, a water-based coolant can get quickly removed using water-based cleaning systems. That said cleaning medias such as modified alcohols bridge the gap across polar and non-polar contaminants offering the opportunity to effectively clean products with oil or coolant contaminations in the same machine. Cleaning at the appropriate temperature and duration, and picking the appropriate size and kind of ultrasonic cleaner are also factors that impact cleaning outcomes.

Can ultrasonic cleaning ruin my components?

With specific precautions, ultrasonic cleaning is deemed safe for the majority of components. Even though the impacts of thousands of implosions per second are quite potent, the cleaning procedure is safe since the energy is contained at a tiny level. The choice of cleaning solution is an essential precautionary measure. Ultrasonics will amplify any harmful effects of the detergent on the substance being cleaned.

What is the duration of the cleaning process?

The cleaning time will vary according to the dirt, solution, temperature, and desired level of cleanliness. After the ultrasonic cleaning activity has begun, the apparent removal of dirt should begin practically immediately. Changing the cleaning time is the simplest (and most frequently misapplied) method for compensating for process variations. Even if an experienced operator may estimate the time of a fresh application cycle, it must often be tested by actual use with the selected solution and the real contaminated components.

How do I administer the foil test?

Cut three pieces of aluminium foil measuring approximately 4 by 8 inches. Each section should be folded around a pole that will be used to suspend the foil in the tank. A clothing hanger is effective. Fill your cleaner with an ultrasonic cleaning solution, degas it, and bring it to normal operating temperature. Suspend the first “square” in the middle of the tank and the remaining two squares a few inches from either end. Fill the tank to the fill line and activate the ultrasonics for approximately 10 minutes. Remove the film and examine: Each of the three sheets of aluminium foil should be perforated and creased to a similar degree.