Mastering Ultrasonic Cleaning

What exactly is ultrasonic cleaning?

Ultrasonic cleaning is a process whereby delicate items are cleaned using a combination of ultrasonic waves and a bath of cleaning solution. The method can be used in a wide number of commercial, industrial and medical settings.

 

What is it used for?


Ultrasonic cleaning is used in circumstances where the items to be cleaned would otherwise risk damage from other standard cleaning processes - examples include watchmakers, jewellers, optical lens companies, as well as a amount of medical and industrial applications.Ultrasonic cleaning is being used for cleaning items that need incredible gentleness to handle - some examples of these include watches, jewels, medical instruments, industrial devices and optical lens. The process can be used on materials with a variety of shapes and sizes, and the process is also useful in cleaning within cracks, crevices and other holes that would otherwise be impossible or impractical to clean. Also because of the nature of its action, the disassembly of component parts is not always required, speeding up the cleaning process.

Materials that may be subjected to the process are metals, plastics or any items that won't be damaged by the solvent used for cleaning. Ultrasonic cleaning works well in removing many different pollutants, including dust, dirt, grease, oil, blood and polishing compounds, amongst others.

How does this work?
For this to work, items that will be cleaned should be placed in a container with the cleaning solution. Based on the application the cleaning solution can simply be common tap water, however another solvent is normally added in order to aid the cleaning process.. Where water is used, it is normally used in conjunction with a surfactant to lower the surface tension of the water, making the cleaning process more efficient.

 

The cleaning solution is then bombarded with very high frequency sound waves (beyond the range of human hearing - hence the term ultrasonic). This can be achieved by either lowering an ultrasonic transducer created from a piezoelectric material straight into the cleaning solution, or by having the ultrasonic transducer built into the ultrasonic cleaning machine itself.

This will cause compression waves in the liquid which will bring forth very small bubbles. The bubbles named "cavitation bubbles" would then implode, causing all the contaminants to be removed from the item as their bonds weaken. Since the implosion is microscopic, the item being cleaned is not damaged but the dirt attached to them will be effectively removed.


The size of the cavitation bubbles can be governed with incredible precision, as the size of the cavitation bubbles depend on the frequency of ultrasonic wave being passed through the solution - the higher the frequency, the smaller the bubbles. Hence, the level of control in the cleaning process implies that individuals could clean even the most fragile items without the chance of having them damaged. With the help of ultrasonic cleaning, items may now be cleaned without needing to worry about the damage that would be completed to the materials, making the whole procedure incredibly less dangerous.