The last time we talked, we discussed how ultrasonic cleaning frequencies and how ultrasonic cleaning is used throughout the industrial world to remove a variety of contaminants ranging from dust to metal chips to carbon fibers to oil to baked-on polymers.
There is not a “One Frequency Fits All” out there. Effective cleaning requires choosing the correct frequency to accomplish any given task.
Ultasonic sound waves create vacuum bubbles in the cleaning solution. When these bubbles hit a dirty surface, the bubble surface is compromised and the bubble implodes. Implosion is the opposite of explosion. In an explosion, the contents of
the blast are pushed out. With an implosion, the contents of the blast are pulled in. For the non-techies – these are like little mini vacuum cleaners. For the Star Trek Steven Hawking crowd, think of a black hole collapsing on itself.
We will specifically discuss 40 kHz and its’ place in the cleaning world. Because ultrasound has vast vibrational properties, ultrasonic systems have the most versatile cleaning abilities in the industrial parts cleaning universe.
The vast majority of cleaning applications out there require a mid-sized cavitation bubble that has enough power to shake the contamination loose from a surface and small enough to penetrate closer to the substrate. Items with many through holes and/ or complicated blind holes won’t clean properly with those lower frequencies because the bubble is simply too large to effectively penetrate those tiny crevices.
Where we see the 40 kHz systems used are in basic carburetor cleaning, removing oils and metal chips from general machine shop applications, soot removal from items damaged in fires, cleaning of ceramics used in the high technology fields, and removal of biological debris from surgical tools. There are so many more that to list all the applications would take volumes of blog space.
If you took the data from all the manufacturers of ultrasonic cleaning systems that offer a multitude of frequencies (yes there are a few that try to go with the “One Frequency Fits All” concept), the percentages would be approximately eighty percent (80%) or more to the 40 kHz team, followed by just under fifteen percent (15%) for the 25 kHz team and the five percent (5%) balance going to the higher frequency teams. More on that high frequency team later.