Along with distributing ultrasonic cleaner equipment and ultrasonic cleaner solutions we at Tovatech offer our expertise in helping companies match the equipment and procedures to the jobs at hand. Since many of the questions we get relate to using the correct ultrasonic frequency we thought we’d present the following suggestions for your consideration. If your application or question is not answered here do not hesitate to call us.
First, it is important to differentiate between frequency and power. Higher frequencies do not mean more powerful ultrasonic cleaning. Generally, the lower the frequency the more robust or stronger is the cavitation action. While this may seem attractive as a means of getting the job done quickly, cavitation at the lower frequencies can damage not only delicate parts but also cause cavitation erosion on the ultrasonic cleaning tank.
Keep in mind too that the lower the frequency the noisier the equipment. There is a noticeable difference between 25 and 37 kHz. That’s one reason why the smaller tanks in the dual-frequency 25/45 kHz TI-H line by Elma have optional insulated lids to reduce noise and at the same time improve thermal insulation.
As ultrasonic cleaning moves into higher frequencies the cavitation bubbles increase in number and decrease in size. Bubble size relates to how much energy is released when they implode. That’s why a higher frequency produces less intense cleaning. But because a higher frequency yields more bubbles, it’s a better choice for cleaning parts with very tiny features such as blind holes, channels and threads. You will get a better distribution of cavitation bubbles on all surfaces of the parts being cleaned.
With that, here are the more commonly used frequencies. Contact us for recommendations on the ultrasonic cleaner models we recommend for using at these frequencies.
For the removal of coarse and tenacious contaminations and for pre-cleaning of robust surfaces such as stainless steel and cast iron we recommend cleaning at 25 kHz.
The most commonly used ultrasonic frequency range is 35-40 kHz for routine cleaning jobs and for cleaning jobs in the laboratory and sanitary sector.
For fine cleaning and for the cleaning of sensitive surfaces such as light metal alloys use an ultrasonic cleaner operating at 45 kHz.
Higher frequencies such as 130 kHz are used for fine cleaning jobs and for the cleaning of highly sensitive surfaces including micro electronics, printed circuit boards and precision optics.
Other Factors Impacting Quality Ultrasonic Cleaning
The correct ultrasonic frequency is only part of the ultrasonic cleaning equation. Ultrasonic power, cleaning time, chemical cleaning solutions, and ultrasonic bath temperatures factor as well into an efficient and thorough cleaning operation. Other contributors to a more efficient cleaning operation are regular bath maintenance through filtration and skimming, and frequent inspection and maintenance of your ultrasonic cleaning tanks.
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What ultrasonic frequencies are commonly employed at your plant and what is being cleaned at these frequencies? Please share any unusual experiences you’ve had and procedures developed for unusual cleaning operations.
Tags: ultrasonic
