How to choose the frequency of ultrasonic cleaning machine? What's the difference between high frequency and low frequency

The principle of ultrasonic cleaning is to produce "cavitation effect" in the cleaning liquid, that is, the cleaning liquid produces tensile and compression phenomenon, the cleaning liquid will produce a large number of tiny bubbles when stretched, the bubble will be crushed when the cleaning liquid is compressed. The local pressure produced and broken by these bubbles can reach the impact force of thousands of atmospheres. This extremely strong pressure is enough to change the material molecules, causing various chemical and physical changes (decomposition, combination, emulsification, dispersion, etc.), which can be used to remove dust, oil, rust and other impurities on the surface of the stripped objects.

Cavitation effect is the most important factor to determine the cleaning effect, and ultrasonic frequency directly affects the cavitation effect. Generally, ultrasonic frequency that produces cavitation effect is most suitable for 20khz-80khz.

The frequency is inversely proportional to the diameter of the bubbles in the liquid and proportional to the permeability. The higher the frequency, the shorter the wavelength, the smaller the diameter of the cavity, the lower the explosion pressure, the better the permeability, suitable for the cleaning of high surface smoothness, fine workpiece. In addition, the frequency should not be too high, otherwise the wavelength will be shortened, cavitation will be weakened, thus reducing the cleaning efficiency.

On the contrary, the lower the ultrasonic frequency, the easier it is to produce cavitation in the liquid, the greater the intensity and the stronger the effect. It is suitable for the dirt with rough surface and difficult to clean. Ultrasonic frequency also affects the high-frequency noise generated during the work, the lower the frequency, the greater the noise, generally under the premise of meeting the cleaning effect, as far as possible to choose a higher frequency.

Based on the above principles:

1, low frequency 17K-23K: suitable for cleaning the dirt is heavy or more difficult to clean the workpiece, and the bubble blasting impact force will not cause damage to the workpiece surface, should choose low frequency ultrasonic cleaning, such as: auto parts, textiles, etc..

2, medium frequency 25K-28K: suitable for cleaning dirt slightly heavy or moderate cleaning difficulty, and bubble blasting impact force will not cause damage to the workpiece surface, should choose medium frequency ultrasonic cleaning, such as: hardware machinery, electroplating industry, etc..

3, high frequency 33K-60K: suitable for cleaning dirt is lighter or easier to clean, and the bubble blasting impact force will not cause damage to the workpiece surface, should choose high frequency ultrasonic cleaning, such as: optical glass, electronic components, etc.

4, high frequency 68K-200K: suitable for cleaning dirt light or easy cleaning, and bubble blasting impact force on the workpiece surface will not cause damage, should choose high frequency ultrasonic cleaning, such as: semiconductor, special high precision parts.