Eight key points for choosing ultrasonic cleaning equipment

1、 Frequency selection

The ultrasonic cleaning frequency ranges from 28kHz to 120kHz, and the physical cleaning force caused by the effect of holes when using water or water cleaning agents is clearly advantageous for low frequencies. Generally, around 28-40kHz is used. For cleaning parts with small gaps, narrow slits, and deep holes, it is better to use high frequency, even several hundred kHz. When cleaning clock parts, use 400kHz. If broadband FM cleaning is used, the effect will be better.

2、 Power selection

The effectiveness of ultrasonic cleaning is not necessarily proportional to the power multiplied by the cleaning time. Sometimes, even with low power, it takes a long time to remove dirt. If the power reaches a certain value, sometimes the dirt can be quickly removed. If the power is chosen to be too high, the cavitation intensity will be greatly increased, and the cleaning effect will be improved. However, this will also cause corrosion points on more precise parts, which is not worth the loss. Moreover, the cavitation at the bottom of the cleaning cylinder vibration plate is severe, and the water point corrosion will also increase. When using organic solvents such as trichloroethylene, there is basically no problem, but when using water or water-soluble cleaning solutions, it is easy to suffer from water point corrosion. If the surface of the vibration plate has been damaged, cavitation corrosion will be more severe under high power, so the ultrasonic power should be selected according to the actual use situation.

3、 Selection of cleaning solution temperature

The suitable cleaning temperature for water cleaning solution is 40-60 ℃, especially in cold weather when the temperature of the cleaning solution is low and the cavitation effect is poor, the cleaning effect is also poor. Therefore, some cleaning machines wrap heating wires around the outside of the cleaning cylinder for temperature control. When the temperature rises, cavitation is prone to occur, so the cleaning effect is better. As the temperature continues to rise, the gas pressure inside the bubble increases, causing a decrease in the impact sound pressure, reflecting the synergistic effect of these two factors.

4、 Use of cleaning basket

When cleaning small items, a mesh basket is often used, and special attention should be paid to the ultrasonic attenuation caused by the mesh. It is better to use a mesh size of 10mm or more when the frequency is 28kHz.

5、 Determination of the amount of cleaning solution and the location of cleaning parts

It is preferable for the liquid level of the cleaning solution to be at least 100mm higher than the surface of the vibrating element. Due to the influence of standing wave field, the amplitude of the single frequency cleaning machine is small at the nodes and large at the amplitudes, resulting in uneven cleaning. Therefore, the location for cleaning items should be placed at the wave amplitude.