How to choose the frequency for ultrasonic cleaning machine?

1. Intensity of cavitation effect

28kHz：

Low frequency, larger cavitation bubbles, stronger blasting energy, suitable for removing stubborn dirt (such as thick oil stains, metal debris, polishing paste).

High impact force, but may cause slight damage to the surface of precision parts (such as aluminum, soft materials).

40kHz：

High frequency, smaller and denser cavitation bubbles, mild blasting force, suitable for fine cleaning (such as electronic components, circuit boards, jewelry), and less likely to damage workpieces.

2. Penetration depth

28kHz：

Longer wavelength, stronger penetration, capable of cleaning complex structures or deep hole parts (such as engine components and molds).

40kHz：

Shorter wavelength, weaker penetration, more suitable for surface or shallow dirt (such as optical lenses, small precision parts).

3. Applicable industries

Examples of cleaning objects in typical frequency application industries

28kHz heavy industry, automotive, metal processing bearings, gears, cutting tools with heavy oil pollution

40kHz electronic, medical, precision manufacturing circuit boards, surgical instruments, watch parts

4. Selection of cleaning solution

28kHz：

Can be paired with high viscosity or cleaning agents containing abrasive particles (such as metal degreasers).

40kHz：

Commonly used low corrosive cleaning agents (such as alcohol, deionized water) to avoid high-frequency cavitation accelerating chemical corrosion.

5. Noise and energy consumption

28kHz: High noise (low-frequency sound waves are easier to hear) and relatively high energy consumption.

40kHz: Low noise (close to the upper limit of human hearing threshold) and low energy consumption.

Summary: How to choose?

Select 28kHz: Clean heavy dirt, large or structurally complex metal workpieces.

Select 40kHz: Clean precision, brittle materials or surface minor stains.

Dual frequency or multi frequency models: catering to different needs (such as 28/40kHz switchable).

Flexible frequency matching based on workpiece material, dirt type, and cleaning requirements can significantly improve efficiency and avoid damage!