How Does an Ultrasonic Cleaner Work? Practical Guide by Anonkia

An ultrasonic cleaner works by using high-frequency sound waves to create microscopic cleaning bubbles in liquid. These bubbles form and collapse rapidly around the surface of the item being cleaned in an ultrasonic cleaning tank. This process is called cavitation, and it helps remove dirt, oil, grease, carbon, polishing compound, dust, and other contaminants from areas that are difficult to clean by hand.

Unlike brushing or spraying, ultrasonic cleaning can reach small holes, grooves, blind corners, and complex surfaces. That is why ultrasonic cleaners are widely used for tools, jewelry, automotive parts, lab instruments, mechanical components, filters, molds, and industrial parts.

For users who need stable and repeatable cleaning results, understanding how an ultrasonic cleaner works also helps when choosing the right frequency, ultrasonic tank size, power level, temperature, and cleaning solution.

An ultrasonic cleaner machine has three main parts: a stainless steel cleaning tank, ultrasonic transducers, and an ultrasonic generator.

The ultrasonic tank holds the cleaning liquid. The transducers are usually attached to the bottom or side of the tank. The generator sends electrical energy to the transducers, and the transducers convert that energy into ultrasonic vibration.

When the vibration passes through the liquid, it produces alternating high-pressure and low-pressure waves. During the low-pressure phase, tiny bubbles are created in the liquid. During the high-pressure phase, those bubbles collapse. This repeated formation and collapse of bubbles creates cleaning energy on the surface of the parts.

The process is powerful, but it is also distributed through the liquid. This is why ultrasonic cleaning can clean areas that are hard to reach with a brush, cloth, or spray gun.

Cavitation is the core of ultrasonic cleaning technology. When ultrasonic waves move through the cleaning solution in a stainless steel ultrasonic bath, they create countless tiny bubbles. These bubbles are not ordinary air bubbles. They are microscopic cavitation bubbles that collapse quickly and release energy near the surface of the item. This energy helps loosen and remove contaminants from the part. It can clean:

• Oil and grease
• Carbon deposits
• Dust and fine particles
• Polishing compound
• Metal chips
• Residue inside small holes
• Contamination on complex surfaces

Cavitation works best when the cleaner, solution, temperature, time, and frequency are matched to the part being cleaned. That’s why there are ultrasonic cleaners with various functions for specific cleaning areas.

The ultrasonic cleaner must be filled with liquid before operation. Water is often used as the base liquid, but for better results, users normally add a suitable ultrasonic cleaning solution.

The cleaning solution helps break down oil, grease, oxidation, or other contamination. The correct solution depends on the material and the type of dirt.

The parts should usually be placed in a basket instead of directly on the tank bottom. This helps protect the tank and transducers. It also allows the liquid to move around the parts more evenly.

For cleaning industrial parts, a stronger basket, lifting system, or custom fixture may be needed.

The ultrasonic generator sends power to the transducers. The transducers vibrate at a selected frequency, such as 28kHz, 40kHz, 60kHz, or higher.

This vibration creates ultrasonic waves in the cleaning liquid, which are the sources of cavitation.

As cavitation bubbles form and collapse around the parts, the cleaning action begins. Contamination becomes loose and separates from the surface.

For oily or heavily contaminated parts, heating and detergent usually improve the cleaning result.

After ultrasonic cleaning, parts should often be rinsed with clean water or another suitable rinse liquid. Drying is also important, especially for metal parts that may rust or components with small holes.

The ultrasonic frequency affects the size and strength of cavitation bubbles. Generally, lower frequency creates stronger cavitation. This means a lower frequency has stronger cleaning power.

A lower frequency, such as 28 kHz, creates stronger cavitation. It is suitable for durable parts with heavy oil, grease, carbon, or stubborn contamination.

Common applications include:

• Automotive parts
• Marine engine parts
• Diesel engine components
• Molds
• Metal hardware
• Heavy mechanical parts

40kHz is one of the most commonly used ultrasonic cleaning frequencies. It offers a good balance between cleaning strength and surface protection.

It is suitable for:

• Tools
• Lab parts
• Stainless steel parts
• Small mechanical components
• Jewelry and accessories
• General repair and workshop cleaning

Higher frequencies create smaller cavitation bubbles. They are better for delicate parts, fine holes, and precision cleaning.

They are often used for:

• Precision components
• Fine metal parts
• Sensitive surfaces
• Parts with small channels or complex details

Anonkia can provide standard 28kHz or 40kHz ultrasonic cleaners, as well as customized frequencies such as 60kHz, 80kHz, 100kHz, 120kHz, or higher, according to the cleaning requirement.

Some ultrasonic cleaners include a sweep frequency function. This means the sweep frequency ultrasonic cleaner can slightly adjust the ultrasonic frequency during operation instead of staying at one fixed point.

Sweep frequency helps reduce uneven cleaning areas in the ultrasonic tank. It can improve cavitation distribution and make the cleaning effect more stable, especially for industrial parts and batch cleaning.

Many Anonkia power-adjustable and industrial ultrasonic cleaners include an automatic sweep frequency function, which is useful for workshops, factories, and users who need consistent cleaning results.

Several factors determine whether an ultrasonic cleaner works well:

• Frequency: lower frequency for heavy-duty cleaning, higher frequency for precision cleaning
• Ultrasonic power: higher power can improve cleaning strength, but delicate parts may need lower power
• Tank size: parts must fit properly inside the basket and the cleaning area
• Cleaning solution: the detergent should match the contamination and material
• Temperature: heating often improves grease and oil removal
• Cleaning time: longer time is not always better; excessive cleaning may affect sensitive surfaces
• Part placement: parts should not block each other or touch the tank bottom
• Degassing: a fresh solution may need degassing before the best performance is reached

For professional cleaning, adjustable power and sweep frequency are helpful because different parts may need different cleaning intensities.

When choosing an ultrasonic cleaner, do not only look at the tank capacity in liters. The internal tank size is more important because your parts must fit comfortably inside the basket.

A simple selection guide:

Anonkia offers benchtop ultrasonic cleaners from small capacities up to 30L, and industrial ultrasonic cleaners from 36L to 1000L. For large or special parts, custom tank size, ultrasonic power, frequency, filtration, lifting system, and immersible ultrasonic plates can be configured. Check the full detailed ultrasonic cleaner specifications for reference.

For small and medium parts, Anonkia benchtop ultrasonic cleaners are suitable for daily cleaning in laboratories, repair shops, jewelry workshops, and small production areas.

For industrial cleaning, Anonkia K Series and KA Series industrial ultrasonic cleaners provide larger stainless steel tanks, heating, adjustable ultrasonic power, and automatic sweep frequency. These machines are suitable for metal parts, automotive parts, mechanical components, molds, and factory cleaning applications.

For oily parts or heavy-duty cleaning, Anonkia can also provide filtration systems. For large or heavy parts, lifting systems can make loading and unloading easier and safer.

To use an ultrasonic cleaner properly:

• Do not run the machine without enough liquid in the tank
• Do not place parts directly on the tank bottom
• Use a suitable cleaning basket
• Choose the correct detergent for the material
• Avoid unsuitable or flammable liquids unless the machine and process are designed for them
• Rinse and dry parts after cleaning when needed
• Test delicate materials before batch cleaning
• Replace or filter the dirty solution to maintain cleaning performance

Further learn how to use an ultrasonic cleaner, turn to the operation guide for the KHTD series ultrasonic cleaner, and the operation guide for the KHTDP series variable power ultrasonic cleaner.

Ultrasonic cleaning is effective, but it is not the same as sterilization. For medical or laboratory use, additional sterilization may be required after cleaning.

Yes. Ultrasonic cleaners work well when the correct frequency, solution, temperature, power, and cleaning time are used. They are especially useful for small gaps, complex shapes, and surfaces that are difficult to clean manually.

Water can transmit ultrasonic energy, but a proper cleaning solution usually gives better results. The detergent helps break down oil, grease, oxidation, and other residues.

28kHz is better for heavy-duty cleaning, 40kHz is suitable for general cleaning, and higher frequencies, such as 60kHz or above, are better for precision cleaning.

Common reasons include weak cleaning solution, wrong frequency, low power, dirty liquid, poor part placement, no degassing, unsuitable temperature, or choosing a tank that is too small for the parts.

It can affect delicate coatings, soft materials, painted surfaces, or sensitive components if the power, time, temperature, or detergent is not suitable. Always test first when cleaning delicate items.

An ultrasonic cleaner works by converting electrical energy into high-frequency vibration, creating cavitation bubbles in liquid. These microscopic bubbles collapse around the part surface and remove contamination from areas that are difficult to reach by hand.

For the best result, users should choose the right frequency, tank size, power, heating, and cleaning solution according to the part material and contamination type.

If you are not sure which ultrasonic cleaner is suitable for your application, send us your part size, material, contamination type, and daily cleaning quantity. We can help recommend the right ultrasonic cleaner or custom industrial cleaning system.