Ultrasonic Systems for Precise Cleaning Applications
2045 Martin Avenue, Suite 204 Santa Clara, CA 95050

Important Questions Customers Ask About Using Ultrasonic Cleaners

June 11, 2019

1. When Should I Use an Ultrasonic Cleaner?

You should use an ultrasonic cleaner when you want quick and complete cleaning action without the use of harsh chemicals or mechanical scrubbing. To get the best possible performance, it is important to choose the right type of ultrasonic cleaner. Key cleaner characteristics include the frequency, power, type of transducer and size of the unit. You also have to decide whether to go with a turnkey solution or purchase the components. A competent industrial ultrasonic cleaner supplier will be able to help ensure you get the cleaning performance you need.

2. How Do Ultrasonic Cleaners Work?

Ultrasonic cleaners work by generating microscopic cavitation bubbles in the cleaning solution. The ultrasonic generator produces a high-frequency electric signal that is converted to ultrasonic waves in the cleaning solution by the transducers. The bubbles form and collapse in tune with the ultrasonic waves. The collapsing bubbles deliver a powerful scrubbing action that removes dirt from the parts to be cleaned. The bubbles form wherever the cleaning solution is present so that ultrasonic cleaning is effective inside hard-to-reach places where other methods can’t easily clean.

3. How do I Select the Right Equipment?

The best way to make sure you get the right equipment for your cleaning application is to discuss your requirements with a competent industrial ultrasonic cleaner manufacturer. Your ultrasonic cleaning partner should have extensive experience and be willing to offer advice on how to achieve your cleaning goals. Together you should look at the physical aspects of your system, for example whether existing tanks can be re-used. Whether you always clean one kind of part or have multiple uses will affect the ultrasonic cleaning equipment. Your cleaning performance may be improved with heating or the addition of a mild solvent. Your ultrasonic cleaning partner can discuss the options with you and suggest the best solutions.

4. How do I Specify Equipment Size?

The parts to be cleaned have to be immersed in a cleaning solution so the ultrasonic cleaning tank has to be big enough to hold the parts. Oddly shaped parts may require a custom tank size because the tank should match the shape of the part to minimize the amount of liquid and the power requirements. Small parts or parts that are easily damaged may need a parts basket to hold them inside the tank. The basket prevents them from touching the bottom or sides of the tank where vibrations may cause breakage. If many different kinds of parts have to be cleaned, the tank should be slightly larger than the largest, and if a basket is used, the tank must be able to hold the basket. Your industrial ultrasonic cleaner supplier can help choose the appropriate tank size.

5. Do I Need to Use a Heater?

Ultrasonic cleaning does not require the use of a heater but heating the cleaning solution may speed up cleaning for some applications. The scrubbing action of the microscopic cavitation bubbles produced by the ultrasonic waves removes even heavy contamination completely. This is especially true for cleaning robust parts at the lower frequencies. When the gentle cleaning action of higher frequencies has to be used for more delicate parts, it may take longer for the removal of heavy, hardened grease and oil-based contaminants. In such cases, using a heater to raise the temperature of the cleaning solution to about 80 degrees centigrade softens the oil and grease and makes it easier to remove, speeding up the cleaning process.

6. What Does Sweep Mode Do?

When the transducers convert the electrical ultrasonic signal to sound waves, they are immersed in the cleaning solution and their surfaces vibrate to produce the ultrasonic waves in the liquid. As the waves spread out through the cleaning tank, the parts to be cleaned interfere with the ultrasonic waves and cause spots where waves are stronger and others where they are weak. This pattern of interference depends on the exact frequency used. If the frequency changes slightly, the pattern of interference changes as well and the spots of weak sound waves move. To avoid uneven cleaning due to the weak spots, sweep mode automatically varies the ultrasonic frequency slightly. The weak spots move around and cleaning is evenly distributed.

7. Is the Use of Auto-Tuning Important?

Yes, with auto-tuning the generator monitors and adjusts the power that is conducted to the transducer array. Auto-tuning allows the system to adjust itself and maintain perfect calibration as the conditions change in the process tank during operation. This means changes such as water level, temperature and chemical changes will not affect the power level in the process tank.

8. What Ultrasonic Frequency Should I Use?

Choosing the right ultrasonic frequency is the key to effective cleaning. Low frequencies generate comparatively large cavitation bubbles that deliver intense cleaning action. Fragile parts or parts with soft surfaces may suffer damage or surface pitting at these frequencies. For high frequencies, the bubbles are smaller and less energetic so that even delicate parts can be cleaned. Metal parts can often be cleaned at low frequencies while semiconductor components or electronic parts with micro-structures may require more gentle cleaning provided at higher frequencies. The fastest most complete cleaning for an application is to choose the lowest frequency that will not damage the parts to be cleaned.

9. What is Important about Ultrasonic Power?

While the ultrasonic frequency determines the intensity of the cleaning action, the system power influences overall cleaning performance. When the system is under-powered, cleaning action may be uneven and incomplete. The system has to have enough power to fill the cleaning tank with ultrasonic waves. Too little power means there will be dead spots and areas where few bubbles are created and cleaning performance is low. Large cleaning tanks will need more power and often require several transducers to clean well, even if the parts to be cleaned are small. When a system has the power it needs, all areas of the tank, including holes, dead ends and crevices in the parts, receive even and complete cleaning action.

10. Is the Agitation of Parts Necessary for Cleaning?

Agitation of the parts is in general not required and industrial ultrasonic cleaners generally have no automatic part agitation mechanisms. If you’re cleaning many small parts in a basket, it may be beneficial to move the parts around during the cleaning process to avoid dead spots where parts interfere with the cleaning action. Kaijo’s “Water Resonance System,” (WRS) helps promote even cleaning by producing an even distribution of cavitation bubbles throughout the cleaning tank. With WRS, no parts agitation is needed.

11. What Kinds of Applications is Ultrasonic Cleaning Used In?

Ultrasonic cleaning is used in a variety of industrial and commercial cleaning processes. It is especially useful in applications where quick and complete cleaning is essential. Industrial plants where hazardous substances can’t be used prefer ultrasonic cleaning because it works with plain water. Environmental concerns make ultrasonic cleaning the best alternative to soaking in toxic chemicals while disposal costs for such materials are eliminated. Saving money is also a factor for applications that require manual scrubbing or expensive cleaning chemicals because ultrasonic cleaning has low operating costs. Overall, ultrasonic cleaners are used in industries as varied as aircraft assembly and maintenance, semiconductor manufacturing, medical instrument production, the food industry and automotive engine parts and restoration.

12. How Much Time is needed to Clean Parts?

The time needed to clean parts varies according to many factors such as the kind of part, the type of dirt and the frequency used. Metal parts with light contamination cleaned at a low frequency might be ready in a few minutes while an average cleaning time for general purpose cleaning is around ten to twenty minutes. Hard, baked on grease and carbon residue such as that found on engine parts may take much longer but heating the cleaning solution may help in such cases. For specific organic contaminants, a mild solvent that helps to dissolve the contaminating material will speed up cleaning substantially. In general, low frequency cleaning is faster than cleaning with higher frequencies and the system has to be powerful enough to fill the cleaning tank with ultrasonic waves. A competent supplier of ultrasonic equipment can evaluate your cleaning applications and recommend solutions that will provide the best possible ultrasonic cleaning performance.

Selecting the Right System for Your Application

Kaijo provides expert help and free consultation for selecting the right industrial ultrasonic cleaner for specific cleaning applications. The company has extensive experience in ultrasonic technology and works with customers in many different industries.  Once an appropriate cleaning system is selected, Kaijo can propose components from their extensive product line of ultrasonic cleaners to assemble a complete ultrasonic system.