How Does Ultrasonic Cleaning Work?
- By Dr Bob Sandor
- Published 10/14/2011
- Computers and Technology
- Unrated
An ultrasonic cleaner, also referred to as a sonicator, is a device that cleans delicate items using ultrasonic waves. These waves are generated in the liquid solvent that is used for cleaning objects placed in a cleaning chamber or tank that is filled with the cleaning agent or solvent.
An aqueous or organic compound, based on the cleaning application and requirement, is agitated using high frequency sound waves. An aqueous base usually needs the addition of a surfactant for enhanced cleansing action. An ultrasonic transducer that is either lowered into the cleaning tank or fixed to the walls of the chamber converts the electrical energy into ultrasonic wave energy. These waves pass through the liquid in alternating waves of expansion and compression.
The low pressure expansion phase creates vacuum filled bubbles as the molecules of the liquid are ‘stretched’ apart. During the compression cycle, the forced high pressure causes the bubbles to implode releasing a high powered liquid stream of energy.
It is this energy that strikes the surface of the object and dislodges the clinging dirt and grime. Pressures of fifty thousand lbs per square inch and temperatures of ten thousand K have also been recorded which can be attributed to these bubbles alone. The scrubbing bubbles remove dirt, oil, dust, grime, grease, pigments, soil, fingerprints, flux compounds, polishing agents, soot, wax and biological entities like blood, etc. For those who work with blood it should be noted that the cleaning solution’s temperature needs to be maintained below 40 degrees centigrade as blood will co
nvert to albumin above this temperature and practically bond to the surface of the instrument.
In general though, the combination of the cavitation force and the surfactant present in the cleaning solution will easily dislodge most tightly adhering contaminants from the surface of the object. This is where ultrasonic cleaners score a point over more traditional methods of cleaning since the bond disruption is at micron levels.
The operative power of the ultrasonic cleaner can also be adjusted according to the type of cleaning required. The higher the frequency of the ultrasonic cleaner, the greater the intensity of the cleaning action but lower the power. This is particularly suited to sensitive and delicate surfaces where even the normal cavitational action can mar the surface. With such objects you may need a pr-clean rinse to remove excess dirt and grime.
Different kinds of ultrasonic cleaners are now available in the market for cleaning a wide range of materials of all shapes and sizes. In some instances, the entire component can be directly placed in the cleaning chamber without the necessity of any disassembly.
Aqueous solutions are less effective in cleaning grease covered surface as compared to solvent-based cleaning systems. Though both work on the same principle, the chemical cleansing action is much better when solvents are used. Unlike the commonly used industrial solvents, these solvents are non-toxic, biodegradable and cost-effective. They don’t harm the environment and are non-corrosive.
Ultrasonic cleaning has a wide range of cleaning applications in many industries including healthcare, automotive, marine, pharmaceutical, engineering, weapons, sports, and electronics.
An aqueous or organic compound, based on the cleaning application and requirement, is agitated using high frequency sound waves. An aqueous base usually needs the addition of a surfactant for enhanced cleansing action. An ultrasonic transducer that is either lowered into the cleaning tank or fixed to the walls of the chamber converts the electrical energy into ultrasonic wave energy. These waves pass through the liquid in alternating waves of expansion and compression.
The low pressure expansion phase creates vacuum filled bubbles as the molecules of the liquid are ‘stretched’ apart. During the compression cycle, the forced high pressure causes the bubbles to implode releasing a high powered liquid stream of energy.
It is this energy that strikes the surface of the object and dislodges the clinging dirt and grime. Pressures of fifty thousand lbs per square inch and temperatures of ten thousand K have also been recorded which can be attributed to these bubbles alone. The scrubbing bubbles remove dirt, oil, dust, grime, grease, pigments, soil, fingerprints, flux compounds, polishing agents, soot, wax and biological entities like blood, etc. For those who work with blood it should be noted that the cleaning solution’s temperature needs to be maintained below 40 degrees centigrade as blood will co
In general though, the combination of the cavitation force and the surfactant present in the cleaning solution will easily dislodge most tightly adhering contaminants from the surface of the object. This is where ultrasonic cleaners score a point over more traditional methods of cleaning since the bond disruption is at micron levels.
The operative power of the ultrasonic cleaner can also be adjusted according to the type of cleaning required. The higher the frequency of the ultrasonic cleaner, the greater the intensity of the cleaning action but lower the power. This is particularly suited to sensitive and delicate surfaces where even the normal cavitational action can mar the surface. With such objects you may need a pr-clean rinse to remove excess dirt and grime.
Different kinds of ultrasonic cleaners are now available in the market for cleaning a wide range of materials of all shapes and sizes. In some instances, the entire component can be directly placed in the cleaning chamber without the necessity of any disassembly.
Aqueous solutions are less effective in cleaning grease covered surface as compared to solvent-based cleaning systems. Though both work on the same principle, the chemical cleansing action is much better when solvents are used. Unlike the commonly used industrial solvents, these solvents are non-toxic, biodegradable and cost-effective. They don’t harm the environment and are non-corrosive.
Ultrasonic cleaning has a wide range of cleaning applications in many industries including healthcare, automotive, marine, pharmaceutical, engineering, weapons, sports, and electronics.
Dr Bob Sandor
Dr. Bob Sandor is a Director at Tovatech, a leading North American supplier of ultrasonic cleaners. When not busy running his company, he explores his fascination with the many aspects of various scientific & industrial devices. For more details on the above you can reach him through the ultrasonic cleaner section of his website.
View all articles by Dr Bob Sandor