The components used in today’s precision assemblies require an extremely high degree of cleanliness. Ultrasonic technology has provided a highly effective way to meet these precision cleaning needs. Sophisticated ultrasonic cleaning technologies are used in the most demanding applications to remove sub-micron particles from components used in disc drive, aerospace, electronics, medical devices, and many other critical industries.
Understanding ultrasonic cleaning begins with looking at the science behind it. This article will discuss some of the basic concepts involved in understanding how ultrasonic cleaning works.
What are Ultrasonic Waves?
The vibration of an object creates sound waves that cause vibration of other molecules that are in contact with that object. As those vibrations travel through a sound conducting media, they in turn cause vibrations which are transmitted throughout the media. In the case of vibrations in air, our ears detect these vibrations and the brain interprets them as sound. A healthy ear can hear sounds of very low 20 Hertz frequency, to a very high frequency of 20,000 Hertz. (For an interesting range demonstration, try the audio test found here.)
Sound waves at a frequency of 20,000 Hz or higher are considered ultrasonic waves.
How Are Ultrasonic Waves Transmitted During Ultrasonic Cleaning?
Science has discovered that ultrasonic waves can be effectively used to assist cleaning. Ultrasonic waves created by an ultrasonic transducer travel through water to impact parts contained in a specially designed parts cleaning tank. The ultrasonic transducer is comprised of elements which are permanently bonded to the side or bottom of a cleaning tank, or in the case of an immersible ultrasonic transducer, sealed in an immersible liquid-tight housing.
Alternating waves of expansion and compression are generated by the transducer to create cavitation bubbles. These bubbles do the actual ultrasonic cleaning work.
How Do Cavitation Bubbles Clean During Ultrasonic Cleaning?
Once formed, cavitation bubbles compress and expand until they reach a particular size, as determined by the frequency and strength of the sound waves. Eventually the bubbles become unstable and violently implode, creating extreme pressure waves. These waves hit the surface of the parts to be cleaned, creating micro agitation to assist in the dissolution of soluble contaminants and mechanically displace the smallest non-soluble particulate. Contaminants adhering to solid surfaces as well as those embedded in crevices are released. For this reason, ultrasonic technology is particularly effective for cleaning assemblies, which may remain intact during cleaning.
Options in Ultrasonic Cleaning Solutions
A wide range of ultrasonic cleaning equipment is available to meet specific precision cleaning needs. For example, Blackstone-NEY Ultrasonics has developed a comprehensive line of individual ultrasonic tanks, multi-tank ultrasonic cleaning systems, as well as single piece flow-through ultrasonic conveyor systems. Pre-engineered platforms are offered in a variety of tank sizes and configurations to meet a wide range of needs.
To learn more about the best ultrasonic cleaning process to meet your needs, talk to the parts cleaning experts at Blackstone-NEY Ultrasonics.