Ultrasound was initially used only for image processing and it was discovered by John Wild – the so-called father of modern ultrasound. Wild managed to identify transducers that emit sound waves which then reflect back and project images of different internal organs.
Nowadays, ultrasound has many applications in a multitude of industries: automotive, pharmaceutical, engineering, and weapons manufacturing, just to name a few.
There is a number of additional uses for ultrasound, including humidification, disintegration, welding, identification, as well as a wide range of medical applications. Whichever field ultrasound may be used in, it is helping companies in their effort to become more environmentally friendly, and more efficient in terms of costs, time and labor.
What is ultrasonic cleaning?
Just like the name suggests, ultrasonic cleaning is a process that uses ultrasound (non-audible sound waves) and a cleaning solvent or a detergent in order to clean certain items. Ultrasonic cleaners are able to function using just water as a cleaning solution, but choosing a type of solvent suitable for the object to be cleaned will enhance the efficiency of the process.
Ultrasonic cleaning is nowadays a conventional cleaning method utilized in a plethora of industries, ranging from laboratory equipment (used for items like glass beaker sets) to jewelry workshops and hospitals. There are even ultrasonic denture cleaners out there and ultrasonic cleaning systems used for carburetor components, as well.
How does it work?
This method of cleaning is based on a process called cavitation – small bubbles are produced with the help of high frequency sound waves and then they implode on the surface of the object immersed in the cleaning solvent.
Through the process of cavitation, contaminants are removed both from the item’s surface, and from the small cracks and recesses. Contaminants can be dust, soil, rust, algae, limescale, bacteria, grease, mold, and so on.
The advantage of ultrasonic cleaning is that it can be used for products made of different materials (like plastic, ceramics, rubber or glass) and of different shapes and sizes, and it is possible not to require the object to be disassembled before cleaning.
Discovered by accident
The history of ultrasonic cleaning started almost 90 years ago, in the early 1930s. One of the Radio Corporation of America (RCA) laboratories, located in New Jersey, discovered that ultrasounds can be used for cleaning by accident.
While trying to cool the inner components of a radio with freon, they noticed a wave movement around a crystal operating at 300 kHz. Although this process was considered interesting, it was not researched as a cleaning method for years to come.
Taken out of the laboratory in the 1950s
During the 1950s, the Bendix Corporation in Davenport, Iowa, created an ultrasonic department that experimented with multiple applications of ultrasound only to discover that ultrasonic cleaning was the most profitable. In 1952, this method of cleaning was used in production for the very first time.
Bendix tried to pioneer ultrasonic cleaning in several industrial environments. The process was highly effective and its popularity in the manufacturing industries increased rapidly. That included electronics companies, those in the medical equipment field, the aircraft industry, automakers, and even missile manufacturers.
Ultrasonic cleaners become popular
In 1959, Time Magazine published an article entitled “Ultrasonics: Unheard Progress” and it was such an optimistic piece of writing that the possibilities seemed endless. “Someday we’ll be cleaning clothes with ultrasonic equipment”, the author wrote.
The Time article focused on a few innovative companies that were researching non-audible sound waves and their applications in industry and everyday life. These companies developed ultrasonic tanks and used them to clean anything – from pens to cash registers and electric shavers.
Most ultrasonic cleaners developed in the late 1950s were operating with frequencies ranging from 18 kHz to 40 kHz. 18 kHz is the lowest frequency and it is still widely used nowadays. Even though Russia developed a 6 kHz system, it wasn’t very popular so it was quite short lived. Until the late 1980s the majority of systems available on the market operated at 25 kHz to 40 kHz.