Ultrasonic cleaning
The vibration generated by the ultrasonic wave is transmitted to the cleaning liquid through the cleaning tank wall so that the micro-bubbles in the liquid in the tank can keep vibrating under the action of the sound wave, destroying and separating the dirty adsorption on the surface of the object.
[1] Ultrasonic cleaners are used to clean many different types of objects, including industrial parts, jewelry, scientific samples, lenses and other optical parts, watches, dental and surgical instruments, tools, coins, fountain pens, golf clubs, fishing reels, window blinds, firearm components, car fuel injectors, musical instruments, gramophone records, industrial machined parts, and electronic equipment, optical lenses, etc.
[4][5] Ultrasonic cleaning uses cavitation bubbles induced by high-frequency pressure (sound) waves to agitate a liquid.
The agitation produces high forces on contaminants adhering to substrates like metals, plastics, glass, rubber, and ceramics.
Contaminants can include dust, dirt, oil, pigments, rust, grease, algae, fungus, bacteria, lime scale, polishing compounds, flux agents, fingerprints, soot wax and mold release agents, biological soil like blood, and so on.
[2] In an ultrasonic cleaner, the object to be cleaned is placed in a chamber containing a suitable solution (in an aqueous or organic solvent, depending on the application).
In aqueous cleaners, surfactants (e.g., laundry detergent) are often added to permit dissolution of non-polar compounds such as oils and greases.
These bubbles collapse with enormous energy; temperatures and pressures on the order of 5,000 K and 135 MPa are achieved;[7][8] however, they are so small that they do no more than clean and remove surface dirt and contaminants.
Some ultrasonic cleaners are integrated with vapour degreasing machines using hydrocarbon cleaning fluids: Three tanks are used in a cascade.
Ideal materials for ultrasonic cleaning include small electronic parts, cables, rods, wires, and detailed items, as well as objects made of glass, plastic, aluminium, or ceramic.
However, some electronic components, notably MEMS devices such as gyroscopes, accelerometers and microphones can become damaged or destroyed by the high-intensity vibrations they are subjected to during cleaning.
