Ultrasonic cleaning
Cleaning with ultrasound is widespread and is used, for example, in mechanical engineering and the jewelry industry to clean metals and plastics. Ultrasonic cleaning always takes place in a liquid medium (e.g. water with cleaning agent). The energy generated by the ultrasonic generator (frequency range above 20 kHz) is converted into mechanical energy by the oscillator. Sound pressure amplitudes disrupt the molecular connection of the liquid due to existing inhomogeneities (contamination, items to be cleaned), and tiny bubbles form in the cleaning liquid, which are very unstable. These bubbles implode and generate powerful pressure pulses. This process is called cavitation. Cavitation causes gentle and intensive cleaning in Allen areas that are reached by the cleaning liquid.
The correct selection of the ultrasound device
The size of the cleaning objects determines the size of the tub and thus the type of device required. When selecting the device, the basket dimensions must be taken into account. To avoid device overload, it is advisable to choose a slightly larger device. This also creates scope for further applications that can be added in future use.
Does an ultrasound machine have to have a heater?
Heated cleaning fluids shorten cleaning time. Dirt is removed more quickly in heated liquids. Devices with heating are usually used for cleaning in the laboratory. Do not heat disinfectant liquids, as protein coagulation can occur at temperatures above 40 °C, which makes cleaning and disinfection more difficult. Devices without heating are used.
Which accessories are necessary?
The cleaning objects and reaction vessels must never lie on the bottom of the tub. The hanging basket prevents scratches on the items to be cleaned and the bottom of the tub. Insert containers for cleaning small parts or for working with aggressive solutions are hung in perforated lids. The use of plastic hanging trays is necessary when working with acids or when removing acid residues.
Which liquids can be used?
In principle, before using strongly alkaline or strongly acidic products, the use of mild, neutral or universal cleaning products should be considered. Some cleaning tasks can only be solved with special cleaners. These requirements are met through special recipes (e.g. through complexing agent-free preparations for laboratories and electroplating, the optical industry and for high-vacuum use).
Water without cleaning agents only cleans to a limited extent. Do not use household cleaners or demineralized water!
The selection of the suitable cleaner essentially depends on the following factors:
• Material of the items to be cleaned
• Type of contamination
• Amount of adhering impurities
Why is cleaning done with ultrasound?
Ultrasound propagates in liquid media in the form of a longitudinal wave. As a result of the alternating sound pressure, compression and rarefaction occur. The tensile forces in the suction phase of the oscillation (dilution) can tear the liquid apart - this results in so-called cavitation; Dissolving processes are accelerated and the resulting currents and turbulences in the liquid infiltrate the dirt.
Advantages of ultrasonic cleaning:
• Improvement in cleaning results
• Intensive and gentle cleaning (no manual processing, no damage to the
• Surface of the items to be cleaned
• No dirt residue in depressions and pores
• Saving time and therefore also reducing costs
• Simple and safe handling
• Fewer chemical additives required than traditional cleaning processes.
Necessary components for ultrasonic cleaning:
The result of ultrasonic cleaning is essentially determined by three components:
• Device
• Accesories
• Chemistry
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