In most cases, the use of ultrasonic in the washing systems of metal components takes place during the final phases of the process in order to definitively remove tough contaminants even on intricately shaped parts.
Materials that can be cleaned include parts from watches, valves, printed circuits, medical instruments as well as micro-precision systems components: on all these elements, the ultrasonic act delicately but at the same time effectively by assuring a final result of high quality.
How are the ultrasonic produced, what are the elements that influence the cavitation phase and what are the final performances of the whole process are the main questions whose explanations can be found below and will allow people to fully understand the advantages related to the use of such technology.
Is the washing by ultrasonic suitable for any occasion?
Cleaning machines for washing metal components that use ultrasonic technology are superior to those that use solvents only.
In addition to the environmental problems related to the use of chemicals for washing, with ultrasonic methodology it is possible to eliminate burned oil and other solid contaminants, such as lapping oxides and polishing pastes and provide excellent penetration and cleaning in the smallest crevices.
Before analyzing the process of washing the metal components by using ultrasonic, it is important to clarify which are the cases in which this technology should not be used.
The combined action of ultrasonic with water and detergents is to be avoided when the metal components to be cleaned are made of « soft or reactive » materials, i.e. pure aluminum and thin metals.
The reason is very simple: for this type of materials the ultrasonic are excessively invasive and there is the risk of damaging them.
If, however, you are dealing with metal components contaminated with thick grease or other similar substances, ultrasonic should be used only after a pre-wash.
How are ultrasonic generated?
The ultrasonic are produced when high frequency sound waves pass through a cleaning liquid, for example water, in which a suitable additive detergent has been dissolved.
It is precisely at this moment that millions of micro-size bubbles are formed and rapidly implode following a change in pressure: the bubbles are the result of the phases of stretching and compression of the sound waves inside the fluid.
This process is called Cavitation: during this phase the micro-size bubbles implode due to the mechanical force of the ultrasonic waves, a large amount of energy is released and, consequently, the temperature increases.
The energy of the ultrasonic transmitted to the solvent removes the dirt from the surface of the metal components: the millions of bubbles formed in the cavitation phase implode on the contaminant, crumble it and free from impurities even the small crevices.
Among the factors that influence the cavitation phase we have:
- external pressure;
- the temperature: a liquid intended for cleaning with a very high temperature reduces cleaning time and removes dirt faster;
- the frequency and power of ultrasonic;
- the nature of the liquid used for cleaning.
The importance of positioning metal components
The final result of the cleaning process of metallic components also depends on the way in which these are positioned inside the working chamber.
The maximum efficiency of the cleaning processes is obtained when there is a close contact between the liquid and impurities, especially in the case where the metal components have special geometric shapes.
Positioning the metal components correctly allows to:
- protect their surface from damage;
- obtain the highest level of ultrasonic cleaning through immersion or jet pressure by spraying;
- obtain the maximum contact between the substrate and the liquid used for cleaning;
- obtain maximum efficiency in the rinsing phase;
- obtain maximum efficiency in the drying phase.
The use of ultrasonic technology in Firbimatic’s metal cleaning machines
Firbimatic only employ the best quality ultrasonic: for this reason, we offer our customers a consulting service that allows us to identify the utilization powers and the oscillation frequencies suitable for the contaminants that must be removed from the metal components.