How to clean lenses with ultrasound
Industrial lenses made only of pure glass are ideal for ultrasonic cleaning. An ultrasonic generator generates a high-frequency electronic signal, which is converted into ultrasonic waves in a liquid by a transducer immersed in an ultrasonic bath. The wave produces cavitation bubbles in the pressure valley of the ultrasonic wave, and the bubbles collapse again at the peak of the wave pressure. These tiny bubbles, which are produced and burst in time with the ultrasonic frequency, have a powerful scrubbing effect on the hard surface of the lens. Anything that sticks to the glass will be removed.
Lower frequencies produce larger bubbles and a stronger cleaning effect, while higher frequencies produce smaller bubbles for finer cleaning. The power of the ultrasonic cleaning system also affects the time required for cleaning. For some pollutants, such as grease and oily residues, a mild detergent helps clean, as does heating a bathtub to soften these deposits.
Strong cleaning by adding detergent and heating can clean pure glass quickly and thoroughly, but these measures can cause damage when lenses have a treated surface or surface film. A more cautious approach to customization is needed.
Gently clean precision lenses
Safe use of the ultrasonic cleaning machine on a variety of industrial lenses should first choose a system, the system can be gentle cleaning while minimizing the lens immersion time in the cleaning fluid. The ultrasonic frequency required must be high enough to avoid damaging the coating, which is softer than pure glass. At the same time, many lens coatings are sensitive to being immersed in water for long periods and may absorb water, discolor, or peel off from the surface of the lens. Therefore, the frequency must be low enough to be effective in cleaning and quickly removing the presence of specific types of contaminants.
Although the selected ultrasonic frequency determines the intensity of cleaning action, the power of the system will affect the speed of cleaning. If the power is too low, too few bubbles are created and the cleaning process takes longer. The right level of power produces the maximum number of bubbles and the fastest cleaning speed. Even higher levels of power are wasted and do not affect cleaning speed.
Heating and cleaning agents are sometimes incompatible with the fine surface treatment of lenses. If the ultrasonic cleaning system is configured correctly to achieve maximum cleaning speed, there is usually no need to add detergent or heat to the tank. The trade-off between the duration of the cleaning process and the addition of detergent or heating can be based on the specific lens treatment that must be cleaned. If the coating is sensitive to exposure to water, heating and specially formulated solvents may accelerate the process and reduce water exposure. In general, cleaning at room temperature with deionized water is the least aggressive and default solution.
