The operating temperature of the ultrasonic cleaning system affects the distribution of the ultrasonic cleaning effect, the power of the ultrasonic cleaning effect, and the effectiveness of the detergent used.
Traditional ultrasonic theory shows that the optimum temperature for an ultrasonic cleaning system is usually 65% of the boiling point of the solution. Although this formula has been used for decades as a general guideline for determining the optimal temperature, it rarely plays a role in determining the optimal temperature for any given application. Temperature is usually more related to the effectiveness of cleaning agents in use than to the effectiveness of ultrasonic cleaning systems. Each cleaning fluid may have the best temperature for its best performance. This is the temperature normally used for a given ultrasonic cleaning application.
The increase in fluid temperature will improve the distribution of the ultrasonic cleaning effect in the water tank, but will also reduce the scrubbing force. As the temperature rises above 80 degrees, you will find that scrubbing motions are more evenly distributed and less intense than at higher frequencies. A simple tin foil test can be used to confirm this information. As the temperature rises, holes in the foil take longer to form. However, the foil appears to be more evenly attacked by the presence of ultrasonic energy. The large holes in the foil are replaced by smaller, more evenly distributed holes, and indentations can be seen between the holes produced by standing waves in the ultrasonic cleaning bath.
Although the physical scrubbing force of ultrasonic cavitation will decrease at high temperatures, the decrease in ultrasonic power can be overcome by improving the effectiveness of detergent. Some detergents work best at high temperatures. By operating the ultrasonic cleaner at these temperatures, the detergent can improve, and the adhesive strength between the cleaned part and the associated contaminant can be reduced to the extent that existing ultrasonic energy can remove it from the surface, even if the scrubbing power is reduced.
Acid cleaners should not be overheated, as many of these liquids will corrode the stainless steel used to make water tanks. When using these liquids, it is best to use the lowest possible temperature to avoid this potential damage.
Summary of temperature effects:
The optimum ultrasonic performance is about 65% of the boiling point of the fluid used
A temperature 65% above the boiling point decreases the scrubbing force of the system but improves the force distribution
Most ultrasonic cleaners use temperatures between 130 and 180 degrees Fahrenheit
When using acidic materials, use the lowest possible temperature to minimize potential damage to the stainless steel tank
