Ultrasonic Cleaning Solution Temperature Control

Pay attention to ultrasonic cleaning solution temperature.

Pay attention to ultrasonic cleaning solution temperature.

The temperature at which an ultrasonic cleaning solution is at maximum effectiveness is usually included in the detail sheets or specified by standard operating procedures provided by technical and trade associations.  As examples the product information sheet for the widely used alkaline elma tec clean A4 suggests temperatures of 50 to 80⁰C whereas MedClean C7 for dental and surgical instruments should be used at approximately 40⁰C.  High ultrasonic cleaning temperatures are generally recommended for parts heavily contaminated by grease and oils but can cause blood to strongly bond on dental and surgical instruments. In general, however, the effectiveness of ultrasonic cleaning solution temperature levels off at approximately 80⁰C above which all you are doing is wasting electricity.

Ultrasonic cleaning equipment such as the Elma E, S and P series available from Tovatech are equipped with heaters that allow users to select the recommended cleaning temperature.  These units are equipped with an auto-start function that will initiate cavitation when the selected cleaning solution temperature is reached, at which time the heater switches off.


Ultrasonic Cavitation Produces Heat

It is important to understand that ultrasonic cavitation energy is transformed to heat during the cleaning process even if the unit’s heater is turned off.  A continually operating unit can raise solution temperature as high as 60⁰C depending on the model.

If you are cleaning products where temperature increases must be limited you should implement a method to cool the solution.  Tovatech offers the Elma cooling coil that is attached to deep-drawn (vs. welded) cleaning solution tanks.  Cooling water is circulated through the coil to prevent overheating of the cleaning liquid.  You can also build your own system.  A customer using the Elmasonic P60H unit to clean vinyl phonograph records activates a pump when the solution temperature nears 50⁰C.  The pump moves the liquid from the tank drain through a tube and a 1 micron filter from which it is returned to the tank.  This, the customer says, both cools and cleans the solution.

The takeaway here is to pay attention to the temperature of your ultrasonic cleaning bath if high temperatures either impede the cleaning process (such as surgical instrument cleaning) or can damage the objects being cleaned.

Contact the ultrasonic cleaning pros at Tovatech for answers to your cleaning challenges and recommendations on the equipment to use.

About Rachel Kohn

So how did an MIT Ph.D. end up selling refrigerators? When I figured out that a lot more scientists buy lab refrigerators than innovative leading-edge instruments. I hope that my many years of lab experience will help you find the right equipment for your work. Before co-founding Tovatech I worked in business development and project management at Smiths Detection, Photon-X, Cardinal Health, and Hoechst Celanese. And before that I spent 12 years as an R&D chemist at Hoechst Celanese and Aventis working on advanced drug delivery systems, polymer films and membranes, optical disks, and polysaccharides. Some day, eventually, I’ll make enough money to develop an innovative technology that will change the world. Read More