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8. Techniques for Optimizing Cleaning Results
There are seven factors related to successful ultrasonic cleaning:
1 Time
2 Temperature
3 Chemistry
4 Proximity to the transducer/part fixture design
5 Ultrasonic output frequency
6 Watts per gallon
7 Loading - the volume (configuration) of the part being cleaned
TIME:
Typical cleaning times may vary tremendously - how dirty is the part and how clean is
clean. As a place to start, a normal trial period is two to ten minutes, since very few
parts are sufficiently clean within a few seconds. Pre-cleaning may be required to
remove gross contamination or to chemically prepare the parts for a final clean. Some
applications require more than one ultrasonic cleaning stage to complete the required
cleaning. Ultrasonic agitated rinsing is required in some cases to remove the wash
chemicals more thoroughly.
TEMPERATURE/CHEMISTRY:
Temperature and chemistry are closely related. Generally, ultrasonic cleaning in an
aqueous solution is optimum at 140 degrees °F. Some high pH solutions will require the
temperature to be higher to enhance the synergistic effect of the chemistry. Check the
specifications of your chemical with the manufacturer.
The following should be considered the main components of aqueous ultrasonic
cleaning chemistry:
A. Water - hard, soft, DI or distilled
B. pH
C. Surfactants
Wetting agents
Dispersants
Emulsifiers
