40kHz Ultrasonic Cleaners / Most Popular General-Use Ultrasonic
40kHz is the most popular single-frequency ultrasonic system found in the
industry today, and has been for some time. If you have an ultrasonic
cleaner in your facility, chances are it is a 40kHz system. This
ultrasonic frequency has a good combination of power, penetration, and even
energy distribution, and can successfully address most cleaning applications
when combined with a properly-engineered cleaning system.
cleaning systems, regardless of manufacturer or frequency, produce a scrubbing
action which is distributed as a series of an equidistant bands known as
Standing Waves which begin at the transducer mounting location, which is
typically the bottom of the tank. The frequency of the ultrasonic cleaner
will determine the distance between these bands of activity. The higher
the ultrasonic frequency, the closer these bands will be to one another, but the
less powerful the activity will be at any one location. High-frequency
ultrasonic systems generally produce a very evenly distributed cleaning effect,
but a less powerful one, while low-frequency ultrasonic systems produce a
cleaning effect with large areas of inactivity, but the cleaning action is more
powerful at standing wave locations.
The photograph at the right depicts Zenith's ULTRAPROBE Ultrasonic Testing
Instrument, which visually displays the ultrasonic scrubbing action distribution
in a 40kHz ultrasonic cleaning system. This patented device is composed of
a quartz test tube which is filled with a colored detergent mixture, and
precious metal particles of a specific size. When the tip of the
instrument is inserted into an ultrasonic cleaning system, the metal particles
migrate to areas of intense ultrasonic activity. Note that there are light
colored bands spaced roughly 1/2 inch apart in this instrument. This is
the scrubbing pattern that a 40 kHz ultrasonic system will produce. As you
can see, there are a large areas of inactivity, but these areas are NOT as large
as those found in a
25kHz system. Cleaning is more consistent when using
40kHz ultrasonic cleaners, but penetration into very find detailed areas, and
completely even energy distribution is still not present. As such, these
systems are considered "general purpose" ultrasonic cleaners.
40kHz ultrasonic cleaners are quieter in operation than a 25kHz system, and
produces a more gentle cleaning action. It is appropriate for the removal
of common contaminants from parts, but may not consistently remove contaminants
from tight tolerance areas. 40kHz also has a tendency to remove particles
which are smaller than
25kHz, but not quite as small as an
80kHz system can
40kHz ultrasonic cleaners are less destructive to the cleaning tank than
When to Use 40kHz Ultrasonic Cleaners:
- When Cleaning Medium to Heavy Parts
- When Removing Most Contaminants Found in Manufacturing
- When Parts have Some Detail, but Not ultra-fine Detail,
such as small blind holes, threaded areas, and Similar Details
- When Higher Frequencies Fail to Clean a Part.
Common Customer Complaints:
- Cleaning is Not Consistent in Very Fine Detailed Areas. Sometimes it Works,
Other times is Doesn't.
For additional information,
Zenith Mfg. & Chemical Corp.
85 Oak St.
Norwood, NJ 07648-0412