Cleaning is a problem we are all faced with every day in both our personal lives and our
professional lives. In its broadest sense it is the removal of undesirable material from a particular
place. In the more technical realm cleaning is usually performed to make a particular material or
component acceptable to the next level of processing. This task is becoming increasingly difficult
as geometries continue to decrease while production rates escalate.
Cleaning can be accomplished by a variety of means. One of the more common methods is
immersion in a liquid. When this is the chosen methodology, it is usually a combination of
chemistry and mechanical activity that is employed. Independently each will remove some soil;
together the effect is multiplied many times.
Some typical sources of mechanical activity include brushing, spraying, and ultrasonics. Brushing
is employed where the parts to be cleaned are geometrically simple, typically having large flat
surfaces with no recessed areas or blind holes. For effective use of its mechanical energy, a spray
must be aimed such that is impinges directly on the soil to be removed. This makes component
orientation critical. Ultrasonics is often chosen because it is not as dependent upon either
geometry or orientation for effective soil removal.
Ultrasound travels in all directions in the solution and, in fact, will actual pass through the
components to reach and clean areas which are otherwise inaccessible. Because ultrasonic
energy penetrates into these crevices and cavities, any type of part or assembly can be cleaned.
There are a number of benefits realized from the application of utlrasonics to precision cleaning.
These include:
- Enhanced cleaning speed - Ultrasonics is faster than any conventional cleaning method. Entire
assemblies can be cleaned without disassembly. Often the labor-saving advantages make
ultrasonics the most cost effective choice.
- Unmatched cleaning consistency - The ultrasonic activity is micro in nature and reaches all areas
for uniform cleaning. This is true for large or small parts, simple or complex parts handled singly
or in batches. Thorough soil removal is not operator dependent.
- Easier compliance with safety and environmental regulations through reduction of dangerous
chemical concentrations or substitution of less aggressive cleaning media.
- Reduction of direct worker contact with hazardous cleaning substances.
- Savings in energy costs, labor and floor space.
In addition to the mechanical advantages provided by ultrasonics, there are a number of chemical
or process benefits which can also be gained.
These include:
- Speeding up the rate at which soil dissolves by intimately mixing the cleaning agent with
the contaminants.
- Carrying fresh solution to the soiled surface through a "micro-streaming" effect.
- Attacking the molecular "cement" by which soil attaches itself to a workpiece surface.
- Preventing formation of a neutral film on the workpiece surface that may impede cleaning.
- Raising the temperature of the liquid, thereby increasing the rate of chemical activity.
Ultrasonic cleaners can bring substantial value to a precision cleaning application. The discerning
engineer will want to include it in his (or her) list of possible cleaning methods.
Copyright Branson Ultrasonics Corporation 1998
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