Knowing your cleanliness requirements can improve the outcome when working with an
BFK Solutions LLC
The boss materializes in your door- way and announces: “Our best customer is complaining about contaminated product. Go pick
out a new cleaning machine.” Your goal
is not just to purchase a new cleaning
system. Your goal is to achieve critical
Look before you buy
Clarify the problem. Have the standards
of cleanliness changed? Is the controlled
environment no longer appropriate to
the application? Perhaps the process is
being run incorrectly; if so, employee
education or training may be needed. The cleaning chemistry may have
been reformulated; there may be a
maintenance problem with simple and
inexpensive solutions.1 If the current
cleaning equipment cannot be brought
up to standards, perhaps a new version
of your cleaning system is in order.
However, you may not want to simply
purchase a clone of your current cleaning machine.
Critical product cleaning requires
planning and evaluation. This involves
determining how clean is clean enough
for your application. It is possible that
the parts or components being assem-
bled have gradually changed over time.
There could be a materials compatibility problem. Materials of construction
are sometimes specified by physical
parameters, not necessarily by chemical attributes. There could be lot to lot
variation; there could be a new supplier.
Speaking of chemical attributes, the
cleaning agent itself may have been
modified, perhaps as a result of safety
and/or environmental regulatory issues.
If it appears that new cleaning
equipment is needed, you have to con-
sider the entire process. Actually testing
the process is a must to achieve effective
critical cleaning and to avoid product
damage. However, testing often requires
using one or more applications labora-
tories. This means working with those
who manufacture or distribute cleaning
chemistries and cleaning equipment.
Some of you may hesitate to work with
applications laboratories. You submit
samples of the product and soil to
the applications lab; you explain what
cleaning chemistries and other process
parameters you would like tested. Time
passes; and eventually, you receive a
multi-page report that boils down to
something along the lines of: “we tested
your subassemblies and the soils you
sent in our standard cleaning system
using our standard cleaning chemistry
with our standard settings; and in our
opinion it worked really well, so purchase our cleaning system.” Such reports
do not provide useful information.
What follows are some basic steps to
preparing to use applications labs productively and with clarity.
Begin by opening your mind to the
range to possibilities in critical cleaning, including aqueous, solvent, and
so-called “non-chemical” approaches.
Perform initial vetting of cleaning
chemistries and processes.
Review potential safety, environmental, and company policy issues.
Determine if company policy and/or
the safety and environmental profes-
sionals have major headaches with pro-
cesses under consideration. If there are
problems with an approach that looks
to be the most viable approach in terms
to surface quality and contamination
control, don’t give up. Review the issues
with those having the objections; it may
be possible to use personal protection,
or, even better, to incorporate engineer-
Review the facility’s logistical and
fiscal constraints. Where will the equip-
ment be located? Conducting the clean-
ing process in a controlled environment
is not effective if the process itself con-
taminates that controlled environment.
What costs are involved? One obvious
cost is capital equipment. However, you
have to consider a number of other
costs such as chemicals, other dispos-
ables and peripherals, and process time.
Contact promising suppliers direct-
ly; 2 this includes both the cleaning
agents and the cleaning equipment. In
some cases, sales representative can pro-
vide useful insights. However, for critical
applications, we suggest that you intro-
duce yourselves to the technical people.
Determine their understanding of your
requirements; get details about their
A preliminary in-house evaluation is
a valuable prelude to working with
the applications lab. At this point,
the more promising process candidates, both for the cleaning chemistry
and the cleaning equipment, should
become apparent. Do a bit of benchtop testing to get a rough estimate of
performance. Dipping the component
in the cleaning agent of interest often
is not informative. It is important to
consider the impact of heat, force, and
time. However, benchtop testing using
stirring bars and small ultrasonic tanks
generally does not emulate the production situation. Please coordinate all testing with your safety and environmental
professionals, and read the Safety Data
Sheets. We occasionally receive inquiries as to how long to clean in heated
alcohol or even acetone. The answer is:
don’t even think about it!