Washing, Rinsing, and Drying
Barbara Kanegsberg
Washing, rinsing and drying are distinguishable steps in the cleaning process
with specific requirements in terms of:
Chemistry
Equipment
Process design
Process control
An awareness of the functions and requirements of the three activities
can help you to achieve a better quality product at increased efficiency
at with
lower cost.
To explore the distinguishing features of the cleaning process, I wrote an article that appears in the September, 2005 issue of “Metal Finishing Magazine.” The principles apply not only to cleaning metal, but also to optics, composites, plastics, and combination parts.
Soil is matter out of place. Washing, rinsing, and drying all remove
soil. The washing step removes manufacturing soils, and soils
introduced by people
and the surrounding environment. The soils may be particles and/or
films. The washing step is often also referred to as the cleaning
step; this
in itself can result in ambiguity. And, of course, we do not
refer to “washing
agents” but rather to “cleaning agents.”
The rinse step removes soil introduced during cleaning, primarily
residual cleaning agent. The rinse step may also continue to
remove residual
manufacturing soils; but if you are too dependent on the rinse
process, you might consider
further optimizing the cleaning process.
The drying step removes soils introduced by the rinse process,
including water and/or organic solvents. These soils may
be trapped in blind
holes or they may be adsorbed into composites. The drying
process is all too often
a major bottleneck (or pain in the neck), because, as the
last step, it may be under funded.
The complete article contains much more detail including,
do’s and
don’t, case studies, and photographic illustrations.
http://www.metalfinishing.com/editors_choice/articles/050901_Kanegsberg.htm
