Vapors and Product Quality
Barbara Kanegsberg,
BFK Solutions LLC
At an American Vacuum Society panel discussion earlier this month, I
was asked a number of questions about the potential for residue from
cleaning
processes to negatively impact vacuum coatings and other engineered coatings.
We tend to associate the negative impact of vapors with critical applications.
However, vapors outgassing from the product can pose problems for many
products.
What sorts of vapors are we talking about?
We’re concerned about a chemical that is adsorbed to the surface or
near-surface of a product, fixture, or tool. The sorts of chemicals of concern
depend on the situation and may include:
• Low boiling solvents
• Water
• High boiling solvents
What are some sources of outgassing materials?
• Ambient atmosphere
• Water or organic solvents used for cleaning
• Residue of cleaning agent additives
• Metalworking fluids
• Carrier fluids for deposition
What are examples where vapors might be a problem?
• Coated materials
• Sealed systems
• Critical operating environments
• Mixed metals, composites, and elastomers
If you have historical success with the product or process, there is
less likely to be a concern with outgassing. The problems arise with
new
products, new uses of old products, and/or manufacturing process changes.
Outgassing is a concern for critical and industrial processes. To avoid
outgassing problems, be alert and vigilant about changes. If you
or your suppliers adopt
a very high boiling solvent such as a bio-based solvent, residue
may remain on the part. If the part is then exposed to high temperature
for a long
period of time or if it is used in a sealed system, the solvent
may volatilize, contaminating other components or compromising coatings.
If you purchase
new cleaning equipment or process equipment, be alert to such details
as the materials of construction of elastomers. If you change a
fixture,
check
that coatings will not adsorb process chemicals.
