In this reprint from Finishing Today magazine, the author explores the problems inherent in aqueous cleaning processes: large footprints, require large capital investments, consume electricity at a prodigious rate, are maintenance intensive, and require expensive waste water treatment systems. Vapor degreasing resolves all of these problems but introduces certain new issues that must be considered when upgrading cleaning systems. With modern equipment and solvents, vapor degreasing is a safe, cost-effective and environmentally acceptable cleaning method.
In the world of precision cleaning, there are four common process choices for engineers: hydrocarbon cleaning, aqueous cleaning, semi-aqueous cleaning, and solvent cleaning with vapor degreasers. Each method has its strength and weaknesses, but the authors suggest that the most environmentally acceptable choice for critical cleaning is vapor degreasing with modern specialty solvents. This is particularly true when energy consumption and costs are compared. The vast majority of atmospheric emissions in the world today come from the burning of fossil fuels, and much of that pollution is generated trying to produce electricity. Using electricity conservatively helps protect the planet and your budget.
Solvents can accomplish this due to the unique nature of the chemistries. For example, if a device has complex geometries, production debris can become trapped in tight spaces, making cleaning with high-boiling fluids difficult and inconsistent. Quality standards on finished components may require black light inspection, particle count, water break or other analysis to confirm cleanliness.
Cleaning with solvents has been a fine choice because they are stable and highly effective. These fluids also are low in viscosity and surface tension, which allows them to get into tight crevices and wet all the surfaces of the parts. They also offer high solvency (“Kb Value”) which allows them to rigorously clean the surface and displace stubborn soils. All of these factors combine to produce the best possible cleaning at the lowest cost-per-part-cleaned.
First Published April 2014
Revised and Updated April 2017