Many times the geometry of a part makes it difficult for aqueous cleaning systems to clean the entire part – inside and out. Small features like blind holes or even through holes with a very small diameter means that the water based solutions may not be able to wick or wet into an area due to high surface tension, or even exit a feature if they do get in. This is where a vapor degreaser can be a great option. The reduced surface tension of a cleaning solvent versus water based chemistries, means that the solvent can go where the water cannot – and come back out again.
A Minneapolis, MN based medical device manufacturer of surgical instruments parts has very small passage ways which are extrude honed with abrasive media and mineral oil and also Swiss machines tight tolerance profiles. The low surface tension of 3M Novec 72DA engineered fluid solvent used in a vapor degreaser allows for cleaning these sensitive parts of all the media and oils without any non-volatile residues.
Video of Automated Vapor Degreaser for Medical Device Instruments
How does a vapor degreaser work? The machine operates by creating a “cloud” or vapor blanket within the machine by boiling solvent in the boil sump. This vapor blanket is typically warmer than the ambient air in the plant. As parts are lowered into this blanket the warmer solvent condenses on the parts – much as water condenses on a cold glass of water on a warm summer day. As the solvent condenses, it runs off the part and drips back into the solvent tank below causing a scrubbing effect on the parts as the solvent condenses and drips off. Because the 3M Novec 72DA engineered fluid solvent has a much lower surface tension than water, the solvent is able to condense inside holes, cavities, etc on the part as well, meaning those areas see the same cleaning effect.
The vapor degreasing cleaning process required the following contaminants to be removed from the parts:
- Hangsterfer Hard-Cut 5418
- Hangsterfer Hard-Cut NG
- Mineral oil
- Extrude hone abrasive flow machining fluid and oil
The process must adhere to the strict requirements of medical device surgical instrument manufacturing for bioburden and cytotoxicity.
Various parts to be cleaned in this industrial degreaser machine included stainless steel and titanium materials which are laser welded and contain internal passageways with 0.005 diameter and 2 inches long. Utilizing the low surface tension and high solubility, solvent for cleaning is essential for cleaning such small aspect ratio geometries.
Vapor degreaser machines are utilized for precision cleaning true oil and other petroleum-based fluids