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Seeing surface residue on Black Anodize finish after Autoclaving (a Mega Steambath)
An ongoing discussion beginning back in 2006 ...2006
Q. I am observing a dark "smokey looking" surface film forming over my black anodized (Type II, Class 2) 6061-T6 machined aluminum parts. The film forms after I run the parts through an AutoClave cycle. Autoclaving is a Steam/Pressure sterilization process commonly used in hospitals. The autoclave uses DI water. If I repeat a process of scrubbing the film off with Alcohol and autoclaving again, the film stops forming after the 3rd or 4th cycle. The parts look great and are spot free every time afterwards... I have sent before and after photos for review.
Help! Time is money and we're not cheap ;-) Can anyone help me identify this film and recommend any process steps our plater can use to prevent filming after autoclaving? Autoclaves produce; 134 °C heated steam at 34 psi for 30 minutes.
I have tried using just Hot water sealed and Nickel/Hot water sealed processes with no success.
electrosurgical products - O'Fallon, Missouri, USA
First of two simultaneous responses -- 2006
I believe what you are seeing is seal-smut. Autoclaving will actually continue the sealing process that was not totally completed when the parts were anodized. Once the parts are completely sealed, the smut will cease to develop. This is probably not your coaters fault, as it can be difficult to get a "completely sealed" part through normal anodizing procedures.
anodizer - Boise, Idaho
Second of two simultaneous responses -- 2006
Joe, a wild guess. Some of the chemical plus dye stuff is still in the pores when sealed. Then the higher temp of the autoclave is forcing it to come out. Eventually, you are flushing it out.
- Navarre, Florida
We currently hard black anodize parts that go through the autoclave cycle without your problem. I would suspect the sealing process.
Have you always experienced this problem? Is something 'new' in the process? Have you tried another supplier as a verification?
- Colorado Springs
September 6, 2018 -- this entry appended to this thread by editor in lieu of spawning a duplicative thread
Q. We are Medical devices Manufacturer. From our in-house manufacturing, I was able to do anodizing of Aluminium made Ster-lization boxes and instruments and also colored. Can someone guide me how to make colored (DIY) instruments autoclavable? I mean any surface treatment which I did in boiling water, or if any other suggestion would appreciate from seniors and Experts.
Manufacturer - Pakistan