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How to avoid particle generation when quarter turns are used in cleanrooms?

With no lube, we have seen in the cycle tester, notable particle FOD

silicone lube we used in a particle test.  We tried about 10 different brands before the one we use for aluminum stopped the particles.  The irony there, it stops for a limited amount of cycles....just enough to qualify the part....but in service, you know the particles come back....but no one cares.....the part passed the initial qualification.  Amazing how the world thinks sometimes

The silicone lube is better than a dry surface but not as good as a small drop of oil.  In a typical small plane cowling, there are just enough oil particles circulating that the wear is minimized.  In an industrial application that is clean, particles are an issue. 

If the operator intentionally applies pressure on the stud when locking and unlocking, wear is just about eliminated.....assuming the operator is informed that applying pressure in the locking and unlocking motion prevents FOD.

the other advise we have is use encapsulated receptacles

furthermore when we ship parts to you, they can contain grease from the production floor, so you'll need facilities to clean mechanical components with dissolvent, so no trace of any other than the original metal will be found.

so Quarter turns without any lubricant, for vacuum and cleanroom conditions is very hard. but teaching how to operate the fastener by the user and using encapsulated receptacles will be the path to go. 


other advise on fasteners used into your cleanroom

Electro polishing for reducing friction and particles
Kolsterising for preventing galling
Cleanroom packaging for minimizing contamination
Rerolled thread Ag or Au plating on request