Cryogenic Deflashing

[Elastomatt]

I am having some parts cryogenically deflashed by a sub-contractor. Are there any issues to be aware of (cracking, reduction of seal 'life'). The parts are small o-rings for a snap on type fitting and should last 30 years+.

appreciate any input to add to my Google search!!

Thanks

 

[acspain]

Elastomatt,

Used to work for a seal manufacturer as a product engineer in charge of some old parts/tooling that required cryogenic deflash. I don't remember ever seeing a performance hit from the process nor product damage. Obviously you want the process to be as short and gentle as possible while getting rid of the flash. The only reason we avoided the process was to reduce cost and steps required to make a part.

I hope that helps.
Andrew.

 

[Elastomatt]

All,

I have received parts back and have a mixed result - the trimming is generally good (once optimum process established). However some parts have got remnants of the flash that was removed stuck to the surface.

Is there a standard method to remove the post trim flash, the sub-contractor we used doesn't have a cleaning facility (just barrels and blasters).

Thanks

Elastomatt

 

[acspain]

Elastomatt,

I am not aware of a standard method to remove the loose flash. My experience is that the parts were placed in a drum made of a perforate metal so that the flash and any media would drop through once tumbled. The materials were also highly filled and contained oils and waxes therefore as a consequence were not sticky. Bottom line, never had a problem with flash stuck to the parts. My only thoughts would be to make sure they are using a perforated container so that at temperature the flash would drop through the holes. I would also expect any natural sticky-ness of the parts to decrease at temperature so can the process go lower in temperature or maybe a little longer to give the flash time to exit.

Cyrogenic deflash is not typically a desireable process. A rotary trim process was preferable if you could not eliminate the flash at the molding tool at my previous employer. Fixing molds can be time consuming and expensive but depending on the number of parts that are being molded can be a cost effective solution.

Good luck.
Andrew.