PEEK Washer/Gasket for Nozzles

[zemlin]

I had been thinking about trying some sort of gasket at the nozzle/throat tube connection for some time. I recently picked up a set of Olsson Ruby nozzles so I could start running filled materials. I was skeptical that the torque spec on the nozzles would be adequate to create a seal on the throat tube. I'm using the Olsson torque wrench printed in Hatchbox PLA to tighten.

My first run with the ruby and CF PETG ended up oozing - made a fine mess of the silicone sock. So I dropped one of these between the nozzle and the throat tube. https://www.mcmaster.com/93785a110 High-Temperature PEEK Plastic Washer
for Number 0 Screw Size, 0.078" ID, 0.188" OD.

So far so good. I ran several more parts in the PETG with no ooze. Now running Hatchbox ABS at 260C and still no issue. The real test will be with CF PC which I expect to run at 300C based on my non-filled PC experience. PEEK glass transition should be at 289C - melting point at 343, so I'll have to see what happens at 300.