Extruder Screw Fatigue
Extruder Screw Fatigue
(OP)
The company I work for extrudes plastic sheet. We recently had a fatigue failure of one of our extruder screws. The fatigue zone was roughly halfway through the screw. We have other, old machines that may also be wearing in this way. Does anyone know of a way to test the screw continuity while it's still in the extruder? I would like to be able to test the screws for cracks without having to pull and clean the screws. Any ultrasonic methods available?
Any guidance is appreciated.
Any guidance is appreciated.






RE: Extruder Screw Fatigue
RE: Extruder Screw Fatigue
I am thinking of a situation that may be similar to a worm gear drive on a mcahine tool where the worm stretches over time.
Of course it is likely I am wrong. Just a thought.
Composites and Airplanes - what was I thinking?
There are gremlins in the autoclave!
RE: Extruder Screw Fatigue
Just a thought: if you have access to the end of the screw(s) you may be able to use ultrasound to detect a crack somewhere down the screw length.
Cheers
Harry
RE: Extruder Screw Fatigue
I just made all that up as a guess so no promises.
There is not any memory with less satisfaction than the memory of some temptation we resisted.
- James Branch Cabell
RE: Extruder Screw Fatigue
The screw must be out and clean. Pulling a screw is not that big a job and should be regular maintenance for this and other reasons.
Regards
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RE: Extruder Screw Fatigue