PLA stress fractures over time, even just holding it straight like when partially off the roll into the extruder is enough to make it brittle after a few weeks. If you aren't using your PLA for more than a couple days eject it and roll it back into the spool.
this post was submitted on 27 Mar 2024
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That adds up. All the spots it broke are where the filament bends pretty substantially. Thanks.
Ooohhhhh thanks for explaining, that makes perfect sense. I've always wondered why my filament is brittle in the extruder but not on the roll.
Thanks for this. I was worried about how some of my filament was wet in a very dry winter, but this explains why it broke in the spots it broke.
Does this apply to printed parts that are under load as well, then, or are they safer because they don’t get bent/unbent the way filament does (assuming you aren’t trying to do a living hinge or other flexing design)?
This is one reason I'm switching away from pla+ back to normal pla. The esun pla+ really seems to get brittle when held under stress. This is an issue with printed parts as well. I've had parts suddenly crack in half where they were stressed over a few months.
Also it's really annoying when little bits of filament get stuck in your filament guide tube :(
That happens to my filament as well, i assumed it was drying out to much. Your humidity is way lower then mine, i'm typically around 50%. Not sure that this is the reason though
UV radiation?
More likely humidity. Mine is in a windowless room and gets brittle like that after sitting.
I had the misfortune to have some PLA snap just before and after the direct drive in my Bambu P1S and it took ages to get it out. I think age and moisture can affect filament, especially it blended with wood dust, sparkles or something which undermines it even further. I've resorted to packing my AMS with silica beads to hopefully mitigate for the issue and I threw out the filament that caused the issue. Ironically this is one of the few places a bowden extruder is any benefit - if the filament snaps just push it from behind through a heated nozzle until the blockage clears.