I’ve been considering getting refills to reduce my plastic consumption, which means I would have to print master spools with PLA or PETG.
Because I don’t consume my filament quickly enough, I got the Sunlu S2 filament dryer, which heats up the filament to 50-60C.
My question is: would it be OK to put a master spool in the dryer, or could it potentially deform?
PETG will not, the glass transition temperature is 80-85C. For PLA it’s 55-60C, so those will go floppy if you go at full tilt, though you should dry PLA at 40-50c-ish.
PETG will creep even at temperatures below 80°C and the higher the temperature is the faster the process is: https://en.wikipedia.org/wiki/Creep_(deformation)
I have a small collection of parts that all experienced creep (as a showcase). Structurally they where all fine in simulation and practice. Over time they all failed due this deformation.
So does PLA, both materials are amorphous polymers so they are never “truly” solid unless they are frozen - nor are they really ever molten either. That is why screws and bolts etc always seem to “work” loose on 3d printer parts - they don’t, the material just flows away from them.
It’s just that at the glass transition temperature is when they go from slowly getting softer the hotter they get to suddenly completely rubbery and floppy.
