I found a small length of filament in the parts bin. I don’t know what it is, and nobody else here does, or remembers ordering it. I’m pretty sure it’s a sample that was sent by Prusa when we ordered the printer, and it’s probably not a special material.
It’s feels “gummy” and a lot softer than PLA, but not really rubbery either. And I tried printing something with it at 230C as if it was PLA and it’s clearly not hot enough: it’s able to flow out of the nozzle but it barely sticks to the bed.
Any idea what it could be?
Well, if we’re ruling out PET and PETG – PET would probably require the temperatures you describe and would be impervious to acetone, as well as extremely flexible – there is an outside possibility it could be HDPE.
HDPE filament is damn rare, though, and I’d doubt anyone would be giving it away as samples given how difficult it’d be to print with most consumer machines. HDPE’s signature tell is that it feels somewhat waxy if you e.g. scrape at it with your fingernail.