Failing to make sheets of PLA

[solarbird]

I failed last night to make a sheet of PLA in my oven. Here are pictures of my failure.

If you know what I did wrong, tell me. (The first picture is actually 200C, I screwed up in my thread when I said it was 215 - I'd just upped the temp to 215 when I typed that.)

Comments

[absynthe]

I would recommend grinding it first, then creating a slurry with acetone, then cooking that after it dries.

[solarbird]

Yeah, grinding is gonna be a thing just because of trying to find something that can grind it that isn't insanely expensive. (All the plastic grinders I find are industrial equipment and so mad spendy.)

However, someone on Reddit has said they use a blender to chop up their used PLA, so I've asked them if just any blender will work. If so, I'll get a thrift-store blender and give that a go.

I don't want to use acetone for a bunch of reasons, plus apparently it's not that great on PLA anyway. (But it does kinda work. Just not as well as with a lot of other plastics.)

[vatine]

No more than "PLA is surprisingly finicky". Back when I was more regularly 3D-printing, we had to re-tweak the hot end for pretty much every new spool of PLA, as they all seemed to require another temperature for optimal working. Some printed grand at 205°C, some required 225°C (and at that point, you better not have a geometry that had a lot of movement that did not require extrusion, so as to avoid burnt non-extruding lumps in the hot end).

But, yeah, grinding might make it easier to get the heat into the PLA evenly. If you go for "ramp up the temperature", do it slowly (maybe 0.5°C - 1°C per minute), so you get a chance to observe what's happening.