Solvent resistance, TPU, PP, ... ?

Filament
1

I need to make a few parts for a physics experiment, and some of them need to be resistant to mineral oil and grease (at least). So far I’ve been prototyping in ABS, but that lacks solvent resistance and also has severe delamination problems. So it’s about time for me to switch over to a plastic that might really be usable for the end product.

One possibility would be TPU. The lab I use has one Lulzbot AO-101 dedicated to TPEs, so that’s a reasonable option. They mostly use Ninjaflex, but I was wondering if anyone has opinions about other (cheaper) brands like SainSmart? I also travel to China occasionally, and filament is roughly 5 times cheaper over there ($5-11 / kg), so I was thinking of grabbing a bunch on my next trip. (I’ve had decent luck with other components from China: LEDs, tungsten sheet, stainless steel spheres.) The flexibility isn’t really required though, and might be a problem for some of the parts.

I also noticed that Gizmo Dorks sells PP (polypropylene) filament. (Only in white and yellow, at least on Amazon.) That has excellent chemical resistance and might be my ideal material, but, does anyone have any experience printing with it? Any printer config files (especially for Luzbot Mini, AO-101, or TAZ)?

Or, any recommendations for other plastics with good solvent resistance?

2

If you have access to a Taz with a Hexagon or equivalent hotend, you might consider Polycarbonate filament. It takes higher heat than the Buddaschnozzle can put out to print it, but the solvent resistance should be much better than ABS

The Chinese Filaments are often cheaper because they cut the ABS plastic with filler powder (melamine powder in particular) which results in crap filament and clogged nozzles. You can luck out and get good filament, it’s very hard to tell before you try it out though. Also filament doesn’t travel particularly well if you will be in a region with very high humidity.

3

The nylon filaments should have good resistance to grease and mineral oil (but not acid or alcohol). They could also solve your delamination problem.