I'm having a lot of trouble printing polypropylene right now, and I think it may have to do with the conditions. I'm using a very thin coat of ABS on the base plate (just as you would do when printing with ABS) in order to promote sticking.
In this following first picture, I attempted with a 240°C tip and a 150°C bed (above PP's Tg). Oddly enough, one side actually looked somewhat decent while the other clearly had trouble sticking. The print speed on this was 1500 mm/min.
In the second picture, I was printing with the tip at 220°C and a 50°C bed. What's interesting in that print (you may be able to see it) is that the polymer extruded with little blips of material followed by a more stringy section, rather than a steady, even filament. (Print speed on this was 2100 mm/min)
Does anyone have suggestions for doing better prints with PP?
Yes. These settings work for Ultimaker as well. Set the printer to print PLA, and put brown tape on the bed under the print. Set the layer to 0.1 mm, set the initial layer to 0.1 mm.
Don't over heat the PP or when it cools it will shrink tons making it want to peel off. PLUS if you don't let the PP go below its Tg (80°C) by making the bed too hot it will stay molten and eventually stick to the nozzle making a truly pants print, and probably detach itself.
I have been making tiny detailed little components with PP this evening, just about to put 21 on to make and then off to bed!
Sorry, PLA settings on the UM is 210°C for Hotend. I am making round PCB spacers, so these are best with a 100% infill and a concentric fill pattern. Also, I recalibrated the platform with a very thin post-it note which is about 50% of the thickness of the UM calibration card. It makes sense to just get the PP soft enough to extrude, in fact I am seeing turbulence at the beginning when the extruder runs some material through the molten material has a curly cable appearance. Like this the material beds itself right into the tape. Lovely.