What are the ideal print conditions for polypropylene? 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?
Polypropylene CAN be printed with excellent results, you just need a good filament roll and good printing setup.
A few days ago I read this topic and was kind of afraid of testing it, now I am so happy I tried it.

I am printing the PP filament from the brand Smart Materials 3D (search on google).

I am using a Prusa i3 Mk2, bed heated to 70ºC and hotend to 210ºC. I ventilate the printer as much as possible: room windows open and fan at 100% after second layer. 

IMPORTANT: apply some cheap brown packaging adhesive strips to the bed, where the part is going to touch the bed, with adhesive facing down. I tried many other solutions but none worked.



I have printed so far at 20mm/s constant, with 0.2 mm layer heigth, 0.4 mm extrusion width, 0.8mm retraction, flow 125%. Still optimizing setings.
Parts come out very nice, with good flexibility and amazing inter layer bonding. Density is a bit lower than ABS, so excellent, and impact resistance is awesome.
Check some parts I printed today: