Polypropylene (PP) filament is a new semi crystalline thermoplastic used in Fused Filament Fabrication (FFF). PP filament has a high level of flexibility. Printing temperature for Polypropylene filament is around 210 – 230°C.
BOM
- Lulzbot hexagon hotend $70 https://www.lulzbot.com/products/lulzbot-hexagon-hot-end
- 24V/4-5A power supply
- 3mm id x 6mm od PTFE tubing 630mm long
- 2x M6 x 0.8mm hex nut
- 3mm print effector
- 3mm extruder drive body
- ~1m 18ga speaker wire
- 2x ~1m 28ga twisted pair
- Heat shrink tubing
Filament
- Gizmodorks [1] $62.50/kg
- Net weight: 0.8kg or 1.76 lbs
- Diameter: +/- 0.05mm
- Roundness: +/- 0.07mm
- Print temperature: 250 - 280°C, while some users print with great results at 210 – 230°C
OpenSCAD design
- End effector - download latest version of Athena SCAD files and SCAD libraries. Change the Bowden dimensions in athena.scad. Render the end effector and print.
- Extruder drive - download latest version of extruder drive SCAD files (requires the SCAD library, as above). Change the filament dimensions in extruder_drive_renderer.scad. Render the extruder drive body and print.
Build Instructions
- Build normally.
- Polypropylene filament is very soft, flexible and elastic, requiring an precisely aligned Bowden sheath with very little obstruction. The hexagon hot ends were found to have a small burr around the entry, causing the filament to catch, bind and kink at the cold end (extruder drive). Reaming the entry with a 3mm drill bit removes the burr and cutting the PTFE Bowden sheath flush with the end of the quick connect attached to the hot end has resolved that problem.
Printing
Sometimes polypropylene filament can be difficult to adhere on the bed platform. One neat trick is to lay clear packing tape on the platform. Packing tape is normally made out of Polypropylene, and Polypropylene filament adheres really well to the clear packing tape. Polypropylene filament will also stick really well to high density polyethylene, which is what some kitchen cutting boards are made out of.
PP filament has a high level of flexibility. Printing temperature for Polypropylene filament is around 210 – 230°C. Some users have reported great printing results with a printing temperature between 250 – 280°C. Every 3D printer is different, and please check if the printer can print at high temperatures. Many filament tubes will melt at temperatures higher than 260°C. For best results, heat the build platform to 120 - 150°C or as high as possible.