Polycarbonate (PC): The Unbreakable Filament

Jackson B.

The Engineering Heavyweight

Polycarbonate (PC) is the material of ballistic police shields, aircraft canopies, and CD/DVD discs. It combines extraordinary impact resistance (genuinely difficult to fracture under normal conditions), a heat deflection temperature of approximately 120–150°C, and optical clarity in its natural form. In FDM printing, the same properties that make PC valuable also make it extremely demanding to print, but for applications that genuinely need these properties, no substitute comes close.

Consider PC when you need parts that must survive severe mechanical impact without breaking; components operating continuously above 100°C; optically clear printed components (PC can be printed as a transparent material with the right hotend and settings, though clarity is limited in FDM), or parts in contact with petroleum products or strong cleaning chemicals that would degrade lesser plastics.

Hardware Requirements

PC printing requires serious hardware. The hotend must be all metal and capable of 270–310°C; typical stock PTFE-lined hotends operate safely only to approximately 240°C. At 280°C, PTFE in the hot zone decomposes into toxic perfluorocarbon gases. An E3D V6 all metal, Dragon HF, or Rapido in all metal configuration is suitable. The bed must reach 100–120°C; most standard bed heaters achieve this, though verify your printer's rated maximum temperature. An enclosure maintaining a 50–60°C chamber temperature is mandatory; without it, large PC prints delaminate catastrophically.

Bed adhesion for PC is the most challenging aspect. PC bonds extremely aggressively to PEI, so aggressively that it can delaminate the PEI coating on removal, destroying the surface. Use Kapton tape on glass as an alternative surface, or experiment with specific PC adhesion products. A large brim (15–20mm) is always required. Some makers use a sacrificial PEI surface reserved exclusively for PC printing and replace it when it degrades. A hardened steel nozzle is recommended; though PC itself is not abrasive, the hardened steel's value is primarily temperature resistance at 280–300°C operating temperatures.

Settings and Troubleshooting

PC print settings: hotend 270–300°C, bed 100–120°C, chamber 50–60°C, no part cooling fan, and print speed 25–40 mm/s. The slow speed is essential, a PC needs full thermal energy in each layer for proper interlayer bonding, and higher speeds don't allow adequate heat soak. Layer height: 0.2–0.25 mm. Retraction 1–2mm on direct drive, PC is less prone to stringing than PETG, so retraction management is simpler. Most PC printing failures come from inadequate chamber temperature, if you're seeing layer delamination, prioritise better enclosure insulation. See our enclosure guide for building or improving your enclosure, and our engineering materials overview for how PC compares to Nylon and PA-CF in the overall engineering material landscape.