How do I print with PC CPE filament?
PC CPE is a polycarbonate + co-polyester blend — it gives you most of the strength and heat resistance of straight PC with better toughness and chemical resistance, and it warps less than PC. Our product listing rates it for thermal stability up to 110 °C+, with high impact resistance, good dimensional stability and strong layer bonding. It's an engineering material intended for enclosed printers with a heated bed.
It is not a drop-in for PETG. Below are the settings that have worked for us and for customers printing this material, plus the one warning that matters most: it sticks to build plates hard enough to take the coating with it.
Hardware you need
Before you load a spool, confirm your printer can do all of this:
- All-metal hotend rated to 280 °C or higher. PC CPE runs at 260 °C, which is past the safe limit for PTFE-lined hotends.
- Bed that holds 100 °C reliably across the whole plate.
- An enclosure. A heated chamber is best (50 °C or more). If your printer has a passive enclosure, close it up and let it soak until the chamber comes up to temperature before starting the print.
- A build surface you're willing to protect — see the bed prep section below.
Dry the filament first — properly
PC CPE is hygroscopic and moisture shows up as popping, stringing, a rough surface and weak layers.
- Dry at 70 °C for 20 hours before printing. This is longer than PETG needs; don't shortcut it.
- Print straight out of the dryer or from a dry box with fresh desiccant. If a spool sits out on the printer for a few days in a humid space, re-dry it.
- A filament dryer or dehydrator that genuinely reaches 70 °C is required — most low-end dryers top out below that.
Starting print settings
| Setting | Value |
|---|---|
| Nozzle | 260 °C |
| Bed | 100 °C |
| Chamber | 50 °C or higher |
| Linear print speed | 20–60 mm/s |
| Max volumetric speed | 8 mm³/s |
| Flow dynamics / pressure advance (K factor) | 0.035 (starting point) |
| Part cooling fan | Minimal to off |
| Drying | 70 °C for 20 h |
Notes on those numbers:
- Volumetric speed is the real limit. Cap it at 8 mm³/s in your slicer and let the slicer scale back your linear speeds automatically. If you only set linear speed, wide external walls and solid infill will over-run the melt zone and you'll get under-extrusion.
- Keep cooling low. Fast cooling is what causes warping and layer splits on PC-based materials. Bridges and small overhangs may need a brief burst, nothing more.
- K factor 0.035 is a starting point, not a spec. Re-run your printer's flow dynamics / pressure advance calibration with this material and use your own result — the correct value depends on your extruder and nozzle.
- Expect to run a flow-rate calibration too. Engineering blends rarely land perfectly on a generic profile.
Protect your build plate — use glue
This is the most important tip in this article. PC CPE bonds extremely aggressively to smooth PEI and glass. At 100 °C bed temperature it can fuse to the surface and tear the coating off your plate when you remove the part.
- Let the bed cool completely before you try to remove anything. Never pry a hot part off.
- Apply a thin, even layer of glue stick over the whole print area before every print with this material. The glue is there as a release layer as much as an adhesive.
- Reapply and refresh the glue regularly — patchy glue means some areas of the plate are unprotected.
- If you have a spare or sacrificial plate, use it for PC CPE.
With glue down and the chamber warm, first-layer adhesion is usually not the problem — release is.
Design and workflow tips
- Add a brim on tall or thin-walled parts. Warping forces are high even though this blend warps less than pure PC.
- Keep the enclosure door shut for the whole print. Opening it mid-print introduces a draft and is a common cause of layer separation on the section printed afterwards.
- Slow down the first layer and consider a slightly larger first-layer Z gap if you see the nozzle skimming.
- Print orientation matters: layer lines are still the weak direction, so orient load-bearing features in-plane.
If prints still fail
Work through it in this order: moisture (re-dry), chamber temperature (too cold), cooling fan (too much), then volumetric speed (too high). Those four cover the large majority of PC CPE failures.
If you're still stuck, contact support with your slicer profile and a photo of the failed part.
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