Polycarbonate (PC) Filament for 3D Printing: Strength, Heat, Drying and Who It's For

What polycarbonate brings that other filaments don't

Polycarbonate, usually shortened to PC, is the engineering plastic behind face shields and tough equipment housings. As a filament, it targets parts that have to take real loads and real heat at the same time. Prusament describes its PC Blend as very strong and rigid, tough even at low temperatures, with good resistance to creep, the slow deformation a plastic suffers when it stays loaded for weeks or months. That last property matters more than people expect for brackets, clamps and anything that sits under constant tension.

On heat, the two manufacturer sheets agree closely. Prusament lists temperature resistance up to 113 °C for PC Blend. Polymaker's datasheet for PolyMax PC gives a glass transition temperature of 113 °C and a heat deflection temperature of 114 °C at 0.45 MPa. Those figures sit well above PLA and PETG, and above ABS and ASA for parts that live near a heat source.

Keep in mind that both products are blends formulated for printability, not pure polycarbonate. Polymaker also notes its mechanical numbers come from 100 percent infill specimens, with lower values between layers than across them. A printed PC part is still a layered object, and its weakest direction is still along the layer lines.

The temperatures and hardware PC demands from your printer

PC prints hot, and that is the first filter. Polymaker specifies a nozzle between 250 and 270 °C and a bed between 90 and 105 °C for PolyMax PC. Prusament goes higher for PC Blend: nozzle at 275 °C plus or minus 10, bed at 110 °C plus or minus 10, and a heated bed is listed as mandatory. Before you order a spool, confirm your hotend and bed can hold those temperatures for hours, not just reach them briefly.

Part cooling flips compared to PLA. Polymaker wants the fan off entirely. Prusament specifies 20 percent. Either way, blasting the part with air is how you get cracks between layers.

The biggest requirement is the enclosure. Polymaker calls an enclosed printer that traps heat a hard requirement, strongly recommends an actively heated chamber at a minimum of 70 °C, and states that large or dense parts will need one. Prusament is more lenient: a skirt or an enclosure is recommended, in a room without cold drafts. Our guide to 3D printer enclosures covers what a closed chamber actually changes. Prusament also notes that no special hotend is required, and that PC Blend gives off a noticeable odor while printing, so plan for a ventilated room.

Moisture and drying: two brands, two answers

Ask whether PC needs drying and you get different answers depending on the brand, which tells you something. Polymaker says its PC absorbs moisture slightly faster than regular PLA, recommends storing spools in a dry box, and gives a drying cycle of 75 °C for 6 hours, only if the material has already picked up moisture. Prusament states the opposite for PC Blend: it is very little hygroscopic and does not need to be dried before printing.

These aren't contradictions so much as two different formulations sold under one generic name. A practical rule works for both. A fresh spool straight out of the vacuum bag usually prints fine. A spool that has been open for weeks in a humid garage deserves a drying cycle if you see bubbles, hear popping at the nozzle, or get a dull, rough surface. Our filament dryer guide walks through those symptoms and what to look for in a dryer.

One warning on drying temperature. A 75 °C cycle is beyond what many entry-level dryers designed for PLA can reach or hold. Check your unit's range before you commit, and skip the kitchen oven unless you can verify its real temperature, since an overshoot will fuse the spool into a solid block.

Warping, cracking and bed adhesion: where PC bites

PC has two well-known habits: it shrinks hard as it cools, and it sometimes sticks too well. On shrinkage, Prusament claims less warping than conventional polycarbonates but warns that large models remain prone to it. The brand's fix list is concrete: add a circular skirt as tall as the model, reduce the number of perimeters and the infill, place the model in the center of the bed, and keep the printer away from drafts. Polymaker adds that a heated chamber minimizes both warping and delamination, especially on big or dense parts.

Adhesion is where PC Blend surprises people. Prusament requires a layer of glue stick as a separating agent on the PEI sheet, smooth or textured, because otherwise the part can bond so strongly it damages the print surface. That is the reverse of the usual logic, where glue is there to make parts stick. Polymaker instead recommends a dedicated adhesive, Magigoo PC, which holds while the bed is hot and releases as it cools.

Then there is cracking along layer lines. Polymaker attributes it to parts cooling too fast and advises keeping ambient air as warm as possible, then annealing the part as soon as the print finishes, at 90 °C for 2 hours, to release the internal stress built up during printing.

PC versus ABS and ASA: which one your part actually needs

ABS and ASA are the engineering filaments most hobbyists already know. They need an enclosure and a hot bed, and they handle heat far better than PLA. So why step up to PC? Two reasons: higher temperature resistance, and more rigidity combined with good creep resistance. Prusament's own examples are a fan shroud sitting next to a hotend, and a drive part that transmits the full torque of a production machine.

The trade-off is demand on your setup. Hotter nozzle and bed, almost no part cooling, an enclosure that goes from helpful to essential, and a separating agent on the bed. ASA also keeps one advantage PC doesn't claim: its reputation for UV resistance outdoors, which matters for a garden fixture or a car part. If your part lives outside without serious heat, ABS or ASA is still the smarter pick.

A simple rule: start with ABS or ASA whenever they are good enough. Move to PC only for parts that have actually failed in ABS, either by softening or by breaking. That way you take on the extra difficulty only when the gain is one your application will really use.

Who PC filament is for, and what printer it takes

Prusament is blunt: if you are new to 3D printing, stick with PLA. PC Blend is aimed at experienced printer owners who want a tough, durable material for prototypes and functional parts under thermal or mechanical stress. Polymaker lists functional prototypes, tooling and end-use parts for engineering applications. Same message from both: PC is a production material, not a learning material.

On hardware, the enclosure is criterion number one. A factory-enclosed printer that can push nozzle and bed to the required values is enough for PC Blend, by Prusament's requirements. For PolyMax PC, Polymaker steers you toward an actively heated chamber, which rules out most consumer machines and points you to the professional segment or to modifying what you own. Our guide to enclosed 3D printers lists what to check.

Before you commit, add up the whole kit: a capable printer, a dryer that reaches 75 °C, the right adhesive, and spools. The entry cost lands above a PLA setup, and our startup budget tool helps you place it between entry-level and mid-range. Finally, no datasheet replaces a trial on your own geometry. Print a small prototype and check it under real conditions before running a batch.

Sources and limits

• Polymaker — PolyMax PC
• Prusament — PC Blend

We organize manufacturer and community documentation; we have not measured these products ourselves. The manual for your exact model takes precedence over general guidance.