Fibre-reinforced filaments

Carbon-fibre-filled filaments are bought for stiffness and dimensional stability, not for bending strength. The fibre stiffens the material and sharply reduces its flexibility — the manufacturer rates the flexibility of PLA/CF as very low — gives a matt, technical finish and lowers the warping tendency.

The warning that drives the cost: carbon fibre is highly abrasive. The manufacturer classes nozzle abrasiveness for CF materials as very high — the top grade in the entire table. A standard brass nozzle will wear out very quickly. A hardened nozzle is required: hardened steel, tungsten carbide or a ruby insert. The minimum size is 0.4 mm; do not print with anything finer.

The second trade-off is detail. For PLA/CF the manufacturer quotes detail printing from 0.4 mm, whereas ordinary PLA goes down to 0.2 mm. The declared temperature resistance of PLA/CF is 70 °C, only 10 °C more than PLA. If you need stiffness and heat resistance at the same time, look at ASA or HT PETG.

PLA/CF parameters: nozzle 220–250 °C, bed 50–70 °C, cooling 60–100%, drying 4 h at 55 °C.

The data comes from Porima's official FDM technical data table. Full listing of 25 materials: print parameters.