Filaments for functional parts

A functional part is one that has to withstand something: a bracket, an enclosure, a machine component, a support under load. Appearance stops mattering here, and what starts to matter is layer bonding, impact resistance and the temperature at which the part loses its stiffness.

The simplest choice is PETG: layer bonding rated very good by the manufacturer, high impact resistance, a declared 85 °C and printing on an open printer. Tough PLA gives very good layer bonding and high impact resistance with the printing comfort of ordinary PLA, but it stops at 60 °C.

Above that come the materials that need an enclosed chamber: ABS (100 °C, a strong smell and a high warping tendency), ASA (110 °C), HT PETG (125 °C, nozzle 270–300 °C and bed 100–120 °C) and PA (150 °C, though drying for 8–12 h at 65–80 °C is mandatory). PLA/CF is a different trade-off: stiffness and a matt, technical finish, but resistance of only 70 °C and a hardened nozzle is required.

The rule when choosing: take the lowest temperature resistance that will do the job. Every degree above that is paid for in printing difficulty.

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