PLA (polylactic acid) is the most common thermoplastic filament in FDM 3D printing: easy to print, cheap and derived from plant resources, but poorly resistant to heat and rather brittle.
In the project
PLA is the default choice for the non-critical printed parts of the running example, such as brackets, housings and jigs: it prints without difficulty and allows fast iteration. Its limits are what steer the trade-offs. It creeps from around 60 °C, so it is best kept away from a motor that heats up or from direct sunlight, and it snaps cleanly under impact. For a part that is loaded or exposed, a PETG, an ABS or a machined part is preferable. This is a textbook criterion for a materials decision matrix, part by part.
The detailed comparison of polymers, covering mechanical and thermal strength, recyclability and environmental footprint, belongs to the materials course. The wiki confines itself to placing PLA as the default prototyping choice and to its limits of use.
See also
- 3D printing — the process that puts PLA to work
- Eco-design — material choice and end of life
- Decision matrix — arbitrating the material and part pairing
- Materials course (colleagues) — comparison of polymers