Learn About PLA (polylactic acid)
Overview
PLA is the most common FFF 3D printing material; it is easy to print, rigid, and does not warp easily. However, it lacks the temperature resistance and strength that many other materials offer. It is an excellent choice for prototypes, concept models, and low-wear toys. PLA is compatible with all Tool Cartridges for the Nautilus 3D printer.
Applications
As previously mentioned, PLA is best used for prototypes and items that will not undergo high temperatures. For example, WingWarp, a San Francisco based software startup, used PLA to print prototypes to be able to test different angles, spacing, and a number of phones for their tripod mount to develop hardware that customers could easily use to engage with their platform. For more information on WingWarp, you can read the full case study here.
Another example is how Mazama Wares used PLA to prototype new homewares designs. Once they finalized a design, a high detail model would also be printed in PLA as a form to create the final mold for slip casting the cups from ceramic. You can learn more about this here.
At Hydra’s own facility we use PLA for some manufacturing aids that do not undergo high stress, such as the magnet orientation check pictured below.
Lets’s Dive A Little Deeper
PLA is easy to print, quite strong, and biodegradable. It is a good choice for large parts due to its low thermal expansion properties, meaning large parts are less likely to warp. Tiny parts also work well with PLA thanks to its low melting temperature.
PLA is a very hard material, which makes parts quite brittle. When PLA parts break they tend to shatter. PLA will also become very brittle if left in the PTFE feeder tubes commonly used on 3D printers including the Nautilus. For this reason, it is strongly recommended to completely unload PLA material from the printer as soon as the print is finished so that the material does not become brittle and break inside the feeder tube next time you go to load/unload or start a print.
PLA is not suitable for all use cases, its low melting temperature means a relatively low-temperature resistance resulting in parts beginning to lose mechanical strength around 60°C (140°F). This, in combination with it being biodegradable, makes PLA not an ideal choice for use outdoors.
PLA is not suited for chemical welding, it is best to use glue when connecting PLA parts.
Despite PLA itself being food safe, we do NOT recommend repeatedly drinking or eating from PLA parts. Bacteria can build up in the small creases between layers. This applies to all FFF 3D printed parts unless post-processed with a food-safe coating.
PLA can be sanded for post-processing; due to the low melting temperature it will get soft rather quickly from the friction so you will have to sand slowly or use wet sanding.
For drying PLA in an oven, preheat the oven to 40-45°C (~100-110°F) before placing your spool inside for 4-6 hours. If your oven does not go that low, you can try to preheat it to the lowest temperature, shut the oven off, and then place the spool inside. Check the temperature inside with a thermometer so you don’t melt your filament!