Thermoplastic polyurethane or similar thermoplastic Elastomers, aka TPE, are the only two truly flexible 3D printing filaments. Both of them have straightforward properties and require similar printing conditions to be used. The most common one is definitely TPU – but there are other types as well.
Be careful when buying these filaments, as there are some pretty huge differences between brands and types, specifically regarding the degree of flexibility. While some have similar flexibility as car tires or strong rubber, others can be as ‘fully’ elastic as a rubber band or bungee cord.
- Bed Temperature: 45-60 °C
- Heated bed optional
- Build Surface: PEI, Painter’s Tape
- Extruder: Temperature 225-245 °C
- Cooling: Fan required
Best Practices and Tips
When printing with elastic filament, it’s always best to use a Direct Drive extruder. Bowden extruders may be able to work with some semi-flexible filaments but not with fully flexible ones. Look for a printer where the hot end’s drive gear and melt zone are as close together as possible. As the filament is prone to coiling, it’s best to use slower feed rates. Changes in print speed can have disastrous effects if they happen too suddenly.
Speed changes can result in jams, and a good base rate to use is about 20mm per second. Trial and error are the way to go here – be sure also to pay attention to the resistance of your filament spool. If it’s too high, instead of smoothly pulling in the filament, it’ll stretch it out, leading to under-extrusion and a messy result.
You can even try mounting the spool on some wheel or bearing to let it spin freely. Printing in lower layer heights can also help – lower layer heights mean less material required, which means less stress on the filament spool.
Another thing that can affect the print quality is excessive retraction motions. Due to the soft and elastic nature of TPU and TPE filaments, it’s important to avoid retraction as much as possible, even at the risk of some oozing without it. Excessive retraction can warp or stain the print and affect lower layers.
- Available in different elasticities
- Impact resistance and vibration dampening
- Very challenging to print
- Prone to stringing, oozing and blobbing
- Only partly compatible with Bowden extruders
After reading this you should be set to start using TPU and TPE filaments in your prints. Do you have a specific project you want to use these materials for? Let us know down below.