TPU (Thermoplastic Polyurethane) and Flex filaments are flexible and elastic polymers that allow printing objects that bend, compress, and return to their original shape. They are essential for covers, gaskets, protective cases, knobs, shock absorbers, and parts subject to elastic deformation. On Strato3D, you will find over 25 TPU filaments with Shore A hardness ranging from 70 (very soft) to 95 (semi-rigid) and Shore D 60-70 (rigid-flexible).
When to use TPU/Flex
- Covers for smartphones, tablets, electronic devices: impact protection.
- Gaskets and o-rings: fluid sealing, vibration dampening.
- Custom soles, midsoles, insoles: orthopedic or sports footwear.
- Knobs, grips, bumpers: comfortable grip on tools.
- Tires and wheels for RC/toys: grip and cushioning.
- Automotive parts: rubber grommets, flexible ducts, parts subject to vibrations.
Technical characteristics
- Nozzle temperature: 220-240 °C.
- Bed temperature: 40-60 °C.
- Shore A hardness: 70 (soft rubber) to 95 (hard rubber). Shore D 60-70 (semi-rigid).
- Elongation at break: 300-700%.
- Thermal resistance: -30 °C to +80 °C continuous.
- Print speed: 20-40 mm/s recommended (250 mm/s for TPU HS).
- Direct extruder: strongly recommended (Bowden systems struggle with soft materials).
Brands you find on Strato3D
TPU by Bambu Lab (TPU 95A), Polymaker PolyFlex TPU 95A, Snapmaker High Flow TPU 95A Black, Siraya Tech TPU 95A, BASF Forward AM Ultrafuse TPU 64D and TPU 85A.
Frequently Asked Questions
Can I print TPU with any printer? Yes, but a direct drive extruder is strongly recommended. With Bowden, soft materials below Shore A 90 "swell" in the tube and cause clogging.
Shore A 95 or Shore A 85? 95A is semi-rigid, with a behavior similar to hard rubber. 85A is clearly flexible like a gasket. For smartphone covers, typically 95A; for o-rings, 75-85A.
Can I print it at 250 mm/s? Only with high-speed formulated TPUs (e.g., Snapmaker High Flow). Standard ones above 60 mm/s create under-extrusion.
Is it oil resistant? Yes, TPU has good resistance to mineral oils and hydrocarbons. For synthetic oils, check the technical data sheet.