TPU

TPU filaments for 3D printing

TPU (thermoplastic polyurethane) is one of the most popular flexible filaments for 3D printing, offering an excellent balance between elasticity, strength, and wear resistance. Thanks to its unique properties, TPU finds wide application in both hobby projects and industrial production, the automotive sector, medicine, and consumer products.

In this article, we will examine the advantages, disadvantages, and differences between the various types of TPU, as well as the best practices for 3D printing with this material.

What is TPU and why choose it for 3D printing?

TPU is a type of thermoplastic elastomer (TPE) that combines the flexibility of rubber with the durability of plastic. This makes it ideal for parts that need to bend, stretch, and compress without breaking.

Main advantages of TPU:

✔ Flexibility and stretchability – The parts can bend and stretch without losing their shape.
✔ Durability – TPU is resistant to impact, wear, and deformation.
✔ Good grip on surfaces – Suitable for rubber handles, protectors, and shock absorbers.
✔ Chemical and UV resistance – TPU is resistant to oils, greases, and most chemicals.

Main disadvantages of TPU:

❌ Slower print – Compared to rigid materials like PLA and ABS, TPU requires a lower speed for precise detail.
❌ Special requirements for the printer – The best results are achieved with a direct extruder, as Bowden systems can create issues when feeding the soft filament.
❌ Difficult setup – Printing with TPU may require more experimentation and final adjustments, especially with different brands and hardnesses.

Differences between types of TPU

'TPU filaments differ in hardness (Shore A), elasticity, and printing speed.'

Shore A hardness and flexibility

• TPU 85A-90A – The softest and most flexible TPU used for shoe soles, prosthetics, wearable accessories. Require slower printing and direct extruder.
• TPU 95A – The most versatile option, suitable for protective cases, automotive seals, handles, and grips. Easier to print, can also be used on Bowden printers (at low speed).
• TPU 98A-100A – Harder TPU with limited flexibility, but with easier printing and higher extrusion speed. Often used for industrial applications and machine parts.

Standard TPU vs. TPU for High-Speed Printing

Some manufacturers offer high flow (HF – High Flow) TPU, which are designed for faster printing (50-100 mm/s), without compromising on quality. They are particularly useful for mass production of flexible parts.

What can you print with TPU?

✅ Rubber protectors and cases – TPU provides shock-absorbing properties, making it ideal for cases for phones, laptops, and cameras.
✅ Seals and gaskets – Thanks to its elasticity and oil resistance, TPU is used in the automotive industry and machine engineering.
✅ Handles and grips – The material has good grip with the hand, making it ideal for sports equipment, tools, and bicycle handles.
✅ Shock absorbers and vibration isolators – TPU is pressure resistant and is often used for rubber feet, shock absorbers, and springs.
✅ Tires for RC cars and drones – Thanks to good adhesion and wear resistance, TPU is used for tires, wheels, and other moving parts.

Best settings for 3D printing with TPU

✅ Nozzle temperature: 210-230°C
✅ Bed temperature: 30-60°C
✅ Print speed:

• Soft TPU (85A-90A) – 20-40 mm/s
• Medium hard TPU (95A) – 30-60 mm/s
• Hard TPU (98A+) – 50-100 mm/s
  ✅ Retraction: Minimum (1-3 mm for direct extruder, 4-6 mm for Bowden)
  ✅ Cooling: Enabled at 50-100% after the first layers
  ✅ Print surface: PEI, glass, adhesive or textured film

Important: TPU is hygroscopic, which means that it absorbs moisture. It is recommended to store it in sealed boxes with a moisture absorber and to dry it if necessary before printing.