Bottom line: flexible filaments are not interchangeable. TPU and TPE differ in hardness range, rebound, chemical resistance and printability, and even within TPU the 65A–95A range behaves very differently. Choose by required deflection, load and environment, then confirm the feed path supports the chosen hardness.
Key differences
| Property | TPU | TPE / TPA |
|---|---|---|
| Hardness range | wide, commonly 65A–95A | often softer |
| Rebound | high | varies |
| Abrasion resistance | good | moderate |
| Chemical resistance | good | material dependent |
| Printability | demanding | often more difficult |
| Typical use | functional flexible parts | soft touch, damping |
Selection order
- Define the required deflection.
- Define load, duration and temperature.
- Choose a hardness range.
- Check feed path and retraction.
- Validate with a real part.
Costly mistakes
- Treating all flexible filaments as equivalent.
- Choosing by hardness only.
- Using a Bowden path for soft grades.
- Skipping drying.
- Testing on a small part only.
Buyer / engineer checklist
- What deflection is needed?
- What load and temperature apply?
- Does the extruder support the grade?
- Is the filament dry?
- Has the part been validated?
Describe the part and its movement and we can narrow the flexible material options.Material advice