TPU (flexible)
TPU filament — how to print flexible parts
TPU (thermoplastic polyurethane) is a flexible, abrasion-resistant filament. It is used for flexible parts where rigid plastics would crack.
Key properties
- Shore hardness typically 85A–95A (soft to flexible).
- Typical printing temperature 210–240 °C, bed 30–60 °C.
- High elongation and recovery after impact.
- Resistance to abrasion, oils and some chemicals.
- Soft filament: slow printing and direct drive are recommended.
Use cases
- Phone cases, holders and cushion parts
- Shoe soles and flexible gaskets
- Vibration-damping spacers
- Flexible grips and bumpers
Advantages
- Flexible, absorbs impact and returns to shape
- Resistant to abrasion
- High surface quality in fine detail
Limitations
- Prints slowly; extruding soft filament is difficult
- Absorbs moisture; drying is required
- Hard to support on thin walls and bridges
Frequently asked questions
Can TPU be printed on a Bowden printer?
It is possible but difficult; a direct-drive extruder feeds soft filament more reliably.
Why does TPU clog?
Moisture, incorrect temperature or excessive retraction cause clogging. The filament should be dried and printed at low speed.
How soft is TPU?
Flexibility is expressed in Shore hardness; 85A is very soft, while 95A is firmer and more durable.