material-knowledge

TPU vs Rigid Filaments: When Flexibility Matters

TPU bends, absorbs shock and seals — things rigid filaments can't do. Learn when flexibility is the right choice.

5 min read

TPU (Thermoplastic Polyurethane) is a flexible filament that bends, compresses and absorbs impact — properties that rigid filaments like PLA and PETG cannot offer. Choose TPU when your part needs to flex, seal, or absorb energy.

Flexibility Comparison

PropertyPLAPETGTPU 95A
FlexibilityRigidSlightly flexibleVery flexible
Shore hardnessRigidRigid95A
Impact absorptionLow (cracks)Medium (dents)High (bounces)
Elongation at break5-20%50-100%300-500%

When to Choose TPU

  • Phone cases and protective covers
  • Gaskets, seals and O-rings
  • Vibration dampeners
  • Flexible couplings and drive belts
  • Wheels and rollers

When NOT to Choose TPU

  • Structural parts (it flexes under load)
  • Precision parts (dimensional accuracy is lower)
  • Parts requiring snap-fit (it deforms instead of snapping)
  • High-temperature applications (deforms above 80°C)

Printing TPU

TPU requires slower speeds and direct-drive extruders:

  • Print speed: 20-30mm/s
  • Nozzle: 210-230°C
  • Bed: 30-50°C
  • Retraction: Minimal (0.5-1mm) — too much causes jams in Bowden systems
  • Cooling fan: 50-70%

Storage

TPU absorbs moisture faster than PLA. Store in sealed bags with desiccant and dry at 50-60°C for 4-6 hours before printing.

Individual results depend on your printer, environment and application.