TPU layer adhesion problems usually come from low temperature, high speed, low flow, excessive retraction or moisture. Flexible filament needs a stable bead and enough thermal energy to fuse layers without collapsing details.
Check the bead
- Consistent width
- No gaps between lines
- Stable pressure
- No bubbles
Adjust the thermal window
Increase temperature in small steps until layers fuse, then check stringing and detail. Reduce the outer-wall speed before increasing temperature excessively.
Control flow and retraction
- Flow calibration
- Wider line
- Minimal retraction
- Short feed path
Validate the real geometry
Test thin walls, thick sections and repeated flex. A small cube can pass while real parts still delaminate. Record the failure location and direction.
| Cause | Symptom | Control | Action |
|---|---|---|---|
| Low temperature | Weak layers | Temperature tower | Raise 5 °C |
| High speed | Thin bead | Outer-wall speed | Slow down |
| Low flow | Gaps | Wall thickness | Calibrate |
| High retraction | Voids | Retraction test | Reduce |
| Moisture | Bubbles | Weight and drying | Dry TPU |
Common engineering mistakes
- Using rigid-material settings.
- Increasing retraction.
- Ignoring drying.
- Testing only a cube.
- Changing several parameters at once.
Checklist
- Is the TPU dry?
- Is the path short?
- Is temperature sufficient?
- Is flow calibrated?
- Was the real part tested?
Request TPU layer-adhesion support through the quote form.