Forming defect
Vacuum leaks in thermoforming
Also called: Weak vacuum, poor draw-down
A vacuum leak means the system cannot pull the sheet tightly onto the tool, so parts form incompletely — soft detail, bridging and inconsistent draw-down from shot to shot.
Why it happens
- Worn seals, gaskets or a poor sheet clamp
- Blocked or too-few vacuum holes
- Cracks or porosity in the mould
- Undersized vacuum reservoir/pump for the part
How to fix & prevent it
- Service seals and ensure a tight sheet clamp
- Clear and add vacuum holes where draw-down is weak
- Repair mould porosity/cracks
- Match vacuum capacity to part volume
How Indu prevents it: Vacuum channels and hole patterns are engineered into our tools and maintained in-house, so draw-down is strong and repeatable across long production runs.
Troubleshooting help
Fighting vacuum leaks on a part?
Send your drawing, sample or a photo of the issue — our engineers will diagnose the cause and reply with the tooling, material and process fix, usually within 24 hours.
ISO 9001:2015 certified · Most quotes back within 24 hours