Cooling & trim defect
Shrinkage & dimensional drift in thermoforming
Also called: Out-of-tolerance parts
All thermoformed parts shrink as they cool; problems arise when shrinkage is larger than allowed for or varies between parts, pushing features out of tolerance and out of fit with the assembly.
Why it happens
- Tool not sized for the material’s shrink rate
- Inconsistent cooling or cycle time
- Material or gauge variation between lots
- Releasing parts before dimensions stabilise
How to fix & prevent it
- Size tooling for the grade’s known shrinkage
- Hold consistent, controlled cooling and cycle
- Use consistent, in-spec sheet lot to lot
- Let parts stabilise, then trim to datums
How Indu prevents it: We compensate tooling for each grade’s shrinkage and hold controlled cooling; parts are made to ISO 2768 with tighter tolerances on critical, CNC-trimmed datum features — and in-house sheet keeps material consistent.
Troubleshooting help
Fighting shrinkage & dimensional drift 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