Sheet & material defect
Brittleness & cracking in thermoforming
Brittleness is when a part fails by cracking or shattering rather than deforming — often from an over-thinned wall, a stress concentration, the wrong grade, or degraded (wet or over-recycled) material.
Why it happens
- Walls over-thinned in deep draws
- Sharp internal corners concentrating stress
- Wrong grade for the impact/temperature duty
- Moisture or excessive regrind degrading the sheet
How to fix & prevent it
- Keep walls uniform; increase gauge where needed
- Add radii to remove stress risers
- Choose an impact-modified or tougher grade
- Pre-dry material; control regrind quality
How Indu prevents it: We match the grade to the part’s impact and temperature duty (including impact-modified and low-temperature grades), keep walls uniform, and control moisture and regrind in our own extrusion.
Troubleshooting help
Fighting brittleness & cracking 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