⛔ Sheet Rupture
Causes, Solutions & Prevention in Thermoforming
Sheet tears at mold contact or during clamping. Production stopper.
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⚠️Root Causes by Category
⚙️ Process
- Sheet overheated — low melt strength
- Sheet too cold — brittle
- Clamp pressure too high
🔲 Mold / Tooling
- Sharp edges without chamfer/radius
🧪 Sheet / Material
- Degraded material — excessive regrind/UV
📐 Design
- Insufficient material for draw depth
✅Solutions & Corrective Actions
Step 1
- Optimize temperature in forming window
Step 2
- Add chamfers (min 0.5mm) to mold edges
Step 3
- Reduce clamping pressure; spring-loaded frame
Step 4
- Verify regrind <25%
🛠️Step-by-Step Troubleshooting
1
Step 1
Optimize temperature in forming window
2
Step 2
Add chamfers (min 0.5mm) to mold edges
3
Step 3
Reduce clamping pressure; spring-loaded frame
4
Step 4
Verify regrind <25%
❓Frequently Asked Questions
What causes sheet rupture?
Sheet overheated — low melt strength; Sheet too cold — brittle; Clamp pressure too high
How to fix sheet rupture?
Optimize temperature in forming window
How to prevent sheet rupture?
Prevention requires systematic process control: verify sheet temperature, maintain mold vents, ensure proper material drying, and document optimal parameters.
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