🔳 Poor Corner Definition
Causes, Solutions & Prevention in Thermoforming
Corners rounded instead of crisp. Common in deep-draw and multi-cavity tools.
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⚠️Root Causes by Category
⚙️ Process
- Sheet temperature too low at corners
- Vacuum rate too slow — sheet cools before corners
🔲 Mold / Tooling
- Vents not at corner locations
- Corner radii too small for vacuum-only
🧪 Sheet / Material
- Material too stiff at forming temperature
✅Solutions & Corrective Actions
Step 1
- Add dedicated vents at every corner (min 2 per corner)
Step 2
- Increase vacuum rate
Step 3
- Consider pressure-assist (2–5 bar) for crisp corners
Step 4
- Apply localized extra heating to corner areas
🛠️Step-by-Step Troubleshooting
1
Step 1
Add dedicated vents at every corner (min 2 per corner)
2
Step 2
Increase vacuum rate
3
Step 3
Consider pressure-assist (2–5 bar) for crisp corners
4
Step 4
Apply localized extra heating to corner areas
❓Frequently Asked Questions
What causes poor corner definition?
Sheet temperature too low at corners; Vacuum rate too slow — sheet cools before corners; Vents not at corner locations
How to fix poor corner definition?
Add dedicated vents at every corner (min 2 per corner)
How to prevent poor corner definition?
Prevention requires systematic process control: verify sheet temperature, maintain mold vents, ensure proper material drying, and document optimal parameters.
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