◆ Common Causes
- •Uneven cooling
- •Non-uniform mold temperature
- •Uneven hold pressure (multi-cavity)
- •Differential fiber orientation (GF reinforced)
- •Non-uniform wall thickness
◆ Solutions
- ✓Improve mold cooling circuit
- ✓Equalize mold temperature
- ✓Optimize hold pressure
- ✓Use cooling fixtures
- ✓Change gate location
◆ Resin-Specific Notes
GF Reinforced
Anisotropic shrinkage from fiber orientation → severe warpage. Review at design stage.
PP
High shrinkage. Uniform cooling is critical.
PA
Consider dimensional changes from moisture absorption.
POM
High shrinkage. Sufficient hold pressure and cooling required.
◆ Resins Prone to This Defect
This content is a field-reference summary. Final judgment requires on-site engineer verification.