◆ Common Causes
- •Excessive residual stress (over-packing)
- •Ejection issues (ejector pin force)
- •Mold temperature too low
- •Environmental stress cracking (chemical contact)
- •Excessive injection speed
◆ Solutions
- ✓Reduce hold pressure
- ✓Improve ejector design; apply release agent
- ✓Raise mold temperature
- ✓Allow sufficient cooling time
- ✓Stress-relief annealing
◆ Resin-Specific Notes
PC
Susceptible to environmental stress cracking. Choose release agents carefully.
PMMA
Brittle material. Watch for residual stress.
PA
Directional cracking due to glass fiber orientation.
This content is a field-reference summary. Final judgment requires on-site engineer verification.