← Defect Guide
Weld Line
A line or seam that forms where two melt fronts meet. Can reduce structural strength.
◆ Common Causes
- •Melt temperature too low
- •Mold temperature too low
- •Injection speed too low
- •Gate position problem
- •Excess mold release agent
◆ Solutions
- ✓Raise melt temperature
- ✓Raise mold temperature
- ✓Increase injection speed
- ✓Change gate location or add gates
- ✓Check and clean vents
◆ Resin-Specific Notes
GF Reinforced
GF reinforcement drastically reduces weld line strength. Review gate placement at design stage.
PA66
Narrow processing window. Maintaining sufficient temperature is critical.
PC
High viscosity. Adequate temperature is essential.
◆ Resins Prone to This Defect
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This content is a field-reference summary. Final judgment requires on-site engineer verification.