How can sink marks be avoided on moldings?

Possible cause:

• Insufficient pressure / dwell pressure to compensate for shrinkage

Remedies:

• Check material feed
• Increase mold temperature
• Reduce melt temperature
• Raise holding pressure
• Prolong hold time
• Extend injection time
• Increase injection pressure
• Reduce injection speed
• Lower screw speed - Enlarge gates and runners

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