Injection Molding
4 views
PP Injection Part Sink Mark—Freeze-off Type
Problem Phenomenon
Although the gate is small and holding time is already long, thick walls still have sink marks.
Cause Analysis
The small gate freezes off early, and holding pressure cannot continue to transmit to thick-wall areas; no matter how long the holding time, it is ineffective.
Solution
①Enlarge the gate to delay freeze-off; ②place the gate near thick-wall areas; ③reduce material at thick walls; ④auxiliary gates if necessary.
Key Takeaway
Holding after freeze-off = ineffective feeding—the gate is the key.
Was this helpful?
0 people found this helpful
Thank you for your feedback!