Injection Molding
2 views
COC Flash
Problem Phenomenon
COC products have thin sheet flash at parting line and ejector pins, transparent parts flash affects optical appearance, residual marks obvious after trimming.
Cause Analysis
When injection pressure is too high or clamping force insufficient, melt squeezes into the parting line gap; COC injection specific pressure can reach 500~1100bar, high clamping requirement; mold wear gap expansion aggravates flash.
Solution
①Calculate clamping force to match high-pressure injection; ②parting line lapping to restore fit; ③optimize injection pressure curve, reduce speed and pressure at filling end; ④check hot runner valve pin sealing state.
Key Takeaway
COC high-pressure injection process has high requirements on clamping and mold precision; flash treatment first checks hardware gap then adjusts process; transparent part flash should take mold repair as the ultimate solution.
Was this helpful?
0 people found this helpful
Thank you for your feedback!