Injection Molding
2 visualizações
PE '2079851475616104452 Flash
Fenómeno do problema
Thin sheet-like flash appears at the parting line, ejector pins and sliders, more obvious with low-viscosity materials such as LDPE/LLDPE, requiring manual trimming.
Análise das causas
PE (especially low-density grades) has low melt viscosity and good flowability, and easily penetrates into the parting line and the fitting gaps of moving parts during high-pressure filling; excessive injection/holding pressure, insufficient clamping force, parting line wear or large fitting gaps all induce it.
Solução
①Gradually reduce the injection and holding pressure by 5%~10%; ②calculate whether the clamping force meets the projected area requirements; ③appropriately reduce the material temperature to increase the viscosity; ④repair the parting line and the fitting gaps of ejector pins/sliders; ⑤for multi-cavity molds, troubleshoot individual cavity overfilling caused by filling imbalance.
Conclusão principal
For PE flash, first 'reduce pressure and temperature', then 'close gaps and increase clamping': low-viscosity materials are extremely sensitive to pressure; only by restraining the pressure in the process and narrowing the fitting gaps in the mold can flash be cured.
Isto foi útil?
0 pessoas acharam isto útil
Obrigado pelo seu comentário!