The gate is the entry point where molten plastic enters the mold cavity. Gate design significantly affects part appearance, mechanical properties, dimensional stability, and cycle time.
Located on the parting line, typically on a side or edge of the part. Simple, low-cost, easy to modify. Gate size: 0.8-3.0mm depth, 1.5-6.0mm width. Best for flat parts and where gate can be easily trimmed.
Small round gate (0.5-2.0mm diameter) feeding directly into the cavity. Self-degating possible for three-plate molds. Best for symmetrical parts and where automatic degating is desired.
Gate located below the parting line, feeding up into the cavity. Ejection automatically shears the gate. Ideal for automatic operation. Gate diameter: 0.5-2.0mm.
Wide, thin gate that spreads material across the cavity. Reduces flow orientation and internal stress. Best for large flat parts and optical parts where flow marks must be minimized.
Hydraulically or pneumatically actuated gate that opens during injection and closes before ejection. Provides the cleanest part with no gate vestige. Used in hot runner systems for cosmetic and appearance parts.