Temperature & Pressure Control Techniques in Injection Molding Process

Temperature Settings
Barrel Temperature: Set according to the type of plastic, usually taking the middle value of the supplier's recommended range.

Nozzle Temperature: Slightly lower than the maximum barrel temperature to prevent drooling or clogging.

Mold Temperature: Adjust according to the plastic's crystallinity and the product structure, affecting appearance and internal stress.

Pressure Control
Plasticizing Pressure (Back Pressure): Generally ≤20 kg/cm² (about 2 MPa); too high will reduce plasticizing speed but improve melt uniformity.

Injection Pressure: Set based on overcoming flow resistance, usually 50%–100% of the injection machine's maximum capacity.

Holding Pressure Time: Typically 20–120 seconds, must be completed before the gate freezes to control shrinkage.