The following is a detailed introduction of common plastic injection molding processes such as PP, PE, PS, PA and other different materials:
Polypropylene (PP)
Barrel temperature Feeding zone 30～50℃ (50℃)
Zone 1 160～250℃ (200℃)
Nozzle 220～300℃（240℃）
The temperature in brackets is recommended as the basic setting value, the stroke utilization rate is 35% and 65%, and the ratio of mold flow length to wall thickness is 50:1 to 100:1
Melt temperature: 220～280℃
Barrel constant temperature: 220℃
Mold temperature: 20～70℃
Injection pressure:
Except for some thin-walled packaging containers Can reach 180MPa (1800bar)
Pressure holding pressure: To avoid shrinkage of the product, it takes a long time to hold the product under pressure (about 30% of the cycle time); about 30% to 60% of the injection pressure
Back pressure: 5 to 20MPa (50 to 200bar)
Injection speed: High injection speed (with accumulator) is required for thin-walled packaging containers; medium injection speed is often more suitable for other types of plastic products
Screw speed: High screw speed (linear speed of 1.3m/s) is allowed, as long as the plasticization process is completed before the end of the cooling time
Metering stroke: 0.5 to 4D (minimum to maximum); 4D metering stroke is important to provide a sufficiently long residence time for the melt
Residual material: 2 to 8mm, depending on the metering stroke and screw speed
Pre-drying: Not required; if the storage conditions are not good, drying at 80℃ for 1h is sufficient
Recovery rate: 100% recovery can be achieved
Shrinkage rate:
Gating system:
Machine downtime:
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