Melt Pump Application in Plastic Extrusion line

Core Functions of Melt Pumps

Melt pumps are positive displacement gear pumps installed between the extruder and die head in plastic bag production lines. Their primary roles include:

Pressure Stabilization: Eliminate pressure fluctuations caused by extruder screw pulsation, ensuring consistent melt pressure (±1% tolerance) for uniform film thickness.

Flow Control: Precisely meter melt volume (accuracy ±0.5%), enabling stable output even with raw material variations.

Energy Efficiency: Reduce extruder motor load by 20-30% by maintaining backpressure, lowering energy consumption per kilogram of plastic processed.

Key Advantages in Plastic Bag Extrusion

Enhanced Product Quality

Thickness Uniformity: Minimize film thickness deviation, reducing waste in downstream processes like printing and sealing.

Surface Finish: Improve melt homogeneity to eliminate gel particles or flow marks, critical for transparent LDPE bags.

Process Optimization

Speed Flexibility: Enable stable operation at higher line speeds (up to 300 m/min for blown film lines) without sacrificing quality.

Material Compatibility: Handle a wide range of resins (LDPE, HDPE, LLDPE, PP) and recycled materials with consistent performance.

Cost Savings

Reduced Scrap Rate: Lower defective product rates by 40-60%, directly cutting material costs.

Extended Equipment Life: Protect die heads from pressure spikes, extending their service life by 2-3 times.

Melt pumps are indispensable for high-volume plastic bag production, offering a balance of quality, efficiency, and cost control that justifies their initial investment.