Components:

Pump Casing: Forms the outer shell of the melt pump, providing support and protection for internal components (e.g., gears, bearings) to ensure stable operation.

Drive Gear and Driven Gear: Core working components that transport melt through intermeshing, which alters the working volume. The drive gear is powered by a motor, while the driven gear rotates in sync with it. Their coordinated motion enables melt suction, conveyance, and pressurization.

Sliding Bearings: Support the gear shafts, reduce rotational friction, ensure smooth gear operation, and withstand both melt pressure and mechanical friction.

Front and Rear End Plates: Seal the pump body, working with the casing and gears to form enclosed feeding, conveying, and discharge zones, ensuring melt transport within a sealed space.

Transmission Shaft: A critical component that connects the melt pump to an external power source (e.g., a motor). It transmits rotational power to the drive gear inside the pump, driving the intermeshing motion between the drive gear and the driven gear for synchronized operation.

Working Principle:

First, the extruder heats and melts plastic raw materials into a viscous flow state for preliminary plasticization. The melt then enters the melt pump, where a pair of precision-intermeshing gears rotates at high speed. At the inlet side, a negative pressure is created to draw in the melt, while at the outlet side, the gears compress the melt to achieve pressurization (up to 10-40 MPa), simultaneously eliminating instability caused by extruder screw speed fluctuations. Pressure sensors monitor inlet and outlet pressures in real time, dynamically adjusting pump speed or extruder parameters via a closed-loop control system to maintain stable pressure and flow. The pressurized melt flows through a connector into the screen changer, where multi-layer high-precision filter screens remove impurities (e.g., carbonized particles or unmelted residues). If a screen becomes clogged, the system automatically switches to backup screens to ensure uninterrupted production. The purified melt then enters the die, where it is uniformly extruded through specifically designed flow channels (e.g., circular pelletizing holes or flat film slits) and shaped into products. After cooling and solidification, the melt is cut into pellets, sheets, or other final forms. By integrating the melt pump’s pressure stabilization, pressurization capabilities, and the screen changer’s efficient filtration, this system significantly improves product dimensional consistency, purity, and production efficiency. It is widely applied in recycled plastic pelletizing, high-precision films, tubing, medical devices, and other fields requiring precise control of flow and pressure.