The synergistic application of melt pumps and screen changers in plastic pelletizing production lines achieves closed-loop control through purification, pressurization, stabilization, and metering, significantly enhancing the process stability and economic efficiency of high-output, high-precision recycling pelletizing.
Screen Changer: Impurity Filtration and Continuous Production Assurance
Dual-Column Dual-Station Design: Driven by a hydraulic system, two screens alternate operation (e.g., Anji dual-column large-area screen changer) to enable screen changes without shutdown. For example, in PET recycling granulation, during screen replacement, one screen operates while the other is replaced, ensuring uninterrupted material flow with pressure fluctuations ≤0.5 MPa, and maintaining product transparency ≥90%.
Backflush Function: Some models (e.g., backflush filters) use reverse high-pressure water flow to clean the filter screens, extending their lifespan to six times that of standard models. This is suitable for high-impurity raw materials (e.g., recycled materials from aluminum foil-lined beverage bottles).
Exhaust System: During screen changes, it removes gases trapped in the melt (e.g., bubbles formed by moisture evaporation in PE pelletizing), reducing surface defects in the final product.
Melt pump: Pressure stabilization, metering, and process optimization
Pressure stability: Through precise gear meshing (e.g., three-gear pumps offer better pressure stability than two-gear pumps), the pressure fluctuation at the extruder outlet is controlled within ±0.2 MPa, ensuring the melt enters the pelletizer in a stable state, with particle size uniformity (CV value) ≤3%.
Precise Flow Control: The rotational speed is linearly proportional to the flow rate (e.g., a 600CC melt pump at 100 rpm achieves a flow rate of 60 L/h), facilitating synchronization with underwater pelletizers to reduce scrap rates.
Reduced energy consumption: By transferring the extruder's pressure-building function to the melt pump, the screw can operate at high speeds while reducing melt residence time, lowering energy consumption per kilogram of material processed by 25% (e.g., energy consumption in a PP recycling pelletizing line decreases from 0.35 kWh/kg to 0.26 kWh/kg).
Improved product quality
Dimension accuracy: The melt pump reduces the dimensional tolerance of extruded products to within ±0.05mm, meeting the high-precision requirements of medical catheters, optical films, and other applications.
Purity: The screen changer's filtration precision can reach 20μm (e.g., metal sintered filter cores combined with multi-layer filter screens), ensuring PET granule impurity content ≤50ppm, meeting food-grade standards.
Improved Production Efficiency
Continuous Production: Dual-column screen changers enable 72-hour continuous operation (e.g., PE/PP recycling lines), achieving a 300% efficiency improvement over traditional manual screen changers.
Production Capacity Adjustment: The modular design of melt pumps supports flexible adjustment of production capacity from 30 to 300 kg/h (e.g., three-gear pumps offer superior pressure stability, suitable for KN95 melt-blown fabric production).
Reduced operating costs
Extended filter screen lifespan: Backflush technology reduces filter screen replacement frequency from once per shift to once every two days (e.g., the Anji 10000-type screen changer has a single-unit filtration area of 1 m²).
High-Output PET Recycling Pelletization
Configuration: Dual-column large-area screen changer (filter area 10,000 cm²) + 600 CC melt pump + dual-column combination.
Results: Output 1.0–2.0 tons/hour, particle impurity content ≤50 ppm, light transmittance ≥90%, meeting bottle flake-grade recycled material standards.
High-precision PP/HDPE recycling
Configuration: Single-plate dual-station hydraulic screen changer (screen diameter 600 mm) + melt pump pressure-boosted dual-column precision filtration system.
Performance: Production capacity of 3,000 kg/hour, particle size tolerance of ±0.03 mm, suitable for automotive modified plastic raw materials. Melt-blown fabric dedicated line
The synergistic application of the melt pump and screen changer, through “front-end purification - mid-end pressure stabilization - end-end metering” full-process control, achieves efficient, stable, and low-cost operation of the plastic pellet production line.
Email: sale@meltpump.com
WhatsApp: +86 158 3833 1071
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WhatsApp： +86 158 38331071
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