In EPP (Expanded Polypropylene) pelletizing production lines, the melt pump and screen changer form a critical equipment combination. Their synergistic operation significantly enhances production efficiency, product quality, and process stability.
Process Flow Optimization
Sequential Configuration: Extruder → Melt Pump → Screen Changer → Die Head → Pelletizer.
The melt pump delivers stable melt flow to the screen changer, maintaining balanced pressure before and after the screen to prevent damage or leakage caused by pressure fluctuations.
Dual Enhancement of Quality and Efficiency
The melt pump's steady output provides continuous, uniform melt flow to the screen changer, while the screen changer ensures melt purity. Together, they enable high-precision EPP pellet production (dimensional tolerance ≤ ±0.05mm).
Actual Results: After implementing this combination on an EPP production line, pellet pass rate increased from 92% to 98%, with daily output rising by 2 tons per line.
Reduced Maintenance Costs
The melt pump minimizes screw wear, while the screen changer extends screen lifespan (single-use duration ≥8 hours), collectively lowering maintenance costs by approximately 30%.
Melt Pump Selection
Based on EPP melt viscosity, output (e.g., 500-2000 kg/h), and pressure requirements (e.g., 20-40 MPa), select a gear-type melt pump (e.g., ZB-B series). Material must withstand high temperatures (≥350°C) and corrosion (e.g., alloy steel).
Screen Changer Selection
Recommended: Hydraulic fully automatic screen changers (e.g., HY-series) supporting rapid screen changes and high-temperature operation. Match screen area to production capacity (e.g., Φ150mm screen for 1000kg/h lines).
The melt pump, extruder, and screen changer must be coaxially aligned to prevent leakage caused by misalignment.
The screen changer should be installed close to the die head to minimize melt residence time.
Monitor pressure and temperature parameters during commissioning to ensure stable system operation.
In EPP pelletizing production lines, the combination of melt pump and screen changer is the core solution for enhancing efficiency, quality, and stability. The melt pump ensures stable melt delivery and energy optimization, while the screen changer enables efficient filtration and continuous production. Their synergy significantly reduces scrap rates, increases output, and accommodates the high-viscosity, high-temperature demands of EPP foaming processes. In practical applications, equipment selection must align with production line scale and process requirements, and strict adherence to installation and commissioning standards is essential to maximize equipment performance.
