Our double-piston four-station back-flush screen changer is engineered for plastic extrusion and recycling pelletizing lines. By altering melt flow direction, it realizes online back-flushing without production shutdown. It delivers stable continuous extrusion performance, and is highly recommended for processing heavily-contaminated recycled plastic materials.
This screen changer features large effective filtration area, automatic PLC-based control and pressure-protection functions. It greatly cuts screen-consumption costs, reduces pressure fluctuation of melt system, protects expensive extruder components, and improves final melt quality. Widely matched with HDPE / PP rigid plastic recycling pelletizing systems and various polymer extrusion production lines.
The equipment contains four independent filter working positions driven by double pistons.
1. Normal Production Status: Multiple filter screens stay in filtering position, plastic melt flows through filter screens for impurity filtration.
2. Online Back-flushing Status: While the rest filter positions keep normal filtering, one single filter station switches to back-flush position. Reverse-flow melt washes contaminants trapped on screen surface and discharges dirt outwards. Back-flushing proceeds without stopping main production.
3. Screen Replacement: When screens reach service limit, single-station piston moves out for manual screen replacement. Other stations maintain continuous filtration, no full-line stop required.
Note: Only one piston executes back-flush or screen-changing action at one time. The other piston must remain in filtering status to guarantee non-stop operation.
1. Non-stop Online Back-flushing Double-piston four-station structural design. Change melt flow path to perform back-flush cleaning while running, no machine halt. Minimize production interruption.
2. Perfect for High-contamination & Recycling Materials Ideal choice for waste plastic recycling pelletizing. Greatly lower frequency of screen replacement caused by large amounts of impurities in recycled feedstock, ensure stable continuous production.
3. Large Filtration Area & Stable Melt Pressure Large available screen area effectively suppresses system pressure fluctuation, upgrades melt quality. Stabilized pressure relieves impact force on screw, barrel and die head, significantly extends service life of these high-cost extruder parts.
4. Cost-saving & Eco-friendly Filter screens can be reused after back-flush cleaning (up to more than 10 cycles in proper conditions). Reduce filter-screen consumables and waste generation, cut overall operating cost.
5. Full Automatic PLC Control with Safety Protection Complete automatic operation controlled by PLC system. Equipped with pressure monitoring, fault alarm and interlock protection functions. High-precision encoder ensures accurate piston positioning for reliable long-term running.
|
Model |
Overall Dimensions L×W×H (mm) |
Screen Diameter (mm) |
Effective Screen Area (cm²) |
Capacity (kg/h) |
Heating Power (kW) |
Working Pressure (MPa) |
| DHX-4-134 | 1600 × 360 × 820 | φ134 | 564 | 1-800 | ≈16 | ≤15 |
| DHX-4-170 | 2500 × 460 × 1000 | φ170 | 907 | 1-1500 | ≈25 | ≤15 |
· HDPE / PP rigid waste plastic recycling & pelletizing line
· Post-consumer plastic re-granulation production
· Various polymer extrusion processes with high impurity content
· Extrusion lines requiring long-time non-stop continuous operation
