Hdpe Sorting Machine | AISORT
Application Overview — Plastic Recycling
HDPE Sorting in Modern Recycling Facilities
HDPE (high-density polyethylene) is the second most recycled plastic after PET, driven by the high value of natural HDPE (milk jugs, detergent bottles) in secondary markets. HDPE sorting separates natural (unpigmented) from colored HDPE and removes PP, PET, and other polymer contaminants. Natural HDPE commands $700-900/tonne vs. $300-500 for colored HDPE, making color sorting the primary value driver.
Material Characteristics and Sorting Challenges
HDPE sorting challenges: distinguishing HDPE from PP (both float in water and look similar — PP contamination above 2-3% severely degrades HDPE recyclate properties); removing HDPE with barrier layers (EVOH, nylon) that are invisible to NIR but compromise recyclate quality; sorting pigmented HDPE by color for markets that require consistent color; and handling thin-wall containers that deform during baling and transport.
Recommended Sorting Technology Stack
NIR (polymer identification: HDPE vs PP vs PET) + RGB (color: natural vs. white vs. blue vs. mixed color). Sink/float pre-separation removes PET (sinks) before optical sorting. For demanding applications (pipe, automotive), a second NIR pass verifies polymer purity.
Performance Benchmarks
| Metric | Target |
|---|---|
| HDPE Purity | >98% |
| PP Removal | <2% PP in HDPE |
| Throughput | 5-12 t/h |
| Container Size | 100mL-20L |
These benchmarks represent achievable performance with modern sensor-based sorting equipment, assuming properly sized, well-maintained equipment operating on representative feedstock. Actual results depend on specific material composition, throughput, and operating conditions.