Zig-Zag Air Classifier for Plastic Recycling
Engineered for high-purity recycling lines, our zig-zag column strips paper, film fines, and dust away from dense PET or HDPE flakes using tightly controlled airflow profiles. Integrate it after drying to lock in premium quality and unlock better downstream pricing.
See the Zig-Zag Column in Action
Watch how cascading chambers, controlled velocity, and cyclone discharge combine to remove label dust without stripping valuable flakes.
Working Principle
A rising column of air carries lighter contaminants upward while gravity pulls heavier flakes downward. Adjustable airflow gates tune the cut point for different polymers and contamination loads.
- Light Fraction Extraction
Labels, film fines, and paper fibers are pushed upward, collected through the top hood, and sent to dust control.
- Clean Flake Discharge
Dense PET, HDPE, or PP flakes fall to the bottom outlet, ready for pneumatic conveying or direct feeding.
- Adjustable Cut-Point
Change fan speed and damper positions to match material density, moisture, and targeted purity.
Performance Advantages
Deliver the low-dust, low-label flakes demanded by bottle-to-bottle, sheet, and fiber producers.
- High-Purity Output
Removes the fines other mechanical cleaners miss, boosting clarity and sale price.
- Energy-Optimized Flow
Balanced blower and rotary valve pairing maintains velocity with modest kW draw.
- Compact Footprint
Vertical zig-zag column integrates above conveyors or mezzanines to save floor space.
- Low Maintenance
Minimal moving parts and stainless wear surfaces keep upkeep predictable.
Applications & Commercial Impact
Increase downstream yield while meeting the strictest global flake import and extrusion standards.
- PET Bottle Flake Polishing
Pair with hot-wash systems to meet bottle-to-bottle specs with < 50 ppm residual paper.
- HDPE Rigids Recycling
Strip labels from blow-molded drums, IBC caps, and injection-grade regrind before compounding.
- Film & Flexible Reprocessing
Remove light film scraps and dust prior to extrusion to stop gel defects and die build-up.
- Alternative Fuels & Biomass
Clean light plastics from RDF or compost streams to satisfy environmental permits.
Technical Specifications
- Blower Motor
5.5 kW high-efficiency unit sized for continuous duty.
- Rotary Valve Motor
1.5 kW sealed drive keeps product moving without bridging.
- Rotary Valve Diameter
Ø 270 mm with abrasion-resistant blades.
- Valve Speed
50 RPM optimized for steady discharge.
- Cyclone Separator
600 L volume captures dust and fines prior to bagging.
Related Equipment
- Thermal Dryer for Plastic Recycling
Reduce moisture to sub‑3% before zig‑zag classification for best separation performance.
- Sink‑Float Separation Tank
Upstream density separation to remove floating PP/PE from heavier PET.
- Friction Screw Washer
High‑energy surface cleaning to strip labels and organics prior to drying.
- PET Bottle Recycling Line
See the complete process and how the zig‑zag column integrates.
Lifecycle Support
1-Year Warranty
Coverage on core components with rapid spare-parts fulfillment from regional hubs.
On-Site Commissioning
Process engineers can align dampers, fan curves, and cyclone ducting during startup.
Line Integration
Custom infeed/outfeed transitions ensure seamless pairing with washers, dryers, and pneumatic transport.
Frequently Asked Questions
It is typically positioned after drying so that flakes are free-flowing and light contaminants can be evacuated efficiently before packing or pelletizing.
Yes. Any application requiring separation of light versus heavy fractions—including PP regrind, paper-plastic streams, or biomass fuel prep—can benefit from the adjustable airflow design.
Operators mainly inspect fan bearings, rotary valve blades, and dust collection points. With proper filtration, the system runs months between planned service stops.
Standard systems cover roughly 300–3,000 kg/h. Final sizing depends on polymer type, bulk density, flake geometry, moisture, and contaminant loading. We adjust column cross‑section/height, number of stages, and blower curve to hit your purity and pressure‑drop targets. Send a sample or data sheet for a fast sizing proposal.
The light fraction exits to a cyclone and then a downstream filter (baghouse or cartridge). Sealed ducting and slight negative pressure prevent fugitive dust. Optional HEPA final stage and spark arrestor are available to comply with stricter regulations.
Product‑contact surfaces are typically stainless steel (304 standard, 316 optional). Clean‑out doors and inspection windows are included; full washdown packages and CIP spray nozzles can be specified for high‑hygiene lines.
Request a Proposal
Share your throughput targets and feedstock mix and we’ll return a tailored airflow model, layout, and pricing.
