The global push for a circular economy has made plastic recycling a vital industry. Converting post-consumer or post-industrial plastic waste into high-quality regrind or pellets is not only environmentally responsible but also economically profitable. Wanplas offers state-of-the-art full automatic plastic recycling lines designed to process a wide variety of plastics, including PE, PP, HDPE, LDPE, and PET. Our waste-to-pellets systems are engineered for minimal human intervention, high throughput, and superior contamination removal. This article details the components, workflow, and benefits of our comprehensive recycling solutions.
The Importance of Plastic Recycling
Plastic waste poses a significant threat to the environment, particularly oceans and landfills. Recycling plastic reduces the demand for virgin resin, conserves fossil fuels, and lowers greenhouse gas emissions. For manufacturers, using recycled pellets (regrind) can reduce material costs by 30 to 50 percent. However, the quality of recycled plastic is often a concern. Contamination, moisture, and polymer degradation can ruin the final product. A high-quality recycling line, like those from Wanplas, solves these problems by ensuring thorough washing, drying, and controlled melting, producing pellets that are almost as good as virgin material.
Workflow of a Full Automatic Recycling Line
A typical Wanplas recycling line consists of several integrated stages: Feeding and Shredding, Washing and Separation, Drying, Extrusion and Filtration, and Pelletizing. The “full automatic” aspect means that material moves between these stages via conveyors and air blowers without manual handling, and the system automatically adjusts speeds based on load sensors.
Stage 1: Shredding and Crushing
The process begins with a heavy-duty shredder or crusher. Wanplas uses low-speed, high-torque shredders for rigid plastics (drums, pallets) and high-speed granulators for films and soft plastics. The machine reduces the waste size to small flakes (10-20mm), increasing the surface area for efficient washing. Our shredders feature reversible rotors and screen exchange systems to control the final flake size. Metal detectors are installed at the feed hopper to protect the blades from tramp metal.
Stage 2: Friction Washing and Hot Washing
Cleaning is the most critical stage. The flakes enter a friction washer, where intense mechanical action removes labels, glue, and dirt. For contaminated films (like agricultural film), we use a hot washer (caustic soda bath) heated to 80 degrees Celsius to dissolve organic contaminants. The friction washer also acts as a label remover. The flakes are then rinsed in a float-sink tank. Since different plastics have different densities (PP floats, PE sinks, PET sinks), this tank can separate mixed plastic streams. Wanplas lines include hydro-cyclones to remove fine sand and grit that would damage the extruder screw.
Stage 3: Dewatering and Drying
Wet flakes cannot be extruded. They pass through a mechanical dewatering screw press that squeezes out 30-40 percent of the water. The remaining moisture is removed by a thermal dryer. Wanplas uses energy-efficient dehumidifying dryers or horizontal fluidized bed dryers. These systems use hot air to evaporate moisture, recycling the air to save energy. The moisture content is reduced to below 0.5 percent, which is crucial for preventing bubbles in the final pellets.
Stage 4: Extrusion and Filtration
The clean, dry flakes are fed into a single or twin-screw extruder. The extruder melts the plastic at controlled temperatures to prevent degradation. The molten plastic passes through a screen changer—either a hydraulic non-stop screen changer or a manual piston type. This device removes any remaining contaminants (gel specks, metal shards) by forcing the plastic through fine mesh screens. Wanplas uses dual-piston non-stop changers to allow screen replacement without stopping production, ensuring continuous operation.
Stage 5: Pelletizing (Water Ring or Strand)
After filtration, the melt is pushed through a die face with multiple holes. Strand pelletizers create long spaghetti-like strands that are cooled in a water bath and cut by a rotating cutter. Water ring pelletizers use a ring of water to cool the strands immediately after the die, which is ideal for sticky or low-melt-strength materials. The pellets are then sent to a centrifugal dryer to remove surface water and finally to a silo for packaging. Wanplas offers underwater pelletizing systems for high-capacity lines (over 1000 kg/hr) to minimize noise and dust.
Wanplas Recycling Product Recommendations
For film washing lines (LDPE/LLDPE/HDPE film, woven bags), we recommend the WRL Series. This line is specifically designed with high-speed friction washers and aggressive drying systems to handle the high volume of air trapped in films. For rigid plastic washing (bottles, drums, crates), the WRS Series offers robust shredders and heavy-duty float-sink tanks. For compounding and masterbatch production, our WPL Twin Screw Extruder is ideal for high-fillers and additives. All our lines are equipped with Siemens PLCs for centralized control, allowing one operator to manage the entire line from a control cabinet.
Customization and Special Applications
Not all waste is the same. Wanplas specializes in custom solutions for difficult-to-recycle plastics. For example, PVC recycling requires special temperature control to avoid chlorine gas release. PET recycling requires crystallization before melting to prevent sticking. We also offer solutions for washing line water recycling, where the dirty water from washing is treated in a clarification tank and reused, reducing water consumption by up to 80 percent. For highly printed or inked films, we can integrate ozone treatment or chemical washing stages to improve the whiteness of the final flakes.
Technical Specifications and Output
Our recycling lines are available in capacities ranging from 300 kg/hr to 2000 kg/hr. The specific configuration depends on the input material. For example, a 500 kg/hr bottle washing line typically includes a bale breaker, shredder, label remover, float-sink tank, friction washer, and a dedicated PET crystallizer/dryer. Power consumption is optimized; for instance, our new generation dryers use heat pumps to recycle thermal energy, reducing drying power by 40 percent compared to standard resistive heating.
Maintenance and Operational Tips
To ensure the longevity of your recycling line, regular maintenance is key. This includes cleaning the screens daily, checking the wear on shredder blades, and lubricating gearboxes. Wanplas machines are designed for easy access to wear parts. We also recommend implementing a quality control lab to test the Melt Flow Index (MFI) and contamination level of the final pellets. This ensures the recycled material meets the specifications required for your end products, whether it is for blown film, injection molding, or pipe extrusion.
Conclusion
Investing in a full automatic plastic recycling line from Wanplas is a step towards sustainable manufacturing and cost reduction. Our turnkey solutions handle everything from dirty waste to clean pellets with minimal labor and maximum efficiency. By closing the loop on plastic waste, you not only reduce your environmental footprint but also secure a stable, low-cost source of raw material. Contact Wanplas today to analyze your waste stream and design the perfect recycling solution for your facility.