High-Density Polyethylene (HDPE, resin code #2) is one of the most recycled plastics worldwide. Found in milk jugs, detergent bottles, pipes, and crates, HDPE’s high melt strength and low moisture absorption make it ideal for closed-loop recycling back into pellets. This guide walks through each step of the HDPE recycling process with the equipment specifications that matter at production scale.<\/p>\n\n\n\n
Post-consumer HDPE (bottles, containers, rigid packaging) is collected from curbside bins, MRFs, and commercial sites. Automated sorting uses near-infrared (NIR) sensors to separate HDPE (RIC #2) from other resins. Pre-sorted HDPE bales typically trade at $200\u00e2\u20ac\u201c$400\/ton depending on color and contamination level.<\/p>\n\n\n\n
Compressed bales are opened by a debaler machine<\/a> that cuts strapping wire and loosens material for conveyor feeding. Operators perform visual QC to remove non-HDPE contaminants (metals, paper, film bags). A trommel screen<\/a> can remove dirt, sand, and small debris at this stage.<\/p>\n\n\n\n HDPE bottles and rigid items are reduced to 10\u00e2\u20ac\u201c20 mm flakes by a single-shaft shredder<\/a> with screen. For thick-wall HDPE (pipes, crates), a plastic crusher<\/a> may be used first for primary size reduction. Consistent flake size is critical for uniform washing and extrusion downstream.<\/p>\n\n\n\n This is the most critical step for pellet quality. The washing sequence typically includes:<\/p>\n\n\n\n Washed HDPE flakes must reach <1% moisture before pelletizing. A two-stage drying process is standard:<\/p>\n\n\n\n Dried HDPE flakes are fed into an extruder that melts, degasses, and homogenizes the material. A screen changer filters out remaining micro-contaminants. The molten HDPE is then pelletized using one of two methods:<\/p>\n\n\n\n Every batch of HDPE pellets must pass quality checks before shipment:<\/p>\n\n\n\n Qualified HDPE pellets are packaged in 25 kg bags or 1-ton bulk bags (FIBCs). Recycled HDPE pellets are used in packaging, pipe manufacturing, automotive parts, construction materials, and consumer goods. Current market price for clean, natural-color rHDPE pellets ranges $600\u00e2\u20ac\u201c$1,000\/ton.<\/p>\n\n\n\n A typical HDPE bottle-to-pellet recycling line includes the following equipment in sequence:<\/p>\n\n\n\n Debaler \u00e2\u2020\u2019 Trommel \u00e2\u2020\u2019 Shredder \u00e2\u2020\u2019 Friction Washer \u00e2\u2020\u2019 Hot Washer \u00e2\u2020\u2019 Friction Washer \u00e2\u2020\u2019 Sink-Float Tank \u00e2\u2020\u2019 Centrifugal Dryer \u00e2\u2020\u2019 Thermal Dryer \u00e2\u2020\u2019 Extruder + Pelletizer<\/strong><\/p>\n\n\n\n Line capacity ranges from 500 kg\/h to 3,000 kg\/h depending on configuration. For a complete system with pricing, see our HDPE bottle recycling line<\/a> page or request a quote through our 2026 machine price list<\/a>.<\/p>\n\n\n\n HDPE has several properties that make it one of the most recycling-friendly plastics:<\/p>\n\n\n\n A complete HDPE recycling line (500 kg\/h) typically costs $80,000\u00e2\u20ac\u201c$150,000 for the washing line and $30,000\u00e2\u20ac\u201c$60,000 for the pelletizing line. Key factors for ROI:<\/p>\n\n\n\n For a detailed cost-benefit analysis, see our plastic recycling startup cost guide<\/a>.<\/p>\n\n\n\n The HDPE recycling process converts used HDPE plastic (#2) back into reusable pellets through 8 steps: collection, debaling, shredding, washing, sink-float separation, drying, extrusion\/pelletizing, and quality testing. The entire process takes HDPE from post-consumer waste to production-ready raw material.<\/p>\n\n\n\n Yes, but it requires an FDA-compliant or EFSA-compliant process with hot washing (85\u00c2\u00b0C+), super-clean decontamination, and documented challenge testing. Standard mechanical recycling produces industrial-grade rHDPE suitable for pipes, containers, and non-food packaging.<\/p>\n\n\n\n A complete HDPE recycling line needs: a debaler<\/a>, shredder<\/a>, friction washer<\/a>, sink-float tank<\/a>, centrifugal dryer<\/a>, thermal dryer, and pelletizer<\/a>. Optional: hot washer for food-contact applications, DAF system<\/a> for water treatment.<\/p>\n\n\n\n A 500 kg\/h HDPE recycling line (washing + pelletizing) costs approximately $110,000\u00e2\u20ac\u201c$210,000 for equipment. Total startup costs including facility, utilities, and working capital typically range $200,000\u00e2\u20ac\u201c$500,000. Payback is usually 12\u00e2\u20ac\u201c24 months at steady utilization.<\/p>\n\n\n\n HDPE (rigid bottles, pipes) and LDPE (films, bags) use different shredding and washing equipment. HDPE is processed as rigid flakes with sink-float separation. LDPE requires specialized film washing lines<\/a> with squeeze drying and film squeezers<\/a> because film material behaves differently in water and tends to wrap around rotating equipment.<\/p>\n\n\n3. Size Reduction (Shredding)<\/h3>\n\n\n\n
4. Washing and Cleaning<\/h3>\n\n\n\n
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5. Dewatering and Drying<\/h3>\n\n\n\n
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6. Extrusion and Pelletizing<\/h3>\n\n\n\n
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7. Quality Control and Testing<\/h3>\n\n\n\n
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8. Packaging and Distribution<\/h3>\n\n\n\n
HDPE Recycling Line Configuration<\/h2>\n\n\n\n
HDPE vs Other Plastics: Why HDPE Is Easier to Recycle<\/h2>\n\n\n\n
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Investment and ROI<\/h2>\n\n\n\n
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Frequently Asked Questions<\/h2>\n\n\n\n
What is the HDPE recycling process?<\/h3>\n\n\n\n
Can HDPE be recycled into food-grade material?<\/h3>\n\n\n\n
What equipment do I need to recycle HDPE?<\/h3>\n\n\n\n
How much does it cost to start an HDPE recycling business?<\/h3>\n\n\n\n
What is the difference between HDPE and LDPE recycling?<\/h3>\n\n\n\n