Application
Post-Consumer r-HDPE Bottle & Drum Recycling and Pelletizing Line
Post-consumer recycled H…
Solution
Rigid Plastic Scrap Recycling and Compounding Pelletizing Line
Turnkey recycling and compounding solution for rigid HDPE, PP, ABS, and PS post-consumer scrap, integrating shredding, tramp metal separation, vacuum devolatilization extrusion, and water-ring pelletizing.
- Solution scope
- Full-Line Integration
- Flow and installation
- Continuous · Inline
- Capacity
- 300–1500 kg/h
This turnkey solution integrates high-torque size reduction, continuous high-accuracy gravimetric loss-in-weight compounding, dual-filtration continuous melt screening, and enclosed water-ring pelletizing specifically engineered for rigid Post-Consumer (PCR) and Post-Industrial (PIR) plastic recycling streams (HDPE bottles/crates, PP battery cases/drums, ABS/PS appliance housings).
Unlike virgin plastic processing, post-consumer rigid plastics arrive with significant dimensional irregularity (thick purging lumps, hollow containers, pipe offcuts), metal contamination, fine mineral fillers, and residual printing inks or odor volatiles. This end-to-end solution systematically addresses each challenge: primary low-speed high-torque shredding followed by fine wet/dry crushing with in-line cross-belt tramp metal extraction; controlled single or twin-screw extrusion compounding with multi-stage high-vacuum degassing; continuous hydraulic or backflush screen filtration to arrest unmelted foreign contaminants; and closed-loop water-ring pelletizing that produces dense, uniform, dust-free recycled pellets directly suitable for premium injection molding, blow molding, or profile extrusion applications.
The problem
What the section changes
Converts bulky, contaminated rigid plastic scrap into high-density, bubble-free, and calibrated recycled pellets in one continuous automated process.
Where the customer starts
Recyclers attempt to feed bulky scrap (HDPE bottles, crates, purgings) into undersized single-screw extruders without proper two-stage size reduction or tramp metal protection. Screws and barrels suffer catastrophic abrasive wear from tramp iron, while unvented moisture and volatile printing inks produce foamy, porous pellets full of black specks and foul odors.
Furthermore, manual screen changers force frequent production stops every 30 to 60 minutes, leading to heavy thermal polymer degradation, massive purgings scrap, and an erratic line output that fails to satisfy industrial quality commitments.
Why the problem happens
Rigid scrap materials possess high structural rigidity and variable wall thicknesses (from 1 mm bottle walls to 40 mm pipe offcuts). Standard single-screw feed throats experience bridging, torque spikes, and motor trips when fed uneven pieces.
Additionally, trapped moisture and volatile organic compounds (printing inks, adhesive residues, residual packaging contents) vaporize under 200°C+ melt processing temperatures. Without specialized high-vacuum devolatilization zones and uninterrupted melt filtration, these volatiles create hollow, brittle pellets and continuous downstream filter blockages.
Target output or state
High-quality, dense, non-porous recycled pellets with uniform particle size, low odor, and stable melt index, ready for up to 50%–100% re-introduction into injection molding, blow molding, or sheet extrusion.
Process
The steps, in the order the material flows
The equipment named here is maintained on the step it belongs to, so the list and the quotation cannot disagree.
-
Two-Stage Size Reduction & Metal Extraction
RequiredRaw Material Preparation
Reduces bulky rigid scrap (drums, crates, purgings) into uniform 8–12 mm granulator regrind flakes while capturing tramp ferrous metal.
Role of the equipmentPrimary low-speed high-torque shredding down to 40–50 mm, followed by high-speed rotary crushing. An overband neodymium cross-belt magnet removes ferrous tramp debris to protect extruder screws.
Equipment Plastic Shredder Plastic Crusher
-
Plasticizing & Dual-Stage Vacuum Degassing
RequiredExtrusion and Melt Processing
Plastifies, homogenizes, and intensely devolatilizes the polymer melt under high vacuum to extract trapped moisture and volatile odors.
Role of the equipmentExtruder with bimetallic screw/barrel (L/D 36:1–40:1). Incorporates dual high-vacuum degassing chambers (-0.095 MPa) to evacuate moisture vapor, printing ink solvents, and monomer volatiles before the die.
Equipment Single Screw Pelletizer Twin Screw Pelletizer
-
Continuous Hydraulic Melt Filtration
RequiredExtrusion and Melt Processing
Filters out non-melting contaminants, unmelted gels, and degraded char particles without interrupting melt flow.
Role of the equipmentContinuous hydraulic dual-piston or backflush screen changer automatically cycles wire mesh screens (80–120 mesh) maintaining steady die pressure and zero production interruption.
Equipment Extruder Screen Changer
-
Water-Ring Pelletizing & Dewatering
RequiredPelletizing
Cuts hot polymer strands into uniform lens-shaped pellets immediately at the die face, followed by instant centrifugal drying and dedusting.
Role of the equipmentEnclosed water-ring cutter chamber with pneumatic blade pressure regulation; slurry flume to centrifugal spin dryer, discharging into double-deck vibrating screen for dust-free, calibrated recycled pellets.
Equipment Water Ring Pelletizer Vertical Centrifugal Dryer Linear Vibrating Screen
Material
What goes in, what comes out
Feed condition and requirements
Post-consumer and post-industrial rigid plastics: HDPE blow-molding containers, PP injection crates/battery boxes, ABS/PS electronics housings, thick-walled pipe scrap, and injection molding sprues. Initial scrap moisture ≤ 2%, bulk density 0.25–0.45 kg/L.
Output condition and boundaries
Solid, fully degassed, uniform spherical or lens-shaped recycled pellets. Free from bubbles, porosity, and metal particles. Moisture content ≤ 0.05%, bulk density ≥ 0.52 kg/L, continuous filtration down to 80–120 mesh. Suitable for 30%–100% PCR blend ratios in commercial manufacturing.
300–1500 kg/h
Basis for the capacity figures
Based on a continuous extrusion and pelletizing line utilizing a single or co-rotating twin-screw extruder (screw L/D 36:1 to 44:1) with a dual high-vacuum degassing zone and continuous plate hydraulic screen changer, operating on clean rigid polyolefin or styrenic regrind.
Fit
Where this section belongs — and where it does not
The boundaries are part of the solution: they keep a machine from being quoted into a case it cannot serve.
Suitable when
Ideal for commercial plastic recyclers and compounders processing rigid post-consumer waste streams (HDPE detergent bottles, milk jugs, PP crates, battery boxes, automotive bumpers, PC/ABS electronic casings).
Suitable for manufacturing plants generating substantial in-house rigid rejects, purgings, and edge trims seeking closed-loop re-granulation for direct reuse in core products.
Not suitable when
Not suitable for un-washed municipal solid waste (MSW) heavily contaminated with organic food waste, wet soil, glass bottles, or abrasive sand exceeding 2.0%.
Not suitable for lightweight, loose post-consumer agricultural films or woven bags without a dedicated compactor/densifier feeding system (which require specialized cutter-compactor recycling lines instead).
Conditions still to be confirmed
Capacity ratings assume clean, washed rigid flakes or pre-sorted scrap with residual surface moisture ≤ 2.0%, bulk density between 0.28 kg/L and 0.45 kg/L, and foreign non-polymeric contamination (paper labels, wood, sand) below 1.0% by weight.
Feedstock containing heavy cross-contamination of incompatible resins (e.g., heavy PVC contamination in an HDPE stream) requires specialized chemical compatibilizers or upstream density-sink float separation, scoped separately.
Site and connections
What the section assumes around it
Utilities
- Power supply
- 380 V / 415 V / 460 V, 50/60 Hz, 3-phase AC.
- Water
- Recirculating soft water loop: 25–40 m³/h; makeup water consumption: ~0.2 m³/h.
- Compressed air
- 0.6–0.8 MPa dry, clean compressed air for pneumatic cylinders, valve actuation, and blade positioning (approx. 0.3 m³/min).
- Exhaust and ventilation
- Exhaust ducting required at vacuum pump discharge and spin dryer outlet to vent organic volatiles and moisture vapor outdoors.
Total installed electrical power ranges from 160 kW to 400 kW depending on line throughput sizing.
Site constraints
- Footprint
- Linear layout: approximately 25 m to 35 m length x 5 m to 7 m width (approx. 150–250 m²).
- Headroom
- Minimum clear ceiling height of 4.5 m (5.5 m at shredder infeed conveyor).
- Environment
- Well-ventilated industrial workshop; floor trench for cooling water drainage; overhead crane (≥ 3T capacity) for extruder maintenance.
Electrical transformer capacity must accommodate total installed load (typically 180 kW to 450 kW depending on line output).
Interfaces
- Mechanical
- DN100 water flume between cutter chamber and centrifugal dryer; DN150 exhaust venting connections on vacuum trap and spin dryer.
- Control
- Integrated PLC automation line architecture with 12-inch industrial touchscreen; interlocking all drives, screen changer hydraulics, and cutter speeds.
- Upstream and downstream
- Upstream: raw scrap feeding belt or forklift bin tipper. Downstream: pneumatic transfer pipe to storage silo or bagging machine.
Targets
What the section is judged on
The numbers are targets agreed per project, not a general promise.
- Pellet Porosity / Internal Gas Blisters
- 0.00% (Solid Cross Section) % Cross-sectional optical magnification test on 50 pellets per hour
- Continuous Running Availability
- ≥ 92% % Total productive operational hours over 30 days without unplanned filter/jam stops
- Finished Pellet Bulk Density
- ≥ 0.52 kg/L Standard graduated cylinder bulk density test per ASTM D1895
How acceptance is judged
Commissioning acceptance requires an uninterrupted 8-hour continuous production run on agreed representative post-consumer rigid plastic feedstock (e.g., washed HDPE flake or crushed PP battery boxes). Line output must achieve ≥ 95% of nominal rated capacity (e.g., ≥ 950 kg/h for a 1,000 kg/h rated line).
Pellet quality criteria: 100% free of porosity or air blisters under cross-sectional magnifier inspection (indicating thorough vacuum degassing); bulk density ≥ 0.52 kg/L; zero metallic inclusions detectable via inline magnetic separation; continuous screen changes executed without line shutdown or melt strand disruption.
Scope of supply
What is in the delivery — and what is not
The confirmed scope is stated in the quotation; this is the boundary of the section as designed.
Included in the scope of supply
- Single / Twin-Shaft Primary Shredder & Crusher System Heavy-duty size reduction skid with D2 alloy blades, soundproof hopper, and overband permanent magnetic iron separator.
- Specialized Single / Twin Screw Recycling Extruder Bimetallic barrel and screw (L/D 36:1–40:1), dual high-vacuum degassing ports with liquid ring vacuum pumps and condensation traps.
- Continuous Hydraulic / Backflush Screen Changer Double-column or backflush screen changer allowing continuous screen replacement under full operating melt pressure without shutdown.
- Water-Ring Pelletizing and Centrifugal Dewatering Skid Enclosed cutting chamber with pneumatic knife blade pressure adjustment, high-velocity water shroud, spin dryer, and vibrating screen.
Not included in the scope of supply
- Washing and float-sink density separation plant Upstream friction washers, sink-float tanks, and hot wash systems for heavily soiled post-consumer waste are customer scope unless quoted.
- Main factory power substation and transformer High-voltage transformer, plant power factor correction panels, and cabling to line master switchgear are customer scope.
- Cooling tower and external water circulation pumps External evaporative cooling tower loop providing chilled water to the water-ring circulation tank.
- Civil works, overhead cranes, and ventilation ductwork Building exhaust hoods, crane hoists for screw removal, and foundation trenching.
Before a price
What we confirm before this becomes a quotation
- 01 Feedstock origin and physical form Source of scrap (PCR hollow bottles, PIR injection sprues, pipe regrind), dimensions, and contamination profile (labels, dirt, metal).
- 02 Target pelletizing capacity and shift schedule Required finished pellet production output (kg/h and metric tonnes per month) and operating hours (24/7 or 2 shifts).
- 03 Melt filtration fineness requirements Filter mesh requirement (e.g., 60 mesh, 80 mesh, 120 mesh) dictated by end-use application (injection molding vs. thin-wall blow molding).
- 04 Building floor plan and utility connection coordinates Factory layout drawings showing raw material staging area, water cooling drain trenches, and primary substation capacity.
Request a Quote Send these points with your inquiry; the section can then be quoted against your line, not against an assumption.
Photos
The section in the workshop
Photos go here once the section has been built and the material is cleared to publish.
-
Placeholder · 1200 × 900 px (4:3)（占位图） Replace with an approved section photos, real workshop or installation views at this size.（按此尺寸替换为正式图片。） -
Placeholder · 1200 × 900 px (4:3)（占位图） Replace with an approved section photos, real workshop or installation views at this size.（按此尺寸替换为正式图片。）
Details
Further details
- Main production problem
- Blockage and bridging
- Line output limited by auxiliaries
- Residual odor and VOC