Solution
Heavy-Duty Single-Shaft Shredding & Granulating System for Polymer Purge Blocks and Heavy Scrap
Integrated two-stage single-shaft hydraulic shredding and precision granulation system designed to transform heavy polymer purge blocks, lumps, and thick scrap into clean 6–10 mm regrind flakes without thermal degradation or motor stalls.
- Solution scope
- Multi-Function System
- Flow and installation
- Continuous · Offline
- Capacity
- 400–1500 kg/h
Extruder purging, material transition lumps, and thick-walled plastic start-up blocks represent one of the most frustrating bottlenecks in modern plastics compounding and manufacturing plants. Solid purge cakes discharged from large compounding extruders or pipe die heads can weigh anywhere from 10 kg to over 80 kg. Because high-molecular-weight polymers like HDPE, polypropylene, ABS, and filled engineering plastics possess extreme impact toughness, processing them with conventional high-speed granulators is notoriously unreliable. Standard granulators experience catastrophic drive-belt slippage, shattered blades, rotor shaft bending, and continuous motor trips caused by localized kinetic shock loads.
To eliminate manual band-sawing, hazardous flame-cutting, and equipment breakdowns, our Heavy-Duty Single-Shaft Shredding & Granulating System provides a robust, two-stage size reduction architecture engineered specifically for dense industrial polymer purges and bulky plastic scrap. The system integrates a low-speed, high-torque single-shaft hydraulic shredder (WT Series), a magnetic de-ironing belt conveyor, a precision secondary granulator (PC Series), and a closed-loop pneumatic cyclone dedusting station into a continuous, automated recycling cell.
During operation, massive purge blocks are loaded directly into the shredder hopper via forklift or tipping skip. An intelligent, load-sensing hydraulic pusher ram steadily advances the scrap against a heavy, counter-bored solid rotor spinning at 60–80 RPM. Hardened, four-way rotatable concave square knives (DC53 / D2 tool steel) peel off smooth polymer chips against reversible stator bed knives without generating high friction or thermal melting. If the cutting resistance approaches motor overload thresholds, the PLC automatically retracts the ram, oscillates the position, and resumes feeding with zero operator intervention.
Pre-shredded 30–50 mm chips discharge smoothly onto an inclined cleated belt conveyor equipped with a high-intensity neodymium overband magnetic separator, which extracts accidental tramp iron, broken bolts, or metal inserts before material enters the secondary granulator. The secondary heavy-duty granulator, operating with a staggered multi-knife rotor, cleanly shears the material down to uniform 6 mm to 10 mm flakes. A high-pressure extraction blower pulls the flakes through the granulator bottom screen under negative pressure, minimizing fines and conveying the regrind to a cyclone separator and dust-filter bagging station ready for immediate reuse in compounding lines.
The problem
What the section changes
Safely and continuously transforms dense, heavy polymer purge blocks, lumps, and thick scrap into clean, uniform 6–10 mm regrind flakes without thermal melting, motor stalling, or manual pre-cutting.
Dónde empieza el cliente
In compounding plants, pipe extrusion facilities, and injection molding factories, extruder startups, color transitions, and emergency shutdowns generate massive solid polymer purges, lumps, and heavy thick-walled parts (ranging from 10 kg to over 80 kg per chunk). Operators often attempt to break these blocks using standard high-speed claw or flat-blade granulators. This leads to chronic rotor stalling, burned drive belts, motor overcurrent trips, shattered knife edges, and extreme safety hazards from projectile kickbacks. Alternatively, plants employ manual band-saws or thermal cutting torchesto section lumps—an exceptionally labor-intensive, hazardous, and polluting practice that leaves tons of valuable prime polymer sitting unrecovered in scrap yards.
Por qué ocurre el problema
Polymer purges possess high mass density and immense impact resistance. Standard granulators rely on high-speed kinetic cutting (500–700 RPM); when a heavy, cold plastic block drops onto high-speed rotating knives, the instantaneous peak torque exceeds the motor rated capacity by 400%+, causing thermal breaker trips, belt slipping, or catastrophic shaft fracture.
Furthermore, without progressive feeding, large lumps wedge between rotor knives and stator bed knives, generating frictional heat that melts the plastic surface, fusing the block against the cutter box into an immovable plastic mass. The proper technical mechanism requires a low-speed (60–90 RPM), high-torque single-shaft shredder equipped with a load-sensing hydraulic pusher to peel thin slivers off the block layer by layer, followed by gentle, low-noise secondary granulation to the final target sieve size.
Producción o estado objetivo
Continuous, single-operator reduction of heavy polymer lumps into calibrated 6 mm to 10 mm regrind flakes. Zero thermal degradation, zero blade burning, low dust generation (< 3%), and immediate re-usability of regrind in prime extrusion compounding recipes at 10% to 30% loading ratios.
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.
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Low-Speed High-Torque Primary Shredding
RequiredRaw Material Preparation
Applies high-torque, low-speed hydraulic-assisted cutting to slice dense polymer purge blocks into coarse 30–50 mm uniform shreds without thermal melting or machine jamming.
Función del equipoEquipped with a solid alloy steel concave rotor, four-way rotatable square concave knives, and an intelligent PLC-driven horizontal hydraulic ram that advances and retracts automatically based on main drive motor current load.
Equipos Plastic Shredder
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Continuous Transfer & In-Line Magnetic De-Ironing
RequiredFeeding and Material Transfer
Transfers coarse shreds from the shredder discharge to the secondary granulator while continuously stripping tramp metal fasteners, broken bolts, and ferrous debris.
Función del equipoHeavy-duty inclined cleated belt conveyor with integrated rare-earth permanent neodymium cross-belt magnetic separator suspended over the discharge head.
Equipos Screw Conveyor
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Secondary Precision Granulation & Sizing
RequiredRaw Material Preparation
Grinds coarse shreds into uniform 6–10 mm regrind flakes with minimum fine dust and calibrated grain geometry.
Función del equipoHeavy-duty staggered rotor design with high-chrome D2 tool steel knives cutting at optimized shear angles against dual reversible bed knives, discharging through an interchangeable punched screen.
Equipos Plastic Crusher
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Closed-Loop Pneumatic Extraction, Dedusting & Bagging
RequiredFeeding and Material Transfer
Immediately conveys granulated flakes away from the screen chamber under negative pressure to prevent friction heat accumulation, separating airborne dust before packing.
Función del equipoHigh-efficiency centrifugal blower, SUS304 cyclone separator with rotary airlock valve, dual-bag dedusting collector, and double-outlet bagging hopper.
Equipos Vacuum Loader
Material
What goes in, what comes out
Condición y requisitos de alimentación
Solid plastic purge cakes, lump blocks, thick-walled pipe heads, failed injection molding start-up shots, and heavy profile cutoffs. Compatible with polyolefins (PP, HDPE, LDPE), styrenics (ABS, HIPS, PS), engineering polymers (POM, PC, PA6/PA66), and modified compounds. Unit block weights from 5 kg up to 100 kg.
Condición y límites de salida
Uniform, clean, free-flowing plastic regrind flakes (6 mm to 10 mm screen aperture). Bulk density ≥ 0.40 kg/L, dust content ≤ 3%, free of oversize splinters or un-cut stringers, ready for direct 10%–30% blend-back into compounding extruders without hopper bridging.
400–1500 kg/h
Base de las cifras de capacidad
Rated capacity (400 to 1,500 kg/h) is determined using solid PP/HDPE/ABS purges (block weight 10 kg to 60 kg) shredded through a 40 mm rotor screen and secondary granulated through an 8 mm or 10 mm screen. Throughput for high-impact polycarbonate or glass-filled purges scales down by 25%–35% due to higher cut resistance.
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.
Adecuada cuando
Ideal for compounding facilities, polymer masterbatch producers, pipe extrusion plants, and rotational molding processors that accumulate massive extruder purge lumps (PP, PE, ABS, PC/ABS, PA6, POM) and defective start-up moldings.
Suitable for rigid plastic recycling operations processing thick-walled crates, battery cases, solid automotive bumper cutoffs, and large thermoforming skeleton roll trim.
No adecuada cuando
Not suitable for ultra-thin post-consumer agricultural films, woven raffia bags, or loose fiber scrap (which wrap around single-shaft rotors and require high-speed dual-shaft shredders with film-specific cutter profiles).
Not suitable for vulcanized rubber tires or scrap materials containing embedded heavy structural steel, rebar, or unyielding rocks.
Condiciones pendientes de confirmar
Scrap materials consist of clean post-industrial polymer purges and thick molded parts free of unyielding tramp metals, rocks, concrete, or hardened tool steels larger than allowable tolerances. Ambient workshop temperature 5°C to 40°C.
Site and connections
What the section assumes around it
Servicios auxiliares
- Suministro eléctrico
- 380 V / 415 V / 460 V, 50/60 Hz, 3-Phase AC (wired per customer factory standard).
- Agua
- None required for standard operation (dry shredding system). Optional water-cooled rotor jacket available for low-melting-point elastomers.
- Aire comprimido
- 0.6–0.7 MPa dry, filtered air, consumption ~0.2 m³/min (for pneumatic valves and pulse-jet dust collector).
- Extracción y ventilación
- Integrated cyclone exhaust routed through cartridge/baghouse dust filtration; no toxic exhaust generation.
Total connected power: 55 kW to 132 kW depending on throughput capacity model selection.
Limitaciones de la planta
- Superficie ocupada
- Approximately 9.5 m length × 3.8 m width × 3.6 m height (including infeed clearance and cyclone collector).
- Altura libre
- Minimum 4.5 m overhead clearance recommended for forklift hopper loading and crane maintenance.
- Entorno
- Standard indoor industrial workshop or covered material processing shelter. Ambient temperature 0°C to 45°C.
Reinforced concrete slab floor with minimum thickness 200 mm and compressive load rating ≥ 3.0 tons/m². Vibration-damping mounting pads included.
Interfaces
- Mecánico
- Flanged connection between granulator base, suction box, and Ø150 mm stainless steel pneumatic conveying pipe.
- Control
- Siemens S7-1200 PLC centralized electrical panel; interlocking between shredder, discharge conveyor, granulator, and blower. Automatic reverse on overtorque.
- Aguas arriba y aguas abajo
- Upstream: Manual forklift tipping or hydraulic hopper tipper. Downstream: Direct discharge into 1,000 kg bulk big-bags or pneumatic transfer to extruder day-bins.
Targets
What the section is judged on
The numbers are targets agreed per project, not a general promise.
- Throughput Stability on Solid PP/HDPE Purges
- ≥ 95% rated capacity kg/h Continuous timed batch weighing on digital platform scale over 4 hours run
- Regrind Particle Uniformity (< 10 mm Sieve)
- ≥ 98.0 % by weight Standard mechanical sieve shaker analysis on 10 kg random sample
- Dust / Fines Content (< 1.0 mm)
- ≤ 3.0 % by weight Laboratory sieve screening per ASTM D1921
- Unscheduled Jamming or Rotor Stall Stops
- 0 stops / 8 hours PLC alarm and fault log recording
Cómo se evalúa la aceptación
1. Continuous 4-hour shredding and granulation trial achieving rated throughput (e.g., ≥ 600 kg/h for solid PP/PE purges) without thermal rotor trip or hydraulic ram overpressure reversal stalls.
2. Regrind size distribution: 100% of finished regrind passing through 10 mm discharge screen with dust/fines (< 1.0 mm) below 3.0% by weight.
3. Regrind bulk density and flowability: Clean, consistently cut flakes ready for direct pneumatic conveying and gravimetric hopper feeding without bridging.
4. Safety compliance: All mechanical interlocks, safety switches on hopper access doors, and hydraulic pressure relief systems function reliably under emergency stop conditions.
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.
Incluido en el alcance del suministro
- Heavy-Duty Single-Shaft Plastic Shredder (WT Series) Heavy welded steel chassis, oversized concave shear rotor (Ø400-Ø600 mm) with rotatable four-way DC53 square blades, horizontal hydraulic ram with proportional pressure sensing, and heavy-duty planetary reducer drive.
- Heavy-Duty Soundproof Plastic Crusher / Granulator (PC Series) Staggered claw/paddle rotor geometry, high-chrome D2 rotary and stationary knives, dual-layer sound-dampened hopper, and gas-spring assisted opening hood.
- Inclined Heavy-Duty Cleated Belt Conveyor with Overband Magnet Oil-resistant PU/PVC cleated belt with side skirts, frequency-controlled gear motor, and permanent rare-earth neodymium cross-belt magnetic separator.
- Closed-Loop Regrind Air-Conveying & Dedusting Cyclone Unit High-pressure centrifugal blower (5.5 kW - 11 kW), SUS304 cyclone separator, dual-bag dust filtering cabinet, and manual twin-spout bagging hopper.
No incluido en el alcance del suministro
- Heavy Infeed Loading Crane / Skid Steer Forklift, overhead gantry crane, or skid steer loader required for lifting massive 50+ kg purge chunks into the shredder hopper.
- External Metal Detection Tunnels for Incoming Scrap Bins Bulk scrap bin pre-sorting conveyors and heavy-duty eddy current sorting lines (available on project request).
- Main Electrical Feeder Cable & Workshop Transformer Mains power distribution cabling from plant substation to shredder master control panel.
Before a price
What we confirm before this becomes a quotation
- 01 Scrap Polymer Composition & Physical Dimensions Base polymer type (PP, PE, ABS, PC, PA66), filler/reinforcement loading (talc, glass fiber), maximum purge chunk weight, and physical dimensions (length, width, thickness).
- 02 Required Output Granule Size & Downstream Destination Target regrind flake size (e.g., 6 mm, 8 mm, 10 mm, 12 mm) and whether regrind will be fed directly to extruder hoppers, intermediate storage silos, or blending boxes.
- 03 Electrical Power & Floor Space Parameters Plant voltage/frequency, transformer power availability, overhead crane or forklift access clearance, and available workshop footprint.
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.
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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
- Problema de producción principal
- Blockage and bridging
- Off-spec pellet size and fines