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A disc plastic pulverizer is an industrial grinding machine that uses a high-speed rotating knife disc to convert thermoplastic scrap — such as PVC pipes, SPC flooring offcuts, and WPC profile waste — into fine, reusable powder typically ranging from 10 to 120 mesh. Unlike conventional crushers that produce irregular chips, a disc pulverizer delivers controlled, uniform particle sizes suitable for direct reintroduction into extrusion, compounding, or pelletizing processes.
The global plastic recycling solutions market reached approximately USD 50 billion in 2024 and is projected to grow at a CAGR of 5–7% through 2025, driven by tightening EU recycled-content mandates and the VinylPlus commitment to recycle 900,000 tonnes of PVC annually. Against this backdrop, the disc grinding pulverizer has become a critical link in closed-loop manufacturing — enabling factories to reclaim production scrap on-site rather than paying for waste disposal and virgin resin simultaneously.
Chenxing Machinery, a Zhangjiagang-based manufacturer with over 20 years of engineering experience, offers the SMP Series Knife Disc Plastic Pulverizer — available in five models (SMP-400 through SMP-1000) spanning throughput capacities from 60 kg/h to 800 kg/h. This guide provides a comprehensive technical overview of how these machines work, their performance characteristics, application scenarios, and a practical framework for selecting the right model for your operation.
Understanding the pulverizer working principle is essential before evaluating any model for your production line.
At the heart of every SMP pulverizer is a circular knife disc mounted with replaceable alloy steel blades (20 to 50 blades depending on model). This disc rotates at high speed — 2,950 to 3,700 RPM — against a stationary counterpart. Pre-crushed plastic scrap (typically 6–10 mm granules from an upstream plastic crusher) is fed into the center of the grinding chamber via a magnetic vibrating feeder, which captures any stray metal fragments before they enter the cutting zone.
Centrifugal force pushes the material outward between the rotating and stationary blades. The plastic is sheared, cut, and impacted repeatedly until the particle size is small enough to pass through the gap clearance and be carried away by the pneumatic conveying system. There is no internal screen inside the grinding chamber — final particle size is controlled by adjusting the blade clearance, disc speed, and downstream vibrating screen mesh specification.
The SMP pulverizer is not a standalone unit; it integrates as a complete grinding system:
Vibratory Feeder — Feeds pre-shredded scrap evenly; magnetic separator removes tramp metal.
Grinding Chamber — High-speed knife disc performs the primary size reduction.
Pneumatic Conveying — An air blower transports ground powder through stainless steel piping to the cyclone separator.
Cyclone Separator — Separates air from powder; powder drops into a rotary airlock valve.
Vibrating Screen — Classifies powder by mesh size. Oversized particles are automatically returned to the grinding chamber for reprocessing.
Bag-Type Dust Collector — Captures airborne fine particles, ensuring zero-dust leakage into the factory environment.
This fully enclosed, automated sequence — feeding → grinding → conveying → classifying → dust collection — runs continuously with minimal operator intervention.
Heat management is arguably the most critical engineering challenge in plastic grinding machine design. PVC and SPC materials are heat-sensitive — excessive temperatures during grinding cause thermal degradation, discoloration, and loss of mechanical properties.
The SMP series employs a dual cooling architecture:
Water Cooling: The main bearing housing and grinding disc assembly are circulated with cooling water, extracting heat directly at the friction source.
Air Cooling: A forced-air system cools the external motor housing and the pneumatic conveying pipeline, keeping powder temperature below the material's degradation threshold.
This combination allows the SMP pulverizer to sustain continuous, 24/7 operation without thermal shutdown — a key requirement for high-volume recycling lines.
The SMP series spans five models with progressively larger disc diameters, blade counts, and motor powers. The table below presents the full technical parameter set for engineering evaluation.
| Parameter | SMP-400 | SMP-500 | SMP-600 | SMP-800 | SMP-1000 |
|---|---|---|---|---|---|
| Grinding Disc Diameter (mm) | 400 | 500 | 600 | 780 | 1000 |
| Number of Blades | 20 | 24 | 28 | 36 | 50 |
| Vibrating Screen Diameter (mm) | 600 | 800 | 1000 | 1200 | 1500 |
| Main Motor Speed (RPM) | 3700 | 2950 | 2950 | 2950 | 2950 |
| Main Motor Power (kW) | 30 | 37 | 55 | 75 | 90 |
| Blower Power (kW) | 4 | 5.5 | 7.5 | 11 | 15 |
| Rotary Valve Power (kW) | 0.75 | 1.1 | 1.1 | 1.5 | 1.5 |
| Throughput Capacity (kg/h) | 60–100 | 150–220 | 200–350 | 250–450 | 500–800 |
| Overall Dimensions (mm) | 2700×2000×3100 | 3200×2000×3200 | 3500×2500×3600 | 3600×3000×3600 | 4000×3500×4200 |
| Machine Weight (kg) | 1000 | 1200 | 1600 | 3500 | 5000 |
Several relationships in the table deserve attention from a process engineering standpoint:
Disc Diameter vs. Throughput: The SMP-400 (400 mm disc) delivers 60–100 kg/h, while the SMP-1000 (1000 mm disc) reaches 500–800 kg/h. The throughput does not scale linearly with disc diameter because larger discs also carry more blades and higher motor power, creating a compound efficiency gain at larger sizes.
Blade Count and Size Reduction Efficiency: More blades (20 → 50 across the range) mean more cutting edges per revolution, directly translating to finer and faster grinding. For applications requiring powder below 60 mesh, the higher-blade models (SMP-800, SMP-1000) are strongly preferred.
Specific Energy Consumption: Using the SMP-600 as a reference (55 kW main motor ÷ 200–350 kg/h), the specific energy ranges from approximately 0.16–0.28 kWh/kg. This is competitive with industry benchmarks and significantly lower than cryogenic grinding alternatives, which add liquid nitrogen consumption of 0.5–1.5 kg per kg of product.
Floor Space Requirements: The SMP-1000 requires a footprint of 4,000 × 3,500 mm. Ensure your factory layout has at least 1.5 meters of clearance on all sides for maintenance access, plus additional space for the upstream crusher and downstream collection system.
The SMP series uses a proprietary knife disc geometry that optimizes the shear angle between the rotating and stationary blades. This design achieves higher throughput per unit of power input compared to conventional flat-disc pulverizers. The blades are manufactured from wear-resistant alloy steel (SKD-11 grade or equivalent, HRC 58–63) and can be re-sharpened 4–5 times before replacement. A segmented blade option is available on SMP-600 and larger models, allowing individual blade replacement instead of the entire disc — reducing maintenance consumable costs by approximately 60%.
The main shaft runs on precision bearings (NSK or equivalent brand), rated for continuous operation at 2,950–3,700 RPM. An automatic lubrication system maintains optimal bearing conditions, and the bearing housing is directly integrated into the water cooling circuit to prevent thermal runaway during extended runs.
A hinged door on the grinding chamber provides full access to the knife disc assembly. Operators can inspect blade condition, adjust clearance, or replace worn blades without dismantling the pneumatic or electrical systems. Typical blade inspection takes under 10 minutes, and a complete blade change on an SMP-600 can be completed in under 2 hours by a trained technician.
All material transfer — from feeder inlet to cyclone discharge — occurs within sealed stainless steel ductwork. The bag-type dust collector at the system outlet captures sub-micron particles, ensuring compliance with workplace dust exposure limits. This is especially critical for PVC processing, where airborne chloride-containing dust poses both health and equipment corrosion risks.
The SMP integrates automatic feeding, grinding, pneumatic conveying, cyclone separation, screening, and coarse material return into a single PLC-controlled sequence. Once started, the system runs unattended except for periodic blade inspection and finished powder collection. Optional features include frequency inverter control for variable speed operation, automatic temperature monitoring with interlocks, and remote monitoring via industrial IoT modules.
As noted above, the combined cooling architecture allows sustained operation without thermal shutdown. The water circuit targets the grinding disc and main bearing — the two highest heat-generation points — while the air circuit handles secondary cooling for the motor and conveyance piping. This design is particularly important for heat-sensitive materials like rigid PVC and SPC compounds, where localized hot spots can cause yellowing, HCl release, and powder quality degradation.
PVC pipe extrusion plants generate significant post-industrial scrap: start-up purges, off-spec pipe sections, saw trim, and dimensional rejects. A PVC pipe production line integrated with an SMP pulverizer enables closed-loop recovery: scrap is pre-crushed in a plastic crusher, ground to powder in the SMP, and fed back into the extruder hopper at 20–30% regrind ratio — without compromising the physical or chemical properties of the finished pipe.
Similarly, PVC window and door profile manufacturers use SMP pulverizers to reclaim off-spec profiles and cut-off ends. The ability to produce consistent 40–80 mesh PVC powder is essential for maintaining extrusion stability and surface finish on new profiles.
SPC (Stone Plastic Composite) flooring production generates edge trim, sawdust-like cutting residue, and off-spec board sections. SPC material contains high filler loadings (typically 60–75% calcium carbonate), making it abrasive to conventional grinding equipment. The SMP series' wear-resistant blades, larger disc diameters (SMP-800, SMP-1000), and robust bearing systems are engineered to handle this abrasive duty cycle. Reclaimed SPC powder can be reintroduced into the mixing and calendering stage at controlled ratios, reducing raw material cost and factory waste disposal volume.
WPC foam board extrusion lines produce decking, wall cladding, and fencing products. Process waste includes start-up boards, edge trim, and cut-offs. Wood flour content (typically 40–60%) makes WPC scrap more friable and easier to grind than pure PVC, but care must be taken to manage moisture content — damp WPC scrap should be pre-dried before entering the pulverizer to avoid clogging the screen and dust collector. The SMP's fully enclosed ducting also prevents wood dust accumulation, mitigating fire and explosion risk.
Beyond pipes and profiles, SMP pulverizers process flat waste from PP, PE, ABS, and other thermoplastic sheet and board production. Application examples include:
PP corrugated sheet edge trim (packaging industry)
ABS automotive interior panel offcuts (returned to injection molding feedstock)
PE waterproof membrane roll-end waste (construction sector)
For operations requiring granulated output rather than powder, the SMP pulverizer integrates upstream of a plastic pelletizer machine. The workflow typically follows: crusher → SMP pulverizer → high-speed mixer (for blending with virgin compound and additives) → plastic extrusion line → pelletizing machine → finished pellets. This integrated approach is common in PVC compounding plants and recycling facilities that supply pelletized feedstock to downstream manufacturers.
For rigid PVC recycling, a PVC hot-cutting pelletizing line can be paired directly with the SMP pulverizer output, creating a complete powder-to-pellet recycling cell.
Selecting the optimal SMP model involves evaluating five key parameters. The decision matrix below provides a structured approach.
Start by calculating your daily scrap generation rate and desired processing window:
| Daily Scrap Volume | Recommended Processing Window | Suggested SMP Model |
|---|---|---|
| Under 500 kg/day | Single shift (8 hours) | SMP-400 or SMP-500 |
| 500–1,500 kg/day | Single shift (8 hours) | SMP-600 |
| 1,500–3,000 kg/day | Single shift (8 hours) | SMP-800 |
| 3,000–6,000 kg/day | Single shift (8 hours) | SMP-1000 |
| Above 6,000 kg/day | Two-shift operation or multiple units | SMP-1000 × 2 or custom solution |
Note: Always factor a 20% capacity buffer above your current scrap generation to accommodate production growth and peak periods.
Material hardness and filler content directly affect blade wear rate and cooling requirements:
Soft / low-abrasion (PE, PP, EVA, flexible PVC): Any SMP model is suitable. Blade life is longest; water cooling may be optional.
Medium hardness (rigid PVC, ABS, PS): All SMP models suitable. Water cooling strongly recommended for rigid PVC to prevent thermal degradation.
High abrasion (SPC with 60%+ CaCO₃, glass-filled compounds): Choose SMP-600 or larger with segmented blades for easier replacement. Budget for more frequent blade inspection cycles.
Heat-sensitive (rigid PVC, EVA, certain engineering plastics): Ensure the model's cooling system capacity matches your throughput. The SMP-800 and SMP-1000 have proportionally larger water jackets for sustained high-load cooling.
The downstream application determines the required powder fineness:
| Application | Typical Mesh Range | Model Recommendation |
|---|---|---|
| PVC pipe extrusion (direct regrind feed) | 20–60 mesh | SMP-400 to SMP-600 |
| SPC flooring core layer production | 40–80 mesh | SMP-600 to SMP-800 |
| Rotomolding powder | 35–60 mesh | SMP-500 to SMP-800 |
| Fine powder for compounding | 80–120 mesh | SMP-800 or SMP-1000 |
Finer mesh requirements generally demand larger disc diameters and higher blade counts for efficient production. The vibrating screen mesh specification is field-changeable, so one machine can serve multiple powder grades by swapping screens.
Before finalizing a model, verify:
Power Supply: All SMP standard motors are 380V 50Hz 3-phase. Alternative voltages (415V, 480V, 60Hz) available on request.
Cooling Water: The water cooling circuit requires a clean, filtered water supply at 2–4 bar pressure. A closed-loop chiller system is recommended for consistent cooling performance.
Floor Space: Confirm the model's overall dimensions plus 1.5 m clearance on all sides. Account for upstream plastic crusher and downstream collection bin space.
Dust Extraction: While the SMP is fully enclosed, a plant-wide central dust extraction system connection is advisable for high-volume operations.
If you anticipate doubling production within 3–5 years, consider purchasing a larger model now (e.g., SMP-800 instead of SMP-600) and running it at partial load. The incremental capital cost is often lower than the cost of replacing and reinstalling a smaller machine later. Alternatively, install two SMP-500 units in parallel — this provides redundancy; if one machine is down for blade maintenance, the other continues production at reduced capacity.
Chenxing Machinery, headquartered in Zhangjiagang City, Jiangsu Province, has been designing and manufacturing plastic recycling solutions since 2002. The company holds ISO 9001 and CE certifications, and its equipment operates in North America, Europe, Southeast Asia, the Middle East, Africa, and South America. With a 20+ year engineering heritage centered specifically on plastic extrusion and recycling machinery, Chenxing brings deep domain expertise to every pulverizer configuration.
One of the strongest operational reasons to choose Chenxing is the breadth of its product portfolio. Beyond the SMP disc pulverizer, Chenxing manufactures the full upstream and downstream equipment chain:
Plastic crushers — PC series, from 5.5 kW to 37 kW, for pre-crushing pipes, profiles, and sheets into 10–14 mm granules
Crushing and grinding machines — NSPC series for combined coarse and fine grinding applications
High-speed mixers — SRL-W series heating/cooling mixer units for PVC compounding
Plastic pelletizer machines — Strand, water-ring, and die-face pelletizing systems
PVC hot-cutting pelletizing lines — Complete PVC/WPC granulation systems
Plastic extrusion lines — Pipe, profile, sheet, and board extrusion
WPC foam board extrusion lines — Celuka process lines for WPC boards
A single-source supplier dramatically simplifies commissioning coordination, after-sales service, and spare parts management — one point of contact for the entire production line.
Every SMP pulverizer undergoes a Factory Acceptance Test (FAT) before shipment, including a 4-hour continuous run with customer-supplied material samples. During the FAT, the following parameters are recorded and documented:
Actual throughput (kg/h) at steady state
Particle size distribution of output powder
Motor amperage draw under load
Bearing temperature rise over the 4-hour run
Exit powder temperature
Customers receive the FAT report for their records and can optionally witness the test in person at the Zhangjiagang factory, attend via live video stream, or commission third-party inspection through SGS, Bureau Veritas, or TUV.
SMP pulverizers are not limited to fixed catalog specifications. Configuration options include:
Motor brand: Simo (standard), Siemens, WEG, or other specified brands
Blade material: SKD-11 (standard), tungsten carbide coating, or customer-specified alloy
Voltage/frequency: 380V/50Hz (standard), 415V/50Hz, 480V/60Hz, or custom
Control system: Standard relay-based, PLC with HMI touchscreen, or full IoT-enabled remote monitoring
Dust collection: Standard bag-type, pulse-jet automatic cleaning, or connection to plant-wide central system
Pipe material: Stainless steel 304 (standard) or 316L for corrosive environments
Post-delivery support includes:
Remote commissioning: Video-guided startup, parameter tuning, and operator Q&A — typically completed in 1–2 sessions
On-site installation: Optional dispatch of a Chenxing engineer to your factory for installation, commissioning, and operator training
Spare parts: Comprehensive inventory maintained for same-day dispatch on wear parts (blades, bearings, screens, seals)
Lifetime technical support: Process optimization advice, troubleshooting assistance, and upgrade recommendations throughout the machine's service life
A plastic crusher uses rotating knives against a stationary bed knife to cut plastic scrap into irregular chips, typically 6–14 mm in size. A disc plastic pulverizer, by contrast, grinds material into fine powder (10–120 mesh, or approximately 125–2,000 microns). Crushers are the first-stage size reduction step; pulverizers are the finishing step. If your goal is to produce powder that can be directly re-fed into an extruder or compounder, you need a pulverizer. If you only need to reduce large scrap to manageable granule size for storage or further processing, a crusher alone may suffice. In practice, most recycling lines use both: a crusher to pre-condition scrap, then a pulverizer to achieve final powder specification.
Yes. While the SMP series is optimized for PVC, SPC, and WPC — materials commonly processed in pipe, profile, and flooring industries — it is also capable of grinding other thermoplastics with moderate hardness and impact resistance. These include PE (LDPE, HDPE, MDPE), PP, ABS, PS, PA (Nylon), EVA, PET, and PC. The key constraints are material hardness (very hard engineering plastics may accelerate blade wear) and heat sensitivity (materials with low melting points or narrow processing windows benefit from the SMP's dual cooling system). For materials outside these categories, Chenxing's engineering team can conduct a trial grinding run to verify feasibility before purchase.
Blade life depends on three factors: material being processed, daily operating hours, and maintenance discipline. Under typical conditions processing rigid PVC at 8 hours/day:
First sharpening: approximately 400–600 operating hours. A gradual upward drift of 8–12% in motor amperage draw at constant throughput signals that resharpening is due.
Re-sharpening cycles: each blade can be re-sharpened 4–5 times before reaching minimum thickness and requiring replacement.
Total blade service life: approximately 2,000–3,000 operating hours for rigid PVC under standard conditions.
Processing abrasive materials like SPC (high calcium carbonate content) will accelerate wear. Using segmented blades on SMP-600 and larger models allows individual section replacement, reducing consumable cost by approximately 60% compared to replacing the entire disc.
For heat-sensitive materials — rigid PVC, SPC, EVA, and WPC — water cooling is strongly recommended and is standard equipment on all SMP models. Without adequate cooling, the friction-generated heat during grinding can push material temperature above its thermal degradation threshold. For PVC specifically, this manifests as yellowing, HCl release (corrosive to machine internals), and loss of mechanical properties in the reclaimed powder. For low-melting-point materials like PE and PP, insufficient cooling can cause powder to soften and agglomerate on the screen, blocking throughput.
The SMP's water cooling circuit targets the grinding disc and main bearing housing — the two primary heat sources. The air cooling system provides secondary cooling for the motor and pneumatic conveyance piping. This dual approach maintains exit powder temperature well below the material's degradation point, even during continuous 24/7 operation.
The SMP series can produce powder from approximately 10 mesh (2,000 microns) down to 120 mesh (125 microns). Particle size is controlled by three adjustable parameters:
Blade clearance: The gap between rotating and stationary blades — smaller gaps produce finer powder. Clearance is adjusted via a calibrated gauge and bolt system accessible through the chamber door.
Vibrating screen mesh: Interchangeable screens determine the maximum particle size that exits the system. Available mesh sizes range from 10 to 120. Oversized particles are automatically returned to the grinding chamber.
Feed rate: Higher feed rates tend to produce slightly coarser powder with a wider particle size distribution; lower feed rates yield finer, more uniform output.
For applications requiring precise particle size distribution control (e.g., rotomolding powder), frequency inverter control on the main motor and feeder is recommended, enabling real-time speed and feed rate adjustment.
Yes. The SMP pulverizer is designed for seamless integration into both new and existing production lines. Typical integration scenarios include:
Upstream connection: Receives pre-crushed scrap (6–10 mm) from a plastic crusher via conveyor or vacuum loader
Downstream connection: Feeds powder into a high-speed mixer for blending with virgin material, then into an extruder hopper
Pelletizing integration: Powder output feeds directly into a pelletizing machine for granulation
Automation interface: Standard I/O signals for start/stop, fault, and running status; optional PLC with Profibus/Modbus/Ethernet IP communication for integration with plant-wide SCADA systems
Chenxing's engineering team provides line layout design support to ensure the SMP fits your existing floor plan, material flow logic, and automation architecture.
A structured maintenance schedule maximizes uptime and blade life:
| Frequency | Task |
|---|---|
| Daily | Visual inspection of blade condition through chamber door; check amperage draw at steady state; verify cooling water flow; inspect dust collector bag pressure drop |
| Weekly | Clean dust collector bags (manual shake or pulse-jet); inspect and clean magnetic separator on feeder; check belt tension (if applicable); verify screen mesh integrity |
| Monthly | Measure blade wear using a gauge; lubricate all grease points; inspect bearing temperature rise during operation; check all electrical connections for tightness |
| Quarterly | Full blade inspection and clearance re-calibration; replace screen mesh if worn; inspect pneumatic piping for leaks; verify PLC/control panel function |
| Annually | Replace bearings (preventive); complete electrical safety inspection; re-calibrate temperature sensors and interlocks; review FAT parameters against current performance |
Yes. Customers can send 50–100 kg of their actual feedstock to the Zhangjiagang factory for a trial grinding run. During the trial, Chenxing engineers record:
Actual throughput at steady state (kg/h)
Particle size distribution of the output powder
Motor power consumption (kWh/ton)
Exit powder temperature
Visual quality assessment of the ground powder
You receive a complete trial report before making any purchase commitment. This is particularly valuable for unusual materials or tight powder specifications, as it validates the SMP's performance on your specific feedstock rather than relying on general reference data.
A disc plastic pulverizer is not merely a grinding machine — it is the economic engine of an in-house plastic scrap recovery system. By converting PVC, SPC, and WPC production waste into reusable powder, the SMP series directly reduces virgin resin consumption, eliminates waste disposal costs, and insulates your operation from raw material price volatility. When the plastic recycling solutions market is expanding at 5–7% annually and regulatory pressure for recycled content is intensifying, investing in on-site pulverization capacity is both a cost-control measure and a strategic compliance enabler.
The SMF series pulverizer platform — including the SMP knife disc variant — has been deployed across PVC pipe plants, SPC flooring factories, WPC decking manufacturers, and recycling facilities worldwide. Each machine's performance is validated through a pre-delivery factory acceptance test, backed by a 12-month warranty, and supported by lifetime engineering consultation.
Step 1 — Tell Us Your Material: Specify your feedstock — material type (PVC, SPC, WPC, PE, PP, ABS, or other), physical form (pipe sections, profile offcuts, sheet edge trim, regrind granules), approximate input size, and any heat sensitivity constraints.
Step 2 — Define Your Output Target: Desired throughput in kg/h, target powder particle size (mesh specification or D50 in microns), and preferred model range (SMP-400 through SMP-1000).
Step 3 — Receive a Custom Proposal: Our engineering team reviews your requirements and provides a tailored configuration — model recommendation, blade material specification, screen mesh selection, motor power confirmation, cooling system configuration, and auxiliary equipment recommendations — typically within 24 business hours.
Step 4 — Validate with a Sample Run: Optionally send 50–100 kg of your feedstock for a trial grinding run at our Zhangjiagang factory. We record throughput, particle size distribution, power consumption, and exit temperature for your evaluation before commitment.
Contact Nicole directly:
Email: ceo@cxsljx.com
Phone WhatsApp WeChat: +8615951187228
Company: Zhangjiagang Chenxing Machinery Co., Ltd.
Website: https://www.chenxingmachinery.com
We respond to all inquiries within one business day. For urgent requests, WhatsApp messages typically receive a reply within 2 hours during China business hours (UTC+8, 8:00–18:00).
