SMP Series Knives Pulverizer

Overview

The SMP Series Knives Pulverizer from Chenxing Machinery is a high-performance disc-type plastic grinding system purpose-built for converting rigid and semi-rigid plastic waste into fine, reusable powder. Engineered for 24/7 continuous operation, the series spans five models — SMP-400 through SMP-1000 — covering throughput from 60 kg/h to 800 kg/h, matching the output demands of small recycling workshops up to large-scale industrial plastic recycling plants.

The machine accepts a broad spectrum of thermoplastic waste materials, including:

• Rigid PVC — pipe offcuts, profile scraps, window frame rejects, board edge trim

• SPC (Stone Plastic Composite) — flooring production waste, edge trims, defective boards

• WPC (Wood Plastic Composite) — decking cut-offs, profile waste, post-industrial scrap

These materials, once ground into controlled particle sizes (typically 10–120 mesh / 125–1250 μm), can be reintroduced directly into PVC pipe extrusion lines, WPC profile production, or SPC flooring manufacturing — enabling closed-loop material recovery and significant raw material cost reduction.

Core Value: The SMP Series replaces multiple standalone grinding, screening, and conveying units with a single integrated closed-loop system — reducing floor space, operator headcount, energy consumption, and material loss while delivering consistent powder quality batch after batch.

Technical Parameters

The SMP Series is engineered with a clear scaling logic: as disc diameter increases from 400 mm to 1000 mm, blade count scales from 20 to 50, main motor power from 30 kW to 90 kW, and throughput from 60–100 kg/h to 500–800 kg/h. This linear scalability allows plant engineers to select the exact capacity tier aligned with their waste volume — avoiding both under-capacity bottlenecks and over-capacity energy waste.

Notes: Throughput values are based on medium-hardness rigid PVC regrind at 40–60 mesh output. Actual throughput varies with material type, feed particle size, screen mesh selection, and ambient temperature. For SPC (high mineral filler content) and WPC (wood fiber content), derate throughput by approximately 15–25%. For detailed material-specific performance data, refer to the plastic pulverizer application guide or contact our engineering team.

Model Selection Guide

• SMP-400 / SMP-500: Suitable for small-to-medium recycling workshops, in-house profile factory scrap recovery, and laboratory-scale testing. Compact footprint, 30–37 kW power draw, ideal where floor space and electrical capacity are constrained.

• SMP-600 / SMP-800: The workhorse tier for mid-to-large plastic recycling facilities. 55–75 kW motors paired with 28–36 blades deliver 200–450 kg/h, balancing capital cost with daily throughput.

• SMP-1000: The flagship model for high-volume industrial operations. 90 kW main motor, 50-blade disc, and 1500 mm vibrating screen handle 500–800 kg/h — suited for centralized recycling hubs and large-scale pipe/profile manufacturers processing multi-ton daily waste streams.

System Configuration & Engineering Details

Every SMP Series pulverizer is assembled from industrial-grade subsystems selected for 24/7 continuous operation in demanding recycling environments. Below is the complete system breakdown — from the grinding chamber core to the dust collection exhaust.

Configuration Overview

Key Engineering Highlights

Blade Metallurgy & Service Life

The grinding blades are machined from D2 (AISI D2 / DIN 1.2379) or SKD-11 (JIS G4404) cold-work tool steel — both high-carbon, high-chromium alloys with exceptional wear resistance. After vacuum heat treatment to HRC 58–62 and double tempering, the blades retain cutting-edge sharpness across 800–1,200 operating hours when processing rigid PVC, and 500–800 hours on highly abrasive SPC (60–75% CaCO₃ filler). Blades are designed with four usable cutting edges; rotation extends total blade service life to 3,200–4,800 hours before replacement. For more on blade selection, see the plastic crusher blade guide.

Bearing System Reliability

All main shaft bearings are SKF or NSK deep-groove ball bearings in ABEC-7 (ISO P4) precision class. C3 internal radial clearance accommodates thermal expansion during extended high-RPM operation. Grease-lubricated with labyrinth non-contact seals, the bearing assembly operates at a steady-state temperature of 55–65°C — well within the 90°C grease service limit. L10 rated life exceeds 30,000 hours under rated load, translating to approximately 4 years of single-shift operation before preventive replacement. This bearing architecture is shared across Chenxing's full plastic machinery product line.

Particle Size Control

The vibrating screen uses interchangeable 304 stainless steel woven-wire mesh panels covering 10 to 120 mesh. Mesh-to-particle-size mapping follows ASTM E11:

The double-deck option produces two size fractions simultaneously — coarse oversize automatically returns to the grinding chamber via the regrind circuit.

Dust Control & Environmental Compliance

The dust collection system employs a two-stage design: a high-efficiency cyclone separator removes >90% of airborne particles by mass, then a pulse-jet baghouse with polyester needle-felt filter bags captures sub-10 μm fines to achieve ≥99.5% overall collection efficiency. Stack emission is maintained at ≤10 mg/Nm³ — compliant with EU Industrial Emissions Directive (2010/75/EU) and most regional environmental standards. Automatic differential-pressure-triggered pulse cleaning eliminates manual filter shaking and extends bag life to 12–18 months.

Core Features

1. Advanced Disc & Blade Design — High Output, Extended Service Life

The SMP grinding disc features an optimized shear-angle geometry machined from D2 (AISI D2) or SKD-11 tool steel, vacuum heat-treated to HRC 58–62. Unlike conventional flat-blade discs that rely predominantly on impact fracture, the SMP blade profile balances shear cutting and high-speed impact — producing more uniform particle morphology and reducing dust-generation of ultra-fines. Each blade has four indexable cutting edges; rotating edges extends blade service life 4×, achieving 3,200–4,800 total operating hours on rigid PVC before full replacement. Compared to the preceding generation of plastic grinding machines, wear rate is reduced by approximately 30%.

2. Precision Bearing System — High RPM, Low Maintenance

Main shaft support uses SKF or NSK ABEC-7 (ISO P4) deep-groove ball bearings with C3 internal clearance. The grease-lubricated, labyrinth-sealed assembly operates at a steady-state 55–65°C across the full 2950–3700 RPM speed range. Tool-free access via the hinged door cover exposes the grinding chamber and bearing housing within seconds — cleaning, inspection, or blade rotation can be completed in under 15 minutes by a single operator, minimizing production downtime.

3. Fully Sealed Grinding Chamber — Zero Dust Leakage

The grinding chamber is enclosed with multi-stage labyrinth seals and PTFE gaskets at all mating surfaces. Combined with the negative-pressure pneumatic conveying system, the entire grinding loop operates under slight vacuum — ensuring no fugitive dust escapes into the plant environment. This design meets occupational exposure limits for respirable PVC dust and eliminates the need for separate room-level dust extraction.

4. PLC Full Automation — Unattended Operation

A Siemens S7-1200 PLC with a 7-inch HMI touchscreen controls the complete process sequence: automatic hopper feeding with level sensor → main motor soft-start via VFD → grinding → pneumatic conveying → screening → regrind return → discharge. Real-time monitoring of motor current, bearing temperature, and screen vibration allows the system to auto-adjust feed rate (PID loop) and trigger overload shutdown. The control logic supports unattended overnight operation, reducing labor to one operator supervising multiple plastic recycling machines.

5. Dual Air + Water Cooling — Thermal Degradation Prevention

Heat-sensitive materials, particularly rigid PVC (thermal degradation onset ~140°C), require stringent temperature control during high-speed grinding. The SMP cooling system combines:

• Water cooling jacket surrounding the grinding chamber — closed-loop circuit maintaining disc-to-material interface below PVC degradation threshold

• Forced-air blower directed at the motor housing and bearing seats — preventing heat soak during extended runs

Material discharge temperature is maintained below 80°C even at maximum throughput, preventing yellowing, HCl off-gassing, and cross-linking that would compromise regrind quality.

6. Interchangeable Screen Mesh — Granular Particle Size Control

The vibrating screen accepts 304 stainless steel woven-wire mesh panels from 10 to 120 mesh (1250–125 μm aperture). Quick-release frame clamps enable mesh changeover in under 5 minutes without tools. The double-deck screen option (available on SMP-600 and above) produces two finished fractions simultaneously — for instance, 40-mesh powder for WPC extrusion and 80-mesh fines for PVC pipe production — while the vibrating screen separator automatically returns oversize to the grinding chamber.

7. Integrated Dust Collection — Environmental Compliance

Two-stage dust control — cyclone separator (≥90% mass separation) followed by pulse-jet baghouse (≥99.5% overall efficiency) — maintains stack emissions ≤10 mg/Nm³. The automatic differential-pressure cleaning logic triggers pulse-jet cycles only when needed, conserving compressed air and extending filter bag life to 12–18 months. Collected dust is recovered as usable product, achieving near-zero material loss.

8. Industrial-Grade Drive & Electrical System

Main motors are IE3 premium-efficiency (IE4 optional), Class F insulation (155°C), with soft-start VFD compatibility. This eliminates across-the-line inrush current, reduces mechanical shock on the drive train, and enables speed trimming for process optimization. All electrical enclosures are IP54-rated with CE-compliant safety interlocks on access doors, emergency stop at operator and panel stations, and overload protection on all three-phase circuits.

Production Process — How It Works

The SMP Series operates a continuous closed-loop process, transforming irregular plastic scrap into precisely sized powder in a single integrated system. Below is the step-by-step material flow.

Step 1 — Automatic Material Feeding

Plastic scrap (PVC/SPC/WPC pipe offcuts, profile trims, board waste) is loaded into the SS304 feeding hopper. A level sensor detects material volume and triggers the screw or belt feeder to deliver a controlled stream into the grinding chamber. Feed rate is regulated by the PLC via PID control — increasing when main motor current drops (under-load) and decreasing when current approaches the set threshold (optimal load). An anti-bridging vibrator prevents irregular scrap from jamming at the hopper throat.

Step 2 — High-Speed Disc Grinding

Material enters the grinding chamber between a high-speed rotary disc (2950–3700 RPM, depending on model) and a stationary disc. The D2/SKD-11 blades mounted on both discs subject the plastic to three simultaneous fragmentation mechanisms:

• Shear cutting — blades slice larger pieces into smaller fragments

• Impact fracture — high-velocity collision shatters brittle material (dominant for highly filled SPC)

• Attrition/friction — inter-particle rubbing between discs produces fine powder

The calibrated disc gap (0.2–0.8 mm, adjustable) determines the mechanical energy input and final particle morphology. A narrower gap favors flake-shaped particles; a wider gap with longer residence time produces more granular powder. This grinding principle also applies in plastic mixing and blending systems where uniform particle distribution is critical.

Step 3 — Dual Cooling (Water + Air)

The grinding process generates frictional heat that must be continuously removed to prevent:

• PVC thermal degradation (dehydrochlorination at ~140°C, causing yellowing and HCl release)

• SPC binder softening and disc gumming

• WPC wood-fiber charring

The water cooling jacket embedded in the grinding chamber housing circulates chilled water (inlet <25°C) through an external chiller or cooling tower loop. Simultaneously, a forced-air blower directs ambient air across the motor housing and bearing seats to prevent heat soak. Together, these maintain material discharge temperature below 80°C at maximum throughput.

Step 4 — Vibrating Screen Classification

Ground material exits the grinding chamber and falls onto the vibrating screen. The 304 stainless steel mesh (10–120 mesh, user-selected) classifies particles by size:

• Undersize (passes through): Finished powder conveyed to the collection system

• Oversize (retained on screen): Automatically returned to the grinding chamber via the regrind chute

The double-deck screen option (SMP-600 and above) produces two finished fractions simultaneously — coarse powder for WPC extrusion and fine powder for PVC injection, for example.

Step 5 — Negative-Pressure Pneumatic Conveying

The high-pressure centrifugal suction fan (4–15 kW, depending on model) creates negative pressure throughout the downstream circuit. Finished powder passing through the screen is entrained in the airstream and conveyed to the cyclone separator. This vacuum conveying ensures no dust escapes at transition points and eliminates the need for mechanical screw conveyors that would add complexity and maintenance points.

Step 6 — Cyclone Separation & Baghouse Filtration

In the cyclone separator, centrifugal force separates >90% of powder mass from the airstream. The remaining air — now carrying only sub-10 μm fines — passes through the pulse-jet baghouse, where polyester needle-felt filter bags capture particles to achieve ≥99.5% overall collection efficiency. Filtered air is discharged at ≤10 mg/Nm³. The pulse-jet cleaning system automatically triggers based on differential pressure across the bags, maintaining consistent airflow without manual intervention.

Step 7 — Rotary Valve Discharge

Collected powder from both the cyclone and baghouse converges at the rotary valve (airlock), which discharges finished product into storage bins, supersacks, or directly into a downstream PVC compounding mixer. The cast-iron 6–8 vane rotary valve maintains the system's negative-pressure seal during continuous discharge, enabling true 24/7 non-stop operation.

Process Summary: Waste enters → auto-fed → ground under shear/impact/friction → cooled below degradation threshold → classified by mesh → fine powder pneumatically conveyed → dust filtered to 99.5% → discharged. Oversize automatically loops back. One operator supervising the PLC HMI can manage the entire line.

Frequently Asked Questions (FAQ)

Q1: What is the typical blade service life when grinding rigid PVC versus SPC, and when should blades be rotated or replaced?

Blade life depends heavily on material abrasiveness. For rigid PVC (no mineral filler), D2/SKD-11 blades at HRC 58–62 typically deliver 800–1,200 operating hours per cutting edge before throughput drops >10% or particle size distribution shifts. SPC compounds containing 60–75% CaCO₃ filler are significantly more abrasive — expect 500–800 hours per edge. Each blade has four indexable edges; rotating at the first sign of throughput decline extends total service life to 3,200–4,800 hours (PVC) or 2,000–3,200 hours (SPC) before full replacement. Monitoring motor current draw at constant feed rate is the most reliable wear indicator — a consistent upward trend signals dulling edges requiring rotation. WPC with 50–60% wood fiber falls between PVC and SPC, with 600–1,000 hours per edge depending on wood species hardness.

Q2: How does throughput vary across rigid PVC, SPC, and WPC, and what blade configuration optimizes each material?

Rigid PVC (unfilled, medium hardness) achieves the rated throughput: 200–350 kg/h on SMP-600 at 60-mesh output. SPC (high CaCO₃ filler, high density) typically derates throughput by 20–25% due to the abrasive filler consuming grinding energy without contributing to friable fracture — the same SMP-600 may produce 150–260 kg/h. WPC (wood fiber + PE/PP/PVC matrix) derates by 15–20% because wood fiber's fibrous nature resists brittle fracture; throughput depends significantly on moisture content — wood fiber above 8% moisture absorbs impact energy and reduces output. For blade selection, we recommend SKD-11 with a slightly more aggressive shear angle (shallower rake) for SPC to promote brittle fracture of the mineral-filled matrix, and D2 with standard geometry for PVC and WPC. Our plastic grinding solutions team can run sample grinding tests with your specific feedstock.

Q3: How do vibrating screen mesh sizes map to final powder particle sizes, and how should I select the right mesh for my downstream process?

Mesh-to-particle-size follows ASTM E11: 20 mesh ≈ 850 μm (coarse regrind for thick-wall pipe), 40 mesh ≈ 425 μm (standard WPC extrusion powder), 60 mesh ≈ 250 μm (PVC pipe/profile production), 80 mesh ≈ 180 μm (thin-wall injection molding), and 100–120 mesh ≈ 150–125 μm (SPC core layer, high-surface-area applications). The key selection criterion is your downstream process requirement — too coarse and dispersion/melting suffers; too fine and you waste energy plus risk thermal degradation from extended residence time. The double-deck option on SMP-600 and above lets you produce two fractions simultaneously — e.g., 40-mesh for WPC decking extrusion and 80-mesh for PVC pipe co-extrusion — with oversize from both decks returning to the grinding chamber. Mesh changeover takes under 5 minutes with the quick-release frame.

Q4: How does disc gap adjustment affect powder particle shape (flake vs. granular), and which setting suits which application?

Disc gap — the clearance between rotary and stationary discs — is adjustable from 0.2 to 0.8 mm via a calibrated micrometer mechanism. At a tight gap (0.2–0.3 mm), the dominant fragmentation mechanism shifts to shear cutting, producing flake-shaped particles with higher aspect ratio and larger specific surface area — ideal for applications requiring rapid plasticization in extrusion (PVC pipe, profiles). At a wider gap (0.5–0.8 mm), particles experience longer residence time with more inter-particle attrition, yielding more equant/granular powder with better bulk density and flowability — preferred for SPC compounding and automated dosing systems where consistent volumetric feeding matters. The gap setting interacts with screen mesh selection: a tight gap with coarse mesh can produce the same nominal particle size as a wide gap with fine mesh, but with different morphology. We recommend starting at 0.4 mm and running trials to dial in the optimal combination for your specific formulation. Our quality control lab can assist with particle size distribution analysis.

Q5: How does the dual air + water cooling system prevent thermal degradation in heat-sensitive rigid PVC, and what is the maximum safe material discharge temperature?

Rigid PVC begins thermal degradation (dehydrochlorination) at approximately 140°C, releasing HCl gas and causing visible yellowing — a critical quality defect in recycled powder destined for white or light-colored pipe production. The SMP cooling system addresses this through two parallel mechanisms: (1) a water cooling jacket around the grinding chamber circulates chilled water (inlet <25°C, outlet <45°C) through an external chiller loop, extracting frictional heat at the source; (2) a forced-air blower continuously flushes the motor housing and bearing seats, preventing conducted heat from the 30–90 kW motor from migrating into the grinding zone. At maximum throughput on rigid PVC, material discharge temperature is maintained below 80°C — providing a 60°C safety margin below the degradation threshold. For facilities without chilled water infrastructure, a cooling tower integration kit is available that maintains inlet water within the required range using ambient evaporative cooling.

Why Choose Chenxing Machinery

Selecting a pulverizer supplier is a multi-year operational commitment — the machine becomes embedded in your production line, and every hour of unplanned downtime costs real revenue. Here is why procurement engineers and plant managers worldwide choose Zhangjiagang Chenxing Machinery Co., Ltd..

Full-Spectrum Plastic Machinery Manufacturer

Chenxing is not a single-product workshop. We design and manufacture complete plastic processing and recycling lines, including plastic crushers and shredders, high-speed mixing units, PVC pipe extrusion lines, WPC profile lines, and SPC flooring production lines. This full-line capability means you source your entire recycling-to-production chain from one manufacturer — ensuring system-level compatibility, unified after-sales support, and simplified spare parts logistics.

ISO-Certified Manufacturing & Quality Control

Our Zhangjiagang manufacturing facility operates under ISO 9001 quality management, with every SMP pulverizer undergoing a minimum 4-hour continuous run test with actual feedstock before shipment. Key quality control checkpoints include: disc dynamic balance to G2.5 (ISO 1940), bearing temperature stabilization test, screen mesh calibration, PLC sequence verification, and dust emission measurement. Full Factory Acceptance Test (FAT) documentation is provided with each machine. Learn more about our quality assurance program.

Global Export Experience & After-Sales Engineering Support

Chenxing machines are operating in recycling plants across Southeast Asia, the Middle East, Africa, Eastern Europe, and South America. Our after-sales engineering team provides:

• Remote commissioning support — video-guided installation and startup

• On-site service — available for complex line integration or training

• Spare parts inventory — blades, bearings, screens, belts, and seals stocked for 48-hour dispatch

• Technical documentation — full English manuals, electrical schematics, PLC program backup

Visit our service and support page for warranty terms and coverage details.

Proven Track Record

Browse our customer case studies to see SMP Series installations in real-world recycling operations — from a 3-ton/day PVC pipe regrind facility in Vietnam (SMP-800 + SMP-600) to an integrated WPC decking plant in Poland running closed-loop scrap recovery with SMP-500.

Factory Visit Welcome

We encourage prospective buyers to visit our Zhangjiagang facility, inspect machines under production, witness live grinding demonstrations with your own material, and meet the engineering team behind your equipment. A factory visit eliminates procurement risk in a way no datasheet can.

Get Your SMP Pulverizer Quote — 4 Simple Steps

Ready to integrate the SMP Series into your recycling or production line? Here is how our inquiry process works:

Contact Information

We respond to all technical inquiries within 1 business day. For urgent requests, contact Nicole directly via WhatsApp at +86 15951187228. Whether you need a single SMP-400 for in-house scrap recovery or a multi-machine SMP-1000 installation for a centralized recycling hub — contact Chenxing Machinery today and let us engineer the right solution for your operation.