PVC Pelletizing Line Case Study: SJZ65/132 Conical Twin-Screw with Hot-Face Pelletizing

Discover how a PVC pelletizing machine built around the SJZ65/132 conical twin-screw extruder delivers stable, high-output PVC granules for pipes, cable compounds, profiles, and recycled PVC. This turnkey PVC granulator package integrates a high-speed mixer, spiral loader, water-ring/hot-face pelletizer, multi-stage pneumatic conveying, cyclone separation, and vibrating screen — engineered for energy efficiency, consistent pellet size, and low maintenance.

Product Overview

Turnkey PVC Pelletizing Equipment Optimized for Rigid & Flexible PVC

  • Complete PVC compounding and granulation line: feeding, mixing, extrusion, hot-face pelletizing, drying, conveying, separation, and screening.
  • Stable throughput of 230–260 kg/h per SJZ65/132 line, ideal for pipe-grade PVC pellets, cable compound pellets, and recycled PVC granules.

Built for Consistency, Safety, and Uptime

  • PLC/HMI control with precise temperature zones and frequency control on main drives.
  • Wear-resistant metallurgy (38CrMoAlA nitrided barrel/screws, bimetallic options) supports long service life and high-quality pellets.

System Configuration and Key Features

Feeding & Material Handling

Spiral Loader (3 units)
  • Rated loading capacity: 1000 kg/h per loader; hopper volume: 150 kg.
  • 114 mm feed tube, 2.2 kW 6-pole motor for stable resin and additive feeding.
  • Optimized for PVC resin, stabilizers, plasticizers, and CaCO3 fillers.

High-Speed Mixing and Cooling

SRL-Z500/1000 High-Speed Mixer Set
  • Total volume: 500 L (hot) + 1000 L (cool); effective volumes: 350 L (hot) + 750 L (cool).
  • Hot mixer: 0–1400 rpm, 75 kW motor with Yaskawa VFD; self-friction heating for fast gelation and uniform dispersion.
  • Cool mixer: 60 rpm, 15 kW motor for rapid temperature pull-down, protecting PVC from thermal degradation.
  • Construction: 304 stainless steel pots (8 mm wall, 10 mm bottom); cast stainless impellers (ZG1Cr18Ni9Ti); dual-seal pneumatic lids.
  • Output: 800–1200 kg/h depending on formulation and cycle time.
  • Electricals: Dongqi temperature controllers, Siemens contactors, Schneider pushbuttons for robust reliability.

Extrusion & Melt Stabilization

SJZ65/132 Conical Twin-Screw Extruder (2 sets)
  • Materials: 38CrMoAlA nitrided barrels/screws with hard chrome plating; nitriding depth 0.5–0.7 mm; surface hardness 800–900 HV.
  • Screw diameter: Φ65/132 mm; effective length: 1430 mm; speed: 1–35 rpm for gentle PVC processing.
  • Drives: 37 kW Siemens(Beide) main motor with Yaskawa VFD; 1.1 kW forced feeder with Yaskawa VFD for steady intake.
  • Heating/Cooling: Cast-aluminum heaters with 250 W cooling fans per zone; total barrel heating power 24 kW.
  • Throughput: 230–260 kg/h (approx. 4–6.2 tons/24 h), depending on recipe and pelletizing method.
  • Gearbox: Heavy-duty reducer from Jiangyin main factory; water-cooling interfaces on barrel ensure thermal stability.
  • Controls: Tight temperature control (±1°C) with Dongqi controllers; Siemens contactors; Schneider pushbuttons; Qiansheng digital indicators.

Pelletizing & Downstream

PVC Hot-Face Pelletizing Die
  • Die steel: ZG40Cr for strength and thermal stability.
  • Cutting: Hot-face pelletizing with 2 blades (Cr12 tool steel) driven by a 2.2 kW motor; Yaskawa VFD for precise cutter speed.
  • Safety: Stainless-steel guard around cutting area.
Pneumatic Conveying & Drying
  • Three-stage air conveying with 3 × 3 kW blowers; 1.5 kW drying blower for moisture removal and pellet surface drying.
  • Stainless-steel air pipes (201 SS) and cyclone separation bins for dust control and efficient transfer.
Cyclone Separation & Storage
  • Cyclone bins constructed from 2 mm 201 stainless steel; capacity: 500 kg per bin.
  • Manual slide-gate discharge valves for controlled unloading.
Vibrating Screen
  • Length: 2.5 m; dual 0.2 kW vibration motors.
  • Effective screening area: 500; removes fines/overs to ensure uniform pellet size for extrusion or injection applications.

Performance and Energy Efficiency

Stable Output with Low Specific Energy

  • Typical specific energy: 0.18–0.28 kWh/kg for standard PVC formulations.
  • Vector-controlled drives (Yaskawa) maintain torque at low screw speeds, reducing melt oscillation and improving pellet uniformity.

Durability and Maintenance

  • Nitrided, hard-chrome surfaces resist abrasion from filled PVC compounds (e.g., CaCO3).
  • Modular design allows fast blade changes, easy screen maintenance, and straightforward access to heaters and fans.

Applications

Building & Construction

  • Pipe and fittings, cable conduits, window profiles, siding, wall panels, waterproof membranes.

Electrical & Cable Compounds

  • Insulation and sheathing compounds; halogenated/heat-stabilized PVC pellets for wire and cable.

Furniture & Home

  • Edge banding, floor skirting, decorative profile substrates, appliance components.

Automotive & Industrial

  • Interior trim components, seals and gaskets, protective sleeves, flexible hose compounds.

Recycling & Circular Economy

  • PVC recycling granulation for reprocessing scrap into stable, reusable pellets.

Quality Control and Safety

Intelligent Control & Traceability

  • Recipe management via VFD/temperature profiles; tight zone control ensures consistent gelation and thermal history.
  • Optional gravimetric feeding and melt monitoring can be integrated for premium grade pellets.

Compliance & Safeguards

  • Emergency stops, guarding on cutting head, interlocks on mixer lids, and proper dust control via cyclone and air conveying.
  • Closed-loop water-cooling compatibility helps minimize water usage and environmental impact.

Commercial Terms & Support

Delivery, Testing, and Acceptance

  • Factory pre-acceptance at supplier site before shipment: layout, configuration, parameter verification, function tests, and programming checks.
  • Final on-site acceptance at buyer’s factory within one week of installation, including 4-hour continuous trial run and performance verification.

Warranty and After-Sales

  • 1-year warranty from final acceptance (heaters 6 months).
  • 4-hour response time and 48-hour on-site service during and after warranty; lifetime paid service with spare parts at ex-factory price.

Logistics and Pricing (Reference from Contract)

  • Turnkey package included mixers, loaders, extruders, pelletizer, air conveying, cyclone bins, vibrating screen.
  • Quoted total: 408,000 RMB (incl. 13% VAT, freight, installation & commissioning) — for reference; customized offers may vary by market and options.

Why Choose This PVC Pelletizing Machine?

Market-Proven ROI and Reliability

  • Conical twin-screw technology excels at low-temperature processing of PVC, reducing thermal degradation, gel formation, and yellowing.
  • Balanced line design (mixing → extrusion → hot-face pelletizing → pneumatic conveying → screening) ensures pellet quality and high uptime.

Competitive Advantages

  • Energy-efficient drives and robust metallurgy extend service life and cut operating costs.
  • Flexible configuration supports rigid PVC, flexible PVC, CPVC (with appropriate upgrades), and filled compounds.

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