China PVC Twin Screw Extruder Factories & Products

Unlike single-screw extruders where conveying relies solely on frictional drag, our conical and parallel twin screw designs utilize counter-rotating, intermeshing screws with positive displacement geometry. By engineering deep flight depths in the feed section and shallow, wide decompression channels in the venting and metering zones, the shear strain rate is maintained within safe parameters. Furthermore, internal closed-loop thermoregulation (using pressurized distilled water or synthetic thermal oil pumped through the hollow screw cores) prevents hot-spot accumulation, ensuring the melt temperature never exceeds the critical PVC degradation boundary of 195°C–205°C.

For standard compounds with under 15 phr CaCO₃, high-grade 38CrMoAlA alloy steel treated via gas nitriding (depth 0.5–0.7 mm, surface hardness ≥ 950–1050 HV) delivers multi-year operational life. For highly loaded formulations (30 to 80 phr filler) or abrasive lead-free stabilizers, we implement PTA (Plasma Transferred Arc) alloy cladding on screw flights utilizing tungsten carbide or cobalt-based Stellite powders (hardness ≥ 58–64 HRC). The barrel is fitted with a centrifugally cast bimetallic alloy sleeve containing nickel, chromium, and tungsten carbide, which extends service life by 300% to 500% compared to standard nitrided barrels.

Dimensional stability is achieved through a multi-tiered feedback architecture. First, melt pressure stability at the die inlet is maintained within ±0.5 bar via high-precision melt gear pump integration and synchronized screw dosing. Second, our vacuum calibration cooling tanks utilize high-response proportional vacuum regulation valves and precision chillers with ±0.2°C water temperature stability. Finally, dual-axis or multi-plane laser micrometers measure outer diameter in real time, communicating via industrial Ethernet (Profinet/Modbus TCP) directly with the servo puller to automatically trim line speed and maintain wall tolerances within ±0.01 mm.

Our standard electrical configuration is engineered around Siemens S7-1200/1500 PLC platforms paired with high-definition multi-touch HMI panels, backed by Schneider or ABB inverter drives. All control software complies with Weihenstephan standards and supports OPC UA and MQTT protocols. This allows our lines to transmit operational metrics—such as melt temperature, zone heater duty cycles, line speed, motor torque, and total energy consumption—directly into enterprise Manufacturing Execution Systems (MES) and ERP platforms for real-time OEE tracking.

Before crating, clients receive complete electrical schematics with European standard component tagging, P&ID layout diagrams, die and screw maintenance manuals, and a Factory Acceptance Trial (FAT) report. When raw resin samples are supplied by the customer, our Haian test bay executes continuous extrusion verification runs, recording continuous laser dimension graphs, melt pressure curves, and energy consumption logs to confirm compliance with contract specifications.

We provide comprehensive Global Service options: our field service engineers travel on-site to oversee mechanical levelling, electrical hook-up, water/air line connection, die tuning, and hands-on technician training. Additionally, all machines incorporate secure industrial VPN routers allowing our senior automation engineers to access the PLC directly for remote parameter optimization, diagnostics, and routine software upgrades. Spare parts are stocked in modular kits ready for international express dispatch.