PVC/PE Coating Line

The 70mm screw is machined from 38CrMoAlA alloy steel — a nitrided material chosen for its hardness and resistance to wear from abrasive plastic granules. The 1:25 length-to-diameter ratio ensures thorough melting and homogeneous melt flow, reducing defects in the finished coating.

Four cast aluminum heaters paired with four dedicated cooling fans allow operators to set independent temperature profiles along the barrel. This zone-by-zone control prevents material degradation and enables consistent coating quality whether processing PVC or PE granules.

Immediately after the extrusion die, dual vacuum tanks hold the molten coating to the correct outer diameter while the stainless steel spray cooling system solidifies it rapidly. The result is tight dimensional tolerances and a smooth, uniform surface on every meter of conduit produced.

The downstream drawing machine uses five pulley sets and a 1.5kW variable-speed motor to maintain constant tension and line speed. Operators can match the draw rate to extrusion output, preventing stretching, sagging, or uneven wall thickness.

A single control cabinet consolidates all electrical and process controls — extruder drive, heater zones, vacuum pump, and drawing motor. The 1,100mm center-line height aligns with standard conduit production lines, and modular subsystems allow individual components to be serviced without shutting down the entire line.