PVC pipe extrusion line

1. SJ92/188 Tapered Twin-Screw Extruder :

• • Tapered Screw Design: Screws gradually decrease in diameter from feed to discharge. This provides high compression ratios ideal for processing PVC powder blends (compacting, melting, degassing).

  • Intermeshing Screws: Rotate outward in the opposite direction ensures excellent mixing, homogenization, and shear control crucial for consistent PVC melt quality and compound dispersion (stabilizers, lubricants, pigments).

  • High Torque & Power (SJ92/188 Spec): Main extruder power AC 110 KW, designed for high output rates of rigid PVC pipe compounds. The size designation (92/188mm approx. screw dia) indicates significant capacity.

  • Precise Temperature Control: Multi-zone barrel heating/cooling allows tight control over the thermal profile needed for PVC processing to prevent degradation.

  • Optimized Feeding: Deep flights in the feed zone ensure efficient intake of low-bulk-density PVC dry blend.

  • Vent Port (Devolatilization): Typically includes at least one vent port to remove moisture and volatiles generated during compounding/melting, improving pipe quality and reducing porosity.

  • Robust Construction: Built to handle the abrasive nature of filled PVC compounds and high processing pressures.

2. Pipe Die Head:

• • Spider-Type or Spiral Mandrel Design: Designed for optimal melt distribution and minimal weld lines. Spiral manddels are common for high-quality pipe, ensuring uniform wall thickness.

  • Precision Sizing: Critical for achieving the target pipe outer diameter (OD) tolerance immediately after extrusion.

  • Multi-Zone Temperature Control: Independent heating zones on die body, mandrel, and die lips ensure precise melt temperature management at the exit point for smooth surface finish.

  • Streamlined Flow Path: Minimizes stagnation areas where PVC could degrade over time.

  • Robust Construction: Handles the high pressure and temperature of the PVC melt from the powerful extruder.

3. Vacuum Calibration Sizing Tank:

• • Vacuum Sizing Sleeves: Precise, water-cooled sleeves that pull the molten pipe OD against their internal surface using vacuum, defining the final external dimensions and roundness.

  • Efficient Cooling: Direct contact with cooled water inside the tank rapidly sets the pipe's external dimensions.

  • Adjustability: Sizing sleeves are precisely adjustable to accommodate different pipe diameters and ensure concentricity.

  • Level Control: Critical to maintain consistent pipe position within the sleeves. Often uses floating plugs or level sensors.