Applications of Conical Twin-Screw Extruder

Conical twin-screw extruders are widely used in polymer processing due to their high shear force, superior mixing capability, and excellent degassing performance, making them particularly suitable for heat-sensitive materials like PVC. Below is a detailed breakdown of their key applications and real-world use cases.

1. PVC Product Processing (Core Application)

① PVC Window & Door Profiles

• Process Features:

• The high compression ratio and forced feeding ensure uniform plasticization of PVC dry blends.

• Vacuum degassing effectively removes volatiles, preventing bubbles and yellowing.

• Typical Configuration:

• Screw Diameter: 55/110mm, 65/132mm (for high output)

• Auxiliary Equipment: Calibration table, haul-off unit, cutter

② PVC Pipes (Drainage Pipes, Electrical Conduits)

• Advantages:

• Higher output (200-600 kg/h, depending on specifications) compared to single-screw extruders.

• Better suited for calcium carbonate-filled PVC formulations (e.g., drainage pipes with 30% CaCO₃).

• Example:

• Production lines for Φ20-Φ110mm PVC-U drainage pipes.

③ PVC Sheets/Corrugated Boards

• Applications:

• Advertising boards, construction templates, anti-corrosion pads.

• Key Requirement:

• Smooth surface finish (requires high-precision dies).

2. Wood-Plastic Composites (WPC)

① WPC Flooring/Wall Panels

• Material Composition:

• PVC/PE/PP + wood flour (30-60%) + additives (coupling agents, lubricants).

• Advantages of Tapered Twin-Screw Extruders:

• High shear force ensures uniform dispersion of wood flour, preventing agglomeration.

• Vacuum degassing removes moisture and volatiles from wood flour.

② WPC Outdoor Products

• E.g., railings, planters, furniture.

3. Recycled Plastic Processing

① PVC Recycled Pelletizing

• Applicable Materials:

• PVC cable scraps, profile trimmings, waste pipes.

• Process Considerations:

• Requires strong filtration (screen changers) to remove impurities.

• Stabilizers must be added to prevent degradation.

② Other Recycled Plastics

• E.g., PE/PP recyclates (screw configuration adjustments may be needed).