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HomeTwin Screw Parallel Counter-rotating Extruder
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TwinScrew’s Counter Rotating Twin Screw Extruder is engineered for PVC profiles, PVC pipes, WPC composites, and other heat-sensitive materials that require high pressure and low-shear processing. With optimized screw geometry, strong conveying force, and exceptional melt uniformity, this extruder provides stable, high-precision extrusion for continuous industrial production.
What Is a Counter Rotating Twin Screw Extruder?
A counter-rotating twin screw extruder operates with two parallel screws rotating in opposite directions.
This opposite motion creates:
- Strong positive conveying
- High pressure buildup at low shear rates
- Uniform plasticizing for PVC and WPC formulations
- Improved dimensional stability at the die
This makes it the preferred technology for rigid PVC profiles, multi-cavity window frames, conduit pipes, and WPC boards.
Key Advantages of TwinScrew Counter Rotating Twin Screw Extruder
1. High Pressure for Precise Shaping
Counter-rotating screws generate substantial pressure, ensuring stable flow and accurate sizing at the die.
2. Low Shear Processing for Heat-Sensitive Materials
Minimized shear heat prevents PVC degradation, yellowing, and plate-out issues.
3. Excellent Melt Homogeneity
Intermeshing geometry maintains uniform plasticizing even with powder formulations like rigid PVC.
4. Energy-Efficient with Consistent Output
Optimized torque and screw engagement deliver stable extrusion at lower energy consumption.
5. Long-Life Screws and Barrels
High-wear alloy materials extend component life under continuous industrial loads.
Counter-Rotating vs Co-Rotating Twin Screw Extruders
| Feature | Counter-Rotating Twin Screw | Co-Rotating Twin Screw |
|---|---|---|
| Screw Direction | Opposite rotation | Same direction rotation |
| Shear Level | Low shear – ideal for heat-sensitive PVC | High shear – ideal for compounding |
| Pressure Build-Up | Very high, stable die pressure | Medium pressure |
| Conveying Force | Strong positive conveying | Moderate conveying |
| Typical Output | Lower RPM, stable output | Higher RPM, higher throughput |
| Best For | PVC profiles, PVC pipes, WPC, low-shear extrusion | Masterbatch, fillers, engineering plastics |
| Melt Uniformity | Excellent for PVC powder | Excellent for compounding |
| Degassing Ability | Strong natural venting | Depends on screw elements |
| Material Sensitivity | Very gentle | More aggressive mixing |
Applications
This extruder is ideal for:
- PVC window & door profiles
- PVC pipes and electrical conduits
- WPC decking & composite boards
- Decorative profiles and construction materials
- PVC foam boards and skirting
- Recycled PVC (rigid and soft)
- High-filler formulations with CaCO₃ or wood flour
Extrusion Process & Zone Functions
Feeding Zone
Optimized channel depth ensures smooth PVC powder feeding and prevents bridging.
Compression Zone
Reverse-shear geometry provides stable melting while keeping melt temperature low—ideal for heat-sensitive PVC.
Metering Zone
Uniform channel depth stabilizes melt pressure and ensures consistent wall thickness and dimensional accuracy.
Degassing Zone
Enhanced vent design removes moisture and volatiles, preventing bubbles or voids in PVC and WPC products.
Die-Entry Stabilization Zone
Controlled pressure buildup ensures precise shaping for multi-cavity profiles and complex cross sections.
Why Choose TwinScrew?
1. High Control Over Core Components
Screws, barrels, control systems, and gearboxes are produced through stable, long-term manufacturing partners for consistent quality.
2. Proven Global Reliability
TwinScrew extruders operate across Europe, Asia, South America, and the Middle East with strong after-sales support.
3. Customizable Screw Designs & Full Line Integration
Tailor-made screw geometry, die design, and complete turn-key system planning for PVC profile, pipe, and WPC production.
4. Excellent Cost Efficiency & Service
Fast spare-part availability and expert technical support reduce downtime and maximize output.
FAQ
Q1. What is the main difference between counter-rotating and co-rotating twin screw extruders?
Counter-rotating: high pressure, low shear, ideal for PVC.
Co-rotating: high shear, best for compounding and mixing.
Q2. How do I choose the right screw diameter and L/D?
It depends on output requirements, material viscosity, and product size. TwinScrew engineers offer selection guidance.
Q3. Can the machine process recycled or high-filler materials?
Yes. Counter-rotating screws provide strong conveying force and stable plasticizing, making them suitable for recycled PVC and WPC.
