Are you considering replacing or upgrading your conical twin-screw for extrusion but don’t know where to start? You’re not alone. We’ve compiled the most frequently asked questions we get from customers around the world—whether they run PVC pipe lines, WPC panels, or profile extruders.

If you’re looking for clear, practical answers—this FAQ is for you.

❓1. What is a conical twin-screw, and how is it different from a parallel twin-screw?

A conical twin-screw has a tapered (cone-like) geometry, where the screw diameter reduces from the feed end to the die end. This design:

• Allows higher torque transfer at lower speeds
• Requires less installation space
• Provides better compression control for PVC materials

A parallel twin-screw has a constant screw diameter and is often used for higher-speed or higher-output applications like PE/PP compounding.

❓2. What materials are conical twin-screws best suited for?

Conical twin-screws are ideal for:

• PVC (Rigid or soft, with or without fillers)
• WPC (Wood Plastic Composites)
• CPVC (Chlorinated PVC – temperature-sensitive)
• Foamed PVC panels and skirting boards
• PVC cable trunking and profiles

They perform especially well when the formulation includes CaCO₃ (calcium carbonate) or other abrasives.

❓3. How do I know if I need to replace my conical twin-screw?

Look for these signs:

• Decreased output or unstable extrusion pressure
• Overheating or inconsistent melt temperature
• Visible wear on screw flights or barrel inner wall
• Black spots or material degradation in the extruded product
• Screws have been used for over 15,000–20,000 hours

If you experience any of these, a replacement or refurbish is likely needed.

❓4. Can you make replacement screws for my existing machine?

Yes! At Zhoushan Juyuan Machinery Co., Ltd., we can manufacture replacement conical twin-screw and barrel sets for most brands, including:

• KraussMaffei
• Battenfeld-Cincinnati
• AMUT
• Jwell
• Theysohn
• And custom or local OEMs

Just send us the screw dimensions or a photo—we will match or improve the original geometry.

❓5. What materials do you use for screws and barrels?

We offer:

• Screws:
  • Nitrided 38CrMoAlA steel
  • Hard-surfaced (Colmonoy or PTA welded) for wear resistance
• Barrels:
  • Nitrided steel
  • Bimetallic liners (Fe-based or Ni-based) for abrasive materials

These materials ensure long service life, especially for high-filler PVC or WPC.

❓6. How long does it take to deliver replacement conical twin-screws?

Typical lead times:

• Standard sizes: 2–4 weeks
• Custom designs: 3–5 weeks
• Emergency orders: Possible within 7–10 days (ask us for rush service)

We ship globally by sea, air, or express.

❓7. Can you help me improve output or energy efficiency?

Absolutely. We can optimize screw geometry to:

• Increase throughput (kg/h)
• Reduce motor load (kWh/kg)
• Improve melt quality
• Enhance feeding and degassing zones

Just tell us your material, output goals, and machine specs—we’ll propose a solution.

❓8. I don’t know my screw model. Can you still help?

Yes. Even if you bought a second-hand machine, we can help.

Send us:

• Photos of your current screw & barrel
• Key dimensions: outer diameter, length, core diameter, pitch
• Your machine brand and material
• Desired output rate

We’ll identify or redesign the matching replacement.

❓9. Do you provide technical support or installation guidance?

Yes. We offer:

• Installation drawings
• Online support (video call or step-by-step instructions)
• Recommendations for startup settings
• Long-term maintenance tips

We want your replacement to work perfectly the first time.

❓10. How can I get a quote?

Contact us with:

• Screw and barrel drawings or measurements
• Material you process (e.g., PVC + 50% CaCO₃)
• Output needs
• Machine brand/model (if known)
• Destination country

📧 Email: cxj.job@gmail.com
📱 WhatsApp: +85244499051
🌐 Website: https://juyuan-machinery.com/

We’ll reply with a detailed quote, material recommendation, and delivery time within 24 hours.