Here are some clear images and useful visual references of a conical twin screw barrel — a specialized barrel + screw set used in extruders for plastics, PVC, WPC, profiles, sheets, etc.

✅ What You’re Seeing

• A tapered (conical) barrel inner bore with two intermeshing screws (twin screws) that gradually increase in diameter — this geometry helps in gentle conveying, efficient mixing and stable output.
• Precision-machined screw flights and matching barrel bores to maintain correct clearance and minimize leakage/back-flow.
• Surface treatments (nitriding, chrome-plating, bimetallic layers) visible on many of the barrels to boost wear- and corrosion-resistance.
• Typical size models like 45/90, 51/105, 65/132, 80/156, 92/188 … as seen in the product specs of conical twin screw barrels.

🔍 Why Choose a Conical Twin Screw Barrel?

• Gentler processing: The conical geometry results in shorter residence time and more uniform shear, which is especially beneficial for heat-sensitive materials.
• Efficient mixing: The twin screw arrangement provides strong intermeshing and dispersive/mixing capability, making it ideal for compounding, filler/wood-plastic, high-additive content.
• High output potential: Because of the geometry and screw design, you can often achieve higher throughput vs standard barrels/screws for certain materials.
• Improved wear resistance: Many suppliers use hardened steel + nitriding + bimetal alloy layers specifically for conical twin screw barrels to handle abrasive fillers, glass fiber, calcium carbonate, etc.

🛠 Key Considerations for Specification & Design

• Diameter ratio & length: E.g., “51/105” means screw Ø51 mm feeding section to Ø105 mm discharge/conical section; the length (L/D) also matters.
• Material & surface treatment: Choose alloy steel grades (38CrMoAlA, SACM645, SKD61) and treatments (nitriding, hard chrome, bimetal) based on wear/corrosion needs.
• Clearance tolerance: With twin screws the fit between screw flight and barrel bore must be much tighter; machining precision is crucial.
• Screw geometry & elements: Mixing zones, barrier flights, variable pitch, venting sections — these affect performance for your specific material.
• Application match: Conical twin screw barrels are widely used for PVC pipe/profile extrusion, WPC, foam board, sheet, etc — choose size/design based on your machine and product.

📩 Contact Information
Zhoushan Juyuan Machinery Co., Ltd.
🌐 Website: https://juyuan-machinery.com/
📧 Email: cxj.job@gmail.com
📞 WhatsApp / WeChat / Phone: +86 13905808474