Nitrided Conical Twin Screw Barrel for PVC Extrusion Φ25-185
Product Summary
This nitrided conical twin screw barrel is manufactured from premium 38CrMoAl steel (1.8509) with gas nitriding surface treatment. It offers a hardness after hardening and tempering of HB260-310 and a nitrided case depth of 0.45-0.7mm with brittleness less than grade 2. The barrel ensures excellent wear resistance and dimensional stability for continuous PVC extrusion operations. Suitable for pipe, profile and sheet applications with high-filler content.
Key Selling Points
Precision Straightness: Screw straightness ≤0.015mm ensures uniform plasticizing and reduced wear on downstream equipment.
Controlled Nitriding: Nitrided hardness HV850-1000 with depth 0.45-0.7mm provides a hard, wear-resistant surface while maintaining core toughness.
Surface Finish: Ra 0.4 surface roughness minimizes material adhesion and improves melt quality.
Proven Material: 38CrMoAl steel offers high fatigue strength and is widely used in demanding extrusion environments.
ISO 9001 Quality: Manufactured under ISO9001:2015 certified processes, ensuring consistent dimensions and performance.
Technical Specifications
Parameter
Value
Hardness After Hardening & Tempering
HB260-310
Nitrided Hardness
HV850-1000
Nitrided Case Depth
0.45-0.7mm
Nitrided Brittleness
Less Than Grade 2
Surface Roughness
Ra 0.4
Screw Straightness
0.015mm
Diameter Range
Φ25/50 – Φ185/340
Material
38CrMoAl (1.8509)
Models and Options
Available in standard diameters from Φ25/50 up to Φ185/340. Custom lengths and compression ratios can be supplied upon request. Standard nitrided finish (no additional coating). Options for optional chromium plating post-nitriding (≥900HV, 0.025-0.10mm).
Materials and Structure
Constructed from forged 38CrMoAl alloy steel, known for its high hardenability and nitriding response. The barrel is milled and heat treated to achieve a core hardness of HB260-310, then gas nitrided to form a hard, wear-resistant surface layer. The conical twin-screw geometry provides efficient compression and plasticizing for PVC powder.
Applications
Designed for PVC pipe, profile, and sheet extrusion lines. Suitable for processing rigid PVC, high-filler PVC compounds (e.g., with CaCO3), and other thermoplastic materials requiring stable low-shear plasticizing. Operates in continuous counter-rotating extrusion mode.
Customization
We offer custom dimensions, special lengths, and alternative surface treatments such as chromium plating or bimetallic lining for extreme wear conditions. Contact us with your drawings or specifications.
A global plastic products manufacturer used our nitrided conical twin screw barrel in a high-filler PVC compounding line. The barrel maintained dimensional stability over 2 years of continuous operation, reducing downtime and improving output consistency. Customer reported 25% longer service life compared to previous supplier.
FAQ
What is the typical lead time for a nitrided conical twin screw barrel?
Lead time depends on size and quantity. Typically 4-6 weeks for standard sizes. Contact us for exact delivery.
Can this barrel be used for UPVC extrusion?
Yes, it is ideal for unplasticized PVC (uPVC) as well as high-filler compounds.
What is the maximum operating temperature?
The barrel can operate up to 350°C surface temperature under normal conditions.
Do you provide a bimetallic option?
Yes, bimetallic lining is available for abrasive materials. See our bimetallic product variant.
What certifications do you hold?
We are ISO9001:2015, ISO14001:2015, and ISO45001:2018 certified.
Can you manufacture based on my drawing?
Yes, we accept custom drawings and can produce to your exact specifications.
What is your MOQ?
MOQ is 1 unit. We also accept batch orders from 1 to 50 pieces.
