What Is a Bimetallic Screw Barrel and Why It Matters in Plastic Processing

In the world of plastic machinery, the bimetallic screw barrel plays a crucial role in ensuring stable, high-efficiency production. As plastic materials become more diverse and demanding—ranging from fiber-reinforced polymers to highly corrosive compounds—the limitations of conventional nitrided barrels have become increasingly apparent. This is where bimetallic technology offers a major breakthrough.

At Tan Star Industries (TSI), we have devoted decades of experience to the research and manufacturing of bimetallic screw barrels that meet the evolving needs of the plastic processing industry. Our goal is to help manufacturers achieve greater precision, durability, and reliability through advanced materials engineering and refined production techniques. In this article, we share an in-depth look at how bimetallic technology works, why it matters, and how TSI’s expertise is helping shape the future of plastic processing.

Understanding the Bimetallic Structure

A bimetallic screw barrel consists of two distinct layers:

• Base metal (substrate): Usually made of high-strength alloy steel, providing rigidity and structural support.

• Alloy layer (inner surface): Made of wear-resistant and corrosion-resistant materials such as nickel-based or tungsten-based alloys, formed through a process like bimetallic centrifugal casting.

This composite design combines the mechanical strength of the base with the surface protection of the alloy, resulting in a barrel that can endure harsh operating conditions while maintaining precise dimensions and smooth internal surfaces.

Key Advantages of Bimetallic Screw Barrels

1. Superior Wear Resistance
   The alloy layer significantly reduces abrasion caused by fillers, glass fibers, and mineral additives, extending barrel life by up to three to five times compared to nitrided barrels.

2. Excellent Corrosion Resistance
   When processing materials containing halogenated compounds (such as PVC or flame-retardant resins), the bimetallic layer prevents chemical corrosion and pitting damage.

3. Enhanced Production Stability
   Consistent inner diameter and surface finish improve plasticizing efficiency, ensuring uniform melt flow and reducing defects such as black spots or gels.

4. Longer Service Life and Lower Maintenance
   The robust structure minimizes the need for barrel replacement, reducing downtime and overall operational costs.

5. Wide Material Compatibility
   Bimetallic barrels are suitable for a broad range of applications, including injection molding, extrusion, blow molding, and recycling systems.

TSI’s Expertise in Bimetallic Screw Barrel Manufacturing

Building upon these advantages, Tan Star Industries (TSI) provides a complete range of bimetallic barrels and bimetallic screws engineered for exceptional durability and precision in demanding plastic processing environments.

Our bimetallic barrels feature inner diameters up to 270 mm and lengths up to 7,500 mm, meeting the needs of a wide range of injection molding and extrusion systems. Each component is produced using advanced bimetallic centrifugal casting, controlled heat treatment, and multi-axis CNC machining, ensuring strong alloy adhesion, uniform hardness, and dimensional accuracy throughout the entire production cycle.

By combining superior metallurgy with decades of engineering experience, TSI delivers products that maintain outstanding wear and corrosion resistance — even when processing glass-fiber-filled, flame-retardant, or high-abrasion materials. Our screw and barrel solutions help manufacturers achieve higher efficiency, longer equipment life, and reduced maintenance downtime.

(See more: Bimetallic Barrels | Bimetallic Screws)

How It’s Made: Precision Meets Durability

The manufacturing of a bimetallic screw barrel involves centrifugal casting, a process where molten alloy is spun inside the barrel shell at high speed. This ensures dense bonding between layers and a uniform alloy thickness. After casting, the barrel undergoes precision heat treatment and CNC machining, guaranteeing concentricity and surface hardness uniformity.

These strict production controls ensure every TSI bimetallic barrel delivers consistent performance, even under high temperature, high pressure, and long production cycles.

Applications Across Industries

Bimetallic screw barrels are widely used in:

• Injection molding machines for automotive, appliance, and electronics components.

• Extrusion lines for pipes, sheets, and profiles.

• Blow molding machines for containers and packaging materials.

• Recycling equipment that handles abrasive or contaminated plastics.

Whether it’s for precision molding or continuous extrusion, manufacturers rely on bimetallic technology to enhance durability and efficiency in their production systems.

Why It Matters — and Why Choose TSI

In modern manufacturing, where uptime and precision directly affect profitability, choosing a bimetallic screw barrel is not just an upgrade — it’s an investment in performance, quality, and consistency.

At Tan Star Industries (TSI), we combine decades of expertise in bimetallic centrifugal casting with precision machining and metallurgical innovation to create barrels and screws that perform reliably in the toughest production conditions. Our commitment to continuous improvement ensures every TSI product exceeds international standards for durability and precision.

Ready to enhance your production line?
Contact Tan Star Industries today to discuss your custom bimetallic screw barrel requirements and experience the next level of efficiency and reliability.