What is a bimetallic screw barrel and how does it differ from a standard screw barrel?- Zhoushan Jiading Plastic Machinery Co., Ltd.

A bimetallic screw barrel is a component used in plastic extrusion or injection molding machinery. It consists of two distinct layers or materials that are bonded together. The primary purpose of a bimetallic screw barrel is to enhance the performance, durability, and service life of the screw barrel in high-wear and high-temperature plastic processing applications. Here's how a bimetallic screw barrel differs from a standard screw barrel:

1.Construction: A standard screw barrel is typically made from a single material, often a high-grade alloy steel. In contrast, a bimetallic screw barrel consists of two layers: a base material and a wear-resistant layer. The base material provides structural integrity, while the wear-resistant layer offers improved resistance to abrasion, corrosion, and thermal degradation.

2.Material Composition: The base material of a bimetallic screw barrel is often a high-strength alloy steel, selected for its strength and toughness. The wear-resistant layer, also known as the bimetallic liner or coating, is composed of a different material, such as a high-performance alloy or a metal matrix composite. The wear-resistant layer is usually applied through processes like centrifugal casting, laser cladding, or plasma spraying.

3.Wear Resistance: The wear-resistant layer in a bimetallic screw barrel significantly enhances its resistance to abrasive wear caused by the continuous contact with plastic materials during processing. This wear resistance helps prolong the service life of the screw barrel and reduces the need for frequent replacements or repairs.

4.Corrosion Resistance: The wear-resistant layer of a bimetallic screw barrel often exhibits excellent corrosion resistance, protecting the screw barrel from the corrosive effects of certain plastics, additives, or processing conditions. This is especially important when processing materials with high chemical aggressiveness.

5.Thermal Stability: Bimetallic screw barrels are designed to withstand high processing temperatures encountered during plastic extrusion or injection molding. The wear-resistant layer helps to improve the thermal stability of the screw barrel, minimizing deformation or degradation due to heat exposure.

6.Cost Efficiency: While bimetallic screw barrels may have a higher initial cost compared to standard screw barrels, their enhanced durability and resistance to wear can result in cost savings over the long term. Reduced downtime for replacements or repairs and improved productivity due to extended service life contribute to overall cost efficiency.

It's important to note that the specific design, materials used, and manufacturing processes of bimetallic screw barrels may vary among different manufacturers and applications. When selecting a screw barrel, it's crucial to consider the specific requirements of the plastic processing application and consult with experts or manufacturers to ensure the suitability of the chosen bimetallic screw barrel.

Single extruder bimetal screw and barrel

Single extruder bimetal screw and barrel

The bimetallic barrel for single screw extruder is a kind of barrel spray 2-5mm thick alloy coat on the barrel inner wall which has excellent corrosion resistance, abrasion resistance and high working temperature. And its useful service life is greatly improved contrast to common nitrided barrel. Bimetal has more obvious advantages when processing special plastics to enhance the abrasion life, such as engineering plastics, fluoride plastics, PPO etc. Our company use special alloy powders being sprayed and welded on the top of screw flights, and use different alloys and welding methods.