Two-Stage Extruder for PVC, Cable Compounds, WPC, and Masterbatch

The two-stage extruder from Nanjing Hundred Horse is designed for special materials that need strong mixing but gentle melt handling. The line combines a twin screw extruder as the first stage and a single screw extruder as the second stage.

This structure is suitable for soft PVC, HFFR cable compounds, XLPE cable materials, wood plastic composites, and high-concentration carbon black masterbatch.

Twin Screw + Single Screw Design

In the first stage, the twin screw extruder provides melting, mixing, dispersion, and devolatilization. It usually operates at higher screw speed to achieve efficient compounding and stable throughput.

In the second stage, the single screw extruder works at lower speed with a larger screw diameter. It reduces shear, controls melt temperature, builds stable pressure, and delivers the material to the pelletizing system.

This separation of mixing and pelletizing makes the process more stable for materials that are difficult to process on a one-stage extruder.

Key Features

• Two-stage structure: twin screw extruder + single screw extruder
• Strong mixing and dispersion in the first stage
• Low-speed single screw operation in the second stage
• Reduced shear before pelletizing
• Improved melt temperature control
• Stable pressure build-up for pellet production
• Suitable for heat-sensitive and shear-sensitive compounds
• Configurable feeding, cooling, venting, die head, and pelletizing system

Applications

The two-stage extruder is mainly used for cable compounds, PVC compounds, WPC materials, crosslinkable materials, and high-loading masterbatch.

• Soft PVC cable compounds
• PVC compounds for cable, hose, and pipe fittings
• HFFR cable compounds
• XLPE cable materials
• Low-smoke halogen-free flame-retardant compounds
• Wood plastic composites
• High-concentration carbon black masterbatch
• Soft PVC medical compounds
• Rigid PVC compounds

When to Use a Two-Stage Extruder

A two-stage extruder is recommended when the material needs good dispersion but should not be exposed to excessive shear or overheating.

• When one-stage extrusion causes unstable melt temperature
• When the formulation is sensitive to shear
• When the material contains high filler or flame-retardant content
• When stable pelletizing pressure is required
• When processing PVC, XLPE, HFFR, WPC, or carbon black masterbatch

Main Advantages

• Better balance between mixing and temperature control
• Lower risk of material degradation
• More stable pelletizing process
• Suitable for difficult formulations
• Flexible line configuration according to material and output requirement

Customized Two-Stage Extrusion Line

Nanjing Hundred Horse can configure the complete line according to the customer’s material, formulation, target output, and pelletizing method. The system can include feeding units, twin screw extruder, single screw extruder, cooling system, die head, pelletizer, conveying system, and control cabinet.

Request a Two-Stage Extruder Configuration

Send us your material type, formulation details, required output, and final product application. Nanjing Hundred Horse will recommend a suitable two-stage extrusion line for your production needs. Request a Quotation