News&Blogs

What Is A Twin Screw Extruder?

Inquire

whatsapp sharing button
pinterest sharing button
twitter sharing button
linkedin sharing button
facebook sharing button
sharethis sharing button

Introduction: Why Twin Screw Extruders Are Essential for PVC Processing

In modern plastic extrusion manufacturing, twin screw extruders are widely recognized as the most reliable solution for processing difficult-to-melt materials such as PVC powder and high-filled compound formulations.


Compared with traditional single screw systems, twin screw extrusion technology offers superior material conveying stability, mixing uniformity, and temperature control — making it the preferred choice for PVC pipe, profile, board, and granulation production lines.


twin screw extruder
SJSZ conical twin screw extruder machine for PVC pipe extrusion


What Is a Twin Screw Extruder?

A twin screw extruder is a plastic extrusion machine that uses two parallel or conical rotating screws inside a heated barrel to convey, melt, mix, and homogenize polymer materials.

Unlike single screw extruders, twin screw systems generate stronger shear and mixing forces, enabling stable processing of:

  • PVC dry blend powder

  • High calcium-filled compounds

  • Rigid PVC formulations

  • Heat-sensitive polymer materials



What Is a Conical Twin Screw Extruder?

The conical twin screw extruder (such as the SJSZ series) is a special design optimized for PVC extrusion.

Its key feature is the tapered screw structure, where the screw diameter gradually decreases along the processing direction. This structure provides:

  • Higher torque output

  • Better powder feeding stability

  • Lower material shear damage

  • Improved plasticizing efficiency


Because of these advantages, conical twin screw extruders are widely used in:

  • PVC pipe extrusion lines

  • PVC profile production lines

  • PVC sheet and board extrusion

  • PVC pelletizing systems



Working Principle of Twin Screw Extruders

The extrusion process consists of several synchronized stages:

Feeding and Conveying

PVC powder or compound material enters the hopper and is evenly distributed between the two screws.


Compression and Plasticization

As the screws rotate in opposite outward directions, the material is gradually compressed, heated, and melted through mechanical shear and barrel heating zones.


Homogenization and Pressure Build-Up

The intermeshing screw structure ensures continuous mixing, uniform melt temperature, and stable pressure before the die head.


Final Extrusion Output

The homogeneous molten PVC is pushed through the extrusion mold to form pipes, profiles, boards, or granules.



Main Applications of Twin Screw Extruders

PVC Pipe Production Lines

Twin screw extruders are the industry standard for producing:

  • UPVC water supply pipes

  • Drainage pipes

  • Electrical conduit pipes

  • Industrial pressure pipelines


PVC Profile and Window Frame Production

Used for:

  • Door and window profiles

  • Decorative panels

  • Skirting boards

  • Construction profiles


PVC Board and Sheet Extrusion

Suitable for:

  • Foam boards

  • Rigid PVC sheets

  • Advertising panels

  • Industrial plastic plates


PVC Pelletizing Lines

Twin screw extruders are commonly applied in PVC compound pellet production with stable granule quality and uniform size distribution.



Technical Advantages of SJSZ Series Conical Twin Screw Extruder

Based on your uploaded technical data, Chenxing Machinery SJSZ Series offers the following engineering advantages:

High Output Capacity

Production capacity range:

  • 60–120 kg/h (SJSZ-45)

  • 200–300 kg/h (SJSZ-65)

  • 300–400 kg/h (SJSZ-80)

  • 600–800 kg/h (SJSZ-92)

Meeting both small workshop and large industrial factory production demands.


Wide Screw Size Options

Available screw diameters:

  • 45/90 mm

  • 51/105 mm

  • 55/110 mm

  • 65/132 mm

  • 80/156 mm

  • 92/188 mm

This allows precise matching to different PVC formulations and output requirements.


Stable Torque Transmission System

Main motor power ranges from:

  • 15 kW to 110 kW,
    ensuring high torque output even under heavy-load PVC extrusion conditions.


Intelligent Heating Control

Barrel heating power up to:

  • 86.8 kW (SJSZ-92)

Multiple heating zones provide accurate temperature control for sensitive PVC processing.


Industrial Structural Design

  • Heavy-duty machine frame

  • High center stability (1000–1200mm)

  • Optimized screw length up to 2500mm effective length

  • Continuous industrial operation capability


Twin screw extruder screw and barrel structure for PVC processing
PVC extrusion production line using conical twin screw extruder


Twin Screw vs Single Screw Extruder: Key Differences

Feature Twin Screw Extruder Single Screw Extruder
PVC Powder Processing Excellent Limited
Mixing Efficiency High Medium
Shear Control Adjustable Basic
Output Stability Very Stable Stable
Investment Cost Higher Lower
Application Focus PVC, Compounds PE, PP, Recycling



How to Choose the Right Twin Screw Extruder?

When selecting a twin screw extruder, consider:

Material Type

PVC powder requires conical twin screw configuration for stable feeding and melting.


Production Capacity Target

Select appropriate model size according to kg/hour output demand.


Product Application

Pipe, profile, board, and pelletizing lines require different downstream equipment matching.


Automation Integration

Modern extrusion factories often integrate:

  • Automatic feeders

  • Gravimetric dosing systems

  • PLC centralized control

  • Online monitoring systems



Why Choose Chenxing Machinery Twin Screw Extruders?

Chenxing Machinery has over two decades of manufacturing experience in plastic extrusion equipment.

Our SJSZ Series conical twin screw extruders are designed with:

  • Precision-machined alloy screws

  • High-strength gear transmission systems

  • Stable electrical control architecture

  • International export-standard manufacturing quality

We supply complete solutions including:

  • PVC pipe extrusion lines

  • Profile production lines

  • Sheet and board production lines

  • PVC pelletizing systems



Call to Action

Looking for a reliable PVC twin screw extruder manufacturer?

Visit www.chenxingmachinery.com
Contact our engineering team for customized extrusion solutions, production line layout design, and technical consultation.


Contact Us

Fill in your material type, product specification and capacity requirement. Our engineer will contact you within 24 hours.

Related Articles

More >>
      Contacts
Phone:+8615951187228
Email:ceo@cxsljx.com
  Address:No.188,Zhenbei Road, Leyu                             Town, Zhangjiagang City,                               Jiangsu Province
Social Media
© Copyright 2026 Chenxing Machinery All Rights Reserved.
We use cookies to enable all functionalities for best performance during your visit and to improve our services by giving us some insight into how the website is being used. Continued use of our website without having changed your browser settings confirms your acceptance of these cookies. For details please see our privacy policy.
×