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日本語 What Is a Co-Rotating Twin-Screw Extruder?
A co-rotating twin screw extruder is a type of twin-screw extruder in which both screws rotate in the same direction. The two screws are arranged in parallel and intermeshed within the barrel.
Co-rotating twin-screw extruders provide excellent mixing, dispersion, and self-cleaning performance. They are widely used in plastic compounding, masterbatch production, pharmaceutical processing, food processing, and reactive extrusion.
Product Recommendations
Different materials and process requirements require different extrusion configurations.According to the material properties, production capacity, and processing objectives, different screw designs and extrusion systems can be selected to ensure stable compounding performance and consistent product quality.
Beyou provides co-rotating twin-screw extrusion solutions ranging from laboratory testing to industrial production lines, covering applications in polymer compounding, masterbatch production, recycling, and functional materials.
The following series are designed to meet different processing requirements and production scales.
Classic General-Purpose Model
- Balanced process flexibility, stable operation, and cost efficiency.
- Ideal for standard compounding applications, including filling, reinforcement, flame retardancy, coloring, blending, and polymer modification.
- Suitable for polymer compounding, masterbatch production, recycling pelletizing, and biodegradable materials.
High Torque, High Mixing Efficiency
- Higher torque and enhanced mixing performance for demanding formulations.
- Suitable for highly filled, reinforced, flame-retardant, and engineering plastic compounds.
- Ideal for medium- to high-output production requiring improved dispersion and processing efficiency.
High-End, High-Speed, High-Torque
- Designed for high-speed, high-torque, and high-capacity continuous production.
- Ideal for polyolefin alloys, functional and flame-retardant masterbatches, biodegradable materials, and highly filled compounds.
- Delivers maximum productivity for large-scale industrial applications.
Small-Scale Experimental Model
- Compact extruder for laboratory R&D, formulation development, and sample production.
- Suitable for universities, research institutes, and industrial R&D centers.
- Ideal for engineering plastics, biodegradable materials, flame-retardant compounds, conductive materials, TPEs, and reactive extrusion.
Comparison of Selectable Parameter Ranges Across Different Series
(Varies by Specific Model)
| Parameters | CTS-C Series | CTS-D Series | CTS-H Series | Lab Series |
| Screw Speed | Up to 900 RPM | Up to 900 RPM | Up to 900 RPM | Up to 900 RPM |
| Length-To-Diameter Ratio (L/D) | 32–100 | 32–100 | 32–100 | 24–100 |
| Power Range | 45–1000 kW | 75–1200 kW | 90–1400 kW | 1.5–30 kW |
| Output Range | 75–4000 kg/h | 150–6500 kg/h | 240–7000 kg/h | 1–120 kg/h |
| Torque Density | 5.5–6 A³ | 5.9–9.5 A³ | 10.5–11.6 A³ | 5.6–7 A³ |
Key Components of a Co-Rotating Twin-Screw Extruder
Feeding System: Primarily consisting of a hopper, feeder, and feeder drive mechanism, this system is used to feed material into the extruder barrel in a stable and uniform manner. It can be categorized into two types: gravity feeding and forced feeding.
Screw Components: Featuring a “modular” design, these consist of conveying elements, kneading blocks, mixing elements, and reverse elements. They can be flexibly combined and arranged according to process requirements to accomplish specific mixing tasks.
Barrel: Typically features a modular, segmented design that allows for the configuration of functional sections such as feed ports, vent ports, and pressure measurement ports, and is equipped with independent heating and cooling systems. Multi-zone temperature control enables stable process temperature management.
The drive system consists of a motor and gearbox, designed to deliver stable and consistent torque to the screws.It is engineered for high load capacity and reliable operation under conditions of high filler content, high viscosity materials, and continuous production.
Heating/Cooling System: The barrel is equipped with resistance heating elements and a multi-zone temperature control system to ensure precise processing temperature regulation.Cooling circuits are integrated to maintain stable thermal balance, reduce localized overheating, and improve processing stability for temperature-sensitive polymers.
Venting/Devolatilization System:The venting port is typically located on the barrel section and can be connected to a vacuum system for efficient removal of volatiles, moisture, and low-molecular-weight compounds.It is suitable for degassing, devolatilization, and drying processes in polymer compounding applications.
Die and Downstream Equipment: The die defines the final product shape, with common configurations including strand dies and underwater pelletizing dies.Downstream systems typically include pelletizers, water circulation tanks, and air-drying units, which together complete the pelletizing or further processing line.
Control System: Typically centered around a PLC and integrated with a touchscreen HMI, this system enables real-time monitoring and control of parameters such as temperature, pressure, rotational speed, and torque. Some systems also support data logging, alarm notifications, and recipe management to enhance production stability and traceability.
How Does a Co-Rotating Twin-Screw Extruder Work?
A co-rotating twin-screw extruder operates through continuous stages of feeding, melting, mixing, devolatilization, and pressurized extrusion. Two intermeshing screws rotate in the same direction to transport and process materials inside the barrel.
1. “∞”-Shaped Forced Conveyance Mechanism
After entering the feed zone, material is transported forward through the screw channels into the intermeshing region.At the meshing point, material is continuously transferred between the two screws, forming an “∞”-shaped conveying path. This positive displacement mechanism ensures stable feeding even at low fill levels.
2. High-Shear Mixing and Homogenization
In the mixing zone, the material is subjected to shear, compression, and elongation forces generated by the intermeshing screws.
This process enables melting, dispersion, and homogenization. Additional shear from screw–barrel interaction further improves mixing efficiency and melt uniformity.
3. De-gassing, Volatile Removal, and Melt Pressurization
In the venting section, moisture, solvents, and low-molecular-weight volatiles are removed under vacuum conditions.
The melt then enters the metering zone, builds stable pressure, and is extruded through the die for shaping
Advantages of Co-Rotating Twin-Screw Extruders
The unique structure and operating principles of co-rotating twin-screw extruders offer the following advantages:
- Efficient mixing for filled and modified materials
- Stable conveying with strong feeding adaptability
- Effective devolatilization and moisture removal
- Good self-cleaning performance reduces buildup
- Suitable for continuous industrial production
Co-Rotating Twin-Screw Extruder Applications
- Polymer compounding and modification (fillers, fibers, additives)
- Masterbatch production (Color / White / Black / Filler / Functional)
- Engineering plastics and high-performance materials
- Reactive extrusion (grafting, polymerization, functionalization)
- LFT long fiber reinforced composites
- Recycling and biodegradable materials (PLA, PBAT, starch blends) etc.
