Comparison of Twin-Screw Extruders and Single-Screw Extruders: Characteristics
Feb 04, 2026
The barrel structure of twin-screw extruders is similar to that of single-screw extruders, also divided into integral barrels and segmented barrels. Intermeshing counter-rotating and conical extruders generally use integral barrels; only a few large extruders use segmented barrels to facilitate machining and save on expensive alloy steel materials. Co-rotating extruders mostly use segmented barrels. The segmented barrel is divided into several sections of equal length. Some sections have feeding ports, some have venting ports, and some have additive ports.
These sections are then connected with screws to form a combined twin-screw barrel.
Characteristics of Twin-Screw Extruders Compared to Single-Screw Extruders:
1. Simple feeding. Because the material is transported based on the positive displacement principle, it can handle materials with very high or very low viscosity, as well as strip-shaped materials, viscous materials, and granular materials.
2. Short residence time of materials in the extruder, with a narrow residence time distribution. Therefore, the extruder is more suitable for processing heat-sensitive materials.
3. Excellent venting performance. This is due to the self-cleaning effect of the intermeshing twin screws, which allows for sufficient surface renewal of the material in the venting section.
4. Excellent mixing and melting effect.
5. Lower power consumption. Power consumption is about 30% lower than that of single-screw extruders, giving twin-screw plastic extruders a significant advantage in energy saving and consumption reduction.
In co-rotating twin-screw extruders, because the velocity directions of the screw flights and grooves in the intermeshing zone are opposite, the relative speed is high, resulting in a considerably high shear rate. This can scrape away any accumulated material adhering to the screw, providing excellent self-cleaning action, thus resulting in a very short residence time of the material and preventing local degradation and deterioration.
