One is a screw and the other is a two screws. All are driven by a single motor. Power differs depending on the screw.
The main body of the twin-screw compressor is not stable and is affected by the radial force of the axial force. The axial force must be formed by the flat-edged piston. The bearing life is short and the screw has high frequency noise.
The single-screw unit is less noisy during operation, but has a smaller stand-alone capacity. The twin-screw unit has a large range of cooling capacity and the unit performance is basically similar. Therefore, the twin-screw units are currently used in the market.
At present, the single-screw extruder is the most widely used and suitable for extrusion processing of general materials. The twin-screw extruder has less heat due to friction, more uniform shearing of the material, greater screw conveying capacity, relatively stable extrusion volume, long material stay in the barrel, and even mixing.