Abstract: Based on force solid plug-force equilibrium analyses, pressure and advancing angle as well as power models were developed for double-conical screws either with a gradually shallower channel or a constant channel. Numerical calculation showed that the conical screw channel may develop higher pressure than cylindrical screw channel, and this trend became stronger with larger conical angle. The effect of conical angle on the pressure differed at different axial position. The conical screw possessed a larger advancing angle than the regular ones, thus resulted in a higher output and a reduced transporting power.

Key words: conical single screw extruder, compression, output, melting