The SJZSJ series of cone-shaped double-screw extruder, developed by our company using the national and international sophisticated techniques, is the advanced product in the new century. It is characterized by good cutting effect, not easy-to-decompose of the materials and excellent mixing plasticization. It is applicable to the modification of various kinds of plastic and the powder-prilling. Especially, polyvinyl choloride powder can be extruded into pipes, panels, slices, films and heterotype panels. Both the specially used high torque decelerating box densmedius and the bearing are made with the technique of high-cutting, low-melt plasticiaing temperature of the screw, the extruder guarantees the high-performance of extruding.