... plastic extrusion line equipped with the conical double screw extruder,and it possesses the advantages ... including the below parts: conical double screw extruder,vacuum sizing platform,tractor,cutting and film coating ... that of single-screw. To match with different moulds,the shape-fixing platform of 4m,6m ... ,8m, or 11m,can be chosen accordingly. The main machine with parallel double ...