This machine unit is a complete pelletizing unit consists of series single screw extruder or conical twin screw extruder and the corresponding down stream machines. The production line is mainly used to produce granules of various applications of such plastic materials as the PET, PP, PA6, PE, ABS, PVC, etc; the granules are of uniform sizes, good density and good looking appearance The production line has the advantages of good plasticization, even mixing and compact structure; the auxiliary machine is of fan sending type collection, vibration separation and cooling, or strand cutting in the stainless water tank. The machines are of high automation and production efficiency.