The screw and the cylinder of SJ-PP type automatic or manual PP plastic strapping band making machine adopts excellent-quality alloy steel through nitrogenization treatment. It has the advantages of long life for use, good abrasion resistant and high output of extruding. With the advantages of automatic temperature control, economical power consumption, high output and easy operating. It uses PE powder mainly I & II grade recycling material as its main raw material. During the process of producing, the granules neednt to be dried or mixed and directly use mineral powder instead of expensive master batch to produce automatic strapping band, which can improve the quality of the products and reduce the production cost of the collocated printing ink EP device to a great extent.