Study On Influence Of Flight Configuration Of Injection Screw To Melt Conveying Performance In Metering Zone

Injection screw is one of the most key parts of injection molding machine that affects the melt conveying performance and plasticization effect directly. It is very necessary for improving the quality of product to establish a reasonable structure of injection screw.This paper utilized POLYFLOW, a CFD software to have three dimentional simulation for melt body in the metering zone of injection screws with different flight cross section. By simulation, the effect on performance of PC melt conveying from different structural screws was discussed.Three kinds of flight cross sections were researched including rectangular cross section, hackle cross section and trapezoid cross section. Pressure fields and velocity fields were obtained by transient simulation in metering zones of screws with different flight cross sections. Then post-processing was made to analyze the melt conveying ability, distributive mixing performance and PC melt flow conditions of different structural screws. Screws with rectangular cross section were studied on the performance of PC melt conveying with various arc radiuses, different screw retraction velocities and screw rotating speeds. The slant angles of hackle cross section affecting PC melt conveying performance were also researched. To trapezoid cross section, discussed various arc radius and slant angles influence to PC melt conveying performance. Furthermore, Orthogonal design was adopted this paper. Flow capacity and reflux were used as the index for the optimizing of trapezoid cross section. Some calculations were given by simulation and analysis which had practical value.