Simulation of Screw Pumping Characteristics for Intermeshing Counter-Rotating Twin Screw Extruders

Intermeshing counter-rotating twin screw extruders play an important role in polymer processing, especially for the extrusion of profiles and pipe, largely from polyvinyl chloride There has been little effort on flow modeling of these machines and most of this has involved representing the machine as a "leaky" positive displacement pump and estimating leakages In recent years, M H Hong and the authors have developed more general methods of simulation of flow in this machine and both applied and experimentally verified it for a few designs Here we extend these efforts to a broader range of screw designs, especially with deeper screw channels where transverse shearing induced by the flights is important Calculations are done for isothermal power law fluids The results are compared with experiment POLYM ENG SCI, 51 37-42, 2011 (C) 2010 Society of Plastics Engineers