MODULAR TANGENTIAL COUNTER-ROTATING TWIN-SCREW EXTRUSION - DETERMINATION OF SCREW PUMPING CHARACTERISTICS OF MODULES AND COMPOSITE MACHINE BEHAVIOR

Extensive experimental studies of a starved flow modular tangential sc rew extruder are described. Die pressures and fill factor profiles alo ng the screw axis are measured and used to determine screw characteris tic curves Q vs. Delta P/L for individual screw elements of varying de signs in a Leistritz twin screw extruder. Superior pumping characteris tics of matched as opposed to staggered elements is found. The experim ental screw characteristic curves are compared with the results of mat hematical simulations of the flow. Agreement is generally good.