A network analysis of a screw mixing zone

Starting from our previous results concerning the melt flow during the disp ersive mixing zones of Maddock and Egan type, one establishes relations for the pressure variation, appropriate for incremental calculation. Because g enerally the melt flow along the mixing zone is non-isothermal, one establi shes relations for the temperature variation along the mixing zone, namely: temperature variation caused by, external heating, by internal friction, b y external friction and due to melt compressibility. By using the established relations one develops a network procedure for pre ssure and temperature variation calculation along the mixing zone. The comp uter program based on the network procedure was used to calculate a usual m ixing zone for a 63.5 mm extruder-screw. The program gives the possibility to represent the pressure and temperature variation between the inlet and t he outlet of the mixing zone. This is useful when we are interested in the optimum design of such mixing zones.