HEAT-TRANSFER IN SINGLE AND TWIN-SCREW EXTRUDERS

The elementary processes during heat transfer in screw extruders are d escribed by a simulation model. The balance equations are solved numer ically with a personal computer. By contrast with known computational approaches, consideration is given to the non-stationary processes in the melt layer between the screw flight and the barrel wall. This is g uaranteed by incorporating the ''pulsating shear'' in this layer into the model as a dissipative energy source. The computational results ar e used to demonstrate, in an exemplary fashion for one extruder series , the influence of all the relevant machine and process parameters on the internal heat transfer.