In the field of polymer processing, a few established models for the conveying and melting behavior within twin-screw extruders exist. These models picture the majority of relevant industry applications well. The polymer solid temperature development is calculated under consideration of thermal conduction and convection, for example within the solid temperature calculation of Melisch [1]. However, the frictional heat, resulting from relative motion within the partially filled screw channel and the heat transfer between cylinder and screw, is being neglected in the models. In order to analyze the other dissipation processes, numerical simulations based on the Discrete Element Method (DEM) have been carried out. With the help of a DEM-simulation-program, a 32 mm twin-screw test stand has been built up. It is possible to simulate the conveying of different polymer pellets, whose material characteristics have been defined in preliminary investigations and were implemented in the simulation. By evaluating the contacts between the particles, the particles and screws and particles and barrel surfaces, the dissipation within the system is calculable. Therefore, it is now possible to evaluate the temperature at the end of different solid conveying zones, in due consideration of friction and heat transfer because of barrel contacts. In upcoming experimental investigations the simulated temperatures at the end of the solid conveying zone will be verified. After the verification it will be possible to build up a new model to calculate the dissipation in the solid conveying zone for common extruder sizes. [1] U. Melisch: Grundlagen zur Simulation des Förder- oder Plastifizierprozesses dichtkämmender Gleichdrall-Doppelschnecken. Dissertation, University of Paderborn, 1998