A comparison between various screw-barrel-concepts for rubberextruders - Part 1: Presentation of the comparison-method

The process in a rubber extruder is explained by means of the drag/pressure flow theory. Important process parameters, beside the screw speed, are the output, head pressure, specific energy and extrudate temperature By means of a simplified theory it can be explained that the output per screw rotati on is influenced by the head pressure. The extrudate temperature increases and the homogeneity of the extrudate improves at increasing head pressure. Various screw-barrel-designs are compared to each other. Results obtained f rom extruder experiments are explained by means of the working principle of the extrusion process. It is shown that the presented procedure to compare different extrusion processes got evidence.