Single screw extrusion of SBR compounds - experimental study and numerical simulation

摘要

The flow behaviour of a SBR compound during single screw extrusion process has been investigated. Experiments were conducted on a single screw extruder equipped with various pressure and temperature sensors along the screw profile. Influences of temperature of feed section, screw and barrel were characterised. In order to modify the pressure drop, different dies were used. Three parameters were varied during the tests: the screw rotation speed (15, 40 and 70 min~(-1)), the temperature of the feed section and barrel (30, 60 and 90 °C) and that of the screw (50 and 90 °C), and finally the die restriction. The characteristic curves of the extruder were deduced from the values of head pressure and flow rate. A comparison of the characteristic curves was made to determine which factor (temperature of the feed section, of the barrel or of the screw) was the most significant. An increase in the temperature of feed section induced a decrease of flow rate and pressure. An opposite effect was observed when increasing the screw temperature. Finally, in order to predict the behaviour of this material during the extrusion process, a numerical simulation has been implemented. The 1D model developed may provide orders of magnitude, but is too simplified to account for the complex conditions prevailing in the process.