Numerical analysis of a reactive extrusion process. Part II: Simulations and verifications for the twin screw extrusion

A newly designed extruder reactor for grafting vinyl monomers onto polyolef ins was studied experimentally and theoretically. The process was made up o f a self-wiping co-rotating twin screw extruder with a separated reaction z one and two vent zones. The reactive extrusion was performed using a linear low density polyethylene, vinyltrimethoxysilane and di-t-butylperoxide und er different operation conditions. For the purpose of process analysis, we built a computer simulation based on the reaction kinetics and rheological models studied in the preceding paper. The flow field in the extruder was c alculated by the flow analysis network [FAN) method with non-isothermal non -Newtonian flow conditions. The iterative procedure was organized to predic t local pressure, filling factor, cumulative residence time and temperature along the extruder. Furthermore, we succeeded in representing the profiles of reaction conversion and shear viscosity. Calculated results showed good agreements with the experimental data.