Abstract: A mathematical model of parallel pressure stabilization apparatus for single screw extruder is established based on the assumptions of power law fluid and isothermal process. Numerical solutions for the model are carried out with the help of MathCAD. The influences of geometrical and technological parameters on the stability of extrusion pressure and output with specified pressure fluctuant pattern at the end of main screw are studied. The simulation results indicate that when the screw speed of parallel pressure stabilization apparatus is fixed, the pressure and output fluctuation of extrusion can be compen-sated up to 97.6% with automatic regulation of filling length of the polymer melt in the barrel. If the screw speed of parallel pressure stabilization apparatus is varied corresponding to the pressure fluctuation, the pressure and output fluctuation of extrusion can be fully compensated.

Key words: Extrusion, Mathematical model, Polymer, Stabilization