Influence of mixed fillers on the resistance to extrusion of molten polymers through nozzles and on the smoothness of the extrudate surface

1. The viscosity of a molten polymer, filled with a combined filler consisting of inert particles, follows practically the law of linear additivity. 2. When the filler is active (chalk) and its concentration is C Cc, the addition of a small amount of glass spheres increases the viscosity of the system. 3. In the case of equal filling, the use of a combined filler can reduce swelling of the extrudate. 4. Replacement of a part of the mineral powder by glass spheres improves the surface smoothness of the extrudate of the filled polymer. 5. The use of a combined filler increases the critical shear stress at which distortions of the extrudate surface appear.