FEEDSTOCK IN THE PRESENCE OF INORGANIC FILLERS UNDER CONDITIONS CORRESPONDING TO PROCESSING OF POLYMERS BY EXTRUSION AND DIE CASTING

This work discusses simulations of rheological behavior of polymer feedstock, under conditions corresponding to polymer processing by extrusion and die casting, on the basis of data obtained by analysis of viscosity of composite melt in the oscillation range from 0.01 to 100 Hz. The considered compositions were based on secondary polypropylene and inorganic fillers (chalk additive and aluminum silicate spheres) and produced by pressing and die casting. Rheological properties of the polymer composition melts were evaluated by a HaakeMarsIII rheometer. It is established that all considered compositions are non-Newtonian, viscoelastic, pseudoplastic fluids, the viscosity of which decreases with the increase in oscillation frequency. Since in the range from 0.01 to 100 Hz the experimental viscosity variations as a function of oscillation frequency are rectified well in logarithmic coordinates, it becomes possible to derive approximation equations for prediction of melt viscosity under conditions corresponding to processing of polymers by extrusion and die casting (about 10,000 Hz).Correlation between the calculated viscosities and experimentally determined elastic modulus of the prepared compositions has been shown.