The characterization of the steady‐state shear and normal stress functions of highly concentrated suspensions formulated with viscoelastic liquids Available to Purchase

The theme of this presentation is the steady‐state flow behavior of filled plastic melts. These are suspensions in which the continuous phase consists of a viscoelastic liquid. The disperse phase comprises solid particles. A concept for the description of such materials is introduced, which allows the influence of the two phases on the shear flow behavior to be approximately separated. The fluid is characterized by its shear stress and first normal stress function, whereas the influence of the solid phase is described by two shift factors B_τ(c_v) and B_N(c_v). Both are functions of the volume concentration c_v. The prerequisite of the proposed concept is the dominance of fluid dynamic forces over direct particle–particle interactions. The concept has been experimentally tested by suspending the same limestone fraction in four different high molecular weight polymeric fluids. The zero shear viscosities of the suspending fluids varied from η₀=0.12 to 80 kPa s; the volume concentrations up to 45%. The steady‐state shear stress and the first and second normal stress differences of the suspensions and the pure suspension fluid were measured. The observed deviations between the concept and the experiments are discussed. Finally the Bagley end effect behavior is documented.