AbstractVarious formulations of unplasticized PVC dry blends were investigated by extrusiometer and laboratory batch mixer (mixing chamber). Torque versus time curves of the mixing chamber experiments were characterized by three, essentially independent data: fusion time, equilibrium torque, and stability time, corresponding to the three distinct phases of the processing. Fair correlation was found between fusion characteristics of the compound and the energy required for its processing in the extrusiometer. The effect of composition on extrusiometric and mixing chamber data was investigated by multiple linear regression technique. The results allow prediction of the effect of recipe changes.