Rheology of poly(vinyl chloride) dry blends. II. Mathematical modeling for physical changes in processing

The effects of physical processing changes on Plasticorder behavior of a typical PVC dry blend are mathematically quantified using the random particulate transition model developed in Part I. The physical processing changes studied are Plasticorder bowl temperature, dry blend charge mass, rotor rpm and resin molecular weight. By quantifying the amount of change observed in the transition parameters (mean time for transition for i to occur, ti and standard deviation of the time required for transition i to occur, ti) as a result of the physical process changes, a two‐fold benefit results. First, a mathematical means of altering only desired fusion characteristics by a precisely predetermined amount is now possible. Second, the sensitivity of different changes, provides insights into the more fundamental aspects of the fusion process itself. The extension of this technique to chemical changes in the dry blend formulation, which is the subject of Part III, is briefly discussed.