Why is the bulk density very different between K57 and K71?
The morphology of PVC Suspension resins can be managed by adjusting polymerization conditions but a high bulk density is generally associated with a lower porosity and vice versa. The grade K57 is used in rigid applications so it is important to have a high bulk density and porosity is not so important. The grade K71 is used in plasticized application so the porosity and the kinetics of plasticizer uptake are more important than bulk density.
