When PVC compounds are mixed under appropriate conditions of heat and shear, a fused mass is produced. This mass has certain melt characteristics which can be defined with a torque rheometer operated under fixed conditions of shear and temperature. The fusion characteristics of a PVC compound are manifest as fusion time, fusion torque, melt torque, melt viscosity, and heat and color stability.

A control lot is to be used as a standard against which other test results are to be compared. Test data are to be evaluated relative to the control lot.

1.1 This practice covers the relative fusion characteristics of poly(vinyl chloride) compounds.

1.2 The test procedures appear in the following order: