The determination of the Melt Flow Rate [MFR / MVR] is carried out according to the standardized ISO 1133 and ASTM D1238 test methods. Polymer melts are melted in a heated test barrel. At the lower end of the test barrel is a standardized capillary is installed. During the measurement the polymer melt will be extruded.

During the test, the amount of material extruded through the capillary per time unit is measured according to a melting time defined in the standards. The determined value is given as Melt Flow Rate (MFR) in g/10min or as Melt Volume Rate in cm³/10min. The test temperature and the load weight are always indicated with the result on the and depend on the material.

The following table shows, for a selection of materials, the test weight and test temperature we recommend for performing the melt flow index test.

Please note, this overview is a recommendation how to carry out the MFR measurement. Material-specific deviations of the test conditions by the polymer manufacturer may occur.