Determination of the Melt Mass Flow Rate (MFR) and Melt Volume Flow Rate (MVR)

ISO 1133, ASTM D1238

Mflow measuring spoon

Extrusion plastometers provide standard values for the melt index (MFR) and volume index (MVR) of filled and unfilled thermoplastics to ISO 1133, ASTM D1238, and other similar standards.

Method A, MFR

The Cflow extrusion plastometer consists of an extrusion barrel which is heated exactly to a preset temperature, a die of standardized diameter, and a piston with a weight applied to its upper end.

  • The extrusion barrel is filled with the material to be tested.
  • After a defined preheat time, the material is extruded through the die by the force of the applied weight.
  • The extrudate is cut off at constant time intervals and weighed. The result is the melt mass flow rate (MFR), which is calculated from the extruded mass per 10 minutes.
  • This method is suitable for individual tests with lower specimen quantities.
Melt flow determination/melt index test ISO 1133-1/-2, ASTM D1238
Fließprüfgerät Cflow

Video of Mflow Extrusion Plastometer


Mflow extrusion plastometer in all models

The modular Mflow extrusion plastometer is used to determine the melt flow rate (MFR) and volume flow rate (MVR).