National Physical Laboratory

Melt flow rate (MFR/MVR)

The melt flow rate method is a measure of the ease of flow of a material.

The principle is to determine how much material is extruded through a die in a given time when a load is applied to the molten sample in a barrel. Testing is carried out under tightly specified conditions of temperature, load and test geometry thereby maximising the comparability of results obtained.

The melt flow rate technique is appropriate for quality control purposes and provides a simple, qualitative measure of the processability of the material. The results obtained are not fundamental rheological properties, and tend to be obtained at relatively low shear rates. However, recent work at NPL has demonstrated that the melt flow rate instrument, with minor modifications, can be used to determine quantitatively accurate shear viscosity and entrance pressure drop data.

NPL Facility: Instrumented melt flow rate instrument for testing wide range of thermoplastics materials.

Last Updated: 18 Aug 2016
Created: 1 Sep 2008


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