MFR and MVR indexes of thermoplastics

The measure of the ease of flow of melted thermoplastic materials represents a typical index for Quality Control of thermoplastics.
The Melt Flow Rate (MFR) and the Melt Volume Rate (MVR) indexes are determined by a viscosity measurement in the molten state and represent the quantity of polymer, expressed in grams or cubic centimeter, which comes out of a standard capillary tube, under a standard weight, in defined temperature and time conditions: dimensions of the capillary, weight, temperature and time are defined by the current ISO and ASTM international standard here listed.

The proper instrument is available at our laboratories and you need only a few grams of polymer in the form of pellets, flakes or dust to carry out the measurement.

Normative requirements

– ISO 1133-1:2011 “Plastics — Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics — Part 1: Standard method”
– ISO 1133-2:2011 “Plastics — Determination of the melt mass-flow rate (MFR) and melt volume-flow rate (MVR) of thermoplastics — Part 2: Method for materials sensitive to time-temperature history and/or moisture”
– ASTM D1238 – 13 “Standard Test Method for Melt Flow Rates of Thermoplastics by Extrusion Plastometer”

In addition to the rheological tests which may be useful in the optimization phase of the transformation process of a polymer and in characterization of a new compound or polymer blend, CPTM can also carry out:

– chemical characterization for the determination of the chemical nature (family, presence of inorganic fillers and various additives), for the assessment of the differences between different batches to check for any abnormalities during processing, for deriving information on new compounds or blend polymer;
– physical and mechanical tests on standard test specimens according to the most important international or industrial standards;
– other tests such as thermal measurement, “ageing” effects, chemical compatibility, sizing assessment, etc.

Here below a non-exhaustive list of the available tests: our staff is at your disposal to discuss any other request.

Fluidity

Melt-mass fluidity index – MFI/MFR
Melt-volume fluidity index – MVI/MVR

Residue

Residue percentage at 600°C
Residue percentage at 950°C
Residue percentage at 1250°C
Filler percentage evaluation: talcum, calcium carbonate, titanium and Carbon Black

Specific weight