A higher accuracy as well as a higher level of automatisation are key advantages of the Melt Flow Indexer mi40.

  • ASTM D1238
  • ASTM D3364
  • ISO 1133

The new generation of melt index measurements is embodied by the mi40 from GÖTTFERT. Users in incoming goods and quality control (QC) departments experience the advantage of an automated and more accurate determination of MFR (Melt Flow Rate) and MVR (Melt Volume Rate) according to ASTM D1238 and ISO 1133.

The mi40 combines all the advantages of the MI-3 with a higher degree of automation. The drive can be used for force-controlled pre-compression or ejection or remaining material with a total force of up to 60 kg. The automatic test-plan-controlled weight selection with up to nine integrated weights simplifies operation considerably. The automatic pre-compression with weight or drive reduces operator influence on the measurement result. Fully automatic multi-weight-measurements with up to eight different weights per barrel filling can also be performed.

Due to the high-precision displacement measurement, even very low or very high MFR/MVR-values can be recorded with high precision. The external piston guidance on the guide rod of the test weight makes it possible to measure even very sticky materials with high repeatability.

Our experience shows that cleanliness has an extremely large influence on the precision and accuracy of melt index measurements. For this reason, the test chamber with exchangeable test barrel can be swivelled out and is therefore particularly convenient to fill and clean. The optional integrated semi-automatic cleaning device makes cleaning even easier.

The basic version of the mi40 plastometer can perform MFR or MVR measurements according to ISO 1133 Procedure B and ASTM D1238 Procedure B. Multi-weight-measurements to calculate the FRR (Flow Rate Ratio) according to ASTM D1238 Procedure D are also possible.

With an optional melt cutting device, the measurement results can also be evaluated according to ISO 1133 Procedure A or ASTM D1238 Procedure A. With special capillaries, measurements can also be performed according to ASTM D1238 Procedure C ("half-die") or ASTM D3364.

The mi40 can also be combined with various add-ons. For example, the "viscosity measurement" add-on turns the mi40 into the mi40 visco - a capillary rheometer. This makes it possible to carry out viscosity measurements in accordance with ISO 11443. In combination with an elongational rheometer the mi40 becomes the D-MELT. In a single test, both the MFR and the MF, a key figure for the extensional viscosity, can be determined.

Technical specifications
  • Force controlled pre-compression / ejection via drive with a force of up to 60 kg
  • Multi-load tests with up to 8 different weights in any order
  • Time measurement accuracy better than 0.001 s
  • Temperature control algorithm, resolution 0 to 320°C: 0.01°C, 320 to 500°C: 0.1°C
  • Precise digital displacement measurement with automatic resolution determination
  • Swing-out test chamber design for convenient filling and cleaning
  • External piston guidence
  • Integrated magazine with up to nine test weights from 0.325 kg to 21.6 kg with automatic selection
  • Other test weights available on request
Optional Units
  • Integrated electrical cleaning device
  • Manual capillary plug (special heated version for high temperatures available)
  • Automatic capillary plug
  • Automatic or manual melt-cutting unit (even for very sticky materials)
  • Nitrogen purge for hydroscopic materials
  • Alternative steel grades for barrel and piston with higher corrosion or abrasion resistance
  • Data protection of parameters and results via uninterruptible power supply
  • Inlet-version for extremely sticky powders

Add-ons for advanced measurements

Directly connected laboratory scale for determination of the melt density.


The residual moisture has a considerable influence on the measurement result for certain test materials. Therefore, it is recommended to dry test materials before a IV measurement and to determine the residual moisture.


The measuring head is mounted below the die. The measurement can be carried out parallel to a viscosity measurement.

  • Determination of the dynamic and static die swell
  • Evaluation of a die swell profile (BASELL method)
  • Swivel arm with continuous height adjustment
  • Laser measuring head in 0.1 μm or 7 μm version
  • Optional with automatic melt cutting device
  • Optional: acquisition of two strings simultaneously
  • Application: Simulation of material swelling behaviour during extrusion




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