melt flow index

initialism: MFI
synonyms: melt flow rate, MFR, melt mass flow rate, melt volume flow
https://doi.org/10.1351/goldbook.12787
Mass of a polymer in grams that flows through a calibrated orifice at constant temperature under a specified load over a \(\pu{10\!{-}min}\) period.
Notes:
  1. There is no suitable SI unit for MFI.
  2. Specified loads are mandated for specific polymers.
  3. The values of MFI as a function of load can give information on the molar mass distribution.
  4. Standard procedures for determining MFI are available from ISO and ASTM.
Source:
PAC, 2013, 85, 1017. (Glossary of terms relating to thermal and thermomechanical properties of polymers (IUPAC Recommendations 2013)) on page 1033 [Terms] [Paper]