What is a Melt Flow Index Tester? A Melt Flow Index Tester, often referred to as a Melt Flow Index Tester, is a device used to measure the melt flow rate of thermoplastic polymers. The melt flow rate (MFR) is an indicator of the material's viscosity, which in turn provides insights into its molecular weight and structure. Essentially, the Melt Flow Index Tester helps determine how easily a...