Melt Flow Index Tester is Instruments of the testing as known as MFI. MRI is a measure of the ease of flow of the melt of a thermoplastic polymer. Presto Group Melt Flow Indexers are specifically designed for easy and accurate measuring of the Melt Flow Rate. Melt Flow Index Tester the determination of the melt flow index of plastic materials is an important parameter in the evaluation of its quality.