The melt flow index (MFI) of a polymer is an important process-relevant property that reflects how well the material flows in the melt. The MFI value indicates how much polymer melt flows through a thin capillary at a certain temperature and imposed load. This ConcepTT concerns the development of an adapted MFI device for testing recyclates, called rMFI ('recycled' MFI). The potential market for this technology is twofold: there are the potential end users of an rMFI and the potential partners for marketing such a device. The final goal of this project is a technical proof-of-concept for rMFI, including an accessible conversion method between rMFI and MFI values.