The recycling of fiber-reinforced thermoplastic composites presents a significant challenge, leading to high waste generation and limited reuse options. The LightCycle project aims to address this issue by developing an energy-efficient and circular method for upcycling glass fiber composite waste and recycling polypropylene (PP). This work focuses on analyzing the material properties of PP regenerates (rPP) from post-consumer waste in Austria, as well as the compounds derived from it and glass fiber-reinforced thermoplastic composites. The goal is to establish material expertise and determine acceptable quality ranges for the LightCycle process. Thermal and rheological material data measurements to analyze the material input quality and the fluctuation range suggest a stable LightCycle process with a wide process
window. Furthermore, the analyzis of first compounds with rPP and two different types of shredded glass fiber reinforced thermoplastic composites highlights the significant impact of the type of flake used on the compound's properties.