When sourcing PP granules, the first step is identifying the correct grade: Homo-polymer (PPH) for high stiffness, Random Copolymer (PPR) for transparency and pressure resistance, or Impact Copolymer (PPB) for low-temperature durability. Key technical indicators include the Melt Flow Index (MFI), which determines processing suitability (e.g., injection molding vs. extrusion), and Density (typically 0.90-0.91 g/cm³). Always request a Technical Data Sheet (TDS) and a Certificate of Analysis (COA) for every batch to ensure consistency in tensile strength and heat deflection temperature.