Polypropylene or polypropylene (PP) is a thermoplastic polymer, produced from propene and hydrogen. The yield index (MFR or MFI) is a quantity used to characterize the molecular mass of PP. The yield index helps determine the melting ability of the material during the machining process.
PP has a high flow index that helps molds to be filled easily during injection or blow molding. However, as the yield index increases, some chemical properties such as impact strength decrease.
PP is very widely used in many different fields: packaging, textile industry (ropes, carpets, …), membranes, stationery, home appliances, laboratory instruments, speakers, animal parts automobile engine and other types of banknotes.