The melt index of plastics refers to the rate at which plastics, in a molten state, flow through a die orifice under certain conditions. The commonly used determination method is to test with a Melt Flow Index (MFI) meter. The melt index is generally expressed in grams per 10 minutes (g/10min) or grams per hour (g/h). A smaller value indicates poorer melt performance of the plastic, and correspondingly, a larger value indicates better melt performance of the plastic.