Melt index is a numerical value that expresses the fluidity of plastic materials during processing. It is developed by the American Measuring Standards Institute based on the method used by DuPont to identify plastic properties. Which's the higher , the better of the processing fluidity of the plastic material.
Plastic melting index test methods include mass method and volume method. Mass method is to use a high temperature heating furnace to make the measured substance reach melting state under specified temperature conditions. The tested substance in this molten state is extruded through a small hole of a certain diameter under the load gravity of a specified weight. In the production of plastics in industrial enterprises and the research of scientific research units, "melt flow rate" is often used to express the physical properties of polymer materials in the molten state, such as fluidity and viscosity. The melting index refers to the average weight of each section of the extruder converted to the extruded amount in 10 minutes.
Melt volume flow rate. It is defined as the volume of melt passing through a standard orifice mold capillary every 10min and is expressed in MVR in cm3/10min.