The plastics converter should choose a material with a melt index so high that he can easily form the polymer in the molten state into the article intended, but on the other hand so low that the mechanical strength of the final article will be sufficient for its use. Melt flow rate is very commonly used for polyolefins, polyethylene being measured at 190☌ and polypropylene at 230 C. Ratios between two melt flow rate values for one material at different gravimetric weights is often used as a measure for the broadness of the molecular weight distribution. The melt flow rate is inversely proportional to the viscosity of the melt at the conditions of the test, though it should be born in mind that the viscosity for any such material depends on the applied force. At the same time, the melt flow rate is a measure of the ability of the material's melt to flow under pressure. The melt flow rate is an indirect measure of molecular weight, high melt flow rate corresponding to low molecular weight. Don't let static charges disrupt your weighing accuracy
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