What is Melt Index?
Melt index is the Melt Flow Rate of plastics (Melt Flow Rate, MFR, MI, and MVR), a representation of plastics’ flowability during processing. It is tested by Melt flow Rate Tester according to the standard of GB/T3682-2000, and ASTM D1238-98. The testing method is as follows:
The plastic pellets are melted into plastic liquids under a certain temperature and pressure for a certain time of 10 minutes, and then the liquids are led to flow through a round tube, the diameter of which is 2.1mm. The flowing amount of the liquid, measured by gram (g), is the Melt Index. For example, 15g/10min means that 15 grams of plastic liquids flow through the round tube in 10 minutes. The larger the Melt Index, the better the plastic material’s processing flowability, and vice versa.
The testing method is easy operation, intuitive and reliable, since the result of Melt Index will be calculated and shown automatically by the Tester. This method is suitable for various kinds of plastics, such as Nylon, PE, PP, POM, PS and so on, and also applicable for industrials and fields like plastic production, petrochemical and research institutes, commodity inspection department.
With regard to Melt Index of recycled PS pellets:
The Melt Index of recycled PS pellets is related with the content of flame retardants in the EPS scraps. Higher content of flame retardants will bring about higher Melt Index of recycled PS pellets. Melt Index of GREENMAX recycled PS pellets is various from 8g/10min to 25g/10min to satisfy different customers.