Load used for melt index measurement
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The conditions typically used for testing the melt index of PE are 190 degrees and a load of 2.16 kg; if the melt index is less than 0.1 g/10 min under these conditions, the load is increased to 5 kg or 21.6 kg. What is the relationship between the melt index under different load conditions? Is there an empirical formula for making such conversions?
There is no conversion formula for this, as resins with different molecular weight distributions yield different values under different testing loads. For example, with the same load of 2.16 kg and the same rate of 0.1 g/10 min, the results for the two resins will be significantly different at 21.6 kg. Of course, for the same material, a fixed conversion parameter can be calculated through multiple measurements, but this approach carries considerable risk.
There seems to be no corresponding conversion formula; it’s just a rule
On page 268 of He Manjun’s book on polymers, there is a statement saying that the melt indices of the same polymer measured under different conditions can be converted using empirical formulas. I wonder if there is such an empirical formula?
This empirical formula can be created by oneself.
It seems not; just test a few more sets by yourself and perform a regression analysis
Different polymers are not the same; with so many types of polymers, there is no universal formula
Yes, in fact, many things follow certain patterns