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Dear Harry,

I want to know the differences between ASTM  and ISO test procedure for MFR/MFI for PP ? 

Thanks for your question.  The main differences between the 2 methods are as follows:

Preheat time is 4 minutes in ISO 1133 vs 7 minutes in ASTM D1238

Start point is 50 mm above the die in ISO vs 46 mm in ASTM

There are slight differences in the area of the piston land (foot) between the 2 methods.