Melt Flow Rate Testing—Part 9

摘要

If you spend a lot of time looking at data sheets you have probably noticed a trend over the last several years in how the melt flow rate (MFR) is reported. Along with, or instead of, the MFR, a new line item is appearing called the melt volume rate (MVR). Whereas the MFR is reported as a mass per unit time, such as grams/10 min, MVR is given as a volume per unit time, such as cm~3/10 min or, regrettably, in.~3/10 min. I say regrettably because one of the areas where the U.S. is out of step with the rest of the world is in its use of the old inch-pound system of units as opposed to the metric system or SI units. We have spent billions of dollars over the last 20 years to adopt ISO standards for just about everything we do in industry, but we just cannot seem to let go of our antiquated system of units, with notable exceptions such as the automotive industry, where the change to SI units has been effectively mandated.