Today ASTM D1238 for melt flow does not currently accommodate a closed loop MFI it is a weight loading standard only.
However, the ASTM Committee D20.30 Thermal Properties, specifically D20.30.08 Thermal Processing Properties responsible for the standard are evaluating closed loop technology, in particular accuracy, repeatability and comparison of the same with dead weight systems. At this point they have a path to updating ASTM D1238 to cover both dead weight and closed loop MFI technology.
ISO 1133-1 does allow for closed loop melt flow technology see extract from the standard in pic.
That said it does not mean ASTM are lagging, rather they take a different approach proving technology works before they add it to a standard by performing actual comparative material tests to verify measurement performance and capability in key parameters including accuracy, repeatability and being able to define a precision and bias statement. In short ASTM wants to see the technology working before it will include it in a standard.
ISO takes a different route; it verifies a technology concept capability to perform a test irrespective of results being correct and or accurate etc. If a Technology is possible, feasible in concept ISO will put it in a standard in readiness for the future technology capability to come along.
I believe MFI technology will follow the same path as tension/compression machines many many years ago and more recently hardness testers in that the use of dead weight to provide a loading force will become extinct. Closed loop systems using a load cell and a control feedback loop will eclipse weight-based products in all areas of capability including but not limited to resolution, accuracy, repeatability, productivity and safety.
At Tinius Olsen our MFI technology application experts and active participants in ASTM standards are;
Harry Yohn – Profile linkedin.com/in/harold-yohn-532b9411
John Thompson – Profile linkedin.com/in/thompson-john-3b85957b
and you can check me out at linkedin.com/in/martin-wheeler-b6475294
