Closed Loop MFI Technology – Whats Happening at Standards.
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
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