White version of Nittaku Premium was approved in 03/14. So it's definitely not ABS. It may be a perfect ball, but if it has a different feel than contemporary ABS balls (and my guess that it is the case), that fact is a showstopper for me.Orange version was approved in 09/20. But it would be strange if change of color would be accompanied by such radical change of material, don't you think?
Are you sure the Nittaku Premium is not ABS. I thought it was the first ABS ball that all the others tried to copy and it just took a long time for companies to copy. Also, when 40+ Poly balls came on the market, the Nittaku Premium may have been approved. But it took them a long time, (maybe till 2015) to get them on the market, and they were not readily available until 2016.
I did not spend much time looking, but the only info I can find on the material used in the Nittaku Premium ball is this:
"The Nittaku Premium 40+ ball is made with
a premium poly material that is exclusive to Nittaku."
That may or may not be an ABS plastic. Acrylonitrile Butadiene Styrene: ABS. Based on this:
"ABS is a
terpolymer made by polymerizing
styrene and
acrylonitrile in the presence of
polybutadiene. The proportions can vary from 15% to 35% acrylonitrile, 5% to 30%
butadiene and 40% to 60% styrene."
ABS can have a range of proportions so, can have a range of properties. So, if DHS and Nittaku were both making ABS balls, they still may not play the same since their formula for ABS production could still be different.