This is a quote from a posting on the Shapeways forum:-
WSF is just Nylon 12 – I believe since Shapeways use EOS machines it’s
probably PA2200. I imagine though that right now PA2200 is becoming
very hard to come by for Shapeways since a factory explosion in Germany
about 2 months ago decimated worldwide stocks of Nylon 12 for all
industries, and afaik, EOS has now completely run out of PA2200.
There has been no response from Shapeways about this. So I don’t know what the situation will be, whether they will offer a substitute material or just withdraw WSF. It is likely that the German factory will be out of production until around October, so the supply of the new underframes & bogies is going to be uncertain until then.