The Brainstorm

well, since you went idle, and I'm about to go to bed..  I have some device for your sorting.  I know it won't work for your asme thing because of the rules, but an awsome idea for separating the materials is their melting point.

melt the materials, the plastic will melt away first, followed by the glass.  the tin will melt a little before the steel.  and they SHOULD all stay liquid, though I didn't check their evaporation points, and this is based on ooooold research...  but you should be able to let them gather in a massive pool where they'll stratify over time if kept still and a temperature conducive to being molten is maintained.