I want to remove molten plastic or rubber with a liquid, what can I use best for that?

Answer

Dear Frank,

In general, plastics dissolve rather poorly in most common solvents (and those that dissolve do so very slowly). Moreover, it is impossible to imagine a solvent without knowing something about the nature of the plastics.

Rubber is in any case insoluble in any solvent, because in rubber the individual molecules are connected to each other.

Since this is apparently on a glass plate, I would use a scraper to mechanically remove the residue.