US Patent 7569658 Process for the solvent treatment of a plastic

Process for the solvent treatment of a plastic, by dissolving the plastic with a solvent and with at least one phase separation agent compatible with the solvent to form a solution, precipitating the plastic by contacting the solution with at least one non-solvent so as to obtain a solvent/non solvent mixture containing precipitated plastic particles, and substantially eliminating the solvent from the mixture and recovering solid plastic particles. After dissolution but before substantially eliminating the solvent a stripping takes place during which at least a substantial portion of the PSA is removed from the solution or from the mixture using a stripping composition.