Separation of solids from plastics, comprises heterogeneous crystallisation of crystallizable plastic followed by separation of the crystals from the mother solution

摘要

A process for separating solids from plastics (1), comprises heterogeneous crystallisation of crystallizable plastics followed by separation of the crystals from the mother solution. The plastic or plastic mixture is dissolved in a solvent (2) or solvent mixture, then the solution temperature and concentration and solubility are adjusted and the crystallite structures are separated out, leaving a cleansed plastic solution (7). The plastic solution (3) is produced at raised temperature, and the temperature is lowered into the crystallisation region. Solubility reducing additives are mixed into the solution, and the solution is stirred during crystallisation (6). The solvent is hexane, octane or nonane.