METHOD FOR SEPARATING FOREIGN MATTER FROM PLASTIC WASTE

摘要

PURPOSE:To separate foreign matters from a plastic waste by melting it and discharging the foreign matters through the upper outlet port of an extruder having a screw shaft inclined upward in the direction of extrusion. CONSTITUTION:A plastic waste contg. foreign matters is melted or dissolved in a solvent without separating by hand. The melt or soln. is fed to an extruder having a screw shaft inclined upward in the direction of extrusion and conveyed upward by the screw, separating solid foreign matters from the melt or soln. during the conveyance and discharging them through the upper outlet port. When the waste is melted, it is kept at the melt temperature at least in the solid-liq. separation zone of the extruder. When a foamed polystyrene waste is treated, dissolving it in styrene as the solvent is advantageous.