A transportable system (100,200) for separating materials in a waste stream, comprising: an arrangement of separators (120,265) and a grinder (125,250); mounted on a transportable platform, the separators and the grinder device being configured in the arrangement to produce three or more product streams from a plastic-rich feed mixture, the product streams including a coarse heavy stream, a ground plastic-rich product stream, and at least one ground light material stream, characterized in that the arrangement comprises: an air-leg separator (120,135,230) as one of the separators separating metal materials from the plastic-rich feed mixture, wherein the air-leg separator is configured to receive the plastic-rich feed mixture and to entrain light materials and allow heavy materials to fall through the air-leg separator, the grinder (125,250) in operable communication with the air-leg separator such that at least a portion of a plastic material exiting the separator enters the grinder, and a second separator as one of the separators in operable communication with the grinder, the second separator being configured to receive a ground material stream from the grinder and to separate at least one ground light material stream from the ground material stream. an arrangement of separators (120,265) and a grinder (125,250); mounted on a transportable platform, the separators and the grinder device being configured in the arrangement to produce three or more product streams from a plastic-rich feed mixture, the product streams including a coarse heavy stream, a ground plastic-rich product stream, and at least one ground light material stream, characterized in that the arrangement comprises: an air-leg separator (120,135,230) as one of the separators separating metal materials from the plastic-rich feed mixture, wherein the air-leg separator is configured to receive the plastic-rich feed mixture and to entrain light materials and allow heavy materials to fall through the air-leg separator, the grinder (125,250) in operable communication with the air-leg separator such that at least a portion of a plastic material exiting the separator enters the grinder, and a second separator as one of the separators in operable communication with the grinder, the second separator being configured to receive a ground material stream from the grinder and to separate at least one ground light material stream from the ground material stream. an air-leg separator (120,135,230) as one of the separators separating metal materials from the plastic-rich feed mixture, wherein the air-leg separator is configured to receive the plastic-rich feed mixture and to entrain light materials and allow heavy materials to fall through the air-leg separator, the grinder (125,250) in operable communication with the air-leg separator such that at least a portion of a plastic material exiting the separator enters the grinder, and a second separator as one of the separators in operable communication with the grinder, the second separator being configured to receive a ground material stream from the grinder and to separate at least one ground light material stream from the ground material stream.