A cylindrical separator for mixed plastics that uses an altered-density fluid and “turbulent laminar flow” will soon be applied to recovering plastics from auto shredder waste. After eight years on the market, this system from TLT Turbo Laminare Trenntechnik in Frankfurt, Germany, now separates about 350 million lb/yr of mixed polymer flake at 21 European installations. A sequence of two TLT altered-density cascades reclaims 1 to 2 tons/hr of PET bottle flake—the first unit separating PET from PP and PE bottle-cap flakes in plain water, the second separating the PP from PE in a lighter-than-water mix (0.92 g/cc) of propanol and water.
The same twin-separator cascade is used in four commercial installations to separate PP, PE, and PS from shredded household appliances. One commercial-scale plant is now being built in Germany to recover PP, PE, ABS, and PVC from auto shredder residue using four cascades. It will start up late this year.