Sorting / Separation

Swim-sink tanks use the different specific weights of the various kinds of plastics to separate them. Typical applications are the separation of PET or PVC (both sink) from polyolefines, such as PE or PP (both of them swim). The light fraction is transported along the surface of the water by means of paddle drums to a discharge conveyor; the heavy fraction are extracted - depending on its amount - either by a pair of pneumatic valves at the bottom of the tank or by a scrape conveyor mounted below the tank.

The function of the pre-washing tank is based on the swim-sink principle i.e on the different specific weights of the various components contained in the feed material that will either cause them to float on the water surface or to sink to the bottom of the tank.

Herbold's SZS air stream separators are used for separating particles of almost constant granule size on the basis of their specific weight.