As the waste travels through the tumbler section waste smaller than the openings falls out the bottom and onto a conveyor. The waste remaining in the tumbler module consists of paper products, low and high-density polystyrene products. Low density polystyrene products float quickly to the surface while paper products stay down in the water flow. The flow of water and waste is passed under a vacuum system which pulls the polystyrene floating on the surface up into the vacuum system and deposits it in a container or conveyor system. The system then removes the paper products from the water flow by means of a screening operation.
Water is recycled through the system by means of a rotating barrel filter system and storage tank.
Sorted polystyrene is dropped into a container and processed for shipping to a recycling facility. The production machine was tested in Los Angles at a material recovery facility that collected food service waste form over 50 locations. The equipment w orked very well in removing low-density polystyrene from the waste stream. A study was completed on the operating parameters and the efficiency of the sorting system. It was found that the system would be more valuable if there were more low-density polystyrene in the waste stream, because much of the waste was contaminated paper that could not be recycled.