Separations
An important part of recycling is collecting and sorting the wastes. Many materials can be easilyt recycled but their presence in any realistic waste collection is so small recycling is not cost effective. Plastics can be readily collected and shredding to a useable form, but to get the most out the waste stream, the plastics need to be sorted and separated. (RDC 1/19/2011)
Recent US Patents
3/8/2011
8,016,119
Apparatus and method for separating plastic film from waste
Legtenberg and Witting of Machinefabriek Bollegraaf Appingedam, Netherlands, separate plastic film from waste using a rotating cylinder with retractable hooks. The circulating hooks displace engaged film material away from the other waste and the engaged film material is subsequently disengaged from the hooks and transported away for further processing and storage. (RDC 9/12/2011)
8/3/2010
7,767,924
Electrostatic separation system for removal for fine metal from plastic
Jeon, Shin and Kim have developed an electrostatic method for separating chopped waste electronic insulated wires. The device consists of a negative induction plate separated by 50 cm from a positive electrodes. The particless, less that 3 mm long are added to the negative vibrating plate. The particles are charged or remain uncharged and vibrated off the plate past the positive electrodes. The electrostatic fields separates the particles with 96 to 100 % efficiency.