Evaluation of mechanical recycling options for electronic equipment

We evaluated two methods of sorting mixed plastic parts from demanufactured electronic goods to increase the value of the plastic. The first process took advantage of high-speed, automated, plastics identification equipment to enrich and segregate target materials before grinding and final purification. The second process was to sort and enrich the plastics by having laborers use a combination of recycling stamps (plastic identity labels) and a spectroscopic instrument to sort die material prior to grinding and purification. Each method has several difficulties associated with it. We found that plastic enrichment by sorting whole parts via either process is not economically promising. Neither method could enrich a mixed plastic stream to an appropriate level to achieve high resale value. Thus, there is little return to offset the considerable costs involved. The study showed that particle-by-particle sorting would be required to further enrich the plastics after whole part sorting in either case. Whole part sorting is only practical when the material source is very controlled and the contamination level is limited.