Plastic separation planning enhancements from new laser identification technology and work measurement analysis

Recycling research strives to increase net revenues by evaluating the extent of disassembly, shredding, and materials separation. While many studies exist that help to clarify recycling potential of metals and glass from end-of-life electronics, much less is known from quantitative models about the optimal recovery of specific types of plastics from personal computers and printers. In this paper, we examine specifically the value relationship between the quantity of plastics separated and the time required for disassembly and segregation. Labor costs for disassembly can constitute a large portion of the total acquisition cost for a recycled material. We have conducted work measurement studies on the disassembly of 17 computers and three printers manufactured by ten producers in the years from 1986 to 1998. For each plastic part separated, we have calculated the weight per total separation time. Each recovered part was identified according to polymer resin using laser Raman spectroscopy by chemometric reference to a library of standards. We extrapolate the time as well as the product input required to accumulate specific types of plastic. As a result, we show how new laser identification technology and work measurement can be used for plastics separation planning.