Gerald R. Winslow

Designing for material separation : Lessons from automotive recycling

Virtually all of the material in today’s automobiles can technically be recycled. The challenge facing engineers is making this recycling process economical, especially for materials in such components as seats and instrument panels. Recycling these components requires the different materials to be separated so that each can be recycled individually. This separation can be accomplished either manually, where workers disassembly and sort the vehicle components by hand, or mechanically, where the vehicle is shredded and the materials sorted by properties such as conductivity and density. In this paper, the usefulness of including likely separation techniques in DFR guidelines is discussed. Three vehicles were dismantled at the VRDC as part of an effort to establish a baseline of current vehicle recyclability. Concurrently, this allowed examination of the effectiveness of the early design for recycling (DFR) efforts. The applicability of common design guidelines to the two types of separation is discussed, and a simple method for determining the appropriate separation process in the early stages of design is presented.

SCREENING STUDY TO EVALUATE SHREDDER RESIDUE MATERIALS

The Vehicle Recycling Partnership (VRP) initiated feasibility studies to evaluate the use of automated separation processes to recover plastics and polyurethane (PU) foams from shredder residue. One of the prevailing issues impeding the commercial success of these processes is contamination of the shredder materials. The contaminants include dirt, oils, glass, metal fines, polychlorinated biphenyls (PCBs) and heavy metals. The presence of PCBs and heavy metals was determined in a number of mixed plastics and PU foam samples separated using an automated separation process. An aqueous cleaning approach was investigated using various commercial surfactants to determine their effectiveness for removing oils, PCBs, and heavy metals. Mass balances of processed and cleaned materials were calculated to determine the cleaning efficiencies of the various surfactants.