Separation and Liberation Factors in Designing for Automotive Materials Recovery 2004-01-0471

One critical aspect of design-for-environment efforts is to increase the effectiveness of materials recovery from end-of-life vehicles. Recovery itself depends on both the amount of material recovered and the purity of the material stream. Shredding, and screening are often used to separate recyclable materials from wastes. However, with the increasing amount of composite components, particularly those made from plastics, separation processes may be inadequate. Instead, liberation processes, which reduce the physical joints between materials, are also important. In this research, samples of ABS and PVC plastics were assembled into various configurations, ground up, and then characterized by their size distributions and degrees of liberation. Two primary fastening methods - adhesive and riveting - were used to simulate how plastic components would be actually attached together. The results from this first phase of the research indicate that within the study parameters: 1) size distribution is largely independent of material type, material thickness, and fastening method; and 2) liberation varies with the type and degree of fastening.