facturers, is designed to facilitate this sorting of materials (in fact the sorting would be extremely difficult without it). These efforts will also involve the dismantlers as well as the materials and parts suppliers.

One approach under consideration at most of the automobile manufacturing companies in Germany and the United States would require the suppliers, as part of the initial contract, to retrieve and recycle the materials in their products at the postconsumer stage. The role of the OEM would be to use some of the recycled materials, but the OEMs are going beyond this and will help set up the infrastructure and markets. This is important because of their specialized expertise. The infrastructure for the recycling of plastics or rubber, for example, is likely to be different from that for metals. As pointed out by Frosch and Gallopoulos (1989), the metal recycling industry is limited by demand considerations (supply is adequate because the magnetic and other properties allow easy separation) while plastic recycling is typically limited by supply considerations (as separation of specific polymers from the fluff, for example, is much more difficult). But because increased vehicle recycling is based on an infrastructure that has been optimized for iron recycling, it will undoubtedly require significant additions to the infrastructure. If separation is accomplished at the dismantling stage, there are likely to be intermediaries to collect, clean, and prepare the materials for the suppliers. The separation of nonmetallic materials will be a major focus of all three groups.

German industry has estimated that separation, collection, cleaning, and grinding of plastics will cost more than $0.30 per pound, enough to make recycling economics problematic for inexpensive commodity plastics such as polypropylene or polyethylene. On the other hand, the economics for many of the more sophisticated engineering plastics, which cost more than $2.00 per pound, appear favorable. Obviously, these numbers are extremely sensitive to disposal costs. Ultimately, if it costs less to make new parts from virgin material than from recycled materials (even after internalizing disposal costs), other options, including new technologies, must be considered. Thus, for example, the environmentally preferable option for many plastics might be as an energy source, rather than a recycled material. There are active projects in GM and elsewhere to study various thermal recovery techniques. For example, GM has an active program on pyrolysis, and Chaparral Steel and other shredders have been attempting to obtain permits to use fluff as a fuel in cement manufacture. Others favor straight incineration for energy recovery. The rationale for such projects is that these materials are derived from petroleum so that thermal recovery offsets the use of virgin petroleum to make new parts, which can be made from "virgin" petroleum more economically. The cement kiln is especially attractive as a variety of the fluff components, including glass, rubber, and residual iron can be used as energy and material inputs for cement manufacture. Social acceptance of such options, however, will be difficult.

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