ABSTRACT
Over the last two decades there has been a significant movement to make automobile components from lightweight composite materials, driven by increasingly stringent fuel efficiency standards and weight reduction goals. As a result, the percentage of plastic materials in a typical American passenger car has increased from 20.2% of weight in 1976 to 25.8% in 2000 (Joshi 1998). As a part of this continuing trend, traditional steel fuel tanks in automobiles are being replaced with tanks made from lighter plastic. The co-extrusion blow-molding process developed in the late 1980s has alleviated concerns over fuel permeation and safety associated with the early mono-layer plastic tanks. Plastic tanks can now be produced with multiple material layers that prevent fuel permeation and meet automotive evaporative emission standards. It is expected that almost 60% of all new passenger cars and light trucks produced in North America will have fuel tanks made from plastic materials (OSAT 1996).
