Application of Nanotechnology in Automotive Fuel Systems in Restricting Permeation 2007-01-1008

The history of the automotive fuel tank started with the conventional steel tank. Steel tanks are inflexible, expensive, and corrode, yet they are impermeable to fuel. Before long, the market began to shift towards plastic fuel tanks because plastic addressed many of the problems that steel tanks had. Also, environmental regulations began to tighten on emissions originating from permeations of harmful hydrocarbons from the fuel tank itself, which was widely prevalent in plastic fuel tanks. Steel was found to be a poor choice as the welding is very porous and a source of emissions, yet it still held much of the fuel system market. Multi-layered plastic fuel tank technology was developed and captured the market, but they also came with a barrage of problems and can only be seen as a temporary solution.

Regulations set by the California Air Resources Board (ARB) were adopted nationally by the Environmental Protection Agency (EPA) and hence OEMs had to limit emissions. An innovative technology based on high density polyethylene (HDPE) compounded with nanocomposites is gaining research interest to develop next generation fuel tanks. The distinction with the HDPE fuel tank that the nanocomposites enhanced tank is that at the nanometer level, where a special clay material is dispersed within the base material (HDPE). Fuel storage systems made with HDPE nanocomposites are monolayered, are shown to have high permeation resistance, and lower tooling and blowmolding machine costs. This paper attempts to address the performance characteristics and benefits of fuel systems that incorporate nanocomposites compared with those made of conventional materials.