The POM "DURACON" series not only features mechanical characteristics required in fuel system parts but also fuel resistance and thermal properties in a balanced manner, and is widely used in mechanisms in automobiles, electrical appliances and electronics being superior in moldability. In particular, DURACON is used in many fuel system parts such as fuel pump modules since it is excellent in fuel resistance and superior in long-term durability.

When resin is used for fuel system parts, parts design taking into consideration material properties under a fuel environment as well as a wide variety of data including resistance to chemicals and long-term properties are required. We proactively carry out not only material measurements in air shown in Fig. 2 but also material data measurements under fuel environments in order to make precise designs under fuel environments possible. Fig. 3 shows long-term properties under gasoline-based fuels. Material properties vary largely depending on fuel environments and an accumulation of material data under fuels become indispensable.

Recently, in addition to the remarkable changes in environments surrounding fuels, consideration of bio fuels as well as gasoline-based/diesel-based fuels have gained momentum worldwide. We also address technical support in terms of material and design which respond to various bio fuels. For example, Fig. 4 (left) shows that ratios of increased weight caused by expansion of DURACON that is dipped in toluene/ethanol are plotted against ethanol volume fractions. No proportional relationship of fuel mixing rates was established, the dipping amount increased once by mixing, and we cannot recognize any tendency unless measurements are actually made. In addition, Fig. 4 (right) shows long-term properties for retention rates of tension strength under an environment of light oil and canola oil (RME). As shown above, we proactively accumulate material data necessary for product designs.

Fuel system parts are generally used in environments in which stress acts. A proactive approach in accumulation of material data is required in precise product lifetime forecasting. In addition, it is envisioned that fuel system parts will be used not only in gasoline fuel but also in a number of bio fuels in the future. Evaluation of lifetime to fracture on a case-by-case basis requires a considerable amount of time and man-hours. Further, in order to forecast and extract potential accidents and troubles in the design step and to take safety measures, it is important to quantitatively grasp lifetime-related factors. We take full advantage of CAE technology shown in Fig. 5 and the large amount of material data to allow for highly precise product lifetime forecasting (Fig. 6).