SUMMARY

This presentation explores the lightweighting of autobody components to increase feul efficiency of vehicles. To achieve this, hollow glass spheres (HGS) were incorporated into unsaturated polyester resin (UPR) to create what is called a "syntactic foam". This resin paste was then used in a Sheet Molding Compound (SMC) line to produce a fiber reinforced syntactic foam composite. By replacing the heaviest filler, calcium carbonate (CaCO3), of typical SMC resin paste with varying types and amounts of HGS, the density of SMC composites commonly used in automotive applications can be decreased from the industry standard of 1.9 g/cm3 to 1.5, 1.2, and 1.0 g/cm3, called mid-, low-, and ultra-low density, respectively. The syntactic foam composites were characterized in terms of tensile, flexural, and impact properties and were compared to standard density ones. The viscosity and microstructure of every composite formulation were also analyzed. Lastly, the water uptake was performed on samples with three different HGS loadings. The effect of HGS, GF, and CaCO3 surface areas in the final composite were investigated and mechanisms for water absorption was discussed.