Next Gen Automotive Heat Shield with Improved Thermo-Oxidative Properties

Alpha Engineered Composites’ thin profile textile composite heat shields provide thermal protection through several thermodynamic mechanisms including: radiation reflection; heat spreading; and finally heat transfer resistance. Typical under the hood automotive applications require heat shield average operational temperature up to 225°C, but newer internal combustion engines are being designed for higher operational temperatures to: increase efficiency through higher compression cycle ratios and lean burning; boost power through turbocharging; increase energy density; and support advanced emissions controls like EGR that can increase average operational temperature up to 300°C. Unfortunately, thermo-oxidative degradation mechanisms negatively impact the polymer structural adhesive within a heat shield textile composite and degrade thermal protection mechanisms. High average operational temperature degradation of traditional versus next generation textile composite heat shields is comparatively studied via radiant panel assessment, combined with both adhesion and thermogravimetric analysis focused on the structural adhesive integrity in the aggregate thin profile textile composite. Property changes, due to thermomechanical degradation, resulting in textile composite loss of integrity including layer delamination, physical polymer microcracking, and buckling of expected geometry and the subsequent negative impact on thermal protection clearly dictates the need to transition to a next generation of structural adhesive polymer chemistry. This transition is also necessary to ensure that under the hood engine compartment integrity is maintained as internal combustion engine technology takes operational advantage of higher operating temperature to reap greater efficiency, power/energy density, and environmental benefits.