Search Results

Continuously improving the physical and thermal properties of under-the-hood composite materials is a challenging requirement facing today's resin manufacturer. Providing meaningful data, so that the best material is selected for each application, is also a challenging task. Long-term performance data is typically unavailable due to time and economic constraints. Traditional short-term data, such as static physical properties, cannot predict the performance of these materials with time, under load, and/or in harsh chemical and thermal environments. This paper illustrates how short-term dynamic mechanical analysis (DMA) testing can simulate long term behavior of vinyl ester resin SMC materials. In particular, it will be shown how creep characteristics, typically requiring lengthy, expensive testing, can be achieved with the DMA by acquiring data over relatively short (thirty minute) time intervals and applying time-temperature superpositioning to make long-term performance predictions.

Under-the-hood components with composites are currently making headway in the automotive arena. The corrosive environment these components are often exposed to, such as elevated temperature motor oil, is an important design consideration; however, as yet there is little commercial experience on the performance of composites under such conditions. This study investigates the effects of hot (160°C) “used” motor oil on vinyl ester glass fiber reinforced sheet molding compound (SMC) materials, simulating an extremely accelerated aging process indicative of under-the-hood conditions. Several SMC formulations were examined which varied in resin identity, filler type, and filler loading. All materials were evaluated for changes in appearance, weight and thickness, flexural properties, and thermal performance at one, three, and six month intervals. In addition to harsh environmental conditions, engine components must exhibit some degree of flame retardance.