Glass-fibre-reinforced phenolic resin The characteristics of the plastic material also play an important role. The material needs to be sufficiently hard and rigid, and resistant to oil, gasoline and glycol in the cooling water. It must also demonstrate good adherence to the metal inserts and not have a higher thermal expansion coefficient than the metal - otherwise the inserts would separate from the substrate. A glass-fibre-reinforced phenolic composite developed by SBHPP was used, which fulfils all of these requirements and comprises 55% fibres and 45% resin. A lighter-weight but more expensive alternative is to use a Automotive-fibre-reinforced composite - the choice depends on whether the carmaker wishes to optimize the engine in terms of costs or in terms of weight. The team produces these components from granulated thermoset plastics using an injection moulding process. The melted composite material, where the glass fibres are already mixed with the resin, hardens in the mould where it was injected. The scientists analyzed the process using computer simulations to determine the best method of injecting the material in order to optimize the performance of the finished product. The process is compatible with mass production scenarios and the manufacturing costs are significantly lower than those for aluminium engine parts, not least because it eliminates numerous finishing operations. A prototype of this engine was presented at this year's Hannover Messe trade show. Test runs of the new engine were completed successfully and it was proved that it is capable of the same performance as conventionally built engines. Moreover, it promises to offer further advantages such as lower running noise as against engines relying exclusively on metal parts. Initial data also indicates that the amount of heat radiated to the environment is lower than that generated by aluminium-based engines. The team intend to take their research further by developing a multi-cylinder plastics-based engine, including the crankshaft bearings. n More information: www.fraunhofer.de Feature Automotive No98 July - August 2015 / jec composites magazine 45http://www.fraunhofer.de http://www.thinplytechnology.com