Australian company GMS Composites has developed a high performance epoxy prepreg resin for the manufacture of composite parts with very high fracture toughness and energy absorption. It has been successfully tested in rally car components.
The GMS EP-620 prepreg employs uses a tough, impact modified epoxy resin system, developed to be capable of high velocity ‘ballistic level’ high kinetic energy absorption and resistance to repeated shock impacts.
According to GMS Composites, the epoxy prepreg resin has over 1.75 times the fracture toughness, and requires 3 times the fracture energy to break, compared with standard prepreg resins tested. The resin can be combined with reinforcement fabrics made from carbon fibre, aramid, S-glass or polyethylene fibres to mould components designed for ballistic protection, personal body armour and vehicle protection in a variety of defence, military, industrial and motorsport applications.
During its development the prepreg was tested by a leading Australian rally team, which replaced the originally fitted fibre reinforced plastic (FRP) composite underside protective covers of the car with identical parts made from GMS EP-620 prepreg with aramid fibre. The front and rear underside covers are typically located beneath the engine, as well covering key parts under the car such as the fuel tank, fuel lines and brake lines.
Under rally racing conditions the GMS EP-620 aramid fibre covers proved to have superior fracture toughness resistance by lasting twice as long as the original composite covers. GMS EP-620 prepreg resin has also been designed for cost effective production. It is reported to exhibit good flow characteristics during moulding and the tack level can be varied to suit individual conditions and requirements. It has a curing cycle from 80°C up to 150°C. At 150°C the resin has a gel time of 2-3 minutes and moulded parts can be fully cured within 20 minutes. The prepreg has a shelf life of over 6 weeks at 23°C, and up to 12 months if refrigerated at -18°C.
Information on the GMS prepreg is available during the JEC Europe 2013 trade show on the stand (Z38) of Carbon Nexus, Australia’s leading centre for Carbon Fibre and Composites Applied Research.