Work Stream 3: Energy Efficient Composite Tooling with Integrated Self-Regulating Heating and Curing Capabilities based on Recycled Composite Waste (ECOTOOL)

There is a considerable potential for composite tooling with integral heating for energy efficient manufacturing with closely matched CTE and reduced lead time. However, many challenges exist such as the safety hazards of current overshoot during exothermic thermoset curing, the intrinsic changes in electrical conductivity of carbon fibre over thermal cycles which require complex control system, and the durability of additive manufactured tooling.                                                                                                                                               ECOTOOL will take a new approach: utilising positive temperature coefficient (PTC) effect where resistive heating with autonomous cut-off and full reversibility can be achieved based on the thermal expansion of polymer matrix at desired temperature, in combination with commercially available tooling prepregs, to develop a safe and self-regulating integral heating composite tool. By embedding this smart heating unit in series connection with rCF resistance heating sections  alternating efficient heating and smart self-regulating units will be developed as integral heating layer in composite tooling. This proposal will therefore develop a new manufacturing instrumentation by upcycling rCF as conductive functional fillers to achieve both self-regulating heating and efficient resistive heating, together with designs capable of achieving various practical manufacturing requirements including different curing profiles and uniform heating over large areas.  ECOTOOL will use industrial scale compounding and assembly, replacing traditional heating trace wires for integral heated composite tooling. The project aims to develop an energy efficient composite tooling with integral heating and safety based on recycled composite waste, allowing flexible manufacturing with reduced cycle time, tailored tool shapes and heating profiles, capable to cure components out-of-oven for a wide range of composite applications. The following objectives will be addressed in ECOTOOL:

• Fabricate sustainable composite tooling based on recycled carbon fibres with high energy efficiency (90% energy use reduction) and tailored heating profiles, closing the loop of advanced fibre reinforced composites;
• Examine the durability and reliability of developed tools, examine the quality of both instrument and composites manufactured by new composite tooling;
• Examine and demonstrate the environmental impact and embedded carbon footprint of developed composite tooling, including the high energy efficiency during the manufacturing stage of the components. The end-of-life options of developed composite tooling will also be explored in collaboration with Gen2.