Heat-based disbonding promises to transform composite use

Developed in collaboration with a team from Oxford Brookes University, the technology - which involves the use of carefully modified structural adhesives – enables composite structures to be separated (or disbonded) quickly and cheaply using a simple heat source.

It is claimed that the research could have a transformational impact on the design, use and end-of-life recycling of products including cars, aircraft and wind turbines.

Project leader, NCC research engineer Lucy Eggleston, said that the group has explored the use of two specific off-the-shelf additives which can be added to any structural adhesive.

The first of these additives, expandable microspheres, have been explored before for disbonding applications, but never for industrial scale applications. These are effectively thermoplastic bubbles containing hydrocarbons with relatively low boiling points, explained Eggleston.

“When they’re exposed to heat the thermoplastic bubble becomes malleable and stretchable and the hydrocarbons boil and expand," she said. "That causes the whole bubble to expand which, when used as part of a joint, causes two surfaces to push apart from one another and breaks apart an adhesive bond.”