Sky-high potential for carbon fibre recycling innovation?

United States – Researchers at Washington State University (WSU) in the USA have discovered a new method to recycle epoxy-based thermoset composites. This is said to offer significant potential for the aircraft recycling industry as production of Boeing 787 and Airbus A350 XWB airplanes generates over 1 million pounds of cured and uncured carbon fibre prepreg waste every year.

While thermoplastics can be recycled without difficulty, processing thermosets is another story entirely because of their cured resin, points out Jinwen Zhang, a professor in WSU’s school of mechanical and materials engineering.

His team focused on a chemical recycling method using mild acids as catalysts in liquid ethanol at a relatively low temperature to break down the thermosets. Zhang describes how raising the temperature of the material led the catalyst-containing liquid to penetrate the composite and break down the complex structure of the cured materials.

‘It is critical to develop efficient catalytic systems that are capable of permeating into the cured resins and breaking down the chemical bonds of cured resins,’ he comments.

The research project was funded by the Joint Center for Aerospace Technology Innovation as well as Global Fiberglass Solutions.