Material Recovery From Recyclable FRP - Innovative recycling process for cleavable epoxies

Fiber-reinforced plastics (FRPs) such as composites made of carbon or glass fiber reinforcement and thermoset matrix (CFRP/GFRP) are increasingly important in lightweight applications, meaning that sustainable, economic recycling processes are, too. Scientists at the Hochschule Niederrhein have developed a process step that greatly increases recycling efficiency for FRP parts based on cleavable epoxy matrix systems. The thermoset matrix in a laminate to be recycled (worn-out part, production waste, discard, etc.) is decomposed in an acid solution, releasing the matrix’s fiber reinforcement and converting the thermoset matrix into a thermoplast-like substance that is easy to process (in injection molding, for instance). Conventional recycling processes for recovering this basic material require a great deal of equipment, material, time, and energy. The fiber reinforcement is subjected to great stress, damaging the material structure and giving rise to short fibers. The matrix’s recyclate is greatly contaminated by acid inclusions. This impedes recycling of these valuable materials. The new process gently separates fiber reinforcement from the matrix, is based on pump operation, and uses a very thin acid solution. This saves a great deal of time, energy, and material. The matrix recyclate thus recovered is also very pure.