Recycling of the fibrous fraction of reinforced thermoset composites

We investigate the feasibility of reusing short fibers recovered from recycled thermoset composites for the production of new composites. Glass fibers were recovered from glass-polyester composites, and carbon and aramide fibers from epoxy based composites. From the different fractions obtained after grinding, a specific fibrous fraction was selected for reuse. This recycled fraction was first characterized in terms of length and residual matrix content, and then incorporated into virgin polymer matrices to prepare new thermoplastic composites. To evaluate the performance of these composites, tensile tests were initially carried out, and the results were compared with similar measurements performed on pristine composites containing short unused fibers of similar length. In most cases examined, recycling does not adversely affect the mechanical performance of the new composite. This overall behavior is explained in terms of fiber length preservation, fiber dispersion mechanism and fiber-matrix adhesion.