Tensile properties and interfacial shear strength of recycled fibers from wind turbine waste

The rapid growth of composites combined with imminent recycling legislation have increased the interest in reusing and recycling of composite waste. Tensile strength and interfacial shear strength (IFSS) of recycled fibers are critical factors contributing to the final properties of recycled products. Here, we focus on the tensile properties of recycled glass fibers from scrap wind turbine blades and their interface strength with polylactic acid (PLA). The single fiber tensile and pull-out tests are used to characterize the fibers recovered through mechanical and thermal processes. It is shown that while pyrolysis can significantly degrade the recovered fibers, ground fibers with a gage length of 20 mm feature characteristic strength comparable to that of virgin fibers. The effect of the fibers surface coating on the IFSS are investigated, with results showing an interface between ground fibers and PLA that is 14% and 26% stronger than pyrolyzed and virgin fibers, respectively.