Mechanical Performance of Recycled Woven Basalt Fiber-Reinforced Composites for Sustainable Manufacturing Applications

This study investigates the impact of basalt fiber recovery on the mechanical properties of basalt fiber-reinforced composite laminates via a thermal recycling process in air at 500 °C. Laminates were produced using a hand lay-up technique with six layers of bidirectionally woven basalt fibers and polyester resin. Thermal analyses (DSC and TGA) established that 500 °C is the optimal temperature for complete combustion of the polyester matrix, which is fully removed with minimal impact on the fiber surface. The energy released during resin combustion, measured using the Mahler-bomb method, was evaluated for potential reuse to improve energy efficiency in the recycling process. The basalt fibers exhibited exceptional thermal stability, showing only a 1.75% mass loss during the process. Recovered fibers retained their original continuous woven structure, enabling the fabrication of new laminates. Chemical and morphological assessments of the recycled basalt fibers via Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM) confirmed minimal alterations in fiber properties. Mechanical testing using three-point bending revealed that the recycled laminates experienced a decrease in flexural strength and flexural modulus of approximately 10.39% and 4.51%, respectively, compared to virgin laminates. Furthermore, the failure mechanisms differed between the two systems: while virgin laminates failed through a combination of fiber breakage, matrix cracking, and interlayer delamination, the recycled laminates predominantly exhibited interfacial failure. As a result, these findings support the feasibility of recycling basalt fibers with minimal impact on mechanical performance, presenting a sustainable approach for composite material reuse.