Study on the Effect of Carbon Fiber Anisotropy on Laser Recycling CFRP Strategy

ABSTRACT The growing use of carbon fiber reinforced polymers (CFRP) has intensified the need for efficient recycling methods to address mounting composite waste. Laser processing, as an emerging CFRP recycling technology, offers non‐contact, environmentally friendly, and highly efficient advantages. However, existing laser‐based recycling techniques neglect the impact of the intrinsic anisotropic thermal conductivity of carbon fibers on recycling outcomes. This study introduces a directionally optimized laser recycling strategy that exploits this anisotropic heat transfer by adjusting the laser scanning direction. Systematic experiments examined the effects of scanning directions (0°/30°/45°/60°/90°) and speeds (2000/3000/4000 mm/s) on ablation morphology, delamination, and the physicochemical properties of regenerated fibers. Results demonstrate that heat conduction pathways critically influence thermal damage and recovery quality. Optimal performance was achieved at a 45° scanning direction and 3000 mm/s speed, yielding complete resin removal with minimal fiber degradation. Under these conditions, tensile strength recovery reached approximately 85%, representing an improvement of about 100% over the lowest value. Raman spectroscopy and X‐ray photoelectron spectroscopy confirmed reduced surface disorder, enhanced graphitization, and improved interfacial bonding. This work establishes a laser recycling methodology that leverages carbon fiber anisotropy, offering a sustainable pathway for high‐performance CFRP reuse.