Eco‐efficient recycling of carbon fibers from CFRP waste: A two‐step strategy by nanosecond pulsed laser

Abstract

The accumulation of CFRP waste poses significant environmental challenges, necessitating the development of green and efficient recycling technologies. This study employs a nanosecond pulse laser (λ = 1064 nm) to develop a two‐step laser recycling method (LRM) for CFRP. By setting stepped process parameters, the method sequentially completes the separation and cleaning of the CFRP layers, recovering carbon fibers that retain their original weave structure in just 147 s. The study delves into the characteristics of the products from the rapid laser pyrolysis of the epoxy resin matrix and unveils the interaction mechanisms between the pyrolysis products and recycled carbon fiber (rCF). The study utilized MATLAB to simulate the effects of defocusing on the distribution of laser energy and proposed an optimization strategy that balances product quality with efficiency. The results indicate that laser‐induced thermal decomposition leads to unique microscopic damage patterns in rCF, including microcracks, etching, and delamination. Cleanliness and resin removal rate serve as crucial indicators for quantitatively optimizing the process. The optimized LRM increased efficiency by 110.20% and achieved a resin removal rate of 97.92%, while maintaining rCF tensile strength and modulus retention rates at 93.38% and 105.77%, respectively. The energy consumption was only 13.77% of that required to produce virgin carbon fibers. The LRM operates under mild conditions without the need for harsh reaction conditions, enabling ultra‐fast on‐site recycling and offering a promising solution to the challenges of CFRP waste recycling.Highlights Using lasers for rapid delamination and cleaning of CFRP carbon fiber layers. The type and quantity of pyrolysis products significantly affect recovery quality. Laser‐induced resin pyrolysis oxidation damages carbon fibers. Laser energy compensation and defocusing strategies balance efficiency and quality.