Sustainable 3D printed electrothermal deicing systems using recycled carbon fiber reinforced polymer-based inks

The need for high-added value and sustainable solutions that make use of carbon fiber reinforced prepreg scrap is an urgent need for the composites sector in its transition to a circular economy approach, as most of current alternatives are just as additive in thermoplastics or concrete based matrices. The present study optimizes the electrical and self-heating properties of recycled carbon fiber reinforced composites manufactured using Direct Ink Write 3D printing technology. Mechanical recycling parameters have a significant impact on the morphology of recycled carbon fibers (RCF) and, consequently, on the final properties of the composites. More specifically, shorter RCFs and higher contents enhance ink homogeneity and repeatability of the 3D printing process. Electrical conductivity increases with RCF content, with 20 %RCF-2mm ink exhibiting the highest value, 1.32 ± 0.5 S/m. Moreover, the electrical conductivity was higher when using longer fibers and the same RCF content due to their higher aspect ratio. Results of Joule heating tests, in total agreement with the electrical conductivity ones, demonstrated the capability of reaching an average temperature of 50 °C by applying just 65 V for the aforementioned condition, as well as an outstanding homogeneity in Joule heating. Proof-of-concept deicing experiment confirmed a rapid and effective deicing using 3D printed circuits, being able to melt a 2.5 mm thick ice layer in 7.5 min. Therefore, a sustainable solution for diverse wind energy or aerospace industry applications is successfully developed from prepreg scrap recycling. • Advanced and sustainable reinforced ink was produced by direct write 3D-printing • Optimization of CFRP recycling allows obtaining high-added-value materials • Innovative deicing based on a reinforced ink with recycled carbon fiber obtained • High electrical conductivity over 1 S/m was obtained by using a recycled product