High strength composites of carbon fiber sheets-veneers sandwich-structure for electromagnetic interference shielding materials

Due to the advantages of porous structure, anisotropy, and fiber composition, wood possesses great potential to be a high-strength electromagnetic interference (EMI) shielding material. This study used vacuum assisted resin transfer molding (VARTM) technology to fabricate EMI shielding composite material by combining carbon fiber sheets and wood veneers via infusion of epoxy resin. The shielding effectiveness of the composites against electromagnetic waves in the 8.2–12.4 GHz (X-band) can reach 40 dB. The flexural and tensile strength (i.e., 442.3 and 195.5 MPa, respectively) of the composite were 6-fold and 3-fold higher than natural poplar (i.e., 69.8 and 55.6 MPa, respectively), respectively. The composites possessed superior thermal conductivity (0.91 W m-1 K-1) compared to poplar, good water resistance and surface hydrophobicity. The addition of carbon fiber sheets not only improved the mechanical performance of samples, but also made samples possessing the ability to shielding electromagnetic waves. This work provides a novel technology to make a natural bio-based high-strength composite material for the EMI shielding applications.