Process and structure of electromagnetic shielding plywood composite laminated with carbon fiber paper

Carbon fiber paper (CFP), a type of flexible planer electromagnetic shielding material with thin thickness, low density, and good adhesion property and permeability, was laminated with wood veneer to produce a plywood composite with good shielding effectiveness (SE). It was found that a hot-press pressure of 1.2 MPa and a double-sized adhesive concentration of 380 g/m2 were most appropriate for the production of CFP plywood composites. SE of plywood composite laminated with single layer CFP was better than that before hot pressed, which result from the formation of three-dimensional and smaller conductive carbon fiber circuitries. The space between two-layer CFPs and the thickness of the surface-layer veneer had significant influence on SE. The SE of the composites laminated with two-layer CFPs was significantly higher than those with one-layer CFPs. The SE in the frequency range of 30 MHz to 1 GHz reached above 30 dB depending on the space between two-layer CFPs and the thickness of the surface veneer, which was sufficient SE for commercialization and the use of plywood composites. © Yuan et al.