CARBON FIBER REINFORCED PANELS WITH ENHANCED THROUGH-THICKNESS ELECTRICAL CONDUCTIVITY BY RECYCLING MACHINING WASTE

Sandwich composite panels with carbon fiber reinforced (CFR) prepregs and functional cores have been manufactured by autoclave molding. Conventional virgin (polymethacrylimide foam) and innovative recycled core materials have been used for this aim. The recycled core has been obtained through direct molding of waste particles from CFRP machining. The recycled composite sandwich panel exhibited good consolidation, and microscopic observation showed good adhesion at the interfaces between the CFR skins and the rigid core. Functional properties in terms of electrical conductivity and material strength were investigated for the molded sandwiches. Thanks to the carbon content of the recycled core, an average electrical conductivity of 0.02 S/cm and 0.05 S/cm were found for in-plane and through-thickness direction, respectively. In the case of the virgin core, the same electrical conductivity of 0.02 S/cm was found only in-plane whereas the sandwich behaved like an insulator through the thickness. Three point bending tests were performed to evaluate the mechanical response of both composite panels. Higher stiffness and strength were measured for the recycled core, despite its aggregated nature. Results confirm the innovation in using CFRP waste to obtain novel functional structures, by extracting its maximum residual value, in the optic of a circular approach.