Effect of Molding Conditions on Mechanical Properties of CFRP Using Nonwoven Fabric with Recycled Carbon Fiber

In recent years, to meet the increasing demand for carbon fiber reinforced plastics (CFRP), it has become essential to recycle carbon fibers from discarded CFRP. Although research on molding using recycled carbon fiber has been conducted so far, no research has been reported that considers the state of resin impregnation inside the molded products. In this study, CFRP products were made by press molding recycled carbon fiber while varying the molding temperature, molding pressure, and molding time, and the correlations between the mechanical properties and the un-impregnation rate inside the molded product were clarified. As a result, it was found that the bending properties of CFRP depended on the un-impregnated ratio, and that the correlation between the bending strength and the un-impregnated ratio was stronger than the correlation between the bending modulus and the un-impregnated ratio. As the un-impregnated rate decreased, the coefficient of variation in bending properties decreased. The slopes and intercepts of the regression lines between the bending strength and the un－impregnated rate were almost the same in recycled CFRP and virgin CFRP. On the other hand, the variation in bending strength was larger in recycled CFRP than in virgin CFRP.