A Novel and Sustainable Approach to Recycle Prepreg Trim Waste Via Sheet Molding Compound (SMC) Technique

Abstract

In this study, carbon fiber (CF) prepreg trim waste was converted to lightweight, high performance and low-cost CF sheet molding compound (SMC) composite. The prepreg trim waste, which is available in the form of spools of tape, was cut into chips of various width and length to prepare the SMC composite using a standard SMC line. The effect of aging was studied by using “tacky” tape, which was properly stored, and “dry” tape, which was aged at ambient or elevated temperatures. The composites were made by combining two or three SMC sheets in a mold and compression molding. The temperature and pressure molding profiles that resulted in the highest degree of cure of the resin in the prepreg and the smaller void content respectively were determined. In addition, the charge size and mass were varied to optimize the flow of the charge to completely fill the mold. The tensile modulus and strength, and impact strength were determined according to the corresponding ASTM standards, as a function of the conditions used to prepare the composites and the location of the testing coupons within the plates. The strong inherent planar anisotropy dominate the behavior of these composites. The samples retained their integrity upon tensile failure, which was not catastrophic. Aged prepreg showed comparable properties to fresh ones. The CF-epoxy SMC composite shows 3 to 4 times higher tensile modulus, 40% higher tensile strength,