Optimization of prepreg compression molding process for production of structures with recycled carbon fibers

Abstract

Carbon fibers are widely used in a growing number of industrial sectors. Their high strength to weight ratio makes carbon fibers suitable for high-value-added applications. However, significant environmental and economic problems are related to composite waste disposal and consumption of non-renewable resources for their production. European legislation has imposed more controls on composite materials waste management. Consequently, development of processes for the recovery of the added value of wastes, instead of its simple disposal, is crucial to promoting the application of EU requirements and the realization of a circular economy model. Currently, thermal processes represent the most promising technology in this direction. Thermal processes include pyrolysis, fluidized bed pyrolysis, and microwave-assisted pyrolysis, but only pyrolysis is implemented on an industrial scale in Europe because of its economic viability and technical feasibility. Although the recovery of carbon fibers has reduced cost, compared to virgin fibers, length, orientation, and sizing of the fibers are lost. In this context the challenge is to realize composites reinforced with reclaimed fibers that can compete economically and in terms of mechanical performance with composite with virgin fibers. In this work, prepreg compression molding technique was used to produce a window frame with non-woven fabrics of recycled carbon fibers impregnated with a fast-curing resin. The fibers were coated with a sizing developed by CETMA and compatible with fast-curing epoxy resin.