Carbon fiber composite materials (CFRPs) have gained special attention thanks to the marketing efforts of the aviation industry, which has resulted in an increased consumption and production of these materials. Focusing efforts and resources toward the development of new fiber recycling and reuse technologies at the end of their lives would extend their use time and help to prevent their scarcity in future applications.
Finding an industrial solution to reuse waste inherent to CFRP manufacturing processes is a target that Airbus and FIDAMC are trying to address.
This project is focused on the reuse of carbon pre-impregnated materials before the curing cycle. The intention is to recycle waste from the manufacture of aircraft parts when they are still fresh (un-cured) which means they have chemical reactivity. This new product is proposed as a raw material for compression molding processes.
The manufacture and machining of composite parts gives rise to a large amount of CFRP waste. Around 40% of material is lost in processes such as cutting, contour patterns, errors ... Most scrtaps (about 60 - 70%) are of uncured pre-impregnated material, implying a high cost associated with its elimination due to being considered as special waste. In addition, waste treatment policy in the European Union aims to limit the impact of waste on the environment and the creation of resource efficiency by promoting the use of waste.
So far, two lines of research have been carried out:
- Studies focused on the manufacture and characterization of panels made with chopped prepregs. These tests involve the development of cutting techniques of the material depending on the origin and characteristics of the waste, and the manufacture and testing of panels with various lengths of fiber. Mechanical tensile and compression after impact tests have been performed. These studies have been complemented with physico-chemical to tests study their glass transition temperature, cured degree for cycle optimization, fiber volume content and micrographs.
- On the other hand, several aeronautical demonstrators have been made such as gasket, manhole, support systems drilling and machining trials to evaluate their feasibility. Other possible applications would be in the construction or automotive sector where parts are already made with materials of this type.