AITIIP Technology Centre leads HELACS, a European project which aims to develop a dual methodology of controlled comprehensive dismantling in order to make possible the classification, recycling and reuse of aircraft parts made of thermoset and thermoplastic composites that have reached their end of life. Annually, the aeronautical industry is depositing more than 40,000 tons of end-of-life composite material waste in landfills. Thanks to the recovery of materials, the technology proposed by HELACS will benefit the change towards an energy efficiency model.
The project focuses its research on the development of a reuse model that will combine a water cutting system (which will allow the thermoset piece to be selectively chopped into a suitable dimension for recycling) and a pyrolysis process (carbonization of the thermoset matrix to reuse the carbon fibers that overcome this chemical decomposition). A robotic technology based on machine learning is being developed to perform cutting by water, that is, a person will mark the cutting path with their movements by using a dummy tool and the robot will clone the path to perform the cut with high pressure water.
On the other hand, HELACS also proposes the reprocessing of thermoplastic composites by using a second resistive welding technology, which will serve to detach the panels and reuse them, as they can melt again once consolidated.
The main goal is to improve the recycling capacity of aircraft components by 40% and, therefore, to reduce the CO2 emission of aircrafts by 50%. HELACS's revolutionary dismantling methodology will provide the necessary tools to make the aeronautical industry of the future more sustainable, incorporating the circular economy in its processes. In general terms, HELACS expects to mobilize up to 30 million euros between now and 2030 and create 750 direct jobs along the entire value chain of the European aeronautical industry.
The research, framed within the Clean Sky 2 Joint Undertaken funding program of the European Union, has a budget of almost two million euros and four partners from Spain, Belgium and the United Kingdom take part in it. AITIIP is responsible for coordinating the project. This technology centre and its partners PLATA, Centexbel and Gen2Carbon will validate the results of the project through a demonstration phase at Teruel Airport.
HELACS will promote the creation of new recovery ways that maximize the retention of value of the different aircraft components. This means the increase of competitiveness and making it possible for Europe to be at the forefront of dismantling processes worldwide. In addition, the extrapolation of the methodology to other sectors (railway, automobile and construction), that generate composite material waste and also need to reformulate their environmental practices, will be studied.
Composite reprocessing: selective water cutting and resistive welding
These days, metal is the main component of aircraft parts but, for the last few years, the aeronautical industry has been incorporating new materials, such as thermoset compounds. They require a recycling system that allows the extraction of the reusable components (carbon fiber), to produce less waste of this composite material, which is hardly recyclable until now. HELACS offers a technological solution to recycle both thermoset materials and thermoplastics, which are currently booming and are considered to be the materials of the coming future for aircrafts.
To that effect, HELACS proposes a dismantling process based on a selective cutting system by high pressure water (more than 4000 bars) that will allow the pieces composed of a thermoset matrix (carbon fiber + epoxy resin) to be cut into pieces. Afterwards, those pieces will undergo a pyrolysis process (heating in the absence of oxygen) by which the matrix will be charred and the carbon fiber which resists the chemical decomposition will be reused.
Beyond the thermoset composite material, there are advanced trials with thermoplastic-based composites that aim to become the key component of the aeronautical parts of the next generation of aircrafts. With the focus on these new materials, HELACS also incorporates a second resistive welding reprocessing technology. This system makes use of an extremely fine resistive mesh (35 µm) installed during assembly at the junction interfaces between panels. This mesh will help at the disassembly stage to detach the panels, by passing an electric current through this element. Acting as an electrical resistance, this will heat up melting the matrix and allowing the separation mentioned.
Thanks to the revolutionary methodologies that the HELACS Project brings up, the aeronautical industry will be able to find an innovative technological system for dismantling and maintenance of aircrafts in order to give new life to materials, as well as developments and innovations that will be transferable to other industries.