Abstract

The current work has been performed in the context of FUSINBUL, an European project framed within CleanSky2 research programme funded by the EU’s Horizon 2020 (Grant Agreement nº 831946). The scope of this project is to accomplish the full barrel demonstrator tests, needed to certify the new conception of fuselage created and manufactured in the Green Regional Aircraft context. Two advanced manufacturing processes for composites materials (prepreg cobonding process in autoclave and LRI infusion process out of autoclave) are developed and validated to achieve full scale innovative pressure bulkheads for Regional Aircraft Fuselage barrel on-ground demonstrators. The design of the tooling has taken into account the main needs of both manufacturing processes to carry out the bulkheads and the industrial requests. In addition to this, innovative tool technologies have been developed and applied, such as cast aluminium by lost foam casting, precise but robust indexing system split and seal system of tool too large to be fabricated one shot, then precisely assembled with no gap or step. For both manufacturing processes, the most advanced techniques of lay-up are used to reduce labor costs and increase the level of industrialization in serial production to achieve bulkheads with a diameter of 3.5m and the required standards in aeronautical industry.

Abstract

It is estimated that the aeronautic industry in the European Union produces annually around 10 tn of uncured prepreg scraps, generated mainly from manual and automated lamination processes of composites, and that the treatment cost for these residues is between 3 and 12 € per kilogram.

This work presents a technology for the reuse of the unidirectional prepreg scrap using a machine that allows the manufacturing companies, mainly form aeronautic sector, the reuse and valorisation of the leftovers of PREPREG in the workshop, involving a reduction in the economic and environmental impact.

The developed solution consists in a machine able to perform the needed processes to reuse the prepreg scrap leftovers in an automatic and efficient way, maintaining the quality and the material properties for the manufacturing of non-critical components. The equipment integrates different technologies that include computer vision to identify the shape of the leftovers and the fibre direction, cutting technology to generate regular rectangular chips aligned with the fibre direction, and a robotic system to pick and place the chips generating an ordered pattern.

The result of the process is a material sheet aiming to control the mechanical properties by using homogeneous chips with controlled fibre orientation following a predefined pattern.