THE WAY TO DECREASE THE CURING TIME BY 50% IN THE MANUFACTURING OF STRUCTURAL COMPONENTS USING THE EXAMPLE OF FML FUSELAGE PANELS

Abstract

Based on the missing cure monitoring in the manufacturing of structural components, the degree of automation and thus the increase in production cannot be improved. Since much more airplanes per month have to be produced promptly, a higher degree of automation is indispensable. Especially in the field of Fibre Metal Laminates (FML), there is a high potential. The development of a new production line that will allow automated fuselage production is the focus of the studies within the joint project AUTOGLARE. In order to ensure the optimal processing of the reinforced adhesive, a process monitoring system has been developed for the in-situ process monitoring of the manufacturing process within an autoclave. The simultaneous measurement of the resin’s temperature and electrical resistance allows for the real-time prediction of the viscosity, the degree of cure and the glass transition temperature (Tg). The curing of the polymer adhesive was modelled in the lab and its electrical properties were correlated to its T g. Finally, the cure monitoring system was installed in the autoclave and several trials and an entire fuselage were executed. The continuous measurement of the temperature and resistance in all sensors was quite smooth and accurate while the ORS system provided successfully the evolution of the Tg at four critical locations. The present scientific publication shows that the use of a process monitoring system can provide a reliable means to achieve online and accurate T g estimation during the FML manufacturing in an autoclave with a potential to decrease the curing time by 50%.