Abstract

LMPAEK/CF laminates collected from scrap waste of Automated Fiber Placement (AFP) manufacturing were recycled obtaining different fiber sizes. The fraction with the smallest average particle size was mixed with different concentrations (5, 10, 20, 30% wt.) of PEKK (60:40). Blends processability was assessed by means of differential scanning calorimetry (DSC) and rotational rheology. Lastly, the mixture with 5%wt of carbon fiber content and PEKK was used for the filament manufacturing. This filament was printed in a robotized cell equipped with a 6-axis robotic arm using a printing head with a 0.8mm nozzle. The mechanical characterization of the printed samples revealed a significant improvement in the mechanical properties compared with neat PEKK or LM-PAEK.

Abstract

Carbon fibre matrix composites are consolidated in high-demanding industries such as aeronautics and aerospace. Nowadays, thermoset composites are fully integrated on several new aircrafts in production. However, thermoplastic composites are progressively emerging as a better solution due to their end-of-life recyclability and optimized manufacturing process. One of the processes used to manufacture final parts from thermoplastic composite materials is press-moulding, in which a high-temperature heating system is combined with the application of pressure at high speeds. This article studies the optimization of press-moulding process in combination with an Additive Manufacturing (AM) produced metallic mould core. The aim of this study is the manufacturing of a thermoplastic aeronautical part, that would be submitted to real-world performance test. For the press-moulding process, a high-temperature infrared heating system was designed, supported by thermal oil mould heating, this heating system was combined with a mould-pressing process by integrating the system in a commercial injection machine. Regarding the AM tooling, produced by Wire Arc Additive Manufacturing (WAAM) process, was designed to reduce tooling weight, and optimise thermal cycle. Moreover, manufacturing data from WAAM tooling was recorded and compared with that obtained from a symmetrical conventional manufacturing made mould. The analysis shows savings in terms of material and energy consumption, as well as cycle times reduction. The final part metrology study shows indistinguishable results between the press-moulding process carried out using the WAAM tooling and that manufactured through conventional methods.