Experimental and numerical study of heat transfer on an industrial FFF printer: Application to PEEK

Abstract. The FFF process is one of the most widely used additive manufacturing processes for shaping thermoplastic polymers. The recent development of industrial printers equipped with high-temperature ovens has made it possible to print high-performance thermoplastics from the PAEK family for applications in the aerospace, medical and other industries. Numerous studies have shown that thermal history is a key factor to improve the mechanical properties of printed parts. Nevertheless, the uniformity of mechanical properties of printed parts is generally poor and highly dependent on the homogeneity of the thermal oven used, which, to our knowledge, has never been properly characterized. For semi-crystalline polymers, the thermal driven crystallization process is also a key factor in adhesion. However, the coupling between phase transformation and heat transfer is often neglected in numerical modelling and its influence has not yet been clearly demonstrated. In this work, we will carry out a preliminary characterization of the printer by measuring air velocity and temperature gradients over the whole printing zone. Secondly, the comparison between simulation and experimental measurements will show the importance of correctly predicting crystallization kinetics to obtain more accurate predictions.