In-line monitoring of the fused filament fabrication additive manufacturing process for fibre-reinforced polymer matrix composites.

In the present work, a novel combination in-line monitoring methodology including Infrared Thermography (IR) and acoustic emission (AE), benchmarked against micro-computerised tomography was developed for the monitoring of the FFF AM process manufacturing pure polymer, short fibre-reinforced and continuous fibre reinforced polymer matrix composite samples. The method allows for the detection of anomalies during the printing process and the verification of their presence after printing without the need for destructive testing. For both the in-line monitoring, the correlation between the printing parameters and the presence of defects and anomalies was investigated. It was found that the in-line monitoring method can detect anomalies during the printing process and can provide information on the efficacy of the printing. This is substantiated by the presence of defects found during the offline assessment. It was also concluded there was a correlation between the structural integrity and print quality of the printed samples and their printing parameters which was identified during the in-line monitoring work.