Numerical analysis and experimental evaluation of temperature profile in a miniaturized screw-assisted 3D print head

Additive Manufacturing (AM) continues to grow rapidly worldwide through its different development research lines, achieving greater maturity in industrial and new potential multidisciplinary applications. One of the key advancements in extrusion-based AM is the design of screw-assisted 3D equipment and operation development, which provide a promising alternative to traditional filament-feeding 3D printers, particularly for polymer composite materials. Such equipment has enabled the expansion of experimentation engineering materials based on granulated or pelletized feedstock by lower energy consumption aligned with sustainability requirements. Monitoring and controlling the temperature profile during the extrusion process, especially in extrusion process screw-based systems, are highly strategic for ensuring phase transformation regions occur assertively, assisting in adjusting the material residence time and preventing material plasticization at the beginning of feeding and possible material degradation in the plasticization regions. This manuscript proposes a numerical-experimental model that estimates the thermal profile of customized and modular equipment for extrusion-based AM containing a miniaturized screw-assisted 3D printhead unit. An in-line passive thermal monitoring system was implemented and preliminary results indicated an approximately 98.2% numerical-experimental agreement with mean absolute percentage errors (MAPE) of 2.55% (surface) and 0.96% (interior) at 200 °C and 2.52% (surface) and 1.30% (interior) at 215 °C. The mean absolute errors (MAE) were 2.69 °C/1.26 °C and 2.95 °C/1.61 °C for surface/interior under 200 °C and 215 °C, respectively. According to the findings, both proposed procedure and numerical predictive model can capture the main thermal gradients along the screw-assisted modular printhead with satisfactory accuracy.