Thermal study of clogging during filament-based material extrusion additive manufacturing: experimental–numerical study

• Published in: International journal of advanced manufacturing technology Vol. 119; no. 7-8; pp. 5143 - 5161
• Main Authors: Taheri, Zahra, Karimnejad Esfahani, Ali, Ramiar, Abas
• Format: Journal Article
• Language: English
• Published: London Springer London 01-04-2022; Springer Nature B.V
• Subjects: Additive manufacturing; Advanced manufacturing technologies; CAE) and Design; Computer-Aided Engineering (CAD; Engineering; Extrusion; Fasteners; Glass transition temperature; Heat; Industrial and Production Engineering; Manufacturing; Mathematical models; Mechanical Engineering; Media Management; Original Article; Overheating; Questions; Sensors; Support vector machines; Temperature distribution; Three dimensional models; Material extrusion; Clogging; Numerical simulation; Buckling; Multi-material printing; Heat transfer
• ISSN: 0268-3768; 1433-3015
• DOI: 10.1007/s00170-021-08281-y

One of the major drawbacks of material extrusion additive manufacturing (AM) is hot-end clogging. This study aims to answer the question, “How clogging happens and what thermal conditions lead to clogging during filament-based material extrusion?” Answering this question requires a clear understanding of temperature distribution inside the liquefier. However, this could not be achieved only through experimental measurements. Therefore, numerical simulations were also carried out by developing a 3D finite volume model of the hot-end. The results obtained from numerical simulations show good agreement with experimental measurements. They also give us a detailed picture of the temperature gradient near the nozzle. A series of experiments were performed to determine at what thermal conditions clogging occurs, and some criteria for avoiding clogging were presented. The temperature distribution of those thermal conditions that leads to clogging is then investigated numerically to analyze the clogging mechanism. As the results show, overheating the heat barrier increases the length of the filament, whose temperature is above the glass transition temperature. As this length exceeds a critical value, the filament buckles under the extruder motor force, and consequently clogging occurs.
Graphical abstract