Mechanics of nozzle clogging during direct ink writing of fiber-reinforced composites

Nozzle clogging frequently occurs while printing fiber-filled polymer inks with extrusion-based additive manufacturing processes, which limits the quantity of fibers that can be added to matrix, part fidelity, and geometric accuracy process. Both in situ X-ray radiography ex computed tomography were used explore mechanisms contribute nozzle clogging. Three considered, fiber volume fractions ranging from 1% 5.75%, nominal lengths 150 470 µm. These results showed specific produced clog depended substantially on fraction, length geometry. Specific included log-jam pileup misoriented near tip, lodging a entanglement accumulation at step-like reductions profile. Suggestions reduce prevalence are presented.