An interlaced toolpath strategy for void reduction in material extrusion additive manufacturing

Material Extrusion (MEX) is one of the most popular forms of Additive Manufacturing (AM) technologies due to its accessibility, versatility, and cost-effectiveness. However, the layer-by-layer and track-by-track nature of MEX technology is prone to the formation of defects, such as voids between deposited material tracks, which are detrimental to the print’s structural integrity and visual quality. Intertrack voids are the primary type of void in most MEX parts. This work proposes an interlaced toolpath material deposition strategy for Fused Filament Fabrication (FFF) technologies that can reduce the formation of inter-track voids. Unlike other proposed void-minimising strategies based on thermal post-treatments, laser, or ultrasonic-assisted deposition methods, the proposed one is a software-based approach that does not require hardware modification or part-post processing. While other state-of-the-art void-minimising strategies concentrate mainly on improving print quality and often omit their corresponding impact on other aspects, this research treats toolpath generation as a multi-objective optimisation problem, aiming to enhance the print’s mechanical performance with an insignificant degradation in the print’s dimensional accuracy.