Material extrusion-based Additive Manufacturing (AM) has been widely used to fabricate high-strength components by utilizing continuous carbon fiber-reinforced plastics (CFRP). However, during fabrication using continuous fiber CFRP, the fibers are pulled by the nozzle, causing misalignment (placement errors) that vary with the fiber toolpath. This study aims to investigate the relationship between fiber toolpaths and placement errors, with a particular focus on the distance from the start point to the cut point of the continuous fiber. An additive manufacturing machine equipped with dual nozzles for thermoplastic and continuous fiber extrusion was used to fabricate both straight and broken-line fiber paths. In the case of straight paths, shorter fiber path lengths tended to result in larger placement errors, with an average error of 3.0 mm observed when the cut point was placed close to the start of the path. Additionally, higher nozzle travel speeds resulted in increased fiber misalignment, with errors of about 4.4 mm on average. In the case of broken-line paths, significant placement errors were observed when the nozzle direction changed sharply. The placement differed from the intended design, with average errors of 6.1 mm in the X-direction and 7.0 mm in the Y-direction from the end point of the designed path. These results suggest that cut-point distance and nozzle speed have a significant influence on fiber placement accuracy.
Mizuno et al. (Wed,) studied this question.