Quick assessment of melt flow index in hybrid bio-composite filaments for bio additive manufacturing

Abstract The use of mechanical property-improving fillers has resulted in defect formation in 3D-printed structures. To the best of our knowledge, this study is the first to modify poly lactic acid (PLA) filaments in bulk by integrating 7–13 wt% holy basil and 0.1–0.4 wt% graphene additive. The results showed a 22–31 % increase in the melt flow index (MFI) of the composites. The filaments’ compositional changes were then submitted to rheological testing to assess the influence on filament structure. To solve common printing difficulties, such as mid-print model voids, we developed a strategy for optimizing extrusion settings using Cura slicing software. In addition, we created an efficient technique of MFI testing of 3D-printed filament systems that does not require the use of expensive laboratory equipment, allowing us to use additional filament property assessment methods. This highlights the need to tune the filament’s extrusion speed in order to improve accuracy and print quality for 3D printing additive prototyping.