Impact of Epoxy Infill on the Mechanical Strength of ABS Specimens Produced by Fused Filament Fabrication

Abstract In this study, the effects of production parameters on the mechanical properties of parts produced using the FFF (Fused Filament Fabrication) technique were investigated, along with the application of epoxy filling. The effects of layer thickness, infill density infill pattern, and epoxy filling on the mechanical performance of the specimens were analyzed. Microscopic images were used to evaluate the distribution and structural integration of the epoxy within the specimens. Experimental results revealed that increasing layer thickness led to a decrease in tensile strength, with the highest strength recorded at 0.1 mm and a significant reduction at 0.3 mm. Higher infill density improved tensile strength but reduced elongation percentage. Epoxy filling provided significant mechanical enhancement, particularly at low infill densities, increasing tensile strength by 12% at 20% infill density and by 8% at 60% infill density. Among the infill patterns, hexagonal infill achieved the highest tensile strength (18.89 MPa), while linear infill exhibited the lowest (15.28 MPa). The homogeneous distribution of epoxy improved mechanical performance, while inhomogeneous dispersion limited mechanical enhancement. Additionally, epoxy-filled specimens exhibited lower elongation percentages than non-epoxy specimens due to their increased rigidity. Specimens with 0.1 mm layer thickness exhibited the highest elongation at break (4.58%), whereas at 0.3 mm layer thickness, elongation decreased by approximately 30% to 3.51%. The results demonstrate the potential of epoxy filler material to improve the tensile strength of 3D-printed composite structures, providing a new perspective that can contribute to the future applications of additive manufacturing.