Formability Assessment of 3D-Printed ABS Sheets Using Nakajima Test

Abstract This study explores the formability of acrylonitrile butadiene styrene (ABS) sheets produced by the fused filament fabrication 3D-printing process. The ABS sheets, fabricated with a diameter of 80 mm, were subjected to the Nakajima test. The investigation focused on assessing the impact of printing pattern (rectilinear, concentric, concentric/rectilinear), sheet thickness (0.8 mm, 1.4 mm, and 2 mm), and forming temperature (35°C, 70°C, and 90°C) on forming depth, utilizing a full factorial design of experiments comprising 27 conditions. Through the application of analysis of variance (ANOVA), a linear model for forming depth was derived, demonstrating high precision and reliability. Results indicate that as temperature increases, formability improves, reaching a maximum at 90°C with a rectilinear print pattern (15.95 mm depth). Conversely, the lowest forming depth (1.45 mm) occurred at 35°C with a concentric printing pattern. Sheet thickness showed minimal impact on forming depth, but forming force increased with thickness.