From 3D models to FDM 3D prints: experimental study of chemical treatment to reduce stairs-stepping of semi-sphere profile

Adaptively computing the layers (LH) for FDM 3D printed samples has been the great potential of accomplishing high quality surface finish results while maintaining a reasonably short printing process time. This research paper presents a stairs-stepping effect of a semi-sphere profile fabricated by FDM 3D technology which is a cost-effective and promising additive manufacturing (AM) technique. In the experimental test, two-LHs (0.04 and 0.32 mm) and three different thermoplastic filament materials (PLA, PLA+, and ABS+) were used. The optimum surface roughness (R_a) obtained at 100% solid infill density with the configuration of a minimum LH was around 3.9092 and 53.2628 μm for a maximum LH after and before chemical treatment respectively. The lowest LH value brings the deviation reduction to achieve a minimum value of R_a, while fabrication time would go up with increasing the number of layers. Within the group of (PLA+, PLA and ABS+) for both LHs, ABS+ has shown low density of 1.02 to 1.1 g/cm³, while PLA+ and PLA has shown almost the same values of density ranging from 1.2 to 1.3 g/cm³. Understanding and improving relationships between thermoplastic filament materials, printing process parameters and properties of FDM 3D printed samples will be a key to improve the extrusion AM processes and expanding their applications globally. To sum up, the chemical treatment (using acetone) was an economical and industrially sustainable world-wide method to improve the poor surface quality finish of AM samples.