Impact of Vapor Polishing on Surface Roughness and Mechanical Properties for 3D Printed ABS

Additive manufacturing (AM) is useful when creating complex geometric models and prototypes. However, a well-known drawback is the fact that parts produced by AM methods typically have lower strength and higher surface roughness than traditionally-formed parts. To compensate for this, the surface finish is commonly improved by mechanical finishing or some type of coating. Another widely used surface treatment for ABS components is vapor polishing. In this process, the part is exposed to a solvent vapor that partially dissolves a surface layer and enables smoothing through surface tension-driven flow; it is known to decrease the surface roughness. However, little work has been reported quantifying the surface roughness change or on the mechanical impacts of this processing method. This work compares the strength, ductility and surface finish of vapor-polished ABS tensile specimens of varying thicknesses (1 mm, 2mm, and 4 mm). Results show that elongation at break is improved, while the modulus of elasticity is reduced in thin specimens. The tensile strength is largely unchanged. The power spectral density for roughness features larger than 20 µm were reduced 10X.