Mixture and Process Optimization of Vapor Smoothing Using Acetone and Ethanol for 3D Printed ABS

The effects of solvent vapor treatment on the surface quality of FDM-printed ABS parts were investigated using acetone-ethanol mixtures. Four binary solvent ratios (100:0, 80:20, 60:40, and 40:60 v/v) were evaluated. Exposure times were varied (30, 40, and 50 minutes) to investigate interaction effects. The exposure was conducted in a closed-chamber at room temperature. For the assessment of surface characteristics, average roughness on flat top, flat side, and curved wall surfaces was measured. Visual gloss and dimensional change were also evaluated. Surface morphology and treatment stability were found to be significantly influenced by the incorporation of ethanol into the acetone vapor. The most favorable balance was achieved with the 80:20 acetone-ethanol mixture. With this mixture, substantial reductions in surface roughness (up to 86.3% on flat side surfaces) were achieved. Minimal deformation and the preservation of edge geometry were also noted. Pure acetone (100:0) produced the smoothest appearance. However, this treatment caused pronounced corner rounding and dimension loss. Insufficient smoothing was observed with mixtures of higher ethanol content (60:40 and 40:60), which was characterized by visible layer lines and lower gloss values. The 80:20 solvent mixture with a 30-minute exposure time proved to be an effective and consistent method for improving the visual surface quality of ABS prints. Effective smoothing was achieved with this ratio. Geometric fidelity was also maintained. As a result, the process is considered suitable for prototypes and end-use components where surface finish is critical. This framework can be enhanced and generalized by further investigation. An analysis of intermediate solvent ratios and the durability of materials over time is necessary.