Surface modification of prototypes in fused filament fabrication using chemical vapour smoothing

Acrylonitrile butadiene styrene (ABS) specimens fabricated by fused filament fabrication (FFF) were post treated by acetone, ethyl acetate and their mixed vapour. The effect of different chemical vapour, exposure time and building orientation on the surface roughness, tensile strength, dimension and weight stability of the ABS specimens were investigated before and after treatment. The results demonstrated that all chemical vapours were capable of improving the surface coarseness of ABS specimens. The tensile strength of specimens treated with the acetone or the mixed vapour decreased with increasing the exposure time. Surprisingly, it did not change for specimens treated with the ethyl acetate vapour when the exposure time reached 30 min. The deviations of length and width of specimens after chemical vapour treatment were lower than 5 %, irrespective of the building orientations. However, the deviations of thickness were high (up to 25 %). The weight of specimens after treatment increased with prolonging the exposure time due to the absorption of the chemical vapours.