Optimization of process parameters and evaluation of surface roughness for 3D printed nylon-aramid composite

Abstract

Abstract Additive Manufacturing (AM) is a latest technology of manufacturing of products by layer over layer deposition. Fused Deposition Modelling (FDM) is a widely used technique amongst the AM technology due its easier operating commands hassle-free pre-processing and post-processing stages. The current investigation is focused on the FDM uses of thermoplastic as the feed material, consisting of polymer composite consisting Nylon and Aramid, which is introduced as a filament. FDM process parameters are optimized to obtain the best quality surface finish by minimizing the surface roughness. Layer thickness, print temperature, raster angle, infill pattern style and infill part density are the influencing parameters considered in this investigation. The values of these factors were taken at three levels each and the interactions between these factors were investigated for the surface finish of FDM built part. Taguchi Design of experiment was used to find the optimum factor levels, significant factors, and interactions. The results from Taguchi method showed the layer thickness of 0.2 mm, print temperature of 280 °C, raster angle of 90°, infill pattern style of tetrahedral and infill part density of 90% were optimal for improving the surface finish. The part printed for validation with optimized process parameters had resulted in the Ra value of 1.5470 µm, 2.145 µm and 1.212 µm, with an error of 1.65%, 2.10% and 1.80% at the top, side, and bottom faces, respectively. The combined objective error was achieved at 2.45%. The errors obtained is attributed to the hardware and/or the variations in the operating conditions. The study highlighted a simple but workable approach for predicting the surface roughness along various surface of FDM built parts.