Design and Development of Hot Vapour Polishing System and Optimization of It’s Process Parameters for FDM Printed Parts

Fused deposition modelling (FDM) is a process of layer-by-layer material deposition using a heated extruder. FDM printed parts have stair-stepped effect and ridge patterns that diminish surface quality. This research intends to develop a low-cost, high-efficiency experimental system for polishing a variety of materials using various chemicals, with a chemical vapour smoothening process. For evaluating the created set-up, tetrahydrofuran (THF) is used and acetone as solvents to polish polylactic acid (PLA) and acrylonitrile butadiene styrene (ABS). Taguchi multi-parameter optimization was used to optimize the input parameters (reagent volume, temperature, concentration, and time) in the vapour smoothening process. With the ideal input parameters, the roughness of the FDM printed parts was reduced by over 95%. The effectiveness of a vapour smoothening system is better when the system temperature is maintained at the boiling point of the reagent, the reagent is of its highest concentration, and when the specimens placed are placed directly over the ultrasonic mist-maker. The system discussed works best with FDM printed parts having minimum porosity and better quality. The hot chemical vapour smoothing approach reduced specimen flexural strength and increased top layer wear. The findings of this study will help develop a large-scale polishing system for FDM printed thermoplastics and enhance the use of FDM components in sectors that need highly polished parts.