Polylactic acid (PLA) is one of the most widely used materials in fused filament fabrication 3D printing, and its mechanical properties can be substantially enhanced by incorporating nanomaterials and optimizing printing process parameters. This chapter used nanoclay as a reinforcing nanoparticle to achieve this goal due to its abundance and cost-effectiveness. Also, the nozzle temperature and raster angle parameters were selected as effective process parameters. In order to investigate and optimize the multiobjective 3D printing process of PLA/nanoclay samples, the response surface method was used as one of the methods of design of experiments. Nozzle temperature (190, 210, and 230°C), raster angle (0, 45, and 90°), and nanoclay weight percentage (0, 2, and 4 wt.%) were studied to optimize output responses. The analysis of parameter participation in density data reveals that the nanoclay weight percentage and nozzle temperature exhibit the most substantial influence, while the raster angle has the least impact. Conversely, the nanoclay weight percentage is the dominant factor when considering tensile strength results. In contrast, the interaction between the nanoclay weight percentage and raster angle has the slightest influence among the parameters under investigation. The multiobjective optimization results indicated that the optimal process conditions for achieving the highest tensile strength (33.78MPa) and the lowest density (1.089g/cm3) were obtained with a nanoclay weight percentage of 4 wt.%, a nozzle temperature of 230°C, and a raster angle of approximately 25.5°.
