Analysis of dimensional quality in 3D printed polylactic acid parts fabricated by fused deposition modeling

Abstract Fused deposition modeling (FDM) is an important 3D printing technique which extrudes thermoplastic polymer through a temperature controlled nozzle and deposits layer by layer over a solid platform to create three dimensional products. As each layer of the developed part is comprised of many rasters placed side by side, the part dimensional quality is directly affected by the accuracy of rasters. In the present study, Polylactic acid (PLA) specimens were printed using FDM 3D printer at nozzle temperatures 190 oC, 210 oC, and 230 °C. The part dimensions were measured using micrometer (Mitutoyo, Japan) while raster width and raster to raster air gap was visualized using SEM microscopy and ImageJ software tool. After analysis of the obtained results, it is observed that the minimum deviation in X and Y-dimensions is achieved at higher nozzle temperature; whereas minimum deviation in Z-dimension is obtained at a moderate nozzle temperature. Moreover, the effect of nozzle temperature on Y-dimension and Z-dimension (at shell) is almost similar. A positive deviation in raster width is observed at lower nozzle temperature and vice-versa. The effect of nozzle temperature on the raster to raster air gap was also significant and found maximum at nozzle temperature of 230 °C.