With the rapid advancement of additive manufacturing, Material Extrusion (MEX) has become widely adopted due to its low cost and high process flexibility. However, optimizing MEX processing parameters to balance multiple performance objectives in engineered polymers such as PETG remains a critical challenge. To collaboratively enhance tensile strength, printing efficiency, and material usage efficiency (MUE) of MEX-printed PETG parts, this study employed a multi-objective optimization using the desirability function method. Using single-factor and Taguchi orthogonal experiments, along with ANOVA and multiple linear regression, the coupling mechanisms among infill density, layer height, infill pattern, perimeter shells, and printing temperature for tensile strength, printing time, and MUE were rigorously characterized to elucidate their underlying interdependencies. Based on the established empirical prediction models for tensile strength, printing time, and MUE, the optimal parameter combination was identified as 52% infill density, 0.25 mm layer height, a grid infill pattern, 5 perimeter shells, and 250 °C printing temperature. Experimental validation yielded a measured tensile strength of 38.81 MPa, with a deviation of less than 1% from the predicted value. Furthermore, the printing time and MUE met the design objectives with excellent stability. The proposed MUE evaluation and multi-objective optimization framework provides essential theoretical and technical support for the efficient and economical manufacturing of MEX-printed PETG functional components.



