# Sustainable Manufacturing Decisions through the Optimization of Printing Parameters in 3D Printing
## 3 Results  
### Optimal Printing Parameters of All Single-Objective Optimizations  
Figure 4 shows the parts after printing. Table 4 summarizes the mean values and S/N ratios of the experimental dimensional accuracy, carbon dioxide emissions, and three printing costs. Based on the results evaluated using Formula 6, the mean effects plot of each factor could be obtained, as shown in Figure 5, and the optimal parameters of all the single objectives could be calculated, as shown in Table 5. Finally, the factor contribution of each single objective could be obtained from the calculation of ANOVA, as shown in the Supplementary Material. Figure 6 summarizes the factor contributions of all the single objectives. From the perspective of dimensional accuracy optimization, when the width accuracy of the printed object is required, the values of the fan rate, printing speed, nozzle temperature, build plate temperature, and layer thickness should be set to 100%, 20 mm/s, 190 \({}^{\circ}\)C, 30 \({}^{\circ}\)C, and 0.3 mm, respectively. When the minimum tolerance of the thickness of a printed object is required, the optimal printing parameters should be changed to a fan rate of 50%, a printing speed of 20 mm/s, a nozzle temperature of 210 \({}^{\circ}\)C, a build plate temperature of 60 \({}^{\circ}\)C, and a layer thickness of 0.1 mm. However, if the carbon dioxide emissions and electricity cost are to be minimized, the fan rate, printing speed, nozzle temperature, build plate temperature, and layer thickness must be set to 100%, 30 mm/s, 190 \({}^{\circ}\)C, 15 \({}^{\circ}\)C, and 0.3 mm, respectively. The best printing parameters for reducing material costs were found to be a fan speed of 50%, a printing speed of 25 mm/s, a nozzle temperature of 200 \({}^{\circ}\)C, a build plate temperature of 30 \({}^{\circ}\)C or 15 \({}^{\circ}\)C, and a layer thickness of 0.3 mm. Finally, from the perspective of the lowest labor cost, the optimal printing parameters were found to be a fan speed of 50%, a printing speed of 30 mm/s, a nozzle temperature of 200 \({}^{\circ}\)C, a build plate temperature of 30 \({}^{\circ}\)C, and a layer thickness of 0.3 mm. The dimensional accuracy of W, material cost, and labor cost were most significantly affected by the layer thickness, and they were 52.81, 57.14, and 87.63%, respectively. Although delta-type machines are suitable for high-speed printing, errors in the rotation of the stepper motor, dimensions, pulley assembly, and toothed belt stretching affect the accuracy of printed parts [31]; in addition, the three-axis parallel motion link affects the end positioning due to kinematic errors, resulting in a larger error in the accuracy of printed parts with the increase in the distance from the center [32]. This caused the error to have the highest significance with regard to OW, OL, and T, which were 29.21, 29.73, and 45.12%, respectively. The CO\({}_{2}\) emissions and electricity cost were most significantly affected by the build plate temperature, with a contribution of 63.95%. for all the needed dimensional accuracies (W, OW, OL, and T) of printed objects. Thus, each of the four dimensions has a weight of 25%. The optimal printing parameters calculated using the desirability analysis are as follows: a fan rate of 100%, a printing speed of 20 mm/s, a nozzle temperature of 210 \({}^{\circ}\)C, a build plate temperature of 60 \({}^{\circ}\)C, and a layer thickness of 0.1 mm. Figure 5: Mean effects plot: (**a**) W, (**b**) OW, (**c**) OL, (**d**) T, (**e**) carbon dioxide emissions, (**f**) material cost, (**g**) labor cost, (**h**) electricity cost. The optimal printing parameters of multiobjective 2 under different weights are all the same, and they are as follows: a fan speed of 100%, a printing speed of 20 mm/s, a nozzle