Parameter optimization of DLP 3D printing machine for thermoplastic polyurethane material to minimize dimensional error

Thermoplastic polyurethane (TPU) is one of the polymer materials used in DLP 3D Printing machines. This study uses parameter analysis to obtain a combination of parameters for TPU material, aiming to obtain printing results with the slightest dimensional error. The dimensions of the specimen refer to ASTM D790-03. The dimensional error calculation compares the printing results with the design dimensions. In the measurement results, the average dimensional error of length is 0.786 %, width is 1.197 %, and height is 9.611 %. In the pilot study, the test parameters obtained the Exposure Time parameters are 50 µm, 70 µm, and 100 µm, while the level values for Layer Thickness are 6 seconds, 7 seconds, and 9 seconds. The results of running by printing specimens with these parameters resulted in successfully printing specimens with the same result as the CAD design. Statistical analysis showed that the three parameters to get the printing results that had the slightest dimensional error were the ET parameter with a level value of 6 seconds and the LT parameter with a level value of 70 µm.