Effect of Model Exposure Time on the Performance of Photocured Digital Light Processing 3D Printing

To explore how exposure duration impacts the dimensional precision and mechanical characteristics of DLP 3D-printed specimens, a study was conducted. This study employed a fractional factorial experimental design method, with exposure time as the variable. The resin material used in this study is free radical photopolymer resin. Dimensional accuracy and mechanical performance tests were conducted on printed samples with different exposure time configurations, and data for different exposure times were collected and subjected to detailed statistical analysis. The experimental results show that with increasing exposure time, the dimensional precision in the X and Y directions initially improves but subsequently deteriorates, whereas the dimensional accuracy in the Z direction remains more stable and is less impacted by variations in exposure time. The highest dimensional accuracy was observed at an exposure time of 3 seconds. Additionally, as the exposure time extended from 2 seconds to 6 seconds, the mechanical characteristics of the samples improved. Microstructural observations of the tensile sample cross-sections revealed that the surface quality of samples exposed for 3 seconds was superior. Balancing high precision and mechanical performance, the optimal exposure time was determined to be 3 seconds. This study not only reveals the mechanism by which exposure time affects the performance of photopolymerization-based DLP 3D printing but also provides theoretical and practical guidance for optimizing printing parameters in real-world applications.