Optimization of scanning path for reducing fabrication time in a novel two-laser beam stereolithography system

The aim of this study is to develop a novel two-laser beam (TLB) stereolithography system and to optimize scanning path for shortening the fabrication time using adaptive crosshatch technique. In the development of TLB system, the wavelengths of the two semiconductor laser beams are determined to be 405 nm (blue light) and 532 nm (green light), respectively, according to the relative absorbance rate of used visible-light curable resin. The blue light laser is suitable for scanning the object contour due to the fast absorbance and caused a narrow cured depth. The green light laser is used for scanning the internal crosshatch for condensing the fabrication time because its high power results in a wide cured width and deep penetration. The influence of photoabsorber, carbon powder with average diameter of 0.1 micrometer, is discussed and specified an optimal weight percentage of 1.5 for controlling cured thickness. An adaptive crosshatch technique is introduced and applied into the fabrication process. In addition, two fan objects with seven blades are fabricated according to the raster scan and adaptive crosshatch scan, respectively. Consequently, the developed system fabricates object quickly with a high accuracy and adaptive crosshatch significantly reduces fabrication time.