The SLA process, also known as light modeling or stereolithography, works on the principle of photopolymerization of liquid photosensitive resins.
The liquid material can rapidly undergo photopolymerization under the irradiation of ultraviolet light of a certain wavelength and intensity, and the molecular weight sharply increases, and the material changes from a liquid state to a solid state. The liquid tank is filled with liquid photocuring resin. Under the action of the deflection mirror, the laser beam can scan on the liquid surface. The scanning track and the presence or absence of light are controlled by the computer. When the light spot is hit, the liquid is solidified.
he beginning of the forming, the working platform is at a certain depth below the liquid level, and the focused spot is scanned point by point on the liquid surface according to the instruction of the computer, that is, solidification point by point. When a layer of scanning is completed, the unirradiated area is still a liquid resin. Then the lifting platform drives the platform down to a height, and the formed layer is covered with a layer of resin. The scraper scrapes the liquid surface of the resin with higher viscosity, and then scans the next layer, and the newly cured layer is firm. The ground is glued to the previous layer and repeated until the entire part is manufactured, resulting in a three-dimensional solid model.