Research of Treating Photosensitive Resin with Ultrasonic in Stereolithography System

In order to increase the building resolution of stereolithography system in Z direction, a novel recoating method, which photosensitive resin is treated with ultrasonic to improve the wetting status between solid resin and liquid resin and to decrease the minimum thickness of the resin layer is investigated. Experiments were carried out to study the influence of ultrasonic treating parameters on the floating property of resin. The experiment results indicate that viscosity of photosensitive resin, surface tension of photosensitive resin and contact angle between solid resin and liquid resin are decreased remarkably in the beginning 5 minutes; and then viscosity, surface tension and contact angle increase with the treating time. When the ultrasonic power is in the range of 40-50 watt, the decrease magnitude of viscosity, surface tension and contact angle reach the maximum. The results of the recoating experiments demonstrated that novel recoating method can obtain thinner resin layer with a thickness of 0.01 mm than recoating method (0.02 mm) which does not treat resin. The novel recoating method provides a solution to increase the building resolution in Z direction for SL system.