Development of Photofabrication Device by UV-Rays through Optical Fiber and its Application for Plaster Mold Casting

摘要

Photofabrication is a rapid prototyping process that produces patterns easily and quickly. Patterns are composed of multilayer photopolymer cured by laser or ultra violet ray. As laser devices are expensive, they have not been widely adopted. The exposure device in this paper used a mercury xenon lamp with an ultraviolet rays irradiated through optical fibers. 200 and 400 #mu#m fibers were used for the exposure device, but it was found that the 200 #mu#m fibers were superior to 400 #mu#m fibers for laminated patterns. Three kinds of photopolymer were used for the investigation. These are urethane (M30), an urethane and unsaturated polyester mixture (FP20), and an unsaturated polyester (G42). Cured resin patterns in plaster molds were heated at 873 K X 10.8 ks. The heated resin patterns disappered and small amount of ash was observed. AC4C aluminum alloy were poured into these molds by centrifugal casting. No cracks were observed in the molds with FP50 and M30 patterns, and fine castings were obtained. Molds with G42 patterns generated cracks due to thermal expansion of the pattern and surface of AC4C castings inferior good compared with the castings of the FP50 and M30 patterns.