光造形法における紫外線硬化性樹脂の造形条件の検討
Study of the Fabricated Condition of UV-cured Resin
式地千明・近藤信幸・八尾幸伸・北村洋一・堀内正仁
Shikichi, Kazuaki / Kondou, Nobuyuki / Yao, Yukinobu / Kitamura, Youichi / Horiuchi, Masayoshi
In the photofabrication system a UV laser scans liquid resin to cure it into thin plates which are then stacked together to fabricate any shape of plastic model. The development of photofabrication has now reached on the brink of achieving a breakthrough for practical application : a mechanical fabrication accuracy of 0.1 mm. However, the photofabrication system is making it impossible to achieve high accuracy in the cured resin model, because of the liquid solid phase change.
Warpage is mainly produced by shape factors, and no method for evaluation has been established. In addition, warpage increases significantly except under optimum fabrication conditions. In this paper, we studied the fabrication conditions for D-MEC SCR100 and SCR200 resin using a simple model.
Conventionally fabrication conditions have been determined from the cross-sectional shape of the cured resin obtained from the laser scans. This study investigates the following two points : (1) With regard to the structural and volume changes of the polymerized resin, the density of the UV-cured resin is measured. (2) With regard to the curing and shrinkage phenomena, warpage is measured.
It has been established that the photofabrication system requires an optimum laser intensity of light 2.3 to 3 times larger than that of the conventional level. A fabrication condition has been determined which minimizes the warpage of the cured resin.
Key words: Rapid prototyping / Photofabrication / UV cured resin / Warpage