2000 年 66 巻 7 号 p. 1053-1058
In stereo-lithography fabrication process, photo-polymer resin is supplied for one layer thickness at first, then photo-polymerized selectively by laser beam, and by repeating the process layer by layer three-dimensional solid parts are fabricated. In this process, since a solidified layer must be connected to the previous layer, excessive exposure is needed to solidify the resin beyond one layer thickness. Therefore surplus growth caused by over-curing occurs at the bottom surface of the solidified layers and leads to a dimension error in the height direction. If the thickness of the surplus growth is predicted beforehand, the accuracy of an object in the height direction can be improved by cutting a few bottom surface layers from slice data in software. In this paper, a formula used to predict the thickness of the surplus growth is derived from the theoretical analysis about the mechanism of the surplus growth, and the validity of the formula is confirmed by experiments.