PROPERTIES OF NOVEL ORNAMENTAL MATERIAL BOARDS MADE FROM SILK FIBROIN SHEET

The material used for Bekko art work is the shell of the hawksbill sea turtle, which has been imported from tropical countries for about 400 years. However, recent enforcement of the Washington treaty has prohibited the importing of turtleshell material, because the hawksbill sea turtle has been recognized as a creature in danger of extinction. We have therefore tried to utilize effectually unused materials (waste) and develop new materials as substitutes for the shell of the sea turtle in order to protect both the turtle and the traditional art industry. We have previously reported that the properties of silk fibroin are similar to those of turtleshell, but a hot melt board made from fibroin powder was opaque, and showed weak strength which made it unsatisfactory as a substitute material for Bekko. In this study, we try to develop laminated boards obtained by the hot-pressing of about 30-100 layers of silk fibroin sheet, and we discuss the appearance and properties of new materials.