| 摘要 |
PROBLEM TO BE SOLVED: To correctly and efficiently mold and bake a decorative tool from of metallic clay by integrally providing a large-diameter part and a small-diameter part in which the cross-sectional outer shapes along the axial direction are approximately similar, and the dimensional ratio in the cross-sectional outer shapes corresponds to the shrinkage ratio of an annular or cloven annular decorative tool at the time of baking. SOLUTION: As a heat resistant low thermal expansion ratio material used for a core material 1 for molding and baking, a baked body, particularly, any of alumina ceramic, mullite ceramic or coagulant ceramic is preferable. In the molding stage, when a sheet-shaped adhesion preventive material 12 has been interposed to the large- diameter part 2 in the core material 1 for molding and baking (e.g. an adhesive tape, etc., in which one side has an adhesive face, and the other side has a sliding face has been stuck on the outer circumference of the large-diameter part 2 with the sliding face as the outside), and metallic clay is wound from the above, after molding, it is preferable that the annular or cloven annular molded part can smoothly be moved to the small-diameter part 3. |
