Three-dimensional decorative piece and method of producing the same

A method of producing a three-dimensional decorative piece having a three-dimensional design, the method comprising:

• a step of molding a core, including filling a flowable synthetic resin into a core molding die engraved with the three-dimensional design and served as an electrode, subjecting the synthetic resin to a first high-frequency dielectric heating while being pressed from above with a first flat plate electrode die, and curing the synthetic resin to form the core having a shape with a first convex portion corresponding to the three-dimensional design;
• a step of forming an upper layer molded body, including placing an upper layer material with a metal vapor-deposited layer between a concave electrode die engraved with the three-dimensional design and a convex electrode die, subjecting the upper layer material to a second high-frequency dielectric heating while being pressed to form the upper layer molded body having a shape with a second convex portion corresponding to the three-dimensional pattern on its front surface side;
• a step of placing a substrate on a second flat electrode plate die and then placing the core on the substrate;
• a step of integrating the upper layer molded body, the core, and the substrate, including positioning the second flat plate electrode die and the concave electrode die opposed to each other while holding the upper layer molded body on the concave electrode die, moving the concave electrode die toward the second flat plate electrode die such that the second convex portion of the upper layer molded body puts on the first convex portion of the core, and subjecting the upper layer molded body, the core, and the substrate to a second high-frequency dielectric heating to bond the upper layer molded body, the core and the substrate all together by fusion;
• and
• a step of melt-cutting the upper layer molded body and the core along the three-dimensional design.