Method and apparatus for producing three-dimensional emblem made of thermoplastic synthetic resin

A method for producing a three-dimensional emblem made of a thermoplastic synthetic resin, the three-dimensional emblem being obtained by welding and integrating an upper layer material containing a vapor-deposited-metal laminated film and a lower layer material containing a thermoplastic synthetic resin sheet through high-frequency dielectric heating with the use of an apparatus for producing a three-dimensional emblem made of a thermoplastic synthetic resin, the apparatus including:

• a slide jig in which an electrode flat plate die and an electrode projecting die are provided in such a manner as to be slidable in a horizontal plane;
• an electrode recessed die that is capable of approaching and separating from the slide jig in a vertical direction and is disposed at a position where the electrode recessed die can oppose the electrode flat plate die and the electrode projecting die;
• and
• a high-frequency oscillator that, in a state in which the electrode recessed die and the electrode flat plate die or the electrode projecting die of the slide jig are opposed to each other, performs high-frequency dielectric heating by continuously generating a high-frequency voltage across the opposing dies,
• the method comprising:
• a lower layer shaping step of disposing the lower layer material between the electrode flat plate die and the electrode recessed die, bringing the electrode flat plate die and the electrode recessed die closer to each other, and performing high-frequency dielectric heating, wherein the lower layer material that has been shaped is held on the electrode flat plate die, and the electrode flat plate die and the electrode recessed die are separated from each other, wherein:
• one or more recesses are formed in a surface of the electrode flat plate die that opposes the electrode recessed die, at a position not overlapping a design portion of the three-dimensional emblem, and
• in the lower layer shaping step, a portion of the lower layer material enters the recess, so that the lower layer material is held on the electrode flat plate die;
• an upper layer molding step of molding the upper layer material by sliding the electrode projecting die of the slide jig such that the electrode projecting die opposes the electrode recessed die, disposing the upper layer material between the electrode projecting die and the electrode recessed die, bringing the electrode projecting die and the electrode recessed die closer to each other, and performing high-frequency dielectric heating, wherein the upper layer material that has been molded is held on the electrode recessed die, and the electrode projecting die and the electrode recessed die are separated from each other;
• and
• a welding step of sliding the electrode flat plate die holding the lower layer material, of the slide jig such that the electrode flat plate die opposes the electrode recessed die holding the upper layer material, bringing the electrode flat plate die and the electrode recessed die closer to each other, and performing high-frequency dielectric heating while pressing the lower layer material and the upper layer material that are laid one on top of the other, thereby welding the lower layer material and the upper layer material to each other, and then separating the electrode flat plate die and the electrode recessed die from each other.