| 摘要 |
<p>The preparatory stage of the press matrice has a central profile. A centering profile is prepd. from this galvanically. The profiling feature for centering can be circular grooves or projections e.g. a circular bead etc. The preparatory stage can be e.g. a lacquer foil. The Lacquer foil carries the sound groove and it will be metal coated, esp. silver coated. The centering features after use are removed by pressing.</p> |
