| 摘要 |
<p>The coin holder consists of a transparent envelope made in two halves (6) of plastics film which is clamped inside a rectangular frame (1) so that it is then ready for mounting in a leaf of an album. In third way, it is protected from the atmosphere and, oxidation. The envelope halved each have a raised ridge at the region of the milled edge, followed by a peripheral flange. The two flanges (14) are then clamped between the two rounded edges (1) of the frame while held in a suitable tool, so that heat and pressure can be applied, and the two frame halves secured together at the corner regions.</p> |
