| 摘要 |
<p>The cover foil comprises at least two superposed parallel layers (22, 24) completely covering the opening. The lower layer (22) is a 50-90 micron plastic film or lacquer capable of being pulled off. The barrier layer (24) is aluminum or plastic 5-15 micron thick. Note: throughout, the term tin has the familiar, rather than the chemical significance, which is excluded.</p> |
