| 摘要 |
<p>A transparent outer container 1 accommodates an inner container 2 containing a coloured liquid substance 3 which, on freezing, expands to a sufficient extent to break the wall of the inner container 2. The container 2 is enclosed within first and second layers 4, 6 of capillary material which extend between two fibre pads 7. A non-permeable opaque layer 5 prevents the liquid being visible when the substance freezes and breaks the container 2. When defrosting occurs, the coloured substance 3 flows in liquids form via the pads 7 to the second capillary layer 6 where it is visible. <IMAGE></p> |
