| 摘要 |
<p>A metal can (10) has an indented base (16) defining an external cavity (20) which is utilised to contain heating means. The heating means comprises quicklime (26) filled within a first chamber (28) and water within a second chamber (32) of the cavity (20). A breakable membrane (24) separates the two chambers (28, 32) and hermetically seals the quicklime (26) into the first chamber (28). To seal the membrane (24), which may be a disc of metal foil, to the sealing surface of an annular flange (34), formed within the cavity (20), a heated sealing head (60) is used to apply the metal foil (24) onto the annular flange (34) such that heat and pressure are applied to the metal foil. The heated sealing head (60) carries a thin compliant layer (62) which is able to conform to the contours of the sealing surface of the flange (34) and thereby ensure that the metal foil (24) similarly conforms whereby a reliable and perfect seal between the metal foil (24) and the sealing surface of the annular flange (34) is achieved.</p> |
