| 摘要 |
<p>A sealed beverage can has fitted therein a capsule (10) forming a secondary chamber within the can, the capsule having an associated standpipe (12) apertured at (14) beneath the capsule and terminating at its upper end (16) just below a deformable roof (18) of the capsule, thereby to form an openable and closable valve at the upper end of the tube, whereby communication between the interior of the capsule and the contents of the can is restricted until at least after the can is inverted during pasturisation, whereafter pressurised gas in the gas headspace is able to enter the capsule through the said aperture after the said valve has opened. The restrictor may comprise a controlled leak across the valve which permits the slow ingress of fluid into the capsule. Alternatively at least part of the wall of the capsule is formed from gas permeable material, the permeability of which is such as to restrict the ingress of gas for a sufficient length of time as to prevent a balancing of the pressures to occur until at least after pasturisation has begun.</p> |
