Expandable container having lid for providing headspace control of a food can

摘要

Expandable Container having Lid for Providing Headspace Control in a Food CanThe invention relates to lids for cans for receiving foodstuff which are to besubjected to a thermal treatment above 50°C as sterilization or at leastpasteurization. The lid (1) has an annular ring (2) seamable to the can body whichring can be firmly and sealingly connected with the can body rim portion and a coverpanel (3) which is sealingly disposed (13) to said ring. The annular ring comprisesa flat web (6) that points towards a vertical central axis (8) of the lid and is axiallyoutwardly inclined (11) with respect to a horizontal plane (15). The cover panel(3) is sealed to the flat inclined web by means of a radially outer ring band (3a).A central area (3b) that is surrounded by the ring band is axially inwardly preformedtowards an interior in a dome or bowl-shaped fashion and thereby stabilized.After closing of the can, it is subjected to the thermal treatment. Upon a changein pressure (in the closed can) occurring during this thermal treatment the coverpanel changes from the preformed position (3b) to an axially outwardly directedbowl/dome-shaped position (3b'). After cooling the closed can, the coverpanel (3) returns - at least substantially exactly - into its preformed position.