| 摘要 |
<p>A metal can end with a tear-open plastics closure in which the closure has a plug part (14) fitting into an aperture (11) in the can end, a rim (17) surrounding the plug part, an d a pull tab (15), wherein a groove (22) extends across the plug part (14) and aligned grooves (24,25) or interruptions extend across the rim (17) to provide a hinge line allowing the tab (15) and the adjacent portion (23) of the plug part to pivot upwardly to provide venting of the can in a first stage of opening before full opening of the closure in a second stage. The closure (12) is of the kind which is moulded on to the can end (10) so as to totally enclose a downturned flange (16) around the periphery of the aperture (11), and to be capable of being sheared against the flange on opening, and the residual thickness of the plastics material below the flange (16) is greater in the main portion than in the vent portion (23) of the closure to provide a temporary arrest after venting. The plug part (14) is stiffer than the metal of the can end so that doming of the can end under internal pressure is concentrated in the metal and the pull tab (15) extends at an angle to the can end surface, rendering it easier to grasp for opening the aperture. A second hinge line may be provided at the far end of the closure, with a further increase in residual thickness, so that the closure can be retained on the can end while being hinged out of the way for pouring. </p> |
