| 摘要 |
<p>METAL CAN END WITH PLASTICS CLOSURE A metal can end with a tear-open plastics closure in which the closure has a plug part fitting into an aperture in the can end, a rim surrounding the plug part, and a pull tab, wherein a groove extends across the plug part and aligned grooves or interruptions extend across the rim to provide a hinge line allowing the tab and the adjacent portion 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 is of the kind which is moulded on to the can end so as to totally enclose a downturned flange around the periphery of the aperture, and to be capable of being sheared against the flange on opening, and the residual thickness of the plastics material below the flange is greater in the main portion than in the vent portion of the closure to provide a temporary arrest after venting. The plug part 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 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> |
