Metallic can lid

Abstract

A reclosable can lid is described which does not require a separation of a metal surface associated with chip formation in the opening process, which ensures the respective required leak tightness on the reclosing, even in the case of a pressure build-up resulting in the respective container, and which has a high functional reliability with a particularly economical manufacturing option.

What is claimed is: 
     
         1 . A method of manufacturing a sealed opening, which can be torn open or pressed in, in an areal sheet metal material, the method comprising the steps of:
 coating the sheet metal material at least at one side by an adhesive lacquer layer;   punching an areal region corresponding to the opening out from the coated sheet metal material in such a manner that the punching die engaging at the coated side cooperates with a die which brings about a smooth cut region and an adjoining slanted cut region of the punched out part;   supplying a lubricant required for the punching process exclusively and solely by the adhesive lacquer layer;   inserting the punched out areal region whose peripheral contour is substantially complementary to the die shape again into the opening in the sheet metal material and holding it therein in a shape matched and/or force transmitting manner; and   covering the microgap formed between the sheet metal material and the punched out areal region at the one side by a film which is areally coated onto or laminated onto the sheet metal material and which is provided with a peripheral weakening or notch adjacent to the microgap.   
     
     
         2 . The method in accordance with  claim 1 , wherein the sheet metal material is provided with an adhesive lacquer layer suitable for use with food at both sides and in particular over the full area. 
     
     
         3 . The method in accordance with  claim 1 , wherein a preshaped film adapted to the sheet metal layer shape is used as the film and this molded film part is joined to the sheet metal layer by means of the adhesive lacquer layer. 
     
     
         4 . The method in accordance with  claim 1 , wherein the punched out areal region is fixed in the opening in a shape matched and/or force transmitting manner by means of a spring force on a return stroke of the punch plunger. 
     
     
         5 . The method in accordance with  claim 1 , wherein the smooth cut region at the punched out areal region extends over less than 50% of the material thickness and the slanted cut region preferably expands conically.