Method of making a can

Abstract

The present invention relates to can-type containers, closed at one end by a flexible bottom attached to the can by means of a crimping ring which is a welded ring.

1 . A method of manufacturing a can comprising, placing a bottom at one end of a body of the can, the bottom being attached to the body of the can through a retaining ring crimped to the one end of the body of the can, wherein the retaining ring is a welded ring and the bottom is formed from a flexible sheet. 
     
     
         2 . The method of  claim 1  wherein the welded ring has been obtained by welding a metal strip followed by folding the strip to form a groove. 
     
     
         3 . The method of  claim 1 , wherein the welded ring also has a flat spot directed inwardly of the ring. 
     
     
         4 . The method of  claim 1 , wherein the flexible sheet has a pre-cut portion consisting of a partial incision of the flexible sheet, maintaining the air impermeability. 
     
     
         5 . The method of  claim 1 , according to wherein the flexible sheet comprises at least one gas-tight layer. 
     
     
         6 . The method of  claim 5 , wherein the gas-tight layer is covered on at least one side by a plastic layer. 
     
     
         7 . The method of  claim 5 , wherein the gas-tight layer is covered by a plastic layer on each side. 
     
     
         8 . The method of  claim 1 , wherein the end of the body of the can is circular in shape. 
     
     
         9 . The method of  claim 1 , wherein the end of the body of the can the is rectangular or square in shape. 
     
     
         10 . The method of  claim 1 , wherein the end of the body of the can is oval in shape. 
     
     
         11 . A method of applying a bottom to a can body comprising:
 (a) providing a can body with a bottom attached to an end,   (b) providing a flexible sheet   (c) cutting the flexible sheet to obtain a cut-out element of a same shape as the end of the can body and with a perimeter slightly larger than a perimeter of the end of the can body,   (d) affixing the cut-out element to the end of the can body,   (e) crimping the cut-out element to the end of the can body by crimping with a retaining ring, the retaining ring being a welded ring.   
     
     
         12 . The method of  claim 11 , wherein the flexible sheet forms a gas-tight layer. 
     
     
         13 . The method of  claim 11 , wherein the flexible sheet forms a gas-tight metal layer having a plastic layer on each side of the gas-tight metal layer. 
     
     
         14 . The method of  claim 1 , which is carried out continuously. 
     
     
         15 . A can having a metal body and at least one end of the metal body closed by a bottom comprising a flexible foil, wherein the flexible foil is held on the metal body by a ring crimped on the metal body, wherein the ring is a welded ring. 
     
     
         16 . The can of  claim 15 , wherein the flexible foil is attached to the crimped ring. 
     
     
         17 . The can according to  claim 15 , wherein the flexible foil is clamped between the metal body and the crimping ring. 
     
     
         18 . A method for making the can of  claim 15  comprising securing a flexible foil to the bottom of the can by crimping a welded ring onto the bottom of the can. 
     
     
         19 . The method of  claim 18 , wherein the flexible foil forms a gas tight layer. 
     
     
         20 . The method of  claim 18 , wherein the flexible foil is directly attached to the welded ring. 
     
     
         21 . The method of  claim 18 , wherein the flexible foil is trapped between the can wall and the crimping ring and is secured after crimping.