Can body and method and apparatus for the production thereof

Abstract

On a can body, including a can casing, which is closed around the can axis and includes a metal layer, and a closure part, which includes a metal layer, a laser connection is produced between the metal layers of the can casing and the closure part in an overlapping region of the closure part and the can casing. In at least one embodiment, the laser connection includes a plurality of perforations along the connecting line, or a plurality of narrowly delimited regions, in which the two metal layers are melted together. A plastic material is arranged on the laser connection. The laser connection ensures stability, and the plastic material ensures leak tightness, of the connection between the can casing and closure part.

1 . Can body comprising:
 a can shell closed around a can axis, which includes a metallic layer, and   a closing part, which includes a metallic layer, wherein in an overlapping area of the closing part and the can shell a laser connection is formed between the metallic layers of the can shell and the closing part along a line of connection, wherein the laser connection comprises many interruptions along the line of connection and a plurality of narrowed areas, in which the two metallic layers are fused together, and a plastic material is arranged at the laser connection, and wherein the laser connection ensures stability, while the plastic material ensures tightness.   
     
     
         2 . Can body according to  claim 1 , wherein the areas, where the two metallic layers are fused together, are formed as narrowed metallic connection points. 
     
     
         3 . Can body according to  claim 2 , wherein the connection points form at least one row along the line of connection, in particular being arranged in the shape of a grid. 
     
     
         4 . Can body according to  claim 1 , wherein the closing part is an upper closing part, particularly including a valve seat, but optionally including a tear-off can top device for a beverage can. 
     
     
         5 . Can body according to  claim 1 , wherein the closing part is a can bottom ( 13 ). 
     
     
         6 . Can body according to  claim 1 , wherein the plastic material is arranged in the form of a coating or of a film at least on the closing part or on the can shell in the overlapping area and is situated between the two interconnected metallic layers. 
     
     
         7 . Can body according to  claim 1 , wherein an inner film is arranged on the inner side of the can shell, the material of the inner film being situated between the two metallic layers in those areas, where the two metallic layers are fused together, is displaced by bringing in laser energy in a point-shaped manner, and there are formed solidified fusion areas of the two metallic layers. 
     
     
         8 . Can body according to  claim 1 , wherein plastic material is arranged in the can's interior along the entire laser connection and is tightly connected to the closing part and the can shell. 
     
     
         9 . Can body according to  claim 8 , wherein the plastic material is arranged in the form of a ring or a disc on the can bottom, and is connected to the can shell radial outside. 
     
     
         10 . Method for the production of a can body comprising a can shell closed around a can axis, which includes a metallic layer, and a closing part, which includes a metallic layer, wherein in an overlapping area of the closing part and the can shell a laser connection is formed between the metallic layers of the can shell and the closing part along a line of connection, the method comprising:
 forming the laser connection is formed with many interruptions along the line of connection and a plurality of narrowed areas, in which the two metallic layers are fused together, and a plastic material is arranged at the laser connection, wherein the laser connection ensures stability, while the plastic material ensures tightness.   
     
     
         11 . Method for the production of a can body according to  claim 10 , wherein the areas, where the two metallic layers are fused together, are arranged as narrowed metallic connection points in at least one row along the line of connection, but in particular in the shape of a grid. 
     
     
         12 . Method for the production of a can body according to  claim 10 , wherein the areas, where the two metallic layers are fused together, are formed by a scanning laser device, wherein the laser beam, is guided along the lone of connection or along the overlapping area and is alternately emitted or interrupted so that connections and interruptions are created. 
     
     
         13 . Apparatus for the production of a can body comprising a can shell closed around a can axis, which includes a metallic layer, and a closing part, which includes a metallic layer, and a laser connection, which is formed between the metallic layers of the can shell and the closing part in an overlapping area of the closing part and the can shell along a line of connection, the apparatus comprising:
 a laser welding device; and   a holding device for holding the can shell and the closing part, wherein the laser welding device includes a scanning laser device, which fuses the two metallic layers together in a plurality of narrowed areas by a scanning laser beam.   
     
     
         14 . Apparatus for the production of a can body according to  claim 13 , wherein the scanning laser device provides a control, a laser source, which provides the scanning laser beam for the time periods desired, and at least two mirrors or reflection surfaces rotating about axes perpendicular to each other, wherein the scanning laser beam from the laser source reaches the respective desired site of the overlapping area via the two rotating mirrors or reflection surfaces, and the holding device holds the can shell and the closing part in a fixed position.