How a two-piece drawn and wall-ironed food can is made
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1. Aluminium or steel strip arrives at the can manufacturing plant in large coils.

  

 

 

2. The strip is lubricated with a thin film of liquid and then fed continuously through a cupping press, which blanks and draws thousands of shallow cups every minute. 

 

 

3. Each cup is rammed through a series of tungsten carbide rings. This is the drawing and ironing process which redraws the cup to a smaller diameter and thins the walls, whilst increasing the height.

4. Trimmers remove the surplus irregular edge and cut each can to a precise specified height. The surplus material is recycled.

 

 

 

 

5. The trimmed can bodies are passed through highly efficient washers and then dried. This removes all traces of lubricant in preparation for coating internally and externally.

 

6. The cans are coated externally by passing them under a waterfall of clear lacquer which protects the surface against corrosion.

 

 

 

 

7. Lacquered external surfaces are dried in an oven

 

 

 

8. The cans are passed through a flanger, where the tops of the cans are flanged outwards to accept the ends after the cans have been filled.

 

 

 

9. The cans are passed through a beader, where the walls of the cans have circumferential beads formed in them to give added strength.

 

 

 

10. Every can is tested at each stage of manufacture. At the final stage they pass through a light tester which automatically rejects any cans with pinholes or fractures.

 

 

11. The inside of each can is sprayed with lacquer.
This special lacquer is to protect the can itself from corrosion and from any possibility of interaction between the contents and the metal.

 

12. Lacquered internal surfaces are dried in an oven.

 

 

13. The finished can bodies are then transferred to the warehouse to be automatically palletised before despatch to the filling plant.

 

 

14. Every can is tested at each stage of manufacture. At the final stage they pass through a light tester which automatically rejects any cans with pinholes or fractures.

 

 

15. The finished can bodies are then transferred to the warehouse to be automatically palletised before despatch to the filling plant.