How a two-piece drawn and wall-ironed drinks 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 clean cans are coated externally with a clear or pigmented base coat which forms a good surface for the printing inks.

 

 

 

 

7. The cans pass through a hot air oven to dry the lacquer.

 

 

 

8. The next step is a highly sophisticated printer/decorator which applies the print design in up to six colours, plus a varnish.

 

 

 

 

9. A coat of varnish is also applied to the base of each can by the rim-coater.

 

 

 

 

 

10. The cans pass through a second oven which dries the ink and varnish.

 

 

 

 

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 cans are passed through a necker flanger, where the diameter of the wall is reduced (necked-in).
The tops of the cans are flanged outwards to accept the ends after the cans have been filled.

 

 

 

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.