ENVIRONMENT

During the rolling process, aluminium foil is passing through the work rolls of the rolling mill. There, the foil is forced to pass through a gap of specific thickness which is less than that of the strip. Thus, it is plastically deformed and its thickness is reduced. The foil is then wrapped again in a coil. This procedure is repeated several times until the desirable thickness is accomplished. Final thickness can be as low as 6μm. During the rolling process aluminium increases in hardness, a phenomenon called work hardening. As a result, aluminium foil’s tensile strength increases. In order to soften it, aluminium coils are placed in large furnaces at high temperatures for a long period of time. Desired mechanical properties are achieved through the annealing process while the rolling oils residues are evaporated.

In Symetal, we redesigned the production process of two product groups (Thin Converter Foil & Medium Converter Foil) aiming to significantly reduce the annealing time and temperature. By altering the above mentioned process we achieved 35,6% reduction in natural gas consumption per tonne of produced aluminium (calculations were based on consumption measurements in all four natural gas furnaces).  Reduction in direct greenhouse gas emissions were equally redused.