Simulating the electromagnetic‐thermal treatment of thin aluminium layers for adhesion improvement

A composite layer material used in packaging industry is made from joining layers of different materials using an adhesive. An important processing step in the production of aluminium‐containing composites is the surface treatment and consequent coating of adhesive material on the aluminium surface. To increase adhesion strength between aluminium layer and the adhesive material, the foil is heat treated. For efficient heating, induction heating was considered as state‐of‐the‐art treatment process. Due to the complexity of the heating process and the unpredictable nature of the heating source, the control of the process is not yet optimised. In this work, a finite element analysis of the process was established and various process parameters were studied. The process was simplified and modelled in 3D. The numerical model contains an air domain, an aluminium layer and a copper coil fitted with a magnetic field concentrating material. The effect of changing the speed of the aluminium foil (or rolling speed) was studied with the change of the coil current. Statistical analysis was used for generating a general control equation of coil current with changing rolling speed. Cross‐sectional diagram of a suggested electromagnetic heating process for thermal treatment of aluminium foil (with boundary approach), which shows magnetic field lines and their direction around a single‐turn induction coil with magnetic flux concentrator.