Engineering and plant construction company Primetals Technologies recently signed the final acceptance certificate with aluminium producer Hulamin following the successful installation and commissioning of new hot-edge inductors for its cold mill rolling line (S5) in Pietermaritzburg.

This upgrade has effectively addressed the tight edge issues in aluminium strip that occurred during high-speed rolling, leading to improved product quality. It has enabled the production of high-quality coils for demanding markets such as the can packaging industry.

Primetals completed the design, procurement, manufacture, supply and commissioning of the inductor system within 18 months.

The moving induction heating head assembly was installed on the exit side of the mill, below the exit delivery table. These assemblies are positioned close to the roll surface, just outside the strip width, effectively counteracting the thermal camber that causes tight edge issues during high-speed rolling.

The hot edge inductors resolved the tight edge issues by providing additional heat to the work roll at the strip edge, expanding the roll and alleviating tight edges. This improvement has resulted in better control of the strip edge shape, enabling Hulamin to ensure product quality alongside improved cold mill capacity.

The implementation of the hot-edge inductors forms part of an integrated series of upgrades to Hulamin’s cold rolling system, resulting in noticeable improvements in the on-line strip shape performance. Hulamin is continuing to further optimise and refine the use of these actuators in its rolling programme.

The collaboration between Hulamin and Primetals from inception to final testing was a significant factor in the project’s success, Hulamin said.

Hulamin’s mill operations team has now fully embraced the system and relies on it daily to achieve improved mill productivity with consistent shape performance. 

“Hulamin is . . . pleased with the implementation and the resulting improvement in product quality. Following this success, discussions are ongoing about implementing similar systems on additional mill lines at their site in Pietermaritzburg,” Primetals Technologies senior fluids engineer Calvin Coetzee said on November 21.