72" 4-High 2000HP Cold Mill
The Challenge
Norandal USA, a manufacturer of light- and medium-gauge aluminum foil used in the packaging and automotive industry needed a major retrofit on their breakdown cold rolling mill.
Shape control for the continuous cast coils needed improvement, and because of this, production levels were limited. PCT Engineered Systems, LLC was subcontracted by Mannesmann Demag, an international mill equipment manufacturer, to provide the PLC control and operator stations, as well as the mechanical and electrical installation for the project. Mannesmann Demag chose PCT because of a past partnership providing turnkey reconstruction management of an aluminum cold mill after a fire. Additionally, Norandal USA directly contracted with PCT to provide a new digital drive system for the cold rolling mill.
The PCT Solution
PCT Engineered Systems worked with Mannesmann Demag and Norandal USA to increase the mill's productivity by improving shape control and reducing between-coil time.Shape control, a major concern for Norandal USA, was improved by providing the following:
- A new hydraulic gauge control system
- A new work roll bending scheme
- New entry bridle equipment
- Upgraded flatness and spray controls
- An ABB shape roll
Once improved shape control was established, the mill became less of a bottleneck in regard to production throughput. Reduction of between-coil time was improved by adding new, electric drive controls using a Eurotherm/SSD digital drive system to improve speed control on the existing motors. PCT also provided a new control system including a GE 90-70 PLC system employing a fiber optic link to the digital drives, and linked via Ethernet to the Mannesmann Demag Maras mill control system.
By improving speed control, PCT has helped Norandal USA decrease the between-coil time, and increase the amount of useable product per coil.
Other modifications provided by PCT included:- Operator interface stations in the pulpit and on the mill
- A new operator's pulpit and control consoles
- A new trim removal system
- High- and low-pressure hydraulic piping routing and installation
- Electrical conduit and cable installation planning and labor
- Remanufacture of the hydraulic gap cylinders to facilitate the improved gauge control
For a project of such magnitude, this complete turnkey upgrade was completed with minimal downtime. To date, the mill has outrun production expectations, and Norandal USA has reported significant improvements in product shape and flatness.