Case Study: Aluminium Cold Rolling – Gränges AB, Finspång, Sweden
Background
Gränges AB, headquartered in Finspång, Sweden, is a global leader in aluminium rolling, with roots dating back to 1922. The company develops advanced aluminium materials used in automotive heat exchangers, building applications, and increasingly battery components for electrification.
To ensure stable production quality, Gränges introduced Lucent’s Alu Treater in 2007 at its cold rolling mill in Finspång to improve process oil purification and filtration efficiency.
Problem
The cold rolling process faced recurring issues related to oil quality and system performance:
- Surface defects on aluminium foil (stains, pinholes) caused by fine particles in the oil
- Rapid differential pressure (DP) increases across filter stacks, requiring frequent maintenance
- High consumption of pre-coat media (e.g., diatomaceous earth)
- Shortened service life of process oil due to contamination buildup
- These problems negatively affected product quality, machine availability, and operational costs.
Solution
Gränges implemented Alu Treater dosing into the clean oil tank of its cold rolling mill. The product is added by a dosing pump, controlled manually or via conductivity monitoring.
Alu Treater 74/76 is a surface-active formulation designed to:
- Bind and remove sub-micron contaminants (soot, metal particles, water)
- Mix with circulating oil applied to the aluminium foil
- Form a secondary filter layer, slowing DP increase and improving pre-coat media efficiency
- Aggregate contaminants into larger droplets for easier capture in the filter
- Alu Treater is FDA-compliant, safe to handle, and compatible with standard filtration systems.
Outcome
The introduction of Alu Treater at Gränges delivered measurable benefits across product quality, process efficiency, and oil control:
Product Quality
- Reduced stains and pinholes on foil due to cleaner process oil
Process Efficiency
- 80% reduction in unscheduled downtime
- 25% increase in production output
- 90% reduction in production waste
- 50% reduction in pre-coat media consumption
System Performance
- Slower DP increase across filter systems
- Extended filter and oil service life
- Reduced wear on spray nozzles, valves, and pumps
Oil Quality Control
- Conductivity reduced by 60%
- Values consistently maintained below 500 pS
- Improved monitoring of oil condition for early detection of water or oxidation contamination