As the demands on the quantity and quality of aluminum foil have increased, so have the demands on the equipment to produce the foil. At present, rolling mills are expected to roll foil to less than six microns thick in widths of up to two meters and be capable of speeds in excess of 2,000 meters/minute. To meet these expectations, Primetals Technologies mills include state-of-the-art features for high-speed operation while process support ensures record start-up time and the ability to achieve that the very first coil rolled following a changed mill set-up be saleable. Industry standards for key metrics are exceeded.
Our portfolio of mill designs is in line with the market trend towards larger coil weights, combined with wider strip to help our customers maximize yield and productivity. Primetals Technologies offers a completely integrated automation and drive solution, including the latest generation of drive technology and a powerful automation platform, ensuring:
- Rolling speeds of 2000m/min
- Product widths > 2000mm
- Finished thickness of 0.0055mm (5.5 micron)
Fig.1- Automatic roll change | Fig.2- 4-Hi mill stand | Fig.3- Foil mill stand
- Our Foil Mills feature a number of automated systems for coil, spool, and scrap handling as well as high speed work roll change.
- Operation and drive-side work roll latching allows for thermal expansion of the rolls to the operator side. This is accommodated by bearing clearances which eliminates potential thrust forces on the mill spindles and work roll bending rams during long period passes.
- Operation and drive side backup roll latching similarly eliminates potential thrust forces on the roll load cylinder during long passes.
- An optimized mill bearing design with specifically tailored tolerances enhance high-speed operation
- Oil air lubrication system to both the work roll and the backup roll bearings maintains bearing temperatures within their operating range under high speed rolling and allows for the use of synthetic oils, which have a better load carrying capability
- A work roll and backup roll bearing temperature measurement function ensures precise monitoring of the bearing temperatures.
- A constant-force ironing roll permits consistently higher coiling speeds
- Spindle piloting eliminates potential roll vibration by providing a positive location of the roll neck in the spindle end.
Fig.4- Rewinder | Fig.5- Foil mill entry | Fig.6- Vapour Shield Oil Recovery System with electrical thermal oil heating unit
- Foil Roughing Mills, Foil Intermediate Mills, Foil Finishing Mills
- Foil Universal Mills
- Bright Finish Mills
- Automated foil feed system
- Entry bridle
- "E-block" configuration, +ve & -ve roll bending
- Automated sequencing of coil and spool handling
- Automated spool keyway positioning
- Coil interlap oiling
- Single or Double Unwinder
- Edge trimming and scrap removal
- Mill bearing temperature monitoring & analysis
- Roll chock cooling
- Hydraulically operated constant force ironing roll
- Automatic pass line height adjustment
- Strip dryness system
- Schneider coolant filtration, manufactured in-house
- Fume cleaning & oil recovery system
- Automatic gauge and flatness control
- Air Bearing Shapemeter
- Shapemeter & spray bar shifting system
- Integral Solenoid Valve (ISV) sprays with hot edge sprays
- Comprehensive monitoring and diagnostics
- Rolling schedule maintenance
- Productivity and yield optimization
Continuous improvements of the quality of rolled aluminum products together with increasing demands regarding mill uptime and productivity are strongly supported by new developments and enhanced functionality of Primetals Technologies electric and automation applications for rolling mills. Today's demands for flexible and economic production of aluminum plate, aluminum strip or foil can only be met by electrical and automation solutions, that are based on a profound knowledge and a deep understanding of aluminum rolling technology. This kind of know how in combination with our expertise in mathematics, physics, control algorithms, mechanical, hydraulic and electrical engineering qualify Primetals Technologies to design and develop technological process models, high-performance control systems, reliable and mill proven drive systems, as well as all other electrical equipment necessary for the operation of rolling mills. In short, Primetals Technologies is able to supply complete mills or rolling mill equipment from one source. All our solutions are well approved and have been optimized in many applications with well-established customers all over the world.
Modern automation concept for improved product quality on Aluminum Foil Mills
Technological controls and process models are the core of our modern automation concept with the goal of maximizing utilization of the mechanical, electrical, hydraulic and other controlled equipment. The control concepts have evolved with the increasing performance of the equipment and increasing demands in terms of tolerances of the final product– from simple analog PI controllers to highly complex and interlinked control systems. These controls and process models are nowadays integrated and the added value is well seen in the resultant strip quality.
These added values are:
• World class thickness and flatness tolerances to meet growing demands worldwide,
• Less off-gauge material,
• Maximum throughput and availability
Scalable Technological Control Systems for Aluminum Foil Mills
These highly standardized EA packages have modular design and defined interfaces.
• Short delivery times thanks to the use of standardized components with high availability
• Fast start-up due to a field-proven solution with references around the world
• High product quality due to integrated suite of quality control functions
• Compact design with highly integrated components and allow installation even in confined areas
• Trouble free implementation due to modular design for new mill plants as well as for upgrades, extensions and revamps also of 3rd party systems
• Additional upgrades with add-on packages allow state-of the art improvements of functionality, strip quality and higher mill productivity even as a later retrofit
• Attractive CAPEX due to standardized solutions
Integrated Digital Drive Systems
Integrated fully digital systems with full capability of technological and diagnostic performance are designed for drive control using high speed multi-microprocessors.
Flexible applications range from single drives with pinion gears to integrated drive systems for twin-drive and tandem-drive. DC converters, AC cyclo-converter drives and AC multilevel drives, cover the wide range of power and voltage ratings required. Comprehensive software development tools and libraries are supplied as part of the system. Diagnostic capabilities with local display of messages, operator control and monitoring are included in the applications.
Technological controls and process models
Primetals Technologies provides a highly standardized TCS (Technological Control System) as a core for the automation of Aluminum Cold and Foil Mills.
The TCS is embedded into a project specific application which is tailor – made to suit the individual automation task. The range of available tools includes the full range of options for Aluminum Foil Mills including model based flatness control and an advanced mill set-up system for fast and smooth acceleration and maximum throughput.
It further includes all relevant gauge and flatness control algorithms for all thickness ranges and alloys. Primetals Technologies offers a fully integrated automation concept which is completed by a user friendly HMI and diagnostic system for intuitive and effective operator support. This can be configured from almost manual operation for simple applications to the highest automation level featuring e.g. auto threading and tail out, automatic roll - change.
General benefits are:
• Steep start-up curves as the "physical knowledge" from many mills is available right from the start
• Integrated automation with high flexibility
• High accuracy through making use of the experience with many thousands of strip mills
• Extension of behavior to new alloys and to new dimensions
Experience on Aluminum Foil Mills
Over the recent decades Primetals Technologies has successfully automated literally dozens of Aluminum Foil Mills all over the world, cooperating with world-class Aluminum producers. The range of Primetals Technologies references covers the full range of Foil mill applications from Universal-, Roughing- and Intermediate-Mills to Finishing Mills rolling ultra-thin gauge as well as Bright finishing mills.