Aluminium foil and aluminium strip products have become an indispensable part of our lives today. Just think of modern architecture, automotive production and, in the foil sector, the ubiquitous aluminium foil in thickness ranges of 0.8 µm e.g. for the electronics industry, 8 - 18 µm for food packaging and up to approx. 40 µm for blister packaging.
After all, according to alufoil (European Aluminium Foil Association), almost 500,000 tonnes of aluminium foil were produced annually in the EU in 2021 and 2022. Or to put it another way: with the amount produced, you could wrap around 3.5 per cent of Germany's territory in thick chocolate aluminium foil every year. Reason enough for us to take a closer look at the topic of thickness measurement in aluminium cold rolling mills.
Especially in foil rolling mills, measurement technology faces great challenges. The space conditions are very cramped, paraffin (jet fuel) is used in the rolling mill for cooling and lubrication, which makes the whole thing literally fire-hazardous. The foils to be measured are highly sensitive and the real-time control of the rolling mill requires high sampling rates and processing speeds of the sensor and the corresponding digital technology.
An economical and operationally reliable answer to these requirements is only possible with X-ray measuring systems. With EMG iTiM xray, EMG offers the right, customised solution for the user in the fields of aluminium foil and cold-rolled aluminium strips.
The compact EMG X-ray generator with 20 kV or 40 kV is used for such applications. It covers a very wide thickness spectrum between 0.5 µm and 20 mm . The combination of X-ray tube and X-ray generator in a "one-box solution" offers decisive advantages for this application scenario:
- The combination of X-ray tube and X-ray generator in a compact housing is extremely robust and low maintenance. The time-consuming lubrication of cable and plug connections is completely eliminated.
- The operating voltage is only 24 V DC. An invaluable advantage for fire protection with regard to sparking.
- A sample magazine with different measuring positions is integrated into the box so that 15 different thickness ranges can be used for quick intermediate calibrations, e.g. during a roll change. In addition, MSA procedures for measuring system analysis can be easily carried out. EMG iTiM generates standardised reports for this purpose.
- Another highlight is the detector head with integrated amplifier and complete digitisation, which can also be replaced as a complete module in the unlikely event of a fault.
In the simplest case, EMG only supplies the measuring heads and detectors for the foil measurement and the user takes care of the integration into the rolling mill. Often the X-ray generator head is installed at a fixed position, sometimes it can also be moved or swivelled. EMG supports these integrations with extensive design and integration know-how right from the start of the project discussion. In addition, the sensitive detector window is protected by an electronically controllable "shutter device". In the event of a foil rupture, the operator can then safely remove the foil remnants with mechanical tools.
The illustration shows an EMG iTiM xray system in use in an aluminium cold rolling mill. The measuring spot of the integrated laser speed measurement is clearly visible.
In this article we have looked in particular at the essential challenge of measuring the thickness of aluminium foils, which are of great importance in various industries, from the electronics industry to food packaging. Given the high production volumes and quality requirements, precise and reliable on-line measurement is essential, and EMG iTiM xray offers a tailor-made solution for this. This innovative X-ray measurement system is characterised by robustness, low maintenance and high flexibility. It enables measurements in a wide thickness range for aluminium foil and strip production and offers advantages such as low operating voltage, modular design and an integrated sample magazine for fast intermediate calibrations. EMG iTiM xray is the answer to the complex requirements of aluminium foil and strip production and enables safe production as well as quality assurance support.
For more information on EMG iTiM, please visit our website and feel free to contact our international sales and service organisation, who will be happy to answer any questions you may have.
Download: Brochure EMG iTiM