The basic quality requirements of a metal service centre relate on the one hand to the dimensional accuracy of the strip, be it the strip thickness, the strip width as well as the corresponding properties of slit strips in different width categories.
And secondly, defined material properties play a major role. At this point, the surface properties of the strips to be processed are of particular interest. While material properties such as roughness or material strength values are seldom in demand here, the correct and uniform oiling, which is a basic prerequisite for the various further processing steps, is often in the foreground.
In the following sections, we will therefore focus on width and thickness measurement as well as oil film thickness determination.
Strip width measurement with EMG BREIMO & EMG iCAM®
There are many reasons why strip width measurement is important in the production and processing of flat metals. Typically, after melting in the hot rolling mill, steel and aluminium products are rolled into strips of several hundred metres in length and of various widths and thicknesses in the cold rolling mill.
The width and thickness of the strips must be closely monitored, as the dimensions are important characteristics for fulfilling customer orders. Material yield is an immensely important value-added factor for metal service centres and metal processors in this respect.
The more precisely the width can be determined for the cutting process, trimming and slitting, the more material can be used and delivered to the end customer.
Strip width measurement with EMG BREIMO: In operation worldwide
Terms like resilience, robustness, reliability and proven, worldwide use may come to mind when you think of the EMG BREIMO electro-optical strip width measurement system. It is used in continuously running production processes in cold rolling, finishing and processing of flat metal products.
By using high-frequency alternating light transmitters, the systems are insensitive to the influence of ambient light, whether artificial (e.g. moving light sources on the crane) or natural light sources (e.g. sunlight through the hall skylight). Due to the possibility of realising a measuring gap in the range of up to 2 m, EMG BREIMO is particularly suitable for use in service centres due to the manifold un-coiling and re-coiling steps in processing. With several hundred systems installed and supplied worldwide, EMG BREIMO can truly be called the "workhorse" of width measurement systems in the metal industry.
With an investment in EMG BREIMO, the user thus relies on a proven, robust, maintenance-friendly system with manageable complexity and high accuracy. The expectations placed in such a standard solution are met in every respect. However, EMG BREIMO reaches its technical limits when it comes to measuring the width of slit strips. This is where a new quality-assuring system from EMG comes into play.
Strip & slit strip width measurement with EMG iCAM®: Extended possibilities
At metal service centres, rolling mill operators and processors, strips are often also split lengthwise into a customer-specific number of slit strips to provide the end customer with an optimal and immediately usable product for their production processes. The intelligent - CMOS camera technology based - width measuring system EMG iCAM® is the perfect answer to these requirements.
The most important features are:
- A scalable width range for narrow strips (< 100 mm), medium strips (100-600 mm) and wide strips (600-2200 mm).
- The possibility to measure the width of slit strip in a range of typically 10 to 500 mm for each individual slit strip thus offers a flexible opportunity to realise a width measurement over the entire strip length with high accuracy in the sub-millimetre range.
Extended functionality, flexibility and intelligence characterise the younger sister of the EMG BREIMO width measurement system in this respect. In close dialogue with EMG, the end user always chooses the right solution for his specific requirements.
Strip thickness measurement with the EMG iTiM system family
As with width, for metal service centres and processors, accurate knowledge of the thickness of incoming material is crucial for allocating material to different end customers, for internal processing and for machine utilisation. The thickness measurement systems used in the metal industry today are mainly based on three different technological approaches: X-ray measurement, isotope measurement and optical measurement methods based on confocal optics and/or laser technology. EMG has fully mapped these technological approaches in the EMG iTiM system family.
Each technology has its own specific advantages and disadvantages, and ultimately the application determines the choice or even the most appropriate combination of measurement methods. Such systems have to work reliably under all plant conditions in very rough, narrow installation locations, for a wide range of alloys and thickness values and sometimes with very high sampling rates for control tasks.
The expansion of the EMG product portfolio to include all thickness measurement methods currently used in the industry (X-ray, isotopes, laser) and the associated design and software know-how opens up completely new possibilities for the user, also for modernisations and conversions.
Lubricants on strips and sheets with EMG SOLID® IR & LIF
Finally, let's look at online oil film thickness measurement in metal service centres and flat metal processing. It ensures uniform oiling of steel, aluminium and copper coils, which is crucial for consistent quality in both further processing and end products. Precise measurement of the oil layer allows the amount of oil to be optimised, reducing waste and costs caused by over or under oiling. Service centres can quickly and easily adjust their oiling systems through online measurement, eliminating the need for time-consuming manual measurements. Excessive oiling can also result in slippery surfaces on the shop floor or on machine parts due to oil leaking from coil edges, posing a hazard to workers. Close control of the oil layer minimises such safety risks. Furthermore, excessive oil consumption is considered critical from an environmental point of view, so accurate measurement and control help service centres to comply with the legal limits for oil consumption.
In terms of technologies for measuring oil films, EMG offers two approaches: infrared spectroscopy with EMG SOLID® IR and laser-induced fluorescence spectroscopy with EMG SOLID® LIF. Both technologies have their own strengths and weaknesses. Therefore, the most suitable technology is selected depending on the application. Currently, the EMG SOLID® IR infrared measurement technology is preferred in about two thirds of the applications, especially due to the influence of oil mixtures. In the remaining cases, the laser fluorescence technology EMG SOLID® LIF is used.
Conclusion - everything from a single source and with a perfect fit
The EMG team's technical expertise in strip guiding and quality assurance enables us to provide effective solutions for metal service centre and strip processing requirements. By working with local partners and affiliates, the EMG team can provide customised solutions that take into account local conditions, integration challenges and customer-specific requirements. EMG's scope of supply includes not only the technical solutions, components and systems, but also the necessary service and consultancy.
Talk to us!
Please do not hesitate to contact our worldwide sales and service organisation via our contact page for any question regarding the use of EMG strip guiding solutions and QA systems!
White Paper - EMG solutions for metal service centres
In addition, the current White Paper: "EMG solutions for metal service centres" is available to you free of charge under the following weblink. There you will find a detailed presentation of EMG solutions with strip guiding and quality assurance systems with a view to the special requirements of metal service centres and flat metal processors.
EMG solutions for steel and aluminium service centres | EMG (elexis.group)
(Our newsletter subscribers have already received this white paper with the October 2023 issue.)