RFID (Radio Frequency Identification), one of the fastest developing identification technologies; It has been adapted to a large number of sectors such as the automotive, aviation, oil, gas, construction and iron and steel sectors. Compared with traditional barcodes, it has different advantages. It scans multiple items at once without seeing directly, offers added security, tags can be coded multiple times, data in the entire process is tracked full-time and fast.
RFID in the Iron and Steel Industry
In the current scheme, low-cost barcodes are used to read the information but they have some limitations such as reading direction, sensitivity to working environment conditions and easy damage. While the initial cost is low, it incurs many intangible costs in use. Read rates are affected by multiple factors such as environmental conditions and processing. When the terminal cannot read the information, it takes time for the worker to find the product. Trucks pile up at transport checkpoints and production line capacity drops. Manual applications in the iron and steel industry also carry a security risk. Manual evaluation and voice intercom are used in the timing of cranes. This situation both carries a security risk and causes high labor cost.
Whatever the company or industry, RFID greatly makes logistics and inventory management efficient. With some smart planning and extensive testing, integrating RFID is one of the simplest ways to increase productivity and cost savings. Iron and steel manufacturers can revolutionize the way they do business with the right solution partner to guide the RFID process. In the steel fabrication industry, the implementation of an RFID-based system increases productivity and reduces cost.
Along with the benefits, the challenges should also be mentioned. The ambient conditions are harsh, the products are made of metal, and the ambient temperature of the factory is high. Therefore, the use of RFID has some technical limitations, but advances in RFID technology offer solutions to these as well.
The challenge is that RFID chips and tags must withstand harsh environments. Steelmaking is a complex process that uses extremely high heat. Steel plates retain heat for a while after they are produced. Sheets must be identified post-production, while still hot, and labels must adhere to hot metal surfaces. Labels must also be resistant to chemicals such as strong acids, alkaline solutions and wetting agents.
Recent advances in RFID technology now allow RFID chips to be applied to almost any type of label. Adhesive or non-adhesive, high temperature, acid and oil resistant labels are produced.
One of the difficulties is the reflection of signals emitted by the chips from metal surfaces. Reflection reduces the terminals' ability to read. To prevent it, it is necessary to place RFID tags at a suitable angle, as far outside of the sheet metal and rolls as possible, and test.
Another problem is that when metal comes into contact with the chip, it can mess up the RFID antenna settings. To prevent the chip from coming into direct contact with the metal and eventually becoming out of alignment, there are chips that absorb reflection. In addition, special antenna designs are used to obtain longer reading distances.
Before moving to RFID, careful evaluation and testing of the above points will increase the overall quality of the application.
ThyssenKrupp, a German-based steel manufacturer, implemented the RFID system. Initially, the main goal was to save time and reduce labor. Manual identification of the sheets by the employee slowed the work. Since the sheets are stored outdoors; rain, ice, snow and sunlight made barcode labels difficult to read.
For this reason, they produced UHF (Ultra High Frequency) smart tags and attached them to the plates. They mounted readers on cranes to scan as the plates were unloaded. Initially, they tested the system at a factory in Brazil, attaching labels to 1000 sheets and being transported to Germany. The application was expanded to the entire Brazilian factory, as it significantly shortened unloading times and saved the company money. They've even launched an RFID-based "borrow box" to track their vehicle and equipment usage.
In another iron and steel producer, it went further and implemented Industry 4.0, which includes RFID and IIot.
In the sample factory; in all phases of melting, ladle tracking, molding and rolling; Industry 4.0 has been applied, including IIoT, RFID sensors, internet, cloud, big data, analytics and machine learning.
In the melting phase; RFID sensors and IIoT devices were used to measure different variables. In this way, the onset and end of heat, slag events, touch events were identified and monitored.
The crucible monitoring phase tracks the journey of heat from furnace to pouring. The assignment of steel weight, residual weight and tare weight to ladles is important for mass analysis of passive RFID tags. These passive tags are hung on crucibles with a specially designed RFID Shield. RFID sensors in the oven area were placed in a specially designed protective cover using a special material.
RFID tags, even inside the protective armor, can be damaged by direct splashes, crash hooks of the crane, and so on. Therefore, in case of damage to the protection armor, it is designed to be replaced quickly and simply.
Thanks to the RFID weighing sensors in the casting station, the flow rates were determined by accessing the weight data via the IIoT connected to it. By combining this information with the configuration of the sub-components of the casting station; Each log was given a heat number. Using RFID sensors placed on conveyors that transport billets from the casting machine, the application determined whether the slab was transported to the rolling mill for hot rolling or to a cooling bed for future use. For the billet transported to the cooling bed, barcode label generation was defined as selective. When the cooled billet is to be reused or if the billets purchased from outside are to be used, it is passed through the reheating furnace. Barcode labels allowed the identification of billets undergoing reheating.
Using RFID sensors, it was possible to determine whether a slab came directly from the casting machine (hot rolling) or from the reheating furnace.
In the rolling phase, the rolling mill automation system monitors the conversion of the billet into rods. So when the rod finally comes out of the cooling bed, the monitoring software knows which log the rod belongs to and therefore has genealogy information such as the heat number and chemistry it belongs to.
In the stacking phase, the automation application receives the stacking identification number and which bars the stack consists of from the stacking automation system. Based on this, the tracking application prints a label with a QR code attached to the package. By scanning the QR code, technical and commercial information is read. This QR code identifies the package in the field for shipment and is useful for identifying rod chemistry by the dealer/end customer if needed. A mobile app helps dealers to scan QR Code and instantly get chemistry details and other necessary details.
In this case study, Industry 4.0 technology, which includes RFID tags and is applied correctly; combined all production phases and linked them together as part of a single process.
In the classical situation without Industry 4.0, a large number of people are employed who are interested in linking the details and knowledge of the process areas. Information is prone to errors and delays. The tracking solution implemented in this application has significantly eliminated human intervention. As the process progressed, enrichment of information was done in near real time. Improved the ability to respond to unforeseen events. It became possible to safely trace the product down to the chemistry records. Post mortem analyzes of different dimensions related to a particular temperature (what went wrong should be corrected and what went right should be repeated) were done easily and transparently.
As the data collected in all processes and stored in the cloud increases, it will be possible to go one step further. Big data techniques and analytics will be used. In this way, uncertainty in the expected final product in a new production process will be eliminated.
Egen is a manufacturer and supplier of RFID tags. With our RFID application machine, we apply RFID chips to labels whose characteristics are determined by the customer. Special for companies; We produce RFID Tags that can contain printed, blank or variable data.
In collaboration with Avery Dennison/Smartrac; We act together with expert business partners who install RFID systems and provide hardware. By sharing our expertise in label adhesives and top surfaces, we produce RFID labels with the most suitable surface, adhesive and chip for environmental conditions.
