Protection against corrosion during the storage and transport of coils guarantees high quality for the further processing of cold-rolled strips. Efficient lubrication during cold rolling is essential for numerous sections of the rolling and cutting lines. technotrans has developed bespoke, sustainable spray lubrication concepts for several production lines of the BILSTEIN GROUP. The result is a resource-saving and health-friendly production, a higher level of flexibility and considerable cost reductions.
The protection of the products has top priority in order to ensure their high quality. Avoiding the corrosion of the materials due to external influences even if they are stored in storehouses plays an important role. This is why the manufacturers apply effective anti-corrosion agents in the form of special oils to the materials during the cold rolling process. To ensure a high level of efficiency, the lubrication systems of the cold-rolling mills must be precisely adapted to the specific situation on site.
Due to the increasing requirements of their customers, especially from the automotive industry, in terms of the product quality and sustainability, the BILSTEIN GROUP with its headquarters in Hagen, Germany, required an effective solution for the lubrication of their cold-rolled strips in order to protect them against corrosion. The company uses a strict zero-defect principle along the entire process chain during the production of several kilometres of its products. For many years, the steel-processing company had been using the well-known lubrication solutions of a long-standing supplier. However, the company wanted to lift its processes to a new level.
Up to this moment, a technically rather simple solution had been used for the lubrication step. When the BILSTEIN GROUP was looking for a new solution provider, technotrans caught their eye because of their fluid technology competence. The company from Sassenberg, which is known for their solutions for the printing industry as well as for the punching and forming sector, transferred its expertise and established technology for airless spray lubrication to the specific requirements of cold-rolling processes. After a successful test phase, technotrans was selected to provide the equipment for two systems of a production facility in Kentucky (USA) and, later on, for additional systems in Germany.
"Thanks to the technotrans technology, we were able to lift the lubrication processes for a high-quality corrosion protection of our cold-rolled strips to a new level," says Eugen Schitz, head of systems and process engineering of the BILSTEIN GROUP. "We benefit from cost savings, reduced maintenance and repairs of our peripheral equipment as well as from a very high level of flexibility as we can process lubricated and unlubricated strips in a single system." The technotrans lubrication system is used during the rerolling and coil slitting processes as well as at the packaging lines of several production sites of the BILSTEIN GROUP. For these varying areas of application, technotrans has developed bespoke solutions based on its spray.xact technology with a strong focus on a high level of efficiency and sustainability.
"Unlike conventional solutions, the technotrans valves open and close in a timed manner due to electrical pulses," explains Schitz. "As there is no need for compressed air, this results in a homogeneous lubrication with only very little mist, even at the very high cold rolling speed of up to 16 m/s."
As the technotrans components are not located above the conveyors when unlubricated products run through the system, there is no risk of oil dropping onto the strips. "This type of contamination of our strips would be very problematic for any subsequent steps, e.g. for paint coating," says Schitz. "Thanks to the expertise of technotrans, we can guarantee a high product quality, which is important for our customers."
Thanks to the low level of mist and minimised aerosols, exhaust systems are no longer required as was the case with the previous solution. This reduces the health hazard for the employees while preventing unwanted oil deposits in the surrounding areas.
BILSTEIN saves costs thanks to the high efficiency of the technotrans solution. Extraction systems and compliance with maintenance intervals for the filters no longer play any role at all for BILSTEIN. In addition, the company does not have to spend money on expensive compressed air.
The spray bars of the rerolling lines can be moved sideways either electrically or pneumatically instead of being installed in a fixed position. The advantage for the BILSTEIN GROUP: The cold-rolled strips can be processed with or without the spray lubrication system depending on the specific customer requirements.
In view of the extremely high cold rolling speed, technotrans has integrated double rows of spray nozzles into the spray bars to ensure that the system can supply the required quantities during the rolling process. As a result, the BILSTEIN GROUP can apply between 0.5 and 2.5 g of oil per m². An additional advantage is that the machine operators can easily adjust and precisely control the desired oil quantities.
During rerolling, the positioning of the spray bars on both sides ensures additional flexibility. The BILSTEIN GROUP can adapt its processes to the specific requirements as different thickness specifications require different rolling intervals. "Ultimately, it doesn't matter whether there is an even or odd number of rolling steps," explains Hary Kosciesza, business development manager at technotrans. "Depending on the specific requirements, spray nozzles, which are located downstream or upstream of the rolling mill, apply the anti-corrosion agent to the metal."
The starting point for the cooperation, now covering a total of eight joint projects, was the set-up of a new BILSTEIN production site in Kentucky, USA. For the new BILSTEIN Cold Rolled Steel LP, technotrans developed a spray lubrication system for the coil slitting line that was put into operation at the end of 2017. In addition, the spray lubrication system also treats the faces of the coils with an anti-corrosion agent inside the connected packaging line.
The BILSTEIN GROUP was so convinced by the solution for the two processes that it decided to use technotrans technology for other processes as well. Spray lubrication systems made by technotrans are now used at several other production sites, e.g. also at the headquarters in Hagen and at the Hugo Volgesang subsidiary. With different spray widths of 500 mm or wider, they ensure optimum lubrication results during the last rerolling pass directly at the rolling mill. In September, a new rerolling, coil slitting and packaging line with a 1,350 mm wide spray lubrication system was put into operation at the main plant in Hagen.