The leading manufacturer of fire-fighting vehicles and equipment had observed oily contamination on its machine tools, which proved aggressive and almost impossible to remove from the material underneath. As experts at MOTOREX were able to determine, unwanted bacterial growth in previously used cooling lubricant from another manufacturer was responsible for the problem. Switching to SWISSCOOL 8000 from MOTOREX made the work cleaner, safer and more enjoyable. In addition, there was a cost benefit.
The Austrian city of Leonding (near Linz) is home to the headquarters and one of the largest factories belonging to Rosenbauer, the world's leading manufacturer of fire-fighting vehicles and equipment. At the company's mechanical production facility, steel, aluminium and cast brass are machined on state-of-the-art, automated CNC lathes and milling machines. The result has to meet the most exacting standards.
However, oily, unpleasant-smelling contamination repeatedly appeared on the machines, which attacked the material underneath and was very difficult to remove. «The coolant we had been using at the time gradually turned brownish, and it looked as though the water and oil components were separating,» reports Michael Brunmayr, Head of Mechanical Production at Rosenbauer. «As a consequence, we found stubborn residues on our machines, which proved very hard to remove, even using cleaning agents. It was taking a huge amount of effort to keep them clean.»
The experts at MOTOREX analysed the existing cooling lubricant in their in-house laboratory and were quickly able to pinpoint the cause of the damage. Thomas Kientzl, the responsible Area Sales Manager, explains: «It's typical of bacterial growth in coolant.»
Following this realisation, a six-month test began, initially on the machine most affected. Kientzl: «We subjected it to a thorough cleaning process and switched to our SWISSCOOL 8000. Afterwards, we held on-site training for application and maintenance and continuously checked the result on the machine.»
SWISSCOOL 8000 is a general-purpose, water-miscible cooling lubricant containing mineral oil, which is boron- and formaldehyde-free. Its additives ensure excellent wettability and cooling and lubricating effects, but also protect against bacterial and fungal growth.
The concentration of the cooling lubricant increases during use because the water content in the coolant system evaporates as a result of circulation, turbulence, high pressures and heat, but the concentrate content (mineral oil and additives) does not. The more effective the flow behaviour and therefore the cleaning effect of a cooling lubricant, the cleaner the machines and the workpiece remain. In addition, less concentrate content is discharged with the chips and workpieces. This has a direct effect on the so-called after driving rate, the concentration of the refill emulsion which is required to maintain the specified target concentration. After driving ensures that all necessary additives enter the emulsion so that it functions correctly.
Whereas conventional cooling lubricants frequently require an after driving rate of 3 to 4 per cent in order to maintain, for example, 8 per cent target concentration, an average of one per cent is sufficient for the high-quality SWISSCOOL 8000. This results in a cost benefit because less concentrate is consumed.
The successful field test convinced Rosenbauer to switch its entire metalworking operation to SWISSCOOL 8000. The cooling lubricant is maintained by belt filters and oil skimmers. Employees regularly measure the emulsion concentration. Production Manager Michael Brunmayr explains: «Since then, our machines have always been clean, which makes our employees' work both easier and more enjoyable. The cutting performance and material compatibility are outstanding. We also save costs as we no longer have to clean, and have a lower after driving rate.»
In addition, the trustworthy, pragmatic cooperation and technical support on-site convinced the customer. As Thomas Kientzl from MOTOREX, who made regular visits to the site, says: «Together, we improved the user process, in particular the continuous monitoring and care processes for the cooling lubricant. This increased its service life and therefore its sustainability. Health and safety and ease of work factors were improved for the employees.»