This company switched to the new TecTalis metal pretreatment in its production process instead of traditional zinc phosphating, the former standard for industrial conversion coating.



Innovation is the great strength of Kögel Fahrzeugwerke, one of the major European manufacturers of semi-trailers. In early 2008, leading the way in its sector, the company switched to the new TecTalis metal pretreatment in its production process instead of traditional zinc phosphating, the former standard for industrial conversion coating. The advantages are a considerable reduction in the burden on the environment, without compromising quality in any way, and enhanced reliability of the pretreatment.

If you know where to look, you can easily read the name of the manufacturer of a semi-trailer as you overtake it. The name is on the back of the trailer, above the license plate, and one name that is encountered more and more often on European roads is Kögel. The long-established manufacturer is headquartered in Burtenbach near Ulm, and is one of Europe’s leading manufacturers of semi-trailers. Kögel’s consistent policy of innovation has brought a steep rise in sales in recent years, and the company is currently growing faster than the market. In 2007, Kögel’s sales surged by an incredible 67 percent, and further strong growth is anticipated in the current year.

Innovation is Key

Innovativeness makes Kögel an acknowledged quality manufacturer. The plant currently operates a three-shift regime, producing about 500 vehicles each week. “We concentrate on three cutting-edge ranges, which are in great demand in the European market. The key to this success is continuous innovation, in our products and in our production processes,” states Plant Manager Franz Tropsch, explaining Kögel’s strategy. “This is why we are always very interested in optimizing our pretreatment processes.” In 2000, Kögel was one of the first trailer manufacturers to introduce cathodic dip coating with prior zinc phosphating for frames, axles and other steel components. Today the sector views the quality of the corrosion resistance and coating of the Kögel trailers as the benchmark. This is also confirmed by container transporters, who put a high value on resistant vehicle frames in view of the rough handling to which containers are subjected. “For our customers, high-quality pretreatment means longer service life and a higher resale value,” explains Tropsch. “Rust is a thing of the past on semi-trailers, but our responsibility goes further than rust prevention. As a manufacturer on an expansion course throughout Europe, not only the quality of the products but also the sustainability of the production processes is crucial.”

The Challenge of Progress

Zinc phosphating has been the standard surface pretreatment method used in the vehicle industry to ensure first-class prepaint treatment. However, it does have two negative environmental aspects. First, energy is consumed to heat the pretreatment baths, and second, phosphate sludge that contains heavy metals is formed during the process, and this has to be disposed of. “We have always worked hand in hand with Henkel in the field of pretreatment. As part of our policy of innovation, we called on our partner to improve this process at the main plant in Burtenbach,” says Tropsch. “Our foremost requirement was to improve the sustainability of the process while achieving the same if not better quality.” Henkel was predestined for this task, as the company has a history of innovative developments for metal pretreatment, which have brought about significant improvements relative to conventional methods. In 1995, for example, chromating was replaced by a new kind of pretreatment method, as was iron phosphating in 2002. In both cases, environmental impacts were drastically reduced and industrial processes were considerably simplified. “In terms of the quality of the coating, zinc phosphating process is the optimum,” says Henkel Project Leader Dr. Torsten Körner. “The challenge we faced was to develop an alternative conversion coating, which would be just as effective and would offer concrete process benefits. These benefits can be expressed by the keywords green, simple, fast and efficient.” The result of Henkel’s development work is the completely new TecTalis process, which Kögel put into operation in January 2008.

In the Fast Lane With Nanotechnology

Technically, TecTalis differs from zinc phosphating in that it has fewer process steps and the baths no longer need to be heated. “Instead of heating the phosphating bath to 60 °C, we can run TecTalis at room temperature. This cuts our energy costs significantly,” emphasizes Tropsch. The TecTalis process uses a solution that contains zirconium. In chemical terms, a pickling reaction occurs in the first step, shifting the pH at the surface of the metal substrate into the alkaline range. As a consequence, the metal ions that will form the coating settle on the surface and bond with it. A conversion layer is created, the components of which include zirconium oxide, a nanoceramic material used in modern dentures. According to Dr. Maximilian Schönherr, Head of Development for surface treatments at Henkel, “In contrast to the crystalline layer obtained by zinc phosphating, TecTalis forms a much thinner, amorphous, surface coating. In fact, it is only 20 to 50 nanometers thick, which is about 100 times thinner than before.”

Switchover on the Existing Plant

An important advantage of TecTalis is that the process can run on existing plants without having to invest in new equipment. “The switchover did involve a substantial risk, as Kögel could have suffered major production losses in the event of a hitch,” says Tropsch. “Since there was no prior experience with the system in an industrial-scale environment, we were prepared for all eventualities. If anything had gone wrong, the line could have been restored to its previous condition and run using the old process within 24 hours.” The switchover was carried out around the beginning of 2008 and took about one week. One crucial prerequisite was the thorough cleaning of the tanks to ensure that zinc phosphate residues could not interfere with the new process. In order to be absolutely sure, the process water was again analyzed very precisely for residual phosphate before the new TecTalis product was added. Dr. Schönherr commented, “This precision ultimately paid off, because the TecTalis process performed perfectly at Kögel from the very beginning.” Kögel head of production Tropsch was also satisfied: “In terms of corrosion protection and paint adhesion, TecTalis meets the high standards to which we had become accustomed from the zinc phosphating process. Our specifications were complied with, and in some cases even surpassed, from day one. Moreover, Henkel provided intensive on-site support during the first few weeks so that we were able to adjust the process to our requirements.”

Clear Reduction in Environmental Impact

By switching over to TecTalis, Kögel is helping to conserve energy resources and is making a considerable contribution to reducing the use of environmentally harmful substances. “Thanks to TecTalis, our pretreatment processes are now free of toxic heavy metals. Moreover, the process generates only about one tenth of the previous amount of sludge residue, which also significantly reduces the burden on the environment,” summarizes Tropsch. “We are therefore setting a new standard throughout Europe for sustainability in metal pretreatment.”

Innovating for Success

The example of Kögel illustrates the great importance of innovation for achieving corporate success. The readiness to accept the risks associated with a pioneering strategy and to introduce innovative products and production processes has a direct influence on product quality and market success. Tropsch says, “We are on the right course with our innovations. The new metal pretreatment process points the way forward – technically, ecologically and economically – and underscores our claim to innovation leadership in our sector.” Due to the immediate convincing results obtained by using TecTalis in Burtenbach, Kögel has now decided to install the process at its plant in the Czech Republic. Where innovation and sustainability are concerned, the trailblazing trailers are out in front.