Extruded lightbar seals -

Tough enough for Autobahn

In Germany, emergency lights on police cars need to operate in difficult conditions – driving rain, heavy snow and the high speeds of the Autobahn, a highway system much of which has no speed limit at all.

When the German company Hänsch Group began developing its new DBS 4000 LED lightbar for police, fire and rescue vehicles, the company’s engineers needed seals they could trust. Three years ago, Trelleborg designers sat down with Hänsch engineers to develop a gasket that could withstand the conditions. “The automotive sector is really very special,” says Markus Keller, Export Manager for the Hänsch Group, based in Herzlake in northwest Germany. “If you’re driving 200 kilometers per hour on the Autobahn, the seal still has to hold, even in the rain, which finds every little crack. It was a big challenge.”

But it wasn’t the only challenge. At the same time, Hänsch was looking to improve fuel economy by designing the DBS 4000 with an aerodynamic aluminum housing that reduces air resistance. “We needed our gaskets to use the least material possible, to reduce weight and save fuel, while also being weatherproof and UV resistant,” says Mike Kallaway, Business Unit President for sealing profiles in Trelleborg Industrial Solutions. Noise was another factor. “On the Autobahn, high pressure from the wind can make the car very noisy,” says Mike Kallaway. “Our gasket was designed to keep noise under control.” 

Manufacturing proximity made a difference, too. “One big plus for Trelleborg was that its factory is very close to ours,” says Hänsch’s Keller, explaining that Trelleborg’s facility in Lathen is only about 25 kilometers from Hänsch’s plant in Herzlake. He says Hänsch was lucky because Trelleborg worked with the material they were looking for, a durable EPDM synthetic rubber. The first DBS 4000 lightbars came out in 2010, and the series has been highly successful, Keller says. “The functioning of seals is always a big issue with lightbars, and these are working very well.”

Fact box

Hänsch to the rescue

The Hänsch Group (officially Firmengruppe Hänsch Holding) makes warning systems for police, fire and rescue vehicles; designing lights and sirens that save lives. The group has three business divisions: warning systems, engineering and signal technology. While Germany remains its primary market, Hänsch is now expanding its sales into the rest of Europe.

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