Energy-saving seals

Close collaboration proved key when ventilation company Rasch experienced issues with the seals on one of its damper products.

Today ventilation systems not only have to manage large airflows to be able to ventilate buildings that are tightly sealed. In a time of increasing climate and environmental awareness, intelligent control systems are becoming more common, making it possible to steer the airflow toward where it is needed or away from where it is not needed. In doing so, energy consumption can be minimized — an increasingly important requirement for real estate firms and property managers, many of whom want to become environmentally certified according to the international BREEAM standard. 

An important element in achieving the goal of low energy consumption in the building’s ventilation system involves the use of dampers with moving parts operated by motorized control systems. Current trends show more and more of these units being installed in modern buildings.

This is where Rasch comes in. Originally a family company started by three brothers in the 1930s, Rasch has grown to become a leading producer of different types of ventilation products, including fireproofing and air dampers for installation in everything from nuclear power plants and mines to schools, offices and shopping centers.

When Rasch was in the process of product development a few years ago to redesign one of its larger louver dampers to make it lighter and smaller, a problem arose: the existing seals made it too heavy, preventing the electric motors from closing the louvers correctly.

“We called our contact at Trelleborg, Peter Somvall, to see if we could work out a solution to the problem,” says Anton Berner, a product developer at Rasch.

Carina Ström, responsible for purchasing at Rasch, says: “We had good dialogue and collaboration from the very start, and Trelleborg has helped us a great deal throughout the process.” 

Trelleborg’s team studied Rasch’s problem inside and out. Peter Somvall, a business developer for sealing profiles within Trelleborg Industrial Solutions, brought a designer and a product developer with him to the facility to speak with the company’s product developers and assemblers.

“We realized very quickly that it was a design problem, not a material problem,” Somvall explains.

Then a process described by everyone involved as “close cooperation” followed, during which Berner and his colleagues visited Trelleborg’s manufacturing site.

“Our collaboration was extremely smooth from day one,” Berner says. “Somvall and his colleagues came to us, studied and examined, took samples, simulated and analyzed, and came up with a sketch that we later discussed and modified. As part of the process, we also developed a prototype that we tested here in our manufacturing site.”

Somvall stresses how it was important for Trelleborg’s team to listen to the assemblers. The key to achieving a successful product is finding a solution that is easy to assemble. 

“We know that it is on the construction site itself that costs develop,” he says. “For this reason, it is important for us to find easy-to-assemble solutions that can be produced in large volumes while observing strict tolerance requirements.”

Trelleborg has been an important supplier of sealing profiles for Rasch’s products, and Somvall says the company learned many lessons during the development of the large louver damper. 

“It has affected the entire product assortment at Rasch,” he explains. “Thanks to our new solution, all the company’s dampers are now easier to operate.” 


For more information
, please go to:

This is an article has been reproduced from Trelleborg's T-Time magazine. To download the latest edition, go to: 

Press Service: This article is available in eight languages. Media are welcome to use this article in their own publications. To download the article and pictures in any language go to If you reproduce information from this release, please give contact details as: