Flexline is MANN+HUMMEL’s answer to the issue of ever decreasing space in passenger car engine compartments. Here Dr. Michael Heim, Head of Air Filter Element Development, introduces the latest air filter generation and examines the benefits in discussion with the project team: Daniel Schmid (air filter element development), Timo Dirnberger (air filter system development) and Dr. Markus Röhrig (Manager for production of flat air filter elements at Marklkofen plant ). Visitors to the IAA will be able to take a look at this latest innovation at the MANN+HUMMEL stand (A41) in hall 8.

Dr. Heim: How have air filter elements evolved over the last 20 years? What has been the overall trend?

Schmid: 20 years ago air filter elements looked more like classic rectangular rods. Now the focus lies more heavily on complex contours and variable geometries. We are also increasingly seeing elements that are missing one or two corners, or that have trapezoid shapes or recesses. These designs have been very successful for us. Flexline now marks the next step in this innovation process, which will further optimise the use of installation spaces through flexible outer contours.

Dr. Heim: This development is hugely influenced by a car’s engine compartment package. How has this changed?

Dirnberger: If you looked into the engine compartment of a VW Golf 15 years ago, you could still see all the way through to the tarmacked road beneath. Today there is barely any space left: the package is more and more tightly packed and there is less and less space in the compartment, which is reflected in the geometry of the filter elements. Flexline allows us to keep up with this trend and offer tailor-made solutions to our customers.









Dr. Heim: What does this added flexibility bring to the air filter system as a unit?

Dirnberger: If we optimise the element in line with the interfering contours in the vehicle, such as a suspension strut tower or headlights, and thus make better use of the package, the filter element as well as the air cleaner can automatically be increased in size. This instantly gives us access to a wide range of benefits. It allows for a greater absorption volume, which results in better acoustics, and it creates a larger inflow surface area, which also allows a lower pressure drop to be achieved. The gains we make in terms of filter element flexibility thus help improve the overall system.

Schmid: We also mustn’t forget the enhanced filtration performance. By optimising the use of space, we are able to install a larger filtration surface and thus meet our customers’ growing requirements in terms of separation efficiency and dust capacity.

Dr. Heim: Producing variable contours also requires massive changes to existing production technology systems. What modifications have been made here?

Dr. Röhrig: In the case of Flexline, we create the element contours using state-of-the-art laser technology. This opens up a host of new possibilities compared to traditional cutting techniques. In addition to straight contours, we can now make just about any design, even curved contours with radii, which would not have been possible with conventional methods. Moreover, the shift away from manual processes and towards laser technology has hugely increased occupational safety for our production staff. Applying the innovative modifications involved in the new sealing concept also requires quite a lot of manufacturing expertise.

Schmid: Overall, the new Flexline production model allows us to also deliver the higher level of component cleanliness that customers have been increasingly calling for in recent years.


Dr. Heim: How important was teamwork to the development of Flexline?

Dirnberger: Fantastic teamwork between the two departments involved (Development and Production) is crucial to implementing innovative solutions such as Flexline. At MANN+HUMMEL, teamwork is a core principle and one that is firmly rooted in our company values. One specialist department alone couldn’t come close to accomplishing such feats.

Dr. Röhrig: Brilliant teamwork was also key to establishing Flexline on the market relatively quickly. The first series production project incorporating the benefits of this geometry system is set for market launch in 2017.

Dr Heim: As the project team, what can we expect from the IAA?

Schmid: Presenting Flexline at the IAA will add further momentum to the product’s fresh concept. It’s a great opportunity to introduce the sector  to Flexline and to show our customers the solutions that it offers.


NB: There will be a special Flexline presentation illustrating the possibilities available with Flexline at the MANN+HUMMEL stand (hall 8, stand A41) at this year’s IAA.