Absolutely Impervious ECU Boxes 2009 GB

Press Release

Pöppelmann – Development partners to the automotive industry Absolutely impervious ECU boxes

Lohne/Germany, February 2009. – The firm of Pöppelmann Kunststsoff-Technik GmbH & Co. KG, Lohne/Germany, has been commissioned by Daimler AG, Sindelfingen, to develop and manufacture ECU boxes for the current Daimler Benz E and S Class cars. The ECU boxes for the new E Class (BR 212, to be launched in 2009) have likewise been developed by Pöppelmann. These boxes, which are installed in the engine compartment of the vehicle, accommodate the electronic control units for the central electrical system and protect them not only against possible mechanical damage but also against external influences in all working conditions, especially against sprayed and splashed water in rainy weather. The extreme demands in respect of strength, rigidity, dimensional stability and resistance to high and low temperatures have been met by Pöppelmann's design and development engineers with a design of the ECU box that is entirely suitable for production in a thermoplastic material, the choice of the latter being a long fibre-reinforced polypropylene (PP LGF 40) for both the box and the cover.

Ingress protection testing chamber for application-specific tests

A particularly challenging problem for Pöppelmann's design and development engineers was that posed by the need for absolute tightness between the box and the cover and at the cable entries and exits. According to requirements, no moisture may enter a rotating specimen ECU box when it is sprayed with water at a rate of 12.5 litres/minute for the duration of 3 minutes – this procedure simulates typical exposure to condensation and sprayed/splashed water when the car is being driven in rainy weather (Ingress Protection IP X5 to DIN 40050). These high demands necessitated the implementation of ingress tests on prototypes and preproduction models throughout the entire development project. In order to be able to perform these tests efficiently and quickly, Pöppelmann and the customer agreed on the installation of an SPK 100 testing chamber for the performance of Page 2 of the press release “Absolutely impervious ECU boxes”

ingress protection tests in compliance with DIN 40050. At the end of a test cycle, a moisture-sensitive paste (water detection paste) indicates the exact location any ingress of water (the paste turns red), enabling the designers to make improvements exactly where they are necessary.

The ECU box and the cover are sealed with a PUR gasket produced by means of the FIPFG process (Formed In Place Foam Gasket). This process is performed by a CNC robot-guided mixing head which places a strand of polyurethane directly into the sealing groove of the cover. This strand then foams to produce an exactly fitting, unlosable gasket. The cable entries and exits take the form of rigid, dimensionally stable polypropylene supporting plates with flexible circumferential sealing lips and a flexible bushing for the cables; the latter may take the form of a two-component part injection moulded in PP and a thermoplastic elastomer.

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Further Information: Pöppelmann Kunststoff-Technik GmbH & Co. KG Dirk Stubbe Daimlerstraße 9, D-49393 Lohne Phone: +49 (0) 44 42/9 82-66 23, Fax: +49 (0) 44 42/9 82-6 69 E-Mail: [email protected], Internet: www.poeppelmann.com

A MS-WORD file of this press release in English and German and printable-grade copies of the enclosed images are available for download at: http://www.poeppelmann.com/aktuelles/presse.gb.epl Page 3 of the press release “Absolutely impervious ECU boxes”

The ECU box, consisting of the housing, the cover and the cable entries and exits, reliably and permanently protects the central electrical system against harmful environmental influences, especially moisture. Foto: Pöppelmann, Lohne