Purity first

Clean room for mass production of commercial vehicle filter

The filtration specialist MANN+HUMMEL offers vehicle manufacturers the option of producing components in a clean room environment.

The filtration specialist MANN+HUMMEL offers vehicle manufacturers the option of producing components in a clean room environment. At the Marklkofen location, one of the largest filter plants in the world, the company produces diesel fuel filters for medium duty engines from Mercedes Benz in a clean room.

Ludwigsburg, 18th September, 2012 – The 500-year old Bavarian regulations governing the purity of beer, the so-called "purity law" is legendary in Germany and now, in parallel, the same theme is ever more important in the field of engine construction. For components of engine peripherals this means the separation of impurities with a diameter smaller than one thousandth of a millimeter. MANN+HUMMEL fulfils the strict requirements of automobile manufacturers for component cleanliness with a Component Cleanliness Management (CCM) program which was established more than seven years ago. In the product development stage, component cleanliness management lays the foundation for a clean product and takes into account all processes starting from the design and purchasing through to production and assembly and storage, transportation and handover to the customer. Suppliers and the complete logistics chain are subject to the CCM requirements. "Our target is to maintain the component cleanliness we provide during production to all processes downstream including the delivery of our products to the customer", explains Thorsten Schmid, CCM manager at MANN+HUMMEL.

MANN+HUMMEL employs a two-stage cleaning concept for the Mercedes-Benz fuel filter module. Stage one removes coarse dirt particles and cooling lubricant residue from the aluminum housing of the module. In stage two fine cleaning of the component is carried out to ensure the required component cleanliness. The assembly of the components is made in a clean room certified to EN ISO 14644 equipped with ceiling, walls and floor which are dirt resistant. The room has a defined air exchange rate. In the clean room the pressure is slightly higher than outside which prevents dust from entering the clean room. The functionality of the clean room is verified by particulate traps.

The company's CCM laboratory carries out measurements on a flow test bench at regular intervals to systematically check the quality of the finished products.

An important point of the CCM concept is the qualification of all employees involved in the process. MANN+HUMMEL ensures that they are familiar with the binding CCM requirements and know how to implement and check these in their daily work. Only trained personnel in special protective clothing (hair nets, laboratory coats, overshoes, gloves) are issued with a personal ID card for access to the clean room. "A continuous dialog with the employees is important to be able to introduce further improvements", explains Schmid.

Vehicle manufacturers require different levels of component cleanliness. In particular, sensitive products are fuel, oil and urea filter systems. For applications in the fuel feed line different manufacturers require a maximum particle size of between 0.2 to 0.4 millimeters. It is essential that common rail injection systems with pressures up to 2,400 bar and nozzle bores with a diameter of approx. 0.1 millimeter are protected against particles in the range of a few thousandths of a millimeter.

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The MANN+HUMMEL Group is a leading global expert for filtration solutions and development partner and original equipment supplier to the international automotive and mechanical engineering industries. Employing 14,338 people at more than 50 locations worldwide, the company achieved turnover of about 2.5 billion euros in 2011. The group’s product portfolio includes air filter systems, intake manifold systems, liquid filter systems, cabin filters and cylinder head covers made of plastic with many integrated functions for the automotive industry, as well as filter elements for vehicle servicing and repair. For general engineering, process engineering and industrial manufacturing sectors the company’s product range includes industrial filters, a series of products to reduce carbon emission levels in diesel engines, membrane filters for water filtration and filter systems.