MANN+HUMMEL has built up its expertise in plastics over decades. Those who visit one of our plants are most likely to see between 10 to 20 large injection molding machines, which amount to several hundred worldwide. If you call us with an idea for a product made from plastic, you will surely find the right partner. This is because we know how to handle plastic and can assess whether your product fits in with our product range and strategy.

Our plastics expertise also helps us to meet the requirements of our customers in the area of acoustics. As well as sounds from the exhaust pipe, many people are unaware that cars also have an intake noise which is similar to the noise generated by a vacuum cleaner. There is therefore the requirement to either remove this partly unpleasant noise or to make it more pleasant. Manufacturers are also increasingly engaged in seeking to achieve a typical sound for their car brand which will make the car soft and quiet, powerful and raucous or unrefined and bold. To do this we have the right tricks up our sleeve such as broadband dampeners, sound pipes and symposers – naturally all in plastic.

The world’s first symposer (2005) produced in series


Our reservoir bottles, which the company gained through an acquisition, are slightly less spectacular with absolutely low noise. Are there some people who can remember the reservoir bottle in the VW Beetle which in former times catapulted the washing water with the pressure from the spare wheel up to the car windscreen? Today we also manufacture such containers for brake fluid and cooling water.

Windscreen washer reservoir for BMW


Crankcase ventilation (CCV) systems also represent a classic example of how plastic can replace metal. Initially the metal cylinder head cover was replaced by a plastic part and this opened up the possibility of exploiting the design flexibility of plastic. We integrated the oil separator for the crankcase ventilation in the plastic cover which gave us a CCV system. The process is always the same. Firstly, plastic replaces metal and then in the second step further functions are integrated in the component.

The same process applies to the oil sump which collects oil on the underside of the engine. In order to reduce costs and weight, the metal sump was replaced by a plastic part and this once again enabled the integration of additional functions. Today we produce sumps which switch oil circuits to warm up the engine more quickly and decrease friction within the engine. This integration of products which were previously separate in a single plastic component naturally also has cost advantages.

Plastic oil sump with high level of integration


After the full exploitation of plastic to substitute metal parts we now enter a phase where we need extra functionality for the engine. It is possible to create efficient actuated products in plastic such as valves which perfectly adjust the engine to the respective driving conditions (mountains, ocean, cold, warm). Whereas in the past engines always worked in the same way, today we have countless little helpers which constantly adjust the engine to take into account the respective driving conditions. The use of plastic here offers countless possibilities.

An agreeable atmosphere for sensitive components

This is achieved by the first parts which we now produce for alternative drive systems. For electric cars, we supply General Motors with battery frames which serve to hold the batteries together. In addition, we manufacture degassing units which serve to equalize pressure within the battery and prevent the ingress of moisture and dirt. In short, we create an agreeable atmosphere for the sensitive components used in alternative drive systems, e.g. for electric car batteries and fuel cells which like their environment to be not too humid, not too dry, not too warm and not too cold. Here we also use our filtration expertise to filter the air, make it dry, clean it and make it humid and we use our plastics technology to cost- effectively produce the required parts in large volumes. This means we are well equipped to meet the requirements of conventional combustion engines and other future engine concepts.

Battery frame for General Motors