EPP: small parts,
EPP: small parts, major effect!
Writing about lightweight engineering and the automotive sector is like taking coals to Newcastle, because there are extensive reports about both in all kinds of offline and online media. For particle foams, however, they mean unforeseen, innovative application possibilities. These can be demonstrated using the example of EPP – expanded polypropylene.
For more than 20 years, the main use of expanded polypropylene has been in the automotive industry, which consumes around 80 percent of the particle foam used in Europe. There are several really good reasons for this long-term use of EPP in the automotive sector: thanks to its high lightweight engineering potential, such as for use in rear seat benches or wheel arches, it effectively reduces vehicle weight. An extremely eco-friendly implication of this: less fuel consumption, lower emissions! And EPP offers a further advantage in terms of sustainability – the polymer foam can be recycled optimally. EPP is convincing both in terms of static and dynamic load thanks to outstanding energy absorption and impressive resilience – an excellent basis for safety-related components in vehicle construction.
Reliable protection of transported goods and functional safety within large temperature ranges as well as resistance to oil and chemicals are further points in favour of expanded polypropylene, making it the ideal material for the automotive sector. The universal particle foam has all the visual advantages on its side, too – all visible EPP parts of the vehicle such as sun visors or lining elements can be adapted in terms of colour to the prevailing design.
Impact absorbers: foam protects!
These are only small EPP moulded parts, but they have a major effect: Car engineers have developed impact absorbers made of EPP in order to exploit two decisive properties of expanded polypropylene – their outstanding resilience and ability to absorb impact energy. With EPP moulded parts integrated in shock absorber systems, pressure is cushioned following impact, reducing the impact energy acting on the chassis. Such a protective measure is particularly valuable in the case of small bumps, in other words crashes at low speeds. Expensive chassis damage can be avoided. Further advantages of impact absorbers made of particle foam: their low weight reduces the overall weight of the vehicle, thus reducing fuel consumption. One practical aspect: distance sensors or temperature sensors can easily be integrated in the innovative system.
Vehicle manufacturers are impressed by the high rigidity of expanded polypropylene and its good bonding possibilities to other materials. These characteristics lead to high-density EPP also being used as a design element.
Standard vehicle parts: attractive-looking safety
Expanded polypropylene offers additional safety on vehicle interiors, too: crash pads and other cushioned inserts made of EPP improve passenger protection, whereby the foam’s good resilience has proved its worth. Adaptation of the cushioning values to requirements is possible thanks to the (almost) freely adjustable EPP density from 20 to 180 mg/l. Films and fabrics are used to “finish” EPP moulded parts and turn them into attractive visible parts on vehicle interiors. The lightweight EPP components make a double contribution to the environment: they can be reused and contribute to reducing CO2 pollution due to their low weight. And because a car is much more than just a means of getting from A to B for most owners these days, integration of designable EPP moulded parts contributes to adapting the look of the standard parts to the prevailing design. Those who ask themselves where the innovative material could be integrated in their car, should take a closer look at luggage compartment inserts, filler pieces or finished parts. These are just three examples of uses in the automotive sector – EPP is used in lots of other places, too, such as: battery cover, knee pads, seat reinforcement, roof braces, head restraints, rear shelf, armrests ... Yet no matter where the numerous EPP parts can be found in vehicles, there is one thing they all have in common: they make the vehicle safer, lighter and thus more environmentally friendly!