Aug 11 2007
Crashpads made of polyurethane rigid foam are used in automobile interiors to reduce the impact force in case of accidents, thus protecting the driver and passengers from serious injury.
Crashpads are usually fitted in areas that pose the greatest danger in accidents, e.g. as side impact protection in doors, direct impact areas for the head - for instance, in the A-pillar or headliner - and in the front impact area of the passenger compartment to protect the occupants’ knees.
Crashpads manufactured using the BaySystems rigid foam system BaySafe® from Bayer MaterialScience meet the requirements for occupant protection with ease, proving their worth thanks not least to their cost-effective production.
Polyurethane foam is also used in cable sets to protect the enclosed cables and make it easier to fit the cable harnesses. This system also allows for the integration of fasteners and ensures lengthwise protection against water ingression.
As cable harnesses are often routed along areas protected with crashpads, it made sense to combine the two and to mold the life-saving padding directly around the cable sets. This now patented development was made possible thanks to close cooperation between LEONI Bordnetz-Systeme GmbH, Kitzingen, Germany and Bayer MaterialScience. The benefits of this combination are clear - integrating the cable set and the crashpad, which is designed to fit perfectly in the installation space, makes for faster assembly, which in turn cuts the customer’s assembly costs. As the crashpads no longer have to be handled separately, this brings additional logistical and cost benefits for automotive manufacturers.
Integrating the cable harness has a negligible effect on the effectiveness of the crashpads: "Using quasi-static pressure tests at a range of temperatures, we were able to prove that integrating the cable harness does not impair the foam padding’s ability to absorb energy effectively," explains Klaus-W. Huland, an expert in polyurethane energy absorption systems at Bayer MaterialScience. "A slightly earlier increase in pressure was detected only in cases of higher levels of deformation." LEONI also commissioned Autoliv to perform head impact tests using dummies, and these tests verified the negligible impact of the cable harness on the foam’s effectiveness.