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The passing of the federal regulation for head impact protection for upper interior components (FMVSS 201U) has led to the use of a variety of foam materials in interior trim pillar and headliner reinforcement applications. Polyurethane foams and expanded bead foams are some of the commonly used foams in these applications. However, the low energy absorption efficiency (35% - 55%) of the current foams requires the use of 20 mm - 40 mm of packaging space to integrate the countermeasures that make it possible to meet the regulations. A newly developed high efficiency olefin based foam is able to meet the performance requirements at a reduced packaging space. A combination of physical structure and superior mechanical properties provides the much needed higher efficiency (80% - 90%) of the olefinic foam. This paper discusses the foam architecture and performance benefits for many interior applications, such as energy absorbing countermeasures in pillar trim, headliners, and door panels.

Revisions to the FMVSS 201 head impact legislation have had a significant impact on the design and engineering of upper interior trim components of cars and light trucks. Structural performance with energy absorbing capability to prevent head injury is now a significant addition to these requirements. However, occupant visibility blockage limits the amount of packaging space available for implementing countermeasures in this area. A novel approach to meeting the FMVSS 201 structural requirements, while keeping the interior trim on the vehicle minimally changed, has been developed. This approach requires the use of energy absorbing rib structures sandwiched between the trim panel and the inner body-in-white (B/W) sheet metal in A and B pillars. Heat staking is used to attach the rib structure to the interior trim panel.