| 摘要 |
Cushions for dynamic impact applications include anisotropic cellular polymers made in an extrusion, expanded bead or reactive foaming process. The anisotropic behavior represented by C<SUB>E</SUB>/C<SUB>T</SUB>, C<SUB>V</SUB>/C<SUB>T </SUB>and C<SUB>H</SUB>/C<SUB>T</SUB>, wherein C<SUB>E</SUB>, C<SUB>V </SUB>and C<SUB>H </SUB>represent the compressive strength of the cellular polymer in each of three orthogonal directions E, V and H, respectively, as measured by compressing a 25-50 mm thick sample of the cellular polymer at a strain rate of 0.08 s<SUP>-1 </SUP>to 25% strain, C<SUB>T </SUB>represents the sum of C<SUB>E</SUB>, C<SUB>V </SUB>and C<SUB>H</SUB>, and at least one of C<SUB>E</SUB>/C<SUB>T</SUB>, C<SUB>V</SUB>/C<SUB>T </SUB>and C<SUB>H</SUB>/C<SUB>T </SUB>has a value of at least 0.40, up to about 0.80. The cellular polymer also preferably has density of 1.75 to 2.35 pounds/cubic foot and a compressive stress in the direction of maximum compressive strength of 290-600 kPa at 25% strain when used for headliner countermeasure applications. The cushions are useful in automotive applications such as automotive headliners, door panels, knee bolsters, pillars, headrests, seat backs, load floors or instrument panels.
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