Importance

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Abstract

This invention relates to a passive restraint for an automobile, and moe particularly, to a knee blocker for automotive applications that is positioned under the steering column forward of the knees. In order to provide energy absorption, the knee blocker includes an energy absorbing core filled with a plurality of thermoset resin pellets. The energy absorbing core is disposed between a metal stamping and a vinyl foam skin padding. Each of the pellets consist essentially of substantially uncured thermoset polymeric resins and microspheres which have been intermixed and extruded. Each of the pellets also has a coating of a B-staged resin. These thermoset pellets are made in the following manner. A low viscosity thermoset resin and microspheres are mixed together without melting the thermoset resin and extruding the mixture to form a continuous strand of paste-like uncured material. The continuous strand is expanded and gelled on a conveyor which preferably includes radiant heater or other means for accelerating the gelling of the continuous strands into solid form. The strands are then cut or chopped into pellet form and may be coated with an adhesive or B-staged material in preparation for forming into structural reinforcements. The pellets are filled with microspheres in the amount of 20 to 35% of resin weight. The pellets may include unexpanded thermally expandable microspheres which permit expansion of the pellets when exposed to heat to provide a pellet having a bulk density as low as 9 pounds per cubic foot. The pellets may be formed of a thermoset resin such as a polyester resin or epoxy resin, vinylester resin, polyurethane resin, or phenolin resin and may include organic, inorganic or glass preexpanded microspheres. Alternatively, the pellets may include unexpanded thermally expandable thermoplastic microspheres or a liquid blowing agent if expansion of the pellets is desired. A cure aid or curing agent may be included in the pellet mix to facilitate curing of the pellet in the final reinforcement and other additives may be incorporated in the pellet mix to improve extrudability or other properties of the pellets.

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First Claim