Load Deflection Testing of Urethane Foams for Automotive Seating
Cellular foam products have been traditionally checked for load deflection by determining the load required to effect a 25% deflection. In seating, on the other hand, the interest is in determining how thick the padding is under the average passenger load (a measurement of padding left for 'ride' and seated height), a second measurement to give an indication of initial softness, and a final figure to indicate resiliency. To most easily fulfill these requirements, load deflection on flexible urethane foams for automotive seating is determined here by measuring the thickness of the pad under fixed loads of 1 lb, 25 lb, and 50 lb on a 50 sq in. circular indentor foot.