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This paper will explore the performance of two polyurethane foam formulations, one that is designed to be high resilient and one that is designed to be low resilient. The two formulations are placed into a full foam seat suspension. Data is generated with each formulation by a forced vibration test with a tekken mass, both at one point in time and over several hours to simulate in vehicle performance. The Seat Effectiveness Amplitude Transmissibility (SEAT) is read over a one-hour course that includes paved and rough roads, which is repeated three times for a total of three hours of data. This data is then compared to the foam data. The data shows that the low resilient foam will have some improvement in the paved roads but will have a vast improvement in the area of the rough roads. Data will be done by road to show the fatigue level occupant, road type, hour of the ride and drive and the foam type.

Historically, polyurethane foam has been classified and determined by IFD (Indentation Force Deflection) and density. The IFD test measures the load bearing property of the foam at a given deflection. However, the expectation of the automotive specifications is that these properties will also define durability and comfort of the foam when used in complete seat applications. Today’s automotive customers are asking for vehicles that last longer, with higher expectations in comfort, appearance, and durability performance. New targets are vehicles that will have satisfactory performance for 150,000 to 200,000 miles. We at Johnson Controls believe that to achieve these types of customer performance standards, new definitions of the molded foams are required. This paper will explain how a new test measurement, called hysteresis loss, is required to meet these new customer requirements.