Abstract
Customers' expectations for a consistent long-term high-level product performance have been increasing year after year, and the automotive industry is leading the trend. As an automotive seating component, polyurethane foam has a direct impact to the perceived value of an occupant, thus providing high durability foam became essential to customer satisfaction. Many tests were developed to evaluate the foam durability in various environments because of the importance of durability. The data used to correlate the results from these tests to that of foam collected from the used vehicles is limited because of the complex nature of aging and usage.
In this study, newly manufactured foams were aged at a high temperature, and their fatigue properties were compared with the properties of foam samples collected from the vehicles of different mileage, age and geographical location.
The results of this study showed that the heat aging at 100°C can be used to estimate the aging condition in a dry, hot climate with approximate mileage of 139,000 miles. However, varying the heated time of the foam for accelerated aging did not vary the fatigue property significantly enough to correlate to different mileage. Instead, an application of weight during the heating process is found to represent the fatigue property of foam at higher mileage than heat aging alone.
Although the level of wear of the foam was found to be different depending on the environmental conditions, 25% compression load deflection (CLD) value before and after repeated compression of all samples of the same size were found to follow a logarithmic relationship. Further study of foam with different levels of wear are necessary for more detailed observations.
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