Evaluation of Automotive Interior Material Life by Accelerated Tests

Abstract

Since factor of automobile interior materials degradation are mainly influence of the heat and the UV light, we will describe about the thermal degradation and photodegradation in this report.The variety of life (Time to elongation 20 %) of ABS/PVC/NBR leather for the instrument panel pad are spread from 150 hours to 800 hours at 110°C. Physical properties among many surface coverings collected from sold cars in the Japanese domestic market and degraded ones by accelerated heat aging test were compared by us and as the result. We can estimate that the degradation for one year in actual condition is equivalent to the degradation in accelerated heat aging test for 96 hours at 110°C. Regarding the light fastness, we examined rate of discoloration of the seat which is exposed to the direct sun by using blue scale specified in JIS L 0841. As the result of comparison among exposure test in an actual car and various accelerated tests, we can estimate that one year of exposure on an actual car is equivalent to (1), 3 months of exposure on under-glass exposure test and (2) 200 hours of exposure on xenon arc weather meter. A xenon arc weather meter in the test of seat upholstery has high acceleration and reproducibility.
Therefore, it can be said that in case of the test with the xenon weather meter, correlation between the test and the actual environment is very high.