A PRACTICAL ACCELERATED UV EXPOSURE TEST FOR POLYMERS INFORMED BY DATA AND EASILY IMPLEMENTED

In an earlier publication Bartosz and Chen [1] developed an accelerated test for UV exposure of plastic materials. This test simulates the damage from multiyear outdoor weathering by exposing test articles under higher intensity UV light but at much shorter times, on the order of weeks only. The equivalence between laboratory exposure time and actual field duration was tallied by accounting for the quantity of photons striking the test surface. The intensity and nature of the UV damage was additionally characterized by fracture studies and compared with field data from one of our products deployed for known exposure times at specific global locations. The similarity in results from both test samples and the fielded samples provided an initial confirmation of this accelerated test. For engineering units that have now sustained long term UV degradation during the four years from when this method was introduced, quantifying their UV damage by measuring the color change over time in CIELAB color space and correlating with our accelerated test has since reinforced its correctness to the point that we have used this method for both analyzing field degradation and screening components in our supply chain. This paper reports on these new developments along with how they further corroborate the effectiveness of this accelerated UV test.