CORESTA Meeting, Smoke/Technology, Hamburg, 1997, ST39

A method of evaluating factors contributing to environmental degradation

Philip Morris USA, Research Center, Richmond, VA, USA
Many factors contribute to the degradation of materials, or components, under environmental weathering. Primary contributions are expected to come from exposure to sunlight, exposure to moisture and mechanical agitation. Since these vary so much with the location and the time of year it is difficult to draw comparisons between the results of external weathering tests. Even if the exposure conditions are carefully monitored a comparison cannot be made without knowing how the exposure factors contribute to the degradation of the sample. This dilemma is usually resolved by setting up a standardized laboratory test where factors influencing degradation are controlled and the sample is run through cycles that are designed to simulate environmental weathering. By running some experiments where factors thought to influence environmental degradation are controlled, it is possible to isolate and quantify the contribution of each of the degradation mechanisms, and also to show the relative importance of any interactive effects. Such an analysis can also be used to identify the sensitivity of the degradation metric to other experimental variables, and to define practical ranges for the controllable parameters.