About the water adsorption characteristics of artificially degraded insulation material surfaces

In order to describe the water adsorption characteristics of insulation materials under humidity conditions, a test procedure called "Water Adsorption Test" has been introduced, which allows one to classify the various insulation materials into so-called water adsorption groups. This procedure is based on a test to be performed on new samples of insulation materials, and previous papers have shown results of the water adsorption test on such insulation materials. In this paper we investigate the influence of artificial degradation of insulation material surfaces on their water adsorption characteristics under humidity conditions. Hereby, the degradation has been performed by illumination of insulation material surfaces with an UV source. In this paper the investigated polymers consist of a glass fibre reinforced epoxy resin as well as a laminate consisting of presspan and polyester foil. We obtained the result, that the classification of the degraded laminate consisting of presspan and polyester foil does not differ from the classification of a new test sample. On the other hand, the water adsorption characteristics of the degraded fibre reinforced epoxy resin are worse in comparison to a new one.