The use of WPC has been rapidly growing in several key market segments, such as outdoor decorations, and also building and construction products [1, 2]. Therefore, evaluation of changes in the properties of WPC under service conditions has become a significant issue, as this indicates the durability of WPC products. Environmental factors – such as UV radiation from sunlight, and also moisture, temperature, and biological decay – result in chemical and physical changes to the structure of the material components in WPC.