Weatherability Tests of Plastic Glazing Materials for Collectors

摘要

Glass has been the traditional glazing material for solar energy collectors; however, thin plastics are much cheaper and easier to install. Most clear plastics deteriorate in the weather and are particularly vulnerable to ultra-violet light (and to elevated temperatures). Therefore various kinds of plastics were tested by exposing them to direct sun-light and also to accelerated weathering at Desert Sunshine Exposure Test, Inc., near Phoenix. Comparable exposures gave consistent degradations. The plastics tested included acrylics, weatherable vinyl (PVC), polyethylene (PE), polypropylene (PP), Tedlar coated fiberglass and Tedlar coated vinyl. Heat seals degraded rapidly, especially at the edges. Acrylics lasted for the equivalent of 20 years. Weatherable PE performs adequately for a year or so, weatherable PVC about two years, Tedlar coated PVC about eight years. (ERA citation 04:046234)