Testing demonstrated that TINUVIN® XT 833 from CIBA Specialty Chemicals not only performs better than currently used UV absorbers, it also greatly increases the life expectancy of PVC membrane.
About 25 years ago, PVC roofing made its way from Switzerland and Germany to the United States, bringing with it a host of desirable features. When it first arrived, seams were solvent-welded and later, as contractors became trained, PVC was heat-welded with a hot-air gun. The new roofing material also saved considerably on time and labor, was lightweight, offered many color choices, resisted animal fats and greases, and provided good reflectivity. However, in the late ‘80s, thin and un-reinforced PVC roofing membranes began shattering in cold weather, due to plasticizer migration and polymer degradation. In addition, government restrictions were placed on the use of heavy-metal lead-based heat stabilizers, a standard of the industry at the time.
These events led to important changes in PVC additives and product design. Like a sandwich, polyester or fiberglass reinforcement was inserted between two layers of thicker PVC film for added dimensional stability, strength, and durability. New additives such as the latest biocides and heat stabilizers were introduced to ensure a variety of properties. Consequently, PVC roofing systems were greatly improved and became one of the single-ply roofing industry's stars.