Exposure to sunlight has a negative effect on the useful life of plastics. UV radiation will break down the chemical bonds of the polymer. The process results in cracking, chalking, colour fading and loss of mechanical properties such as tensile strength, elongation and tearing strength. UV stabilizers will slow down this degradation process. For products that require a longer lifetime UV stabilisers are added to both yarns and lamination during the production process.
UV stabilisers in plastics usually act by absorbing the UV radiation and converting the energy as low level heat. The chemicals used are similar to those used in sunscreen lotion, which protects the skin from sunburn. The solar radiation is measured in kilo Langley (Kly) per year and mapped worldwide per region.
All our products with UV stabilisers have an indicative Kly value, which will give you an idea about the expected lifetime under normal conditions. The retained strength after the given Kly period should be at least 50%. Please note that these values are only an indication since there are many circumstances that influence the result such as cloudiness, atmospheric humidity, snow reflection and altitude.
In our Know How PDF-document “UV Stability” you find an explicit clarification.