The film material used in the film structure is composed of base cloth and coating. Coating materials are mainly polyvinyl chloride and tetrafluoroethylene. The commonly used film materials are polyester fiber coated polyvinyl chloride (PVC) and glass fiber coated polytetrafluoroethylene (Teflon). PVC material is the main characteristics of low strength, large elasticity, easy aging, large creep, poor self-cleaning, but cheap, easy to manufacture, rich color, good folding resistance. In order to improve its performance, the surface can be coated with a layer of polytetrafluoroethylene coating, improve its anti-aging and self-cleaning ability, its life can reach about 15 years. Teflon material has high strength, large elastic modulus, good self-cleaning, durable and refractory properties, but it is expensive, not easy to fold, high requirements for cutting and making accuracy, life generally in more than 30 years, suitable for permanent buildings.
