Static affects many fabrics. According to the AATCC (American Association of Textile Chemists and Colorists), static in polyester is caused by an electron unbalance on the surface of the fabric. When it is synthetic, they rub against each other causing electrons to transfer and unbalance the charges. This is why polyester garments tend to have static when they come out of the drier. Since polyester is a thermoplastic, it is a good insulator of electricity, and this makes the static load it receives stay on its surface. In order to avoid and control static levels on the fabrics, during their manufacturing different anti-static products are used to help keep their levels low, not only during manufacturing but also during its utility life. Polyester fabrics are strong, durable, and are used to make a great variety of products.