Polyester fiber, commonly known as "Dacron," is a synthetic fiber obtained by spinning a polyester made from organic dicarboxylic acids and diols. Abbreviated as PET fiber, it is a type of high molecular compound. Invented in 1941, it is one of the major varieties of synthetic fibers. The advantages of polyester fiber include excellent wrinkle resistance and shape retention, with high strength and elasticity recovery. It is durable, wrinkle-free, and non-static.

Polyester fibers are known for their high strength and modulus, as well as low water absorbency, making them widely used in both civilian and industrial fabrics. As textile materials, polyester short fibers can be spun alone and are particularly suitable for blending with other fibers; they can be mixed with natural fibers like cotton, linen, and wool, as well as with other chemical short fibers such as viscose, acetate, and polyacrylonitrile fibers. Fabrics made from pure or blended polyester generally retain the excellent properties of polyester fibers, such as wrinkle resistance, crease retention, dimensional stability, abrasion resistance, and washability. Some inherent drawbacks of polyester fibers, such as static phenomena during processing, difficulty in dyeing, poor sweat absorption and breathability, and tendency to melt into holes when exposed to sparks, can be mitigated and improved to some extent by blending with hydrophilic fibers.