Because of their many desireable qualities, polyester fibers and fabrics have many uses.
Polyester is often used in outerwear because of its high tenacity and durability. It is a strong fiber and consequently can withstand strong and repetitive movements. Its hydrophobic property makes it ideal for garments and jackets that are to be used in wet or damp environments--coating the fabric with a water-resistant finish intensifies this effect.
Many jackets and quilted garments are made of polyester. Since polyester can be molded into almost any shape, certain insulating properties can be built-in to the fiber. One method is to create hollow fibers:
This process traps air inside the fiber which is then heated by the body. The warm air stays inside and helps warm the body in cool weather. A second method is to use crimped polyester in a fiberfill. The crimp helps keep in warm air. Polyester is an ideal fiber to use for this since it will retain its shape, unlike its cotton and wool counterparts that tend to flatten out over time, significantly reducing their ability to trap warm air.
Polyester is often used in pants, shirts, suits, and bed sheets either by itself or as a blend, because of its wrinkle-resistant property and its ability to retain its shape. Since these garments are frequently worn and washed, its stain-resistancy and durability are also desireable.
Polyester also has industrial uses as well, such as carpets, filters, synthetic artery replacements, ropes, and films. The pie chart below, taken from Fiber Science by Kathryn L. Hatch, summarizes many of polyester's uses: