polyester, synthetic fiber, produced by the polymerization of the product formed when an alcohol and organic acid react. The outstanding characteristic of polyesters is their ability to resist wrinkling and to spring back into shape when creased. In addition, polyesters have good dimensional stability, wash and dry easily and quickly, and have excellent wash-and-wear or minimum-care characteristics; one of their principal uses is in apparel fabrics of this kind. Microfiber, which was introduced in 1986, is a variety of polyester that has extremely thin filaments (half as thick as silk fibers). Polyesters are also used in casement curtains, throw rugs, and as a cushioning or insulating material.

Organic compound, any of a class of polymers formed by ester linkages between monomers. They are usually prepared from equivalent amounts of glycols and dibasic carboxylic acids, which undergo condensation polymerization to produce the polyester and water. Polyesters are strong, colourfast, and resistant to corrosion and chemical attack but tend to build up a static electric charge. In addition to the familiar fibres and films (e.g., Dacron, Mylar), polyesters are used to make reinforced plastics, automotive parts, boat hulls, foams, laminates, tapes, piping, bottles, disposable filters, encapsulations, and coatings.

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