Fibers, Polyester

Abstract

AbstractPolyester fiber is the largest volume, most versatile synthetic fiber in the world. Useful textile fibers of poly(ethylene terephthalate) (PET) were invented in the 1940s and commercially introduced by Du Pont and ICI in the 1950s. A broad range of PET processing options allows the fiber to be engineered for a variety of uses by modifying the filament size, cross‐sectional shape, polymer molecular weight, tensile strength, composition, dyeability, luster, and color, as well as other fiber properties. PET is produced by ester interchange of dimethyl terephthalate and ethylene glycol to form monomer, or by direct esterification of terephthalic acid with ethylene glycol to form oligomer. The low molecular weight monomer or oligomer is polycondensed at high temperature and reduced pressure to form PET polymer.Polyester is melt‐spun over a wide range of spinning speeds depending on the desired use. The mechanical and thermal properties of PET fiber are affected by the degree of molecular orientation and crystallinity, which depend on the fiber formation process used. At low spinning speeds, fibers are usually further drawn to obtain useful tensile properties. At high spinning speeds, useful PET yarns can be obtained directly. Additional processing steps, including drawing, thermal treatment, texturing, and others, significantly influence the fiber physical properties and applications.