Polyester is a widely used and versatile synthetic polymer. In the 1920’s, research labs at DuPont made groundbreaking discoveries regarding synthetic fibers, which led to the development of nylon. A decade later in Britain, scientists built on this research and came up with the first polyester fiber. DuPont bought the production rights shortly afterwards, and at the end of the 1940’s, polyester became available in the US. Polyesters have come a long way since those first fibers, and they are in high demand in a wide range of industries, including clothing, fabrics, furnishings and insulation.
Types and Properties
Polyester is polymerized from the monomer ethylene, the same gas emitted from ovripe bananas. Polyesters can be thermoset or thermoplastic, saturated or unsaturated. The two main types of polyester are PCDT (poly-1, 4-cyclohexylene-dimethylene terephthalate) and PET (polyethylene terephthalate). PET is strong and versatile, and is the most commonly used polyester. All polyesters share several characteristics: they are thermoplastic, durable and tough, chemically resistant and non-allergenic, they don’t shrink, stain or wrinkle and are hydrophobic. These qualities are enhanced by polyester’s ability to be dyed and cleaned easily and to retain its shape. Polyester fibers can be blended with other materials, such as cotton, to enhance properties such as breathability.
Production and Processing
Polyester is made from mono-ethylene glycol (MEG), derived from liquefied petroleum gas (LPG), which is combined with either dimethylterephthalate (DMT) or purified terephthalic acid (PTA). A catalyst may be added, the most common of which is antimony trioxide (ATO). Polymerization occurs in the melt phase before further processing methods are applied, depending on the desired output. These methods include staple, filament, fiberfill and tow. Staple and filament methods are the most commonly used. Here, polyester fibers are either produced in continuous, smooth lengths (filament) or shorter lengths to facilitate blending (staple).
As a textile, polyester is in high demand in the fashion, interior and design markets. You might remember the brightly colored polyester suits of the 1970’s, when the craze began. Since those days, polyester has come a long way, and new blends facilitate better breathability and moisture-wicking. Polyester is contained in jackets and coats, fleeces, sports clothing, shoes, threads for sewing, bedding, furnishings, curtains and drapes, suitcases and plenty of other textile applications. On an industrial level, high-strength polyester fibers reinforce seat belts, plastic, belts and conveyor belts, among other things.