How is Polyester Plastic Made

Polyester was developed in the years 1939-1941 by British chemists at Calico Printers Association, Ltd., based on the work of W.H. Carothers in 1926 at the United States based E.I.D. Pont de Nemours and Co.  DuPont bought the rights in 1946 to produce polyester fiber in the United States.  By 1951, DuPont had begun to market the fiber under the name Dacron.

Polyester is made up of long-chain polymers. Today there are two primary types of polyester called polyethylene terephthalate (PET) and poly-1, 4-cyclohexylene-dimethylene (PCDT).  PET is the most popular type as it is applicable to a wider variety of uses and is stronger than PCDT.  However, PCDT is more elastic and resilient and is used in heavier consumer applications.

Synthetic polyester is made using a chemical reaction involving coal, petroleum, air and water.  Polyester is made up of purified terephthalic acid (PTS) or its dimethyl ester dimethyl terephthalate (DMT) and monotheluene glycol (MEG). It holds 10% of the market share for all plastic materials, coming third in terms of popularity after polyethylene (33.5%) and polypropylene (19.5%).

The most common type of chemical reaction used to make polyester takes place at high temperatures in a vacuum. A petroleum by-product, alcohol, and carboxyl acid are mixed to form a compound known as monomer or “ester.” This reaction is known as polymerization.  The polymer material created during polymerization is extruded while hot into long fibers that are stretched until they are about five times their original length. The resultant fiber forms an arrangement of molecules that is very strong.

Polyester fibers or threads are made using a spinning process.  There are two types of spinning processes.  One is the filament type, where long fibers are twisted together, and the spun types, in which short pieces of fiber are combined to form something called “staple.” These processes allow for material blends to be made using cotton or wool spun in with the polyester.

Synthetic fabrics like polyester are often criticized for having a less natural feel than fabrics such as cotton, silk, or wool. However, polyester does have some distinct advantages over natural fibers.  Polyester is wrinkle resistant, more durableand has high color retention.  Synthetic fibers also can exhibit superior water, wind and environmental resistance. For this reason, polyester is often used in tents, outdoor clothing such as windbreakers and parkas, and umbrellas. Polyester fabrics have come to replace some of the old school natural fabrics.  For example, “China silk “ is the term used by the textile industry for fabrics made of 100% polyester that closely resemble the sheen, drape, and durability Polyester Plasticof insect-derived silk.

Polyesters can be thermoplastics or thermosets. Most polyesters are thermoplastics, meaning they may change their shape with the application of heat. Polyester is combustible at high temperatures but tends to shrink away from flames and is self-extinguishing upon ignition. So just leave your windbreakers off of the ironing board!

Unsaturated polyesters (UPR) are thermoset resins. They are used for non-metallic body fillers, fiberglass laminating resins, and casting materials. Fiberglass-reinforced unsaturated polyesters are used in a wide range of applications including the bodies of yachts and automobiles.

Fabrics and threads made of polyester are used widely in apparel, home furnishings, and in commercial applications. Some examples include blankets and hats, bed sheets, and computer mouse pads.  Industrial polyester fibers are made into ropes, safety belts, tire reinforcements, and conveyor belts.  Polyester is also used to make bottles, films, and holograms. It is used as a wood finish on pianos, guitars, and yacht interiors.


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