Science, Tech, Math › Science Polyethylene Terephthalate Share Flipboard Email Print Guido Mieth/Taxi/Getty Images Science Chemistry Basics Chemical Laws Molecules Periodic Table Projects & Experiments Scientific Method Biochemistry Physical Chemistry Medical Chemistry Chemistry In Everyday Life Famous Chemists Activities for Kids Abbreviations & Acronyms Biology Physics Geology Astronomy Weather & Climate By Todd Johnson Science Expert B.S., Business Management, University of Colorado Boulder Todd Johnson has worked on the development, commercialization, and sales sides of the composites industry since 2004. He also writes about the industry. our editorial process Todd Johnson Updated January 03, 2020 PET plastics or polyethylene terephthalate is used in many different products. The properties of PET make it ideal for a number of different uses and these advantages make it one of the most common plastics available today. Understanding more about the history of PET, as well as the chemical properties, will allow you to appreciate this plastic even more. In addition, most communities recycle this type of plastic, which allows it to be used again and again. PET Chemical Properties This plastic is a thermoplastic resin of the polyester family and is commonly used in many different products, including synthetic fibers. It can exist in both a transparent and a semi-crystalline polymer, depending upon the processing and thermal history. Polyethylene terephthalate is a polymer that is formed by combining two monomers: modified ethylene glycol and purified terephthalic acid. PET can be modified with additional polymers as well, making it acceptable and usable for other uses. History of PET The history of PET began in 1941. The first patent was filed by John Whinfield and James Dickson, along with their employer, the Calico Printer's Association of Manchester. They based their invention on the earlier work of Wallace Carothers. They, working with others, created the first polyester fiber called Terylene in 1941, which was followed by many other types and brands of polyester fibers. Another patent was filed in 1973 by Nathaniel Wyeth for PET bottles, which he used for medicines. Advantages of PET PET offers several different advantages. PET can be found in many different forms, from semi-rigid to rigid. This is largely dependent upon its thickness. It is a lightweight plastic that can be made into a number of different products. It is very strong and has impact-resistant properties as well. As far as color, it is largely colorless and transparent, although color can be added, depending upon the product that it is being used for. These advantages make PET one of the most common types of plastic that are found today. Uses of PET There are many different uses for PET. One of the most common is for drink bottles, including soft drinks and more. PET film or what is called Mylar is used for balloons, flexible food packaging, space blankets, and as a carrier for magnetic tape or backing for pressure-sensitive adhesive tape. In addition, it can be formed to make trays for frozen dinners and for other packaging trays and blisters. If glass particles or fibers are added to the PET, it becomes more durable and stiffer in nature. PET is largely used for synthetic fibers, also known as polyester. PET Recycling PET is commonly recycled in most areas of the country, even with curbside recycling, which is simple and easy for everyone. Recycled PET can be used in a number of different things, including polyester fibers for carpeting, parts for cars, fiberfill for coats and sleeping bags, shoes, luggage, t-shirts, and more. The way to tell if you are dealing with PET plastic is looking for the recycling symbol with the number "1" inside of it. If you are not sure that your community recycles it, simply contact your recycling center and ask. They will be happy to help. PET is a very common type of plastic and understanding its composition, as well as its advantages and uses, will allow you to appreciate it a little bit more. You most likely have lots of products in your home that contains PET, which means that you have the opportunity to recycle and allow your product to make even more products. Chances are you will touch different PET products over a dozen times today.