What Are PET Plastics

Learn about the common plastic used In water bottles: PET

Plastic bottles
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PET Plastics are some of the more commonly discussed plastics when searching for solutions for drinking water. Unlike other types of plastics, polyethylene terephthalate is considered safe and is represented on water bottles with the number "1", indicating it is a safe option. These plastics are a type of thermoplastic polymer resin, useful in various applications including in synthetic fiber production, in containers containing food and in thermoforming applications. It does not contain polyethylene - despite its name.

The History

John Rex Whinfield, along with James Tennant Dickson and others who worked for the company Calico Printers Association, initially patented PET plastics in 1941. Once created and found to be highly effective, production of products using PET plastics became more popular. The first PET bottle was patented years later in 1973. At that time, Nathaniel Wyeth created the first official PET bottle under this patent. Wyeth was the brother of a well-known American painter named Andrew Wyeth.

Physical Properties

A number of benefits come from the use of PET plastics. Perhaps one of the most important characteristics of it is its intrinsic viscosity. It absorbs water from the surroundings, which makes it hydroscopic as well. This allows the material to be processed using a common molding machine and then dried.

  • It has an excellent level of wear resistance compared to other plastics.
  • It has a high flexural modulus (making it flexible.)
  • It has a superior level of stability making it versatile and strong.
  • It has a low coefficient of friction making it useful in various applications in which other plastics are not.
  • The plastic's chemicals do not leak into the fluid or food stored within it - making it one of the most important products for food storage.

The plastic's chemicals do not leak into the fluid or food stored within it - making it one of the most important products for food storage. These physical properties make it an advantageous option for manufacturers who need safe plastics for use with food products or for continuous use.

Uses in Everyday Life

There are both industrial- and consumer-related uses for PET plastics. The following are some examples of the most common uses for polyethylene terephthalate:

  • It is commonly used in bottles and other plastic containers. This includes soda bottles, bakery products, water bottles, peanut butter jars and even in frozen foods packaging.
  • It is used to hold cosmetics. Since it is easy to mold, manufacturers can create very specific shapes for a variety of cosmetic products.
  • It is commonly used for the storage of chemicals, including household cleaners.

Why do manufacturers turn to PET plastics when they could choose other types of materials that may be more readily available? PET plastics are durable and strong. Most applications can be used repeatedly (recycling is a possibility with these products). In addition, it is transparent, making it quite versatile for various applications. It is resealable; because it is easy to mold into any shape, it is easy to seal. It is also unlikely to shatter. Moreover, perhaps most importantly in many applications, it is an inexpensive type of plastic to use.

Recycling PET Plastics Makes Sense

RPET plastics are a similar form to PET. These are created after the recycling of polyethylene terephthalate. The first PET bottle to be recycled occurred in 1977. As a main component in many of the plastic bottles used today, one of the most common discussions about PET plastics is recycling it. It is an estimate that the average household generates about 42 pounds of plastic bottles containing PET annually. When recycled, PET can be used in numerous ways for various applications, including use in fabrics such as t-shirts and undergarments.

It can be used as a fiber in polyester-based carpeting. It is also effective as a fiberfill for winter coats and for sleeping bags. In industrial applications, it can be very effective for strapping or in film and can be useful in the creation of automobile products including fuse boxes and bumpers.

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Johnson, Todd. "What Are PET Plastics." ThoughtCo, Apr. 5, 2023, thoughtco.com/what-are-pet-plastics-820361. Johnson, Todd. (2023, April 5). What Are PET Plastics. Retrieved from https://www.thoughtco.com/what-are-pet-plastics-820361 Johnson, Todd. "What Are PET Plastics." ThoughtCo. https://www.thoughtco.com/what-are-pet-plastics-820361 (accessed June 11, 2023).