Understanding the Different Types of Plastics

There are a number of different types of plastics in use today, and though many can seem similar, the differences between them can make a big difference in their suitability for different applications. From beverage bottles to utensils, it’s important to understand the different types of plastics to ensure you choose the right material for your products and operations.

Generally, plastics are man-made materials that can be molded into any shape, size and texture required for their intended purpose. Their unique chemical structure, which is comprised of long carbon chains, gives them the ability to bend and shape into a variety of forms. This flexibility, as well as their resistance to stains and heat, helps them to resist natural degradation processes and last for long periods of time compared to most other substances.

These properties are what allow the various plastics to be used in so many different types of applications, from water bottles and food containers to garden hoses and shatterproof windows. Among the most common and versatile plastics is polyethylene terephthalate, better known as PET, which can be found in everything from soda bottles and frozen meals to utensils and clothing fibers.

Another popular plastic is low-density polyethylene, or LDPE. While it is not as durable as HDPE, it can be molded into a wide variety of items. This includes the liners in some food cartons and ice cream containers, corrosion-resistant work surfaces and protective shells for computer hardware casings. It is also used to produce disposable diapers, sanitary products and garbage bags.

Polystyrene, or Styrofoam, is a common form of foam plastic that’s often used to insulate and protect products during shipping and storage. It’s also widely used to make cups, food containers and packaging tape. Unfortunately, Styrofoam is considered a dangerous plastic because it can leach harmful toxins such as styrene into foods and drinks.

The Society of the Plastics Industry has developed a Resin Identification Code system that divides plastics into 7 categories based on their physical properties. Group 1 encompasses those plastics that can be softened or bent by heating, while groups 2 to 6 are considered thermosetting, meaning they cannot be reshaped once they are moulded. The most interesting and high-performance plastics fall into the category of 7, which include nylon, aramids (best known as Kevlar and Nomex), polycarbonate and TPU.