Types of Hard Plastics

Plastics are a polarising material: on the one hand, they provide amazing benefits that help people every day and have boosted economies around the world; on the other hand, many types of plastic can be toxic to humans, animals and the environment. Hard plastics, referred to as rigid plastics, include polyethylene, polypropylene and a range of engineering materials such as acetal (polyoxymethylene), known by brand names such as Acetron(r) or Delrin(r).

The most common rigid plastics are made from high-density or low-density polyethylene. This type of plastic is strong, resistant to moisture and chemicals and can withstand high temperatures. It is often found in milk cartons, detergent bottles, cereal box liners, and buckets, as well as in toys, car parts, and park benches. It is less brittle than glass and can be easily moulded to the desired shape.

Polypropylene is the second most popular commodity plastic. It is a durable, clear and tough thermoplastic that can withstand a range of temperatures. It’s also a very ductile plastic, meaning it can stretch and flex under pressure rather than simply break or shatter like glass or metal. It is used in everything from Tupperware to car parts, thermal vests, and even disposable diapers. It’s also used for living hinges (thin pieces of plastic that allow a product to bend from 1 to 180 degrees) due to its ability to take repeated compressions without fatigue.

Rigid plastics are a great alternative to metals for products that require strength, resistance to corrosion, or both. They are also incredibly lightweight for their size and can be moulded to create a very smooth finish. Plastics can also be produced with built-in assembly features, cutting down production time and cost. Unlike metals, which can be scratched, rusted or damaged by heat, most plastics are highly abrasion resistant and non-conductive.

While the majority of plastics can be recycled, the process of recycling hard plastics can be complex because they are so brittle. The best way to avoid this is to reuse your plastics as much as possible before disposing of them, and if possible, rinse and clean your containers before recycling.

When you do have to dispose of your plastics, try to drop them off at a recycling or reclamation center instead of throwing them away in the trash. Most hard plastic waste is accepted at curbside recycling centers, but it’s a good idea to check with your local facility for specific guidelines.

Alternatively, many manufacturers choose to use hard plastics for a variety of industrial applications because they’re a durable, safe and cost-effective option. Piedmont stocks industry-leading hard plastics in a wide range of sizes, grades and finishes. To learn more about which materials would be the best for your next project, contact one of our expert materials specialists today.