Choosing Polystyrene for Thermoforming

Polystyrene is one of the most commonly used thermoplastics, best known for creating a lightweight foam used in packaging and insulation. However, polystyrene is much more versatile than most people realize. Our thermoforming company in North Carolina wanted to share a more in-depth look at polystyrene, including how it's formed, pros and cons of using it, and whether it's right for your next project.

What Is Polystyrene?

Styrene is a clear, liquid compound that occurs naturally in cinnamon, coffee beans, and peanuts, and it can also be isolated from the resin of sweetgum trees. Because the need for styrene is so high, the overwhelming majority of it is produced by removing the hydrogen from ethyl benzyne, thus creating styrene as a byproduct.

The monomer is then heated which causes the molecules to link, creating a chain, or polymer, called polystyrene. This is a clear, hard, brittle material in its original polymerized form without any additives. However, most polystyrene is made into a foam material called expanded polystyrene (EPS). Dow Chemical trademarked their EPS and is the widely known "Styrofoam."

Pros and Cons of Polystyrene

Like all thermoplastics, polystyrene has positive and negative qualities that can determine whether it's the right material for your next project.

Pros of Polystyrene

• Easy and inexpensive to produce
• Incredibly stable plastic that responds well to heat, making it a good option for thermoforming and injection molding;
• Lightweight
• Impact-resistant in both solid and foam states
• High insulating capability
• Food-safe, used in a variety of food packaging and storage materials

Downsides of Polystyrene

• Very difficult to recycle. The material is sorted, cleaned, shredded, and heated to a paste which is then dried into pellets or bricks, then reused.
• Can be incinerated but produces excess carbon dioxide which is harmful to the environment;
• In its foam state, polystyrene is too bulky to be cost-effective to ship for recycling or degrading, so much of it ends up in landfills.
• Polystyrene used in food packaging or disposable cutlery will have food particles that contaminate the material so it can't be recycled.

Uses for Polystyrene

Polystyrene is used in a wide variety of both single-use and long-term applications. This includes, but is not limited to:

• Foam insulation in houses
• Foam interior for car seats
• Disposable cups, plates, and cutlery
• Jewel cases used for CDs
• Food storage containers
• Housing and cases for electronics
• Packaging peanuts
• Foam trays used for meat packaging
• Egg cartons
• Medical devices, including test tubes and petri dishes
• Refrigerator and freezer insulation
• Instrument panels in cars and vehicles

Is Polystyrene Right for Your Next Manufacturing Project?

When you need a lightweight, impact-resistant polymer that can hold up to long-term use, polystyrene is an excellent option. While it is often used for single-use plastics, manufacturing does seem to be moving away from it due to its lack of sustainable recycling options, choosing to use polystyrene instead for plastics needed to be stable, durable, and cost-effective.

Contact Us for Thermoforming and Injection Molding in North Carolina

If you need custom plastics, we are proud to be a leading thermoforming and injection molding company in North Carolina. We work with a wide variety of companies across multiple industries, providing high-quality, durable plastics at a low per-unit price and fast lead time.