What is Structural Foam?

Structural foam products are used widely in a variety of industries. These products are created by combining nitrogen gas with a melting polymer and injecting it into a mold. This results in a lighter-weight core with a strong, solid outer layer. Due to the foaming process, these products can be anywhere from 20 to 40% lighter than solid polymers, aluminum, steel, and sheet metal while still maintaining their strength and impact resistance.

How are Structural Foam Molded Products Made?

To create foam molded products, nitrogen gas is mixed in with the polymer while it is melting. This mixture is then injected into a mold under low pressure. The gas is released and expands after injection and undergoes a chemical reaction, causing foam to form. When the foaming plastic touches the cold walls of the mold, it solidifies, producing a solid outer layer with an almost honeycombed interior.

Benefits of Structural Foam Molding

Easily Produce Large Products

Since this molding process uses lower pressure, the process allows for the production of larger parts or multiple parts in a single cycle. The lower pressure process also reduces the risk of these large molded products warping.


The low-pressure process also allows for the use of lower-cost materials. It is not uncommon to use 100% regrind HDPE in this process.

When creating larger or thicker parts, the cycle times for structural foam molding are also shorter than high-pressure processes trying to make the same parts, making it the cheaper manufacturing process for large or thick parts.

Highly Moldable

These products undergo less stress during the molding process and are highly resistant to deformation, allowing for more molding shapes and sizes. Without having to worry about damage during the process, you can design a more complex mold and maintain the proper look of the product.

Lightweight Parts that are Still Durable

Structural foam molded products are more lightweight than their injection molding counterparts while still being able to maintain their strength and impact resistance. These products are also element and temperature-resistant, so they can withstand a wide range of environments without experiencing any thermal expansion or damage.

Turn to Port Erie Plastics for Your Structural Foam Molding Needs

At Port Erie Plastics we are dedicated to providing our customers with the highest quality structural foam molded products. Our structural foam injection equipment allows us to produce parts up to 7.5 feet in length with a range of wall thickness from 0.200 inches to 0.500 inches. You can choose from polyethylene or polypropylene for our structural foam molded products.

With over 70 years of experience, we also have extensive experience in a wide range of other plastic capabilities including custom plastic injection molding, mold design, engineering, secondary operations, and so much more.

Our team is eager to help you in whatever way we can, so contact us today to see what we can do for you.

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