Part FAQs

Structural foam molding is unique in the size, strength and versitility it provides. The range of opportunity it brings designers and engineers is just as great.

Along with the Q&As below, we’ve created a Structural Foam Molding Design Guide to help you get the most out of this valuable process.

What materials do you mold?

Our most popular material is recycled high density polyethylene. Other popular materials are polypropylene, ABS, Styrene.

How thick of a part can you make?

Suggested nominal wall section is .250 inches. Parts can be made with thicker wall sections but this increases cycle time and adds to the cost.

How thin of a part can you make?

.180 inches is about as thin as you can make while still maintaining a cellular core.

How big of a part can you make?

Our largest machine can hold a tool up to 107 X 161 in size.

How small of a part can you make?

Our smallest machine is 350 tons.

Can you get a flame retardant material for the molding?

Yes, structural foam materials can include flame retardant properties that meet various flammability specifications.

Can structural foam & gas-assist parts be painted?

Yes, if your product requires a more attractive and finished appearance the structural foam components can be painted.

Painted finishes can also be applied to structural foam parts when a very high level of finish is desired. However, the cosmetic finish produced with the latest structural foam molding technology means that painting is not needed for many parts even those that are visible on the exterior of a finished product.

What color is the material?

Recycled material is black. Virgin material can be just about any color you wish.

Can you insert mold steel bars or other reinforcements into structural foam parts?

Yes, however the difference in thermal expansion between the insert and the structural foam plastic material can cause issues with the heating and cooling cycle.

Can the parts be printed with logos or identifying information?

Most often they are pad printed, painted or hot stamped.

Can SF parts be glued together?

In similar fashion as typical thermoplastics, structural foam parts made out of the correct materials can be glued together.

Can structural foam parts be screwed together?

Yes, you can drive screws directly into the structural foam panel or insert threaded fasteners.

What is the surface finish of structural foam parts?


In its most basic form, single-nozzle structural foam molded parts will have a visible swirl on the outer surface. This swirling is also known as silvering or streaking. Swirling is usually not an issue for parts that do not require a high cosmetic finish, for example on reservoir or tank units that will be buried underground.

When a product’s specifications call for a more attractive outer surface, techniques such as gas-assisted molding reduces and even eliminates swirling. These advanced techniques are outlined below.

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