Louisville, KY – What is High-Density Urethane Foam? | Sign Company News

High-density urethane foam, or HDU for short, is an excellent material for various sign applications. It is especially well-suited for dimensional lettering and logos.

Below we review the basics of HDU sign foam, how it’s made, some of the types of signs we make using HDU, and the advantages this substrate has over others.

What is High-Density Urethane Foam?

HDU foam board is a rigid foam plastic. It is denser than standard low or medium-density foams. It is derived from renewable resources like soybean oil and castor beans and is mixed with a blowing agent to make foam. The blowing agent in HDU foam is usually pentane, which creates closed cells within the foam board. Cells determine the density of the HDU. Closed cells will make a more durable substrate.

Is high-density foam the same as polyurethane?

No, high-density urethane foam (HDU) and polyurethane are not the same. Polyurethane is a type of plastic which is either rigid or flexible, while HDU foam board is always rigid. Polyurethane is also made with a blowing agent, which creates open cells, while HDU foam board has closed cells.

Also, HDU is made from renewable resources like soybean oil and castor beans, while polyurethane is made from petroleum.

How is High-Density Urethane Foam Made?

The manufacturing process for HDU foam board begins with mixing the two main ingredients: the renewable resource (soybean oil or castor beans) and the blowing agent (pentane).

The soybean oil or castor beans are combined with a small amount of isocyanate, which helps the two ingredients mix evenly. Then, the blowing agent is added. The mixture is then placed in a mold where it expands and hardens into the foam board.

What Types of Signs are Made with High-Density Urethane Foam?

• Dimensional Letters
• 3D Logos
• Monument Signs
• And more

Advantages of Choosing High-Density Urethane Foam

• Lightweight: HDU foam board is much lighter than wood or metal, making it easy to transport and install.
• Durable: HDU foam board is very strong and resistant to impact. It will not crack, chip, or dent easily.
• Resistant to Fading: HDU foam board does not fade easily in sunlight, making it perfect for outdoor signs.
• Easy to Work With: HDU foam board is easy to cut, shape, and drill. It can be worked with standard woodworking tools.
• Versatile: HDU foam board is used for a wide variety of indoor and outdoor sign applications.
• Weather-Resistant: HDU foam board is resistant to moisture, making it a good choice for signs exposed to the elements.
• Customizable: HDU foam board can be painted any color, making it easy to produce custom signs.

At FASTSIGNS® of Louisville, KY, we specialize in custom signs using high-density urethane foam, as well as many other sign products and services. Contact us today.