How Urethane Pour Foam Is Made

What is Urethane Pour Foam?

Urethane pour foam is essentially do-it-yourself polyurethane. Polyurethane is a complex long chain of molecules derived from petroleum containing carbamate groups. The result is a durable, heat resistant, and flexible plastic-like material. In the case of urethane pour foam, the polyurethane is made from two liquids which, when combined, form a foam which can be used to fill molds. When hardened, pour foam is lightweight and rock hard.

How is Urethane Pour Foam Made?

The component liquids are held in separate steel mixing tanks, ensuring they stay agitated and at a low temperature to keep them inert. These components are known as polyol, a complex form of alcohol, and diisocyanate, a basic petroleum polymer that's highly reactive with alcohol. The two chemicals are pumped out of their holding tanks in a 1:2 polyol to diisocyanate ratio. They meet at a single junction which leads into a heat exchanger, which is essentially a series of heated pipes. As they pass through the pipes their temperature rises to a level where a chemical reaction occurs. Liquid polyurethane is what leaves the pipes. It can be kept as it is to make polyurethane coatings or further processed to take on other forms depending on the needs of the manufacturer.

Why Does Urethane Pour Foam Come in Two Separate Containers?

Polyurethane is a very versatile material. Depending upon how they are processed after the basic polyurethane liquid is produced; they can take on four different forms: elastomers, coatings, flexible foams, and cross-linked foams. Elastomers are stretchy, but revert back to their original shape. Spandex is one of the best examples of an elastomer. Polyurethane coatings are common in many types of water resistant paints used on cars and aircraft. Flexible foams are used in packing materials and mattresses. Cross-linked foams are very hard, making up items such as door linings and dashboards for cars.