Cast urethane is used for a variety of everyday products. With the various advantages this polyurethane polymer has to offer, it has become a popular choice for many industrial and manufacturing applications covering a broad range of molded parts. The same properties that make this material suitable for some projects, however, also make it a detrimental choice for others.
Cast urethane is a quick mold process. With rapid set up, easy pouring, and simple mold making, urethane is the easy choice for projects that require a strong product in a minimum amount of time. The mold used for this process is made by pressing the prototype into vulcanized rubber to make an impression that will then be used to mold the cast urethane parts. Urethane products created in this way require very little industrial tooling or finishing, as the cast is an exact replica of the prototype.
This quick mold process does have some downsides, however. The finished cast product is only as good as the impression made by the prototype. In addition, the vulcanized rubber mold is only usable for a limited number of castings before the quality of the cast begins to degrade. Also, if there is no prototype, there is no way to make the mold to form the cast urethane.
The second property of cast urethane is its strength in comparison to its weight. Cast urethane can adhere to many metals, or be used to replace metal in a variety of applications to dampen noise and extend the usable life span of certain products. Bearings, pulley wheels, rollers, and wheels made of this material have been used to replace metal parts with very little difficulty. The urethane products offer long lasting strength and durability with minimal need for lubrication. With cast urethane's resistance to abrasion, chemicals, and impact, it can withstand the rigors of mechanical processes better than most plastics and many metals.
While the light weight and brute strength of urethane products offer definite advantages, there are also drawbacks to using cast urethane in some cases. Larger parts may require more in-depth mold making processes and longer curing times before the parts are ready to be used. In addition, urethane bearings and bushings should not be used in machinery that sees regular operating temperature in excess of 212 degrees Fahrenheit (100 degrees Celsius), as these excessive temperatures can cause degradation of the part.