Polyurethane coated rollers are made by a process of bonding polyurethane to a metal core. This process begins with the cleaning of the metal core. Any dirt or contaminants on the surface of the metal will cause the polyurethane to not bond properly. Once the metal core is clean, a primer is applied to help the polyurethane adhere to the surface. The next step is to apply the polyurethane coating itself. This is done using a machine that lays down a thin layer of polyurethane onto the surface of the metal core. The thickness of the polyurethane coating can be controlled by adjusting the settings on the machine.