Coatings Stand Up to Harsh EnvironmentsCoatings Stand Up to Harsh Environments

Coatings are getting tougher and more effective to meet the demands of harsh environments. A wide variety of coatings helps guard various products and structures against corrosion, rust, and damage by salt water, chemicals, and extreme temperatures.

From electronics, cars, and airplanes to industrial machinery, highway bridges, and oil and gas platforms, a growing number of objects are being protected by increasingly sophisticated materials.

Some of the most demanding environments are outdoors or in industrial plant settings. Here, field-applied coatings are used as topcoats on metal structures with piping, tanks, and other components, such as oil tankers and platforms, chemical plants, waterways, and bridges. These structures require heavy-duty coatings to protect them against corrosion, such as coatings made with Bayer MaterialScience raw materials.

"As a raw materials supplier we make heavy-duty coatings for infrastructure, such as waterways, bridges, and oil and gas operations," Ahren Olson, Bayer's market manager for corrosion protection, told Design News. "We specialize in polyurethane to protect surfaces from UV and the environment around them." In oil and gas, for example, Bayer's coatings protect exposed structural steel and piping. In industrial applications people are looking for coatings with high levels of chemical resistance.

Typically, these coatings are applied using a system approach. First there's a coat of zinc-rich primer that protects the steel; the zinc portion sacrifices itself in the process through oxidation. Then an epoxy intermediate coat is applied, which holds down the zinc and provides corrosion protection. The top, outermost layer is usually a polyurethane. That's where Bayer comes in, on the topcoat.

Engineers who design these structures are looking to increase design life, so they want coating solutions that will cost less over the life of the structure, Olson told us. Before, these structures were expected to last 10 to 15 years, but now it's more like 50 to 100 years. This shift has been happening over the last decade or so, especially in the bridge and highway industries.

"These coatings are mostly organic-based materials, so they do get punished by UV, salt, and the environment," said Olson. "And there's always maintenance involved, since there's always some mechanical damage that can't be avoided by using coatings."

Reducing the cost of repainting these huge structures is also important, since that cost is astronomical. To help owners of these structures achieve these goals, Bayer has introduced a coating system that uses two layers of paint to achieve the equivalent levels of corrosion protection provided by the traditional three-layer system.

Olson said: