Engineering Composites and Plastics

In 1996, the plastics industry accounted for 274.5 billion in shipments (11). It is difficult to estimate the use of plastics for corrosion control, as in many cases, plastics and composites are used for a combination of reasons, including corrosion control, light-weight, economics, strength to weight ratio, and other unique properties. 

Certain polymers are used largely, if not exclusively, for corrosion control purposes. The significant markets for corrosion control by polymers are composites (primarily glass-reinforced thermosetting resins) PVC pipe, polyethylene pipe, and fluoropolymers. 

In the context of corrosion, composites refer to glass or other fiber or flake-reinforced thermosetting resins. Composite products use for their anticorrosion properties are fiberglass-reinforced pipe and storage tanks, fiber-reinforced plastic grating, handrails, I-beams, and other shapes equal to these that are made of steel. 

The Composites Institute, a division of the Society of Plastics Industry, Inc., estimates that composite shipments in 1998 were 1.63 billion kg and have increased 53% (K. Walshon, Society of Plastics Industry, Composites Institute, Personal communication, Oct. 1999) since 1991. Table 4.10 shows the distribution of composite shipments according to industry sectors and indicates that the largest shipment percentage is to the transportation and construction sectors. Corrosion-resistant applications account for only 11.8%. 

The cost of composites was estimated by one major manufacturer of fiber-reinforced plastics (FRP) for corrosion-resistant applications to be 9.70/kg ( 4.41 /lb). This works out to 1.864 billion spent on composites in the United States for industrial corrosion-resistant applications. 

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