An introduction to composite materials

A composite material, or composite, is made of two or more materials, often with very different physical or chemical properties, which work together to yield a material with unique characteristics not present in the individual constituents. The constituent materials remain separate and distinct within the finished structure rather than being blended or dissolved.

FRP Composites

Fibre-reinforced polymer (FRP) composites are comprised of two categories of materials: the matrix, and the reinforcement.

A polymer matrix resin, either thermoplastic or thermoset resin, such as polyester, isopolyester, vinyl ester, epoxy, phenolic, binds the fibre reinforcement such as glass, carbon, aramid or other reinforcing material such that there is a sufficient aspect ratio (length to thickness) to provide a reinforcing function in one or more directions.

FRP composites may also contain fillers, additives, and core materials to modify and enhance the final product. This combination of plastic and reinforcement can produce some of the strongest materials for their weight that technology has ever developed, and the most versatile. It is possible to produce an endless variety of composites to meet the exact requirements of very specific applications.

Benefits of using FRP composites

FRP composites offer many advantages compared to traditional materials, including:

  • High strength-to-weight ratio
  • Corrosion resistant
  • High impact strength
  • High electric strength (insulator)
  • Low thermal conductivity
  • Non-magnetic
  • Transparent to radio and radar frequencies
  • Low maintenance
  • Long-term durability
  • Parts consolidation
  • Dimensional stability
  • Design flexibility
  • Reproducibility and matching
  • Customised surface finish
  • Rapid installation

FRP composites can also be engineered for additional attributes, such as light transmission, high dielectric strength, and conductivity.

Uses of FRP composites

FRP composites are ultramodern materials with versatile applications ranging from space shuttles to common household objects. Their high strength-to-weight ratio makes them useful in aviation and aerospace, as well as automotive and rail transportation. They are also widely used in civil infrastructure and construction in products like swimming pools, bathroom fixtures, wall panels, and roofing, and they enable architects to create previously unattainable structures. Their corrosion resistant properties make them an ideal choice for industrial applications such as wastewater and sewage treatment processing, wind energy spinners and nacelles. They are also used for marine craft and jetties. The world’s first single-engine, light-sport aircraft, produced by Italian aviation company NASHERO, is composed almost entirely of carbon fibre polymer (CRFP) and combines high performance with excellent fuel savings. NASA and Boeing have successfully built and tested an all-composite CRFP cryogenic rocket fuel tank which could reduce the weight of the tank by 30 percent and cut launch costs by at least 25 percent. The Ocean Eagle 43, a naval vessel in service off the coast of Mozambique, is one of the largest CRFP structures ever built using a vacuum bag infusion process and uses one-fifth the fuel of conventional surveillance ships.

The use of FRP composites has transformed the marine, automotive, and aerospace markets. Many specific applications in infrastructure and chemical processing have seen similar dramatic conversions. There is huge potential for a similar technology shift in the architectural and building and construction segments as the building industry takes advantage of the design flexibility, durability, low weight, corrosion resistance, and other properties that composites offer.

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