Composite materials are made up of different materials which are combined to improve their properties. They can be a combination of natural and synthetic materials but fall into three main categories:
Fibre-based composites are reinforced with fibres. By mixing resin or concrete with fibres of glass or carbon we get the ability to mould complex shapes, but reinforcing them with the fibres makes them very strong.
|Glass-reinforced plastic (GRP)||Glass fibres and resin||Boats, instrument cases|
|Carbon-reinforced plastic (CRP)||Carbon fibre and resin||Formula 1 car bodies, crash helmets, sports equipment|
|Glass-reinforced concrete (GRC)||Glass fibre and concrete||Street furniture, urban features|
Particle-based composites are made with small particles of material. By mixing smaller particles of sand with larger particles of cement and aggregate, such as stones, we get a very strong and dense material suitable for building large structures.
|Concrete||Cement, sand and aggregate||Buildings, street furniture|
|Cermet||Ceramic (cer) and metal (met)||Electronic components that need to operate under very hot temperatures|
Sheet-based composites are often available in large sheets. By mixing wood fibres or thin slices of wood veneers with resin it is possible to form large and stable sheets for furniture panels and interior construction.
|Medium-density fibreboard (MDF)||Wood pulp and resin||Furniture and interior cladding|
|Plywood||Wood veneers and resin||Furniture and construction|
|Chipboard||Wood chip and resin||Furniture panels and construction|
Like all modern materials, composites are engineered to improve their properties. There are many more combinations of materials that are designed to meet a particular need or purpose. For example, wood has been reinforced with strips of carbon to make a wooden bicycle frame.
Often the original material has a useful feature, the ability to be formed or a certain appearance, but lacks strength or durability. In this case different material combinations can solve the problem and new composites are being developed all the time.