Composites are composed of fiber reinforcements and a resin matrix that bonds the fibers. They can also include core materials, fillers, additives and surface finishes to provide unique performance attributes.
The primary functions of the resin are to transfer stress between the reinforcing fibers, act as a glue to hold the fibers together, and protect the fibers from mechanical and environmental damage. Resins used in reinforced polymer composites are either thermoplastic or thermoset.
The mechanical properties of FRP composites are dependent on the type, amount, and orientation of fiber that is selected for a particular service. Fiber reinforcements carry load along the length of the fiber to provide strength and stiffness in one direction.
Additives & Fillers
Additives are used in composites to modify materials’ properties and tailor the laminate’s performance. When added to the resin, fillers can improve properties including water resistance, weathering, surface smoothness, stiffness, dimensional stability and temperature resistance.
Core materials are used extensively throughout the composites industry to fabricate stiff and yet lightweight composites products. Core material is “sandwiched” between fiber reinforced laminate skins to significantly increase stiffness and flexural strength while reducing warpage of flat surfaces.
Surface finishes are mainly used for UV protection, corrosion resistance and aesthetics. They can be molded in process or secondarily applied coatings and support the long term appearance of composite products.