FRP vs GRP
In modern engineering, materials play a vital role defining the design, structure, performance, and efficiency of the product. Sometimes, the naturally occurring engineering materials are not able to satisfy the specifications of a product. Therefore, new materials were developed to accommodate a wide variety of engineering requirements by combining two or more materials together. These are known as composite materials.
Concrete, plywood, Aerogel, and carbon fibre are reinforced polymers; all are composite materials. This article focuses on a specific class of composite materials, which are known as fibre reinforced polymers. These materials are light weight, strong, and robust.
What is Fibre Reinforced Plastic/Polymer (FRP)?
Fibre reinforced polymers are made of two primary constituents; fibres and a polymer matrix. In FRP, the fibre is embedded in a polymer matrix. This structure gives completely different chemical and physical properties than the properties of the individual materials. In fact, these materials satisfy higher engineering requirements than the ordinary materials. Hence composites are applied in less sophisticated to very sophisticate and demanding manufacturing tasks. Mechanical, civil, biomedical, marine, and the aerospace industries are main users of composite materials.
The primary role of fibres is to provide strength and stiffness to the material. But the fibre alone is brittle (ex: glass). Therefore, the fibres are encased in a coating of polymer materials. Polymer matrix holds the fibres in their position and transfers the loads between the fibres. It also contributes to the inter-laminar shear strength.
The fibres used in composite are as follows; E-glass, S-glass, Quartz, Aramid (Kevlar 49), Spectra 1000, Carbon (AS4), Carbon (IM-7), Graphite (P-100), and Boron. Polyesters, Vinyl Esters, Epoxies, Bismaleimides, Polyimides, and Phenolics are the polymers used. Each polymer has different chemical and physical properties; therefore, contribute differently to the composite structure. As a result, the composite properties are also different based on the polymer.
Polyester and vinyl are low cost materials, hence used extensively in commercial applications. Epoxies are used for high performance continuous fibre matrices. It also performs better than vinyl and polyester in high temperature conditions. Bismaleimides and Polyimides are high temperature resin matrices for use in temperature critical engineering applications. Phenolics are high temperature resin systems with a good smoke and fire resistance; therefore, used in aircraft interiors.
What is Glass Reinforced Plastic (GRP) / Glass Fibre Reinforced Plastic (GFRP)?
Glass Reinforced Plastic, commonly known as fiberglass, is a fibre reinforced polymer with glass fibres in the composite structure. The polymer is usually the epoxy, polyester, or the vinyl. Fibreglass materials are commonly used in high performance leisure aircrafts and gliders, boats, automobiles, bathtubs, hot tubs, water tanks, roofing products, pipes, cladding, cast, Surfboards, and external door skins.
What is the difference between FRP and GRP?
• FRP is a composite material, where high strength fibres are included in a polymer matrix. They are used in many commercial and engineering applications due to their high strength and light weight. FRP is widely used as a substitute for metal and wood. Best example is the use of carbon fibre reinforced polymer (CFRP) instead of aluminum and titanium or high grade steel in aircrafts.
• Fibreglass or GRP is a composite material made out of glass fibres and uses polyester, vinyl, or epoxy as the polymer. It is used to make gliders, boats, and bathtubs. Fibreglass is used mainly for commercial applications. Fibre glass is one type of FRP.