Fiberglass is a lightweight, extremely strong, and robust material. Although strength properties are somewhat lower than carbon fiber and it is less stiff, the material is typically far less brittle, and the raw materials are much less expensive. Its' bulk strength and weight properties are also very favourable when compared to metals, and it can be easily formed using moulding processes.
The plastic matrix may be epoxy, a thermosetting plastic (most often polyester or vinylester) or thermoplastic. Common uses of fiberglass include high performance aircraft (gliders),Boats, automobiles, baths, hot tubs, water tanks, roofing, pipes, cladding, casts, surfboards and external door skins.
Polyester resins are the most widely used resin systems, particularly in the marine industry. By far the majority of dinghies, yachts and workboats built in composites make use of this resin system. Polyester resins such as these' are of the 'unsaturated' type. Unsaturated polyester resin is a thermoset, capable of being cured from a liquid or solid state when subject to the right conditions. It is usual to refer to unsaturated polyester resins as 'polyester resins', or simply as 'polyesters'. There is a whole range of polyesters made from different acids, glycols and monomers, all having varying properties. There are two principle types of polyester resin used as standard laminating systems in the composites industry. Orthophthalic polyester resin is the standard. Economic resin used by many people. Isophthalic polyester resin is now becoming the preferred material in industries such as marine where its' superior water resistance is desirable. It is usual to refer to unsaturated polyester resins as 'polyester resins', or simply as 'polyesters'.