fibreglass otherwise glass-reinforced plastics; fibre-reinforced polymer (rus. стеклопластики) — composites, composed of glass fibre (see glass fibre) and a polymer matrix.


Fibreglass is the most easy-to-access and the cheapest form of high-strength fibre, and fibreglass plastic is one of the most inexpensive and widely used types of composite material and a leader in today’s consumption in the world. Glass fibres are added to the polymer matrix in various forms: monofilaments, yarns, cords, fabrics, tapes and mats. The production which is pre-impregnated with polymer binder is called a prepreg. Thermosetting binders can be polyester, epoxy, phenol-formaldehyde, organic silicone resins, and polyimides, and thermoplastic binders can be aliphatic polyamides, polycarbonates, polystyrene, polysulfones, polyformaldehyde, polyethylene, polypropylene, and polyacetals.

The density of fibreglass plastic is 1.8-2.2 g/cm3, reinforcement-directed strength can reach 2000 MPa, i.e., the strength of high-quality steel. Fibreglass plastics outperform steel and aluminium alloys in specific strength (strength-to-density ratio). The disadvantage of fibreglass plastic is a low elastic modulus, so if the designs require high stiffness, the plastic is reinforced with both glass and carbon fibre. The best adhesion of the binder with glass fibre is achieved through using nascent fibre. The application of the glass fibre sizer is required for textile processing of fibres into yarns, cords or fabric, it impairs their wetting by the binder and results in significant loss of strength.

Fibreglass plastic is used for making pipes to withstand high water pressure and corrosion, solid-fuel rocket case, small vessel and boat bodies, automotive structural elements, various construction and other products.


  • Lourie Sergey
  • Mileiko Sergey T.
  • Nazarov Victor G.


  1. Concise Encyclopedia of Composite Materials / Ed. by A. Kelly. — Elsevier Science, 1994. — 378 p.
  2. Composite Materials: Handbook (in Russian) / ed by. V. V. Vasil'ev, et al. — Moscow.: Mashinostroenie, 1990. — 512 P.

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