S-glass

The standard general purpose grade of glass fibre, originally developed for electrical insulation applications, hence the E designation. It accounts for the great majority of glass reinforcement used in composites and its composition is defined in standards such as ASTM D578.

Fibre drawn from molten glass, the most widely used reinforcement for polymer composites. Different formulations, such as E-glass, E-CR glass, S-glass and AR glass, balance cost, strength, electrical performance and chemical resistance. It is the standard reinforcement in GRP laminates, including liquid applied GRP flat roofing systems.

A synthetic fibre spun from aromatic polyamide, best known in its para-aramid form. It combines high tensile strength and toughness with excellent impact and abrasion resistance, though it is sensitive to ultraviolet light, absorbs moisture and is notoriously difficult to cut and machine. It is widely used in ballistic protection, ropes and hybrid composite laminates.

A reinforcement in which nearly all fibres run in a single direction, held together by light stitching, a binder or occasional weft threads. It delivers the highest stiffness and strength along the fibre axis and is used where loads are strongly directional, for example wind blade spar caps and bonded strengthening plates.