Tow

A reinforcement fibre produced by carbonising a precursor, most commonly polyacrylonitrile (PAN) or pitch, to give continuous filaments composed largely of carbon. It offers very high stiffness and strength for its weight and is the principal reinforcement in high performance composites. Grades are commonly described by modulus class, such as standard, intermediate and high modulus.

A bundle of parallel, untwisted glass fibre strands wound onto a cylindrical package. Direct rovings feed processes such as filament winding, pultrusion and weaving, while assembled (multi end) rovings are designed for chopping in spray up; rovings are specified by tex and by sizing type.

Reinforcement in which virtually all fibres run in a single direction, supplied as dry tape, lightly stitched or bound fabric, or prepreg. Unidirectional plies give the highest stiffness and strength along the fibre direction but need supporting plies in other orientations.

A process in which continuous fibre tows, wetted with resin or pre-impregnated, are wound under tension onto a rotating mandrel in controlled patterns and then cured. It is the standard method for pressure vessels, pipes, tanks and other axisymmetric structures.

A fabric woven from tows that have been spread into thin, flat tapes before weaving, giving an ultra light reinforcement with very low crimp. The format reduces ply thickness and resin rich zones and is used where minimum weight matters, such as high performance marine, motorsport and aerospace structures.

A robotic process that lays narrow tows of prepreg or dry fibre onto a tool surface under controlled heat, pressure and tension, steering each tow individually. It enables complex curvature and tailored fibre paths on large structures with high deposition accuracy and low material waste.