Apart from glass fibres, that represents 95 % of polymer reinforcement fibres, numerous other fibres can be used.
Aramid and carbon fibres account for most of the last other 5 %.
All special fibres are employed for specific aims:
* Carbon fibres (CF): high mechanical performances and electrical conductivity.
* Aramid fibres: high mechanical performances and impact behaviour.
* Steel fibres and steel cords: tyres, conveyor belts, ESD compounds.
* Textile fibres as nylon, polyesters...: reinforcement of rubbers and soft plastics.
* Mineral fibres as boron, quartz, whiskers... and industrial fibres as PE, PTFE, PBO...: very specific applications.
* Natural fibres as jute, flax and so on are developed to replace glass fibres with sustainable materials.
Carbon fibres are used for polymer reinforcement under various forms:
* Short fibres dispersed in the matrix
* Yarn, roving, stratipreg or prepreg, mats, 2D and 3D reinforcing structures.
Versus short glass fibres, short CF lead to high reinforcement ratios for the modulus and tensile strength but the impact strength decreases.