Aramid fiber is primarily composed of poly(p-phenylene terephthalamide) (PPTA) polymers. Its molecular structure is exceptionally robust, as it incorporates both aliphatic and aromatic main chains. Aramid fiber consists of a multi-filament structure formed by bundling together individual monofilaments, each approximately 12 µm in diameter. Aramid fabric is a sheet-like material created by arranging these aramid fibers in either a unidirectional or bidirectional pattern; unidirectional sheets are the most commonly used type. Its key mechanical performance parameters include:
| Specification | Unit Weight (g/m²) | Width (mm) | Tensile Strength (MPa) | Elastic Modulus (GPa) | Guaranteed Strength (kN/m) | Design Thickness (mm) |
| AFS-40 | 280 | 100,300,500 | 2060 | 118 | 400 | 0.193 |
| AFS-60 | 415 | 100,300,500 | 2060 | 118 | 600 | 0.286 |
| AFS-90 | 623 | 100,300,500 | 2060 | 118 | 900 | 0.43 |
| AFS-120 | 830 | 100,300,500 | 2060 | 118 | 1200 | 0.572 |
In addition to possessing the common characteristics shared by all FRP (Fiber-Reinforced Polymer) composite materials-such as being lightweight yet high-strength, exhibiting a high elastic modulus, and offering excellent corrosion resistance and durability-aramid fiber also boasts its own unique attributes. These include strong resistance to alkali corrosion, non-conductivity, and superior resistance to dynamic loads and impact forces. Consequently, it finds extensive application in projects involving seaports and docks; in construction environments requiring high levels of electrical insulation-such as subways, tunnels, and electrified railways; and in structural components subjected to high fatigue demands or frequent, intense impact loads. Furthermore, as an organic material, aramid fiber exhibits superior resin impregnation capabilities compared to other FRP materials (which are often inorganic). The curing time for aramid-based systems is typically only one-third to one-quarter that of other FRP materials, thereby enhancing economic efficiency and offering distinct advantages that other FRP materials cannot match.
