Application fields and application progress of para-aramid

According to statistics, more than 75% of casualties on the battlefield are caused by low-speed, medium-speed stray bullets or bomb fragments, and no more than 25% of casualties are caused by direct bullet hits. Therefore, people pay more and more attention to the use of high-performance bulletproof vests. Early hard bulletproof vests were made of special steel plates, super-hard aluminum alloys, etc. The bulletproof vests were heavy and not flexible. Later, they were gradually replaced by soft bulletproof vests. The so-called soft bulletproof vests refer to those made of high-performance organic fibers such as para-aramid. The requirements of bulletproof vests for fiber materials are high strength, high modulus and certain toughness. High strength and high modulus make the fiber have excellent impact resistance, and high toughness enables the fiber to effectively absorb the kinetic energy of the bullet during deformation. Although carbon fiber also has high strength and modulus, its toughness is poor and its weavability is also poor, so it cannot be used as a fabric for bulletproof vests. The bulletproof vests woven from para-aramid are light in weight, comfortable to wear, flexible, and easy to move. They have now been equipped by the armies of many countries in the world.

Para-aramid has been used in offshore engineering. Previously, offshore projects were mostly equipped with steel cables and wire ropes. However, in deeper waters, steel cables and wire ropes are prone to breakage due to their heavy weight, and another alternative material needs to be found. Para-aramid has low density, high specific strength and specific modulus, as well as good solvent resistance and low elongation. Therefore, the cable made of multiple strands of para-aramid has high strength, and even if it breaks, it will not rebound and hurt people.

Due to its excellent mechanical properties, para-aramid is a very ideal composite reinforcement. The engine casings of the "Trident" missiles equipped by the SS-24 and SS-25 missiles of the Soviet Union are all made of Kevlar fiber-reinforced epoxy resin composite materials. The casings of many aerospace engines also use Kevlar fiber-reinforced composite materials.

Para-aramid is also used in data cables of electronic products. It can provide effective structural support for cables, protect internal wires, and improve the overall tensile strength and bending resistance of cables.Due to the excellent chemical resistance and heat resistance of para-aramid, vacuum hoses reinforced by para-aramid will have very good application prospects in the field of oil and gas extraction in the future. In addition, para-aramid can be processed into filaments, staple fibers, chopped fibers and pulp, each of which has different application fields.

Application fields of different types of para-aramid
Para-aramid filaments: with excellent weavability, used in bulletproof vests and bulletproof fabrics.
Para-aramid staple fibers: made of para-aramid filaments, curled and cut, with lengths of 38mm, 5lmm, 76mm and other specifications. The products are used in high-temperature resistant non-woven fabrics, spinning, core-spun yarns and anti-cutting fields.
Para-aramid chopped fibers: made of para-aramid filaments, cut by special cutting equipment, with specifications of 1mm, 3mm, 6mm and so on. The products have excellent properties such as high temperature resistance, friction resistance, good dimensional stability and high strength and high modulus, and are used in engineering plastics, friction materials, composite reinforcement materials and aramid paper and other fields.
Para-aramid pulp: It is made from para-aramid filaments and is processed by surface fibrillation. The product has excellent properties such as high temperature resistance, friction resistance, high fibrillation degree, low static electricity, good dimensional stability, environmental protection, high strength and high modulus, and good dispersibility. It is mainly used in friction materials, sealing materials, composite materials, aramid paper and other fields.