Introduction to aramid 1414

Aramid fibers are mainly divided into two types, "Para aramid fiber" (PPTA) and "meta aramid fiber" (PMIA).

DuPont's para aramid brand name is Kevlar and meta aramid brand name is Nomex. The Japanese counterpart aramid is called Twaron, technora. The meta aramid is called conex. Korea has Kolon and Hyosung. China has commercial aramid products from Yantai and Sichuan, para aramid taparan and meta aramid tametar.

Kevlar is also translated into Kevlar or Kevlar. It is the brand name of a kind of aramid fiber material developed by DuPont company in the United States. The original name of the material is "poly (p-phenylenediamine)". The repeating unit of the chemical formula is - [- co-c6h4-conh-c6h4-nh -] - the amide group on the benzene ring is the para structure (the meta structure is another product with the trade name Nomex, commonly known as fireproof fiber)

In the 1960s, DuPont company developed aramid 1414, which is a new type of aramid fiber composite material. The aramid composite material was officially commercialized in 1972 and its trademark was Kevlar. The models are divided into k29, K49, k49ap, etc.

Because of its low density, high strength, good toughness, high temperature resistance, easy processing and molding, its strength is 5 times that of steel of the same quality, but its density is only one fifth of that of steel (Kevlar density is 1.44g per cubic centimeter, and steel density is 7.859g per cubic centimeter). As Kevlar brand products are tough and wear-resistant, rigid and flexible, they have the special ability of being invulnerable. It is called "armored guard" militarily.

The emergence of anti tank weapons has prompted people to improve the armored performance of tanks and armored vehicles. Generally, to improve the protective performance of tanks and armored vehicles, it is necessary to increase the thickness of metal armor, which will inevitably affect its flexibility and mobility. The appearance of "Kevlar" material makes this problem solved easily, and the protective performance of tanks and armored vehicles has been improved to a new stage. Compared with glass fiber reinforced plastics, the weight can be reduced by half when using "Kevlar" material under the same protection conditions. Moreover, the toughness of "Kevlar" laminated sheet is three times of that of steel and can withstand repeated impact. "Kevlar" plate combined with steel armor is more powerful. If "steel jujube aramid jujube steel" composite armor is used, it can resist anti tank missile with armor piercing thickness of 700mm, as well as medium bullet.

The composite armor of "Kevlar" laminated sheet steel and aluminum plate has been widely used not only in tanks and armored vehicles, but also in nuclear powered aircraft carriers and missile destroyers, which greatly improves the protective and maneuverability of the above weapons. The composite material of Kevlar and boron carbide is an ideal material for helicopter cockpit and cockpit. According to the test, it can resist armour piercing bullets much better than glass fiber reinforced plastics and steel armor. In order to improve the survivability of battlefield personnel, people pay more and more attention to the development of bullet proof vests. "Kevlar" material is also an ideal material for making bullet proof vests. It is reported that using "Kevlar" material instead of nylon and glass fiber can at least double its protective capacity under the same conditions, and has good flexibility and comfortable wearing. The bulletproof vest made of this material only weighs 2-3 kg and is easy to wear and move. Therefore, it has been used by police and soldiers in many countries.

In the 1980s, when China imported DuPont products, the U.S. government did not allow DuPont to import Kevlar brand products into China. Later, it gradually relaxed the import restrictions.

Nowadays, Kevlar is also used to form a protective film for optical fiber transmission. Kevlar layer has good flexibility to protect optical fiber from damage. The outer surface, or outer layer, is called the Kevlar layer.

7.1mm dual core motorcycle Razr mobile phone (Motorola introduced the material of Kevlar brand products into andorid mobile phones, becoming the leader among the ultra-thin materials, only 0.3mm thick)