Synthetic fiber aramid
Synthetic Fiber Aramid Today I will take you to learn about a landmark product in the material industry. It is widely used in many fields such as aerospace, automobiles, electromechanical, construction, and sports in my country, and is one of the indispensable materials in future life.
Small fibers have great power, breaking down the bones and rebuilding the body.
Selecting silk and practicing needlework for embroidery can make it both soft and strong.
Yes, it is a new type of product with excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, light weight, insulation, anti-aging, long life cycle, stable chemical structure, no droplets when burning, and no poisonous gas. High-tech synthetic fiber – aramid.
1. Application value
Aramid fiber is an important national defense and military material. In order to meet the needs of modern warfare, body armor in developed countries such as the United States and the United Kingdom are all made of aramid. The lightweight of aramid body armor and helmets has effectively improved the military’s rapid response capability. and lethality. During the Gulf War, U.S. and French aircraft used aramid composite materials extensively.
In addition to military applications, it is now widely used as a high-tech fiber material in various aspects of the national economy such as aerospace, electromechanical, construction, automobiles, and sporting goods. In terms of aviation and aerospace, aramid fiber saves a lot of power fuel due to its light weight and high strength. According to foreign data, during the launch process of a spacecraft, every kilogram of weight reduced means a cost reduction of US$1 million. .
In addition, the rapid development of science and technology is opening up more new civilian spaces for aramid. According to reports, aramid products account for about 7 to 8% of body armor, helmets, etc., aerospace materials and sports materials account for about 40%; tire frame materials, conveyor belt materials, etc. account for about 20%, and High-strength ropes and other aspects account for about 13%. The tire industry has also begun to use aramid cords in large quantities to reduce weight and rolling resistance.
The reason why aramid fiber can generate such considerable economic value is mainly due to its irreplaceable mechanical strength and heat resistance. Aramid pulp is obtained after surface fibrillation treatment of aramid fibers. Its unique surface structure greatly improves the adhesion of the mixture, so it is very suitable as a reinforcing fiber for use in friction and sealing products. .
2. Characteristics of aramid
① Good mechanical properties Meta-aramid is a flexible polymer with higher breaking strength than ordinary polyester, cotton, nylon, etc., larger elongation, soft hand feel, and good spinnability. It can be produced into different sizes and lengths Short fibers and filaments are made into fabrics and non-woven fabrics with different yarn counts in general textile machinery. After finishing, they can meet the requirements of protective clothing in different fields.
② Excellent flame retardant and heat-resistant properties. The limiting oxygen index (LOI) of meta-aramid fiber is greater than 28, so it will not continue to burn when it leaves the flame. The flame retardant properties of Newstar® meta-aramid are determined by its own chemical structure, so it is a permanent flame retardant fiber that will not reduce or lose its flame retardant properties due to use time and number of washings. Newstar® meta-aramid fiber has good thermal stability, can be used continuously at 205℃, and can still maintain high strength at high temperatures above 205℃. Newstar® meta-aramid has a high decomposition temperature and will not melt or drip under high temperature conditions. It will only start to carbonize when the temperature is greater than 370°C.
③ Stable chemical properties: Meta-aramid has excellent resistance to most chemicals, can withstand most high-concentration inorganic acids, and has good alkali resistance at room temperature.
④ Radiation resistance: Meta-aramid has excellent radiation resistance. For example, under long-term irradiation with 1.2×10-2 w/in2 ultraviolet rays and 1.72×108rads gamma rays, its intensity remains unchanged.
⑤Durability: Meta-aramid has excellent friction and chemical resistance. After 100 times of washing, the tearing strength of fabrics processed with Newstar® meta-aramid can still reach more than 85% of the original strength.
The temperature resistance of para-aramid is higher than that of meta-aramid. Its continuous use temperature range is -196 ℃ ~ 204 ℃, and it does not decompose or melt at high temperatures of 560 ℃. The most significant characteristics of para-aramid are high strength and high modulus. Its strength is greater than 25 g/den, which is 5 to 6 times that of high-quality steel, 3 times that of glass fiber, and 2 times that of high-strength nylon industrial yarn; its modulus is 2 to 3 times that of high-quality steel or glass fiber, and 10 times that of high-strength nylon industrial yarn.
3. Development Prospects
In recent years, aramid fiber output has increased at an average annual rate of almost 10%. With the rapid development of high-tech and the expansion of market demand, the global output of aramid fiber (mainly meta-aramid and para-aramid) has exceeded 80,000 t/a. Aramid 1414 fiber is the most produced high-performance fiber to date. The largest and most versatile fiber. At present, the total production capacity of aramid fiber has reached 82,000 tons, of which the total production capacity of aramid 1414 fiber has reached 55,000 t/a, and the total production capacity of aramid 1313 fiber has reached 23,000 t/a.
The output of aramid fiber in my country is very small. At present, domestic demand mainly relies on imports and is subject to many restrictions. The price of Kevlar short fiber produced by DuPont in the United States in the Chinese market is 250-290 yuan/kg (2.2dtex 38-51mm).The price is 620~700 yuan/kg
(440dex). From a global perspective, with the advancement of technology and the expansion of manufacturers, especially with the increasing awareness of people’s safety, aramid fiber will definitely show greater development potential.
