Aramid 1313 and Aramid 1414
Aramid is a new type of high-tech synthetic fiber with excellent properties such as ultra-high strength, high modulus, high temperature resistance, acid and alkali resistance, and light weight. 2 to 3 times that of steel wire, the toughness is 2 times that of steel wire, and the weight is only about 1/5 of steel wire. At a temperature of 560 degrees, it does not decompose or melt. It has good insulation and anti-aging performance, and has a long life cycle. The discovery of aramid fiber is considered to be a very important historical process in the material industry.
Fireproof fiber—aramid 1313
Aramid 1313 was first successfully developed by DuPont of the United States, and it was industrialized in 1967. The product is registered as Nomex® (Nomex). This is a soft, white, slender, fluffy, and lustrous fiber. Its appearance is no different from that of ordinary chemical fibers, but it has extraordinary "special functions" in one body:
long-lasting thermal stability
The most prominent feature of aramid 1313 is its high temperature resistance. It can be used for a long time at a high temperature of 220°C without aging. Its electrical and mechanical properties can be maintained for 10 years, and its dimensional stability is excellent. The thermal shrinkage rate is only 1% at around ℃, and it will not shrink, embrittle, soften or melt when exposed to high temperature of 300 ℃ for a short time. It only starts to decompose at a strong temperature above 370 ℃, and starts to carbonize at about 400 ℃. , such a high thermal stability is unique in the current organic heat-resistant fibers.
Outstanding Flame Retardancy
We know that the percentage of oxygen volume required for a material to burn in air is called the limiting oxygen index, and the greater the limiting oxygen index, the better its flame retardancy. Usually the oxygen content in the air is 21% and the limiting oxygen index of aramid fiber 1313 is greater than 28%. It is a flame retardant fiber, so it will not burn in the air, nor support combustion, and has self-extinguishing properties. This inherent characteristic derived from its own molecular structure makes aramid 1313 permanently flame retardant, so it has the reputation of "fireproof fiber".
excellent electrical insulation
The dielectric constant of aramid fiber 1313 is very low, and its inherent dielectric strength enables it to maintain excellent electrical insulation under high temperature, low temperature, and high humidity conditions. The breakdown voltage of insulating paper prepared with it can reach 100,000 volts/ ㎜, is the best insulating material recognized worldwide.
Excellent chemical stability
Aramid 1313 is a linear macromolecule composed of amide bonds connecting aryl groups. In its crystal, hydrogen bonds are arranged in two planes to form a three-dimensional structure. This strong hydrogen bond makes its chemical structure extremely stable and can be Resistant to most high-concentration inorganic acids and other chemicals, hydrolysis and steam corrosion.
excellent mechanical properties
Aramid 1313 is a flexible polymer material. Its low stiffness and high elongation make it have the same spinnability as ordinary fibers. It can be processed into various fabrics or non-woven fabrics by conventional spinning machines, and it is wear-resistant and tear-resistant. very broad.
Super radiation resistance
Aramid 1313 has excellent resistance to α, β, χ rays and ultraviolet radiation. With 50Kv x-ray radiation for 100 hours, the fiber strength remains 73% of the original, and at this time the polyester or nylon has already become powder. The unique and stable chemical structure endows aramid fiber 1313 with excellent performance. Through the comprehensive utilization of these characteristics, a series of new functions and new products have been continuously developed, and the application fields are becoming wider and wider, and the popularity is getting higher and higher.
Special protective clothing
Aramid 1313 fabric does not burn, drip or smoke when exposed to fire, and has excellent fireproof effect. Especially when encountering a sudden high temperature of 900-1500 ℃, the cloth surface will be carbonized and thickened rapidly, forming a unique thermal insulation barrier to protect the wearer from escaping. If a small amount of antistatic fiber or aramid fiber 1414 is added, it can effectively prevent the fabric from bursting and avoid hazards such as lightning arcs, electric arcs, static electricity, and flames. Aramid 1313 colored fiber can be used to make various special protective clothing such as flight suits, chemical defense combat uniforms, fire fighting uniforms and furnace front work clothes, electric welding work clothes, pressure equalizing clothes, radiation protection work clothes, chemical protective clothes, high-voltage shielding clothes, etc. Aviation, aerospace, military uniforms, fire protection, petrochemical, electrical, gas, metallurgy, racing and many other fields. In addition, in developed countries, aramid fabrics are also widely used as hotel textiles, rescue passages, home fireproof decorations, ironing board coverings, kitchen gloves, and flame-retardant pajamas for the protection of the elderly and children.
high temperature filter material
The high temperature resistance, dimensional stability and chemical resistance of aramid fiber 1313 make it occupy a leading position in the field of high temperature filter materials. Aramid filter materials are widely used in chemical plants, thermal power plants, carbon black plants, cement plants, lime plants, coking plants, smelting plants, asphalt plants, painting plants, and high-temperature flue and hot air in electric arc furnaces, oil boilers, and incinerators. Filtration can not only effectively remove dust, but also resist the chemical erosion of harmful fumes, and at the same time help the recovery of precious metals.
honeycomb structure material
Aramid 1313 structural material paper can be used to make bionic multi-layer honeycomb structure boards, which have outstanding strength/weight ratio and rigidity/weight ratio (about 9 times that of steel). Corrosion resistance, aging resistance and good electromagnetic wave permeability are suitable for making broadband wave-transmitting materials and large rigid sub-stressed structural parts (such as wings, fairings, cabin linings, doors, etc.) on aircraft, missiles and satellites. Floors, cargo compartments and partition walls, etc.), are also suitable for making sandwich structures for yachts, racing boats, high-speed trains and other high-performance requirements.
Bulletproof fiber - aramid 1414
Almost simultaneously with the invention of aramid 1313, DuPont developed another high-performance synthetic fiber - aramid 1414 in the late 1960s. Its product first came out in 1972 and was named Kevlar® (Kevlar).
Aramid 1414 has a golden yellow appearance and looks like a shiny metal thread, but it is actually a liquid crystal polymer composed of rigid long molecules. Because its molecular chains are highly oriented along the length direction and have extremely strong interchain binding force, it endows the fiber with unprecedented high strength, high modulus and high temperature resistance.
The discovery of aramid 1414 is considered an important milestone in the development of the material world. Aramid 1414 has extremely high strength, greater than 28 grams per denier, 5 to 6 times that of high-quality steel, 2 to 3 times the modulus of steel or glass fiber, 2 times the toughness of steel, and only the weight of steel 1/5. (The strength and toughness of aramid 1414 also make it extremely difficult to cut and process, requiring expensive special tools).
Aramid 1414 has an extremely wide continuous use temperature range, and can operate normally for a long time in the range of -196°C to 204°C. The shrinkage rate at 150°C is 0, and it does not decompose or melt at a high temperature of 560°C. Its heat resistance is better than that of aramid fiber 1313, and it has good insulation and corrosion resistance. It has a long life cycle, so it won the "" Synthetic steel wire" reputation.
Aramid 1414 was first used in cutting-edge fields such as national defense and military industry. In order to meet the needs of modern warfare and anti-terrorism, the military and police of the United States, Russia, Britain, Germany, France, Israel, Italy and many other countries have used bulletproof vests, bulletproof helmets, anti-stab and anti-cut clothing, EOD clothing, high-strength parachutes, bulletproof vehicles, etc. Aramid 1414 is widely used in the body and armor plates. In body armor, due to the high strength, toughness and weaving properties of aramid fiber, it can absorb and disperse the impact energy of the bullet to other fibers of the braid to avoid "blunt trauma", so the protective effect is remarkable. The lightweight of aramid body armor and helmets has effectively improved the rapid response and protection capabilities of the army.
Now, in addition to the military field, aramid 1414 has been widely used as a high-tech fiber material in various aspects of the national economy such as aerospace, electromechanical, construction, automobiles, marine aquatic products, and sporting goods.
In aerospace, aramid fiber resin-based reinforced composites are used as structural materials for aerospace, rockets and aircraft, which can reduce weight, increase payload, and save a lot of power fuel. For example, the shell, interior decoration parts and seats of Boeing aircraft have successfully used aramid 1414 materials, and the weight has been reduced by 30%.
Aramid 1414 is the most ideal cord fiber due to its small specific gravity, high strength, good heat resistance, and good adhesion to rubber. Aramid cord can reduce the thickness of the tire, reduce the weight, dissipate heat easily, reduce deformation, reduce rolling resistance, improve high-speed running performance, prolong the service life of the tire, and greatly improve the puncture resistance. Features that allow a flat tire to be driven to the garage without damaging the side of the tire. Aramid 1414 is especially suitable for high-speed driving or heavy-duty car and aircraft reinforced tire cords, and has great development prospects. At present, several major tire giants in the world, such as Michelin, Goodyear, Pirelli, etc., have adopted aramid 1414 as tire cord, which is widely used in the field of high-end cars.
In civil and structural engineering, because aramid 1414 has light weight, high strength, high elastic modulus, corrosion resistance, non-conductivity and impact resistance, it can be used for bridges, columns, subways, chimneys, water towers, tunnels and electrified railways, seaports, etc. It is especially suitable for the reinforcement and repair of concrete structures.
In addition, aramid 1414 can also be used as a skeleton material in inflatable rubber products (such as inflatable life rafts, inflatable pontoons, etc.), corrosion-resistant containers, light oil tanks and large-diameter crude oil suction pipes; Cut-resistant protective gloves; using its self-lubricating properties, heat resistance and toughness, it can replace carcinogenic asbestos to make heat-insulating protective screens, protective clothing and sealing materials; it can also replace asbestos and glass fibers to reinforce resins, used as Friction resistance, heat insulation and electrical insulation materials; making ship ropes, submarine cables, radar buoy systems and optical fiber reinforced ropes; making high-strength and low-weight sports equipment, such as skis, rowing boats and kayaks, etc. In short, any occasion that requires high strength, tensile resistance, tear resistance, puncture resistance and high temperature resistance is the field where aramid 1414 shows its talents and has irreplaceable advantages.
