What is para-aramid fiber and what is the synthesis method of para-aramid fiber
The full name of aramid fiber is "aromatic polyamide fiber", which refers to a long-chain synthetic polyamide fiber in which more than 85% of the amide bonds are directly connected to the benzene ring, high temperature resistance, high strength, high modulus, insulation and other outstanding properties.
It is a new type of special polymer material. At present, there are two kinds of aramid fibers on the market that have achieved a wide range of commercial applications and production, namely meta-aramid and para-aramid.
1. What is para-aramid?
The full name of para-aramid fiber is "poly-paraphenylene terephthalamide" (PPTA) fiber, which is an organic polymer fiber synthesized from terephthaloyl chloride and p-phenylenediamine. The No. 1 and No. 4 positions, also known as aramid 1414, TAPARAN, KEVLAR , TWARON, It has excellent properties such as high strength, high modulus, high temperature resistance and flame retardancy, and is known as the world's three high-performance fibers together with carbon fiber and high-strength high-modulus polyethylene
2. What is the synthesis method of para-aramid fiber?
PPTA is obtained by polycondensing p-phenylenediamine and terephthaloyl chloride as monomers in N-methylpyrrolidone (NMP)-calcium chloride through low-temperature solution condensation.
The main outstanding advantages of para-aramid are high strength and high modulus. Its tensile strength is 6 times that of steel wire, and its tensile modulus is 2~3 times that of steel wire and glass fiber. Decomposition, no melting, acid and alkali resistance, density (1.44g/cm2) density is only one-fifth of steel wire, with good flame retardancy, limiting oxygen index above 29.
Belongs to A class flame retardant materials. It is mainly used in safety protection, bulletproof, rubber product reinforcement, high-strength cables and asbestos friction material replacement.
3.Para Aramid filament fabric weave with 100% para aramid filament and 100% para aramid spun yarn . Our products are very rich, with various weights and textures, we can provide various specifications of aramid fabrics, from 120 grams to 635 grams per square meter, different textures, different densities of fabrics, textures include plain weave, twill, jacquard and other special textures.
Also we can offer customized service according to buyer requirements. the color of para aramid woven fabric is colorful , we have colors in black, red, navy blue, red, orange.
4. Para Aramid fabric is sensitive to light, it have to keep in anti light bag for to prevent discoloration.
Para aramid fabric property
- Inherently Flame Retardant, High Temperature Resistance, High Strength, High Modulus, Tensile Strength
- Bulletproof, explosion-proof, electrical insulation, arc-proof
- High dimensional stability: extremely low creep, small size, light weight
- Corrosion resistance, acid and alkali resistance, organic solvents resistance
- Heat and fire resistance, excellent cut resistance
- Negative coefficient of thermal expansion
- Excellent thermal stability , Low heat conductivity , no melting no dripping
- Soft and comfortable hand feel ,wear flexible
- Low flammability the limiting oxygen index(LOI) is 29% start to carbonise and decompose above 500°C
- Excellent high temperature resistance, It is able to work for a long period of time under acid base from -200°C to 250°C
- 70% strength of threads remains after being in 290°C for 1000 hours
- Para aramid is sensitive to prolonged exposure to ultraviolet (UV) rays although it does not imply a deterioration of it
What are the applications of knitted para-aramid fabric?
1) Para aramid filament fabric is used in bulletproof vests to protect soldiers, prison guards, patrol officers, military and law enforcement personnel, and cash movers from being stabbed by bullets, fragments, and sharp objects.
2) Para aramid filament fabric are used in bulletproof armored vehicles, aircraft, ships, cash transport vehicles and private vehicles to protect the safety of life and property.
3) Para aramid fabric has excellent bulletproof performance, and there are mainly soft structures and hard structures in military protection. Aramid fabrics can be made into bulletproof vests, explosion-proof blankets, or compounded with resin to make hard helmets and armor explosion-proof inner liners.
4) use the para aramid knit fabric for Anti gloves and lining of firefighter suit and rescue suit.
The difference between meta-aramid and para-aramid:
The temperature resistance of para-aramid fiber is higher than that of meta-aramid fiber. The continuous use temperature range is -196℃～204℃, and it will not decompose or melt at a high temperature of 560℃. The most notable characteristics of para-aramid fiber are high strength, high modulus,high temperature resistance, acid and alkali resistance, and light weight.It has good insulation and anti-aging performance, and has a long life cycle. Aramid fiber cloth has excellent properties such as high strength, high modulus, high temperature and alkali resistance, light weight, insulation, anti-aging, long life cycle, stable chemical structure, no molten droplets when burned, and no toxic gas.
Polyisophthalamide fiber is referred to as meta-aramid fiber; polyterephthalamide fiber is referred to as para-aramid fiber.
