Para-aramid twisted fiber is a high-performance synthetic fiber with remarkable properties and wide-ranging applications. The following presents a detailed account:

Definition

Para-aramid twisted fiber is made by twisting para-aramid fibers. Para-aramid fibers belong to the aromatic polyamide family, with their molecular structure characterized by amide linkages in the para (1,4) positions on aromatic rings. They are formed by the polymerization of aromatic diamines and aromatic diacid chlorides, and then spun into fibers through processes like gel spinning or dry-jet wet spinning.

Properties

- High Strength: It has extremely high tensile strength. On a weight-for-weight basis, it is several times stronger than steel, making it ideal for applications requiring high strength, such as in ballistic armor and reinforcement fabrics.

- Excellent Heat Resistance: It can withstand high temperatures with a high melting point and good thermal stability. It can work for a long time in the temperature range from -200°C to 250°C, and 70% of its strength remains after 1000 hours at 290°C.

- Good Chemical Resistance: It shows remarkable resistance to a wide range of chemicals, including weak acids, weak bases, and most organic solvents.

- Low Flammability: It is inherently flame-resistant with a limiting oxygen index (LOI) ranging from 29% to 40%. It starts to carbonize and decompose above 500°C and has no melt drip property.

- Lightweight: Despite its high strength, it is lightweight, which is advantageous for applications where weight reduction is crucial, such as in the aerospace industry.

- Good Electrical Insulation: It is electrically non-conductive, making it suitable for applications requiring electrical insulation.

Applications

- Protective Equipment: It is widely used in making bulletproof vests, bulletproof helmets, explosive search and discharge suits, and military and police training suits, as it can quickly absorb and disperse the impact energy of bullets.

- Automotive Industry: It is used in brake pads, tire reinforcement, and automotive hoses. Aramid-reinforced tires have advantages such as higher driving speed, better handling, and reduced fuel consumption.

- Textile Industry: It can be used to make protective clothing, gloves, firefighter uniforms, flame-retardant curtains, and fire blankets.

- Electronics and Communication: It is often used as a reinforcing material in optical fiber cables to protect optical fibers and cable cores from overload axial strain.

- Other Fields: It is also used in industrial conveyor belts, ropes, nets, and composites.