What is PBO Spun yarn ?

PBO (Zylon), the Chinese name is polyparaphenylenebenzoxazole, please refer to the following molecular structure diagram. PBO is a unique conjugated rigid rod-shaped molecule in structure.




The molecular structure is highly symmetrical, which gives PBO fiber excellent mechanical and thermal properties. The tensile strength reaches 5.8GPa, the thermal decomposition temperature is 650°C, and the limiting oxygen index is greater than 68%. Due to its unique molecular structure and special manufacturing process, PBO fiber has the characteristics of ultra-high strength, ultra-high modulus, high temperature resistance and high thermal environment stability.

It has excellent overall performance and is known as the 21st century super fiber. The application fields of PBO spun yarn are mainly in the civilian field, such as: flame-retardant and high-temperature resistant protective clothing, protective clothing for fire protection and high-temperature furnaces, flame-retardant and high-temperature resistant gloves, machine protective covers, heat shields,heat resistant filter fabric , fireproof cloth, high temperature filter fabric.

Thermal properties

PBO fiber products have extremely excellent heat resistance. The thermal decomposition temperature is ≥650°C in nitrogen atmosphere and ≥600°C in air atmosphere. Its thermal properties are the highest among organic fibers. PBO fiber can be used in high temperature environments for a long time and maintain a high strength retention rate. The limiting oxygen index of PBO fiber is greater than 68%. It does not burn in the air and has no melting droplets. It can be used as a fire retardant material.

Chemical stability

Dielectric properties

PBO fiber property

• LOI＞68
• Light weight 
• High temperature resistance up to 650℃
• Excellent strength & modulus
• Good flame resistance
• Excellent thermal stability
• Excellent creep resistance
• Good chemical resistance

PBO fiber disadvantages

• Very poor UV resistance
• Poor compressive strength
• Strength loss in exposure to strong acids

What are the applications of PBO?

1. PBO Spun yarn is used to make high temperature yarn, PBO spun yarn is used to make fire protection clothing, fire protection clothing, high temperature furnace clothing. Fire and safety clothing made from the flame retardant properties of PBO spun yarn is very useful for rescue workers who jump into the scene of a fire without fear of being burned.
   
   
2. PBO spun yarn woven fabric used to make heat resistant filter cloth, fire cloth, high temperature filter cloth, It is mainly used in coal-fired power plants, waste incinerators or cement plants to filter hot gases. In this application, a polyimide filter cloth separates dust and particulate matter from exhaust gases.
   
   
3. Machine protective cover, heat shield For example, in terms of machinery, metals get very hot when they are welded. Since most robots are made of metal or resin, it is common for them to melt due to heat during welding if they are not covered with thermal shield, Therefore, by covering the robot with fabric made of PBO spun yarn as a protective cover, the robot becomes very durable.
   
   
4.  Fireproof gloves, flame retardant and high temperature gloves Fireproof gloves made of PBO spun yarn have very good flexibility and heat resistance.
   
   
5. High strength rope, lifting rope, cable.
   
   
6. Rope, sewing thread, woven fabric, weft free cloth.