Know About Para Aramid

What is Aramid and how are the fibres manufactured?

'Aramid' is a contraction of 'aromatic polyamide', created at the 1960’s in a lab in the US, a super synthetic fibre with the Thermal Properties of asbestos and the Robustness of glass fibre to meet th e need for upgrading critical applications such as Tyres, Parachutes and Ballistic Protection.

Its chemical name is para phenylene terephthalamide or PPD-T. The yearn of aramid fibres consists of yellow filaments of around ten microns in diameter, and then assembled onto bobbins.  

The process to the final thread includes two parts: polymerisation and spinning.

First, let Paraphenylenediamine react with terephthalyl chloride, in an organic solvent,  the PPD-T is obtained. Then, the polymer is dissolved in sulphuric acid, partially oriented into a crystal liquid form. Next, it is extruded in a die and spun; by an air jet the filaments are cooled. Next, the fibres goes through washing, drying and finally spooled into a final roll of yarn.

Why Aramid Fibres are so pupolar and well adaptable in vast fields?。

Excellent Tensile Modulus and Resistance

The tensile strength of aramid fibre is equivalent to 6 times that of steel , 3 times higher than that of glass fibre, 2 times of the nylon industrial wire, and a traction modulus that can be up to 2-3 times to steel and glass. The chemical properties make it a outstanding material with excellent tensile strength.

Thermal Resistance

Our fibres have long-lasting thermal stability, can undertake Continuously Usage at an average temperature up to around 220°C-250 °C, possesses the Shrinkage Rate of 0 at 150°C and Does Not Decompose or Melt at 560°C.The Elastic Modulus under tension keeps more than 80 % at 300°C.

Usually the oxygen content in the air is 21%, the limit oxygen index of Para-Aramid is about 30%, so it will not burn in the air, making it belongs to the flame-retardant fibres. It is self-extinguishing, does not help combustion and does not produce molten droplets. Encountered up to 425°C, the fibres swell and carbonise rapidly, forming a unique thermal insulation layer that blocks the heat from the outside as an effective protection. This inherent characteristic of the molecular structure makes aramid permanently flame retardant and it is known as a "Fire Resistant Fibre".

Chemical Resistance

Aramid fibres have excellent chemical resistance and are also resistant to mould and rust. Normally, only when the aramid is exposed to relatively high concentrations of acid or alkali solutions for a long time will the performance of the aramid have a noticeable impact.

Electrical Insulating Properties

Aramid fibre electrical conductivity is very low, and because the fibre moisture absorption is low, in high and low temperatures and humidity environment it can maintain excellent electrical insulation properties. The resistance of para-aramid reaches 5×1014Ω/cm, and due to this ability, it has a very good prospect of application in the field of electrical and electronic enhancement.

Lacking Resistance to UV 

Aramid fibres are highly sensitive to UV rays (loss of characteristics and discolouration), when applied, better not be exposed to bright light and sunlight for a long time, or the strong lighting environments will cause lighter colours and weakened mechanical properties of Aramid.

TO CONCLUDE:  Specialties of Aramid Fibres

• Excellent strength to weight ratio-strong and light
• High tensile resistance +High elastic modulus +Low density  
• Carbonisation at 425 °C +Excellent thermal stability from –70 °C to 200 °C
• Good fatigue resistance +Excellent vibration damping ability
• Excellent dielectric property
• Good chemical resistance to fuel and seawater

​​​​​​​Comparative To Other Synthetic Fibres