High-performance fibres are actively used in soft based armours by police officers and security personnel to achieve the desired protection. High-performance fibres used for such purposes include p-Aramid, Ultra-high molecular weight polyethylene or UHMWPE etc. Each of these materials have high tenacity (20-45 gpd), high modulus (700-2000 gpd) with a low density (0.97-1.45g/cm3).
1. Ultra High Molecular Weight Polyethylene (UHMWPE):
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene, (HMPE), it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very rugged material, with the highest impact strength of any thermoplastic in existence.
Fig: Chemical formula of UHMWPE (Image: fluorocarbon)
It is highly resistant to corrosive chemicals, has extremely low moisture absorption and a very low coefficient of friction; is self-lubricating and highly resistant to abrasion, in some forms being 15 times more resistant to abrasion than carbon steel.
UHMWPE fibres are commonly used in soft body armor and have contributed to vast improvements when it is compared with p-aramid fibres making them 40% stronger. For body armor, the fibres are aligned and bonded into sheets, which are then layered at various angles to give the resulting composite material strength in all directions.
Primary reasons to use UHMWPE fibre:
1. It offers excellent resistance to stress and cuts
2. Its high strength-to-weight ratio makes it hard to penetrate on impact.
3. It has strong chemical resistance and is highly resilient to most alkalis and acids etc and saves the vest from extreme deterioration.
4. They have low density making the vest lightweight and can also be used for floatable ballistic vests.
2. Para-aramid:
These materials are derived from a group called ‘aromatic polyamides’. These are synthetic fibres that have high resistance to abrasion, low density, high tensile strength and modulus. The polymers in aramid fibres contain phenol rings joined together through ‘amide groups. It is this unique structure that gives them unmatched strength.
Fig: Chemical Structure of Para-aramid fibre (Image: Polymerdatabase)
Primary reasons to use p-Aramid fibre:
1. The high strength-to-weight ratio makes them extremely capable of utilizing and increasing the performance of reinforced material in their composites. The aramids are tough, structurally rigid, and offer high cut resistance.
2. Their molecules are linked with an ultra-strong hydrogen bond that helps in transferring mechanical stress very efficiently.
3. Its high strength-to-weight ratio and exceptional heat resistance make aramids suitable for wide applications in ballistic vest manufacturing.
At MKU, we conduct constant and rigorous quality checks on the materials we use to make our vests. Continuous evaluation of ballistic solutions and their resulting performance through our exhaustive testing process, through accredited international laboratories, is maintained as mandatory. We strive to offer our customers the very best protective armour ensuring the usage of proven materials only for extraordinarily improved ballistic protection levels, while being significantly lightweight and hence enhancing the effectiveness and mobility of military troops, police officers and security personnel.