Common Bulletproof Materials for Bulletproof Products
Ultra high molecular weight polyethylene fiber (UHMWPE) is a fiber spun from polyethylene with a relative molecular weight of 1 to 5 million. It is currently the strongest and lightest fiber in the world, with a strength 15 times higher than steel wire, but very light, up to 40% lighter than materials such as aramid.
Common Bulletproof Materials for Bulletproof Products
With the development of society and the advancement of technology, bullets are constantly being updated and upgraded, and their power and damage efforts are constantly improving. This has prompted people to constantly increase their requirements for bulletproof equipment to meet better defense capabilities. Therefore, various new types of bulletproof materials are constantly being developed, which provides strong conditions for the advancement of bulletproof technology. So how many commonly used bulletproof materials do you know?
1. Kevlar
In the early 1970s, Kevlar, a synthetic fiber with ultra-high strength, ultra-high modulus, and high temperature resistance, was successfully developed and quickly applied in the field of bulletproof.
The emergence of this high-performance fiber greatly improves the performance of soft textile bulletproof vests, and also greatly improves the comfort of bulletproof vests. The new bulletproof vest uses Kevlar fiber fabric as the main material and bulletproof nylon cloth as the cover. Compared to nylon and fiberglass bulletproof vests, it reduces weight by 50%; When the mass per unit area is the same, its protective force can be increased by at least twice and it has good flexibility.
"Kevlar" is a trademark name, and its actual material is polyphenylenediamine, which belongs to a liquid crystalline rod-shaped molecule. This liquid crystalline rod-shaped molecular structure can form highly ordered phase domains in concentrated solutions. During directional stretching during spinning, the phase domains form almost perfect molecular orientations along the shear direction, endowing Kevlar fibers with extremely high strength and modulus.
2. Ultra high molecular weight polyethylene fiber (UHMWPE)
Ultra high molecular weight polyethylene fiber (UHMWPE) is a fiber spun from polyethylene with a relative molecular weight of 1 to 5 million. It is currently the strongest and lightest fiber in the world, with a strength 15 times higher than steel wire, but very light, up to 40% lighter than materials such as aramid.
In terms of national defense and military equipment, due to its good impact resistance and high energy absorption, this fiber can be used in military applications to make protective clothing, helmets, and bulletproof materials, such as armor plates for helicopters, tanks, and ships, radar protective casings, missile covers, bulletproof vests, stab proof vests, shields, parachutes, etc. Among them, the application of bulletproof vests is the most eye-catching.
It has the advantage of softness and has become the main fiber occupying the bulletproof vest market. In addition, the specific impact load value U/p of ultra-high molecular weight polyethylene fiber composite materials is 10 times that of steel, and more than twice that of glass fiber and aramid. Bulletproof and riot helmets made of resin composite materials reinforced with this fiber have become substitutes for steel helmets and aramid reinforced composite helmets.
3. Liquid bulletproof materials
The main component of liquid bulletproof materials (TBS) is a specially designed "shear thickening liquid (STF)", which is generally composed of a mixture of dispersed particles SiO2 and organic dispersion media such as vinyl ethanol, polyethylene glycol, propylene glycol, or mineral oil. In the shear thickening liquid, particles are freely suspended. When the liquid is stirred by violent impact, special particles collide with each other, forming resistance to this stirring.
When the stirring force is strong enough, these particles are actually locked in each other. When bullets hit this material at high speed, the "shear thickening liquid" bulletproof vest will attract impact energy and quickly become extremely hard, thereby absorbing the impact energy of the bullet.、
4. Carbon nanotubes
Carbon nanotubes are one of the materials with the best mechanical properties discovered so far, with extremely high tensile strength and elongation at break. Its density is only one sixth to one fourth of that of steel, and its tensile strength per unit mass is 276 times that of steel. Its elastic modulus parameter is 2.4 times stronger than Kevlar, and its comprehensive performance far exceeds any other material discovered and manufactured by humans. Its bulletproof effect is mainly reflected in its elastic modulus, which means that carbon nanotube fiber helmets or bulletproof vests have a minimum impact strength of 2.4 times higher than Kevlar.
5. Graphene
As the thinnest, strongest, and most conductive nano material discovered so far, graphene is known as "black gold" and is the "king of new materials". Scientists even predict that graphene will "completely change the 21st century" and is highly likely to trigger a disruptive new technology and industry revolution that will sweep across the world.
Scientists studying graphene bulletproof vests say that bulletproof vests made of graphene have twice the protective ability of existing bulletproof vest technology (Kevlar). Although graphene is still unable to be made into strong materials alone, it can be laminated into structural materials in multiple layers, which can prevent its outward fragmentation process after being hit by a bullet. Graphene bulletproof materials can be widely used in military products such as armed helicopter protective armor, bulletproof vests, light protective armor, explosion-proof equipment, etc. They have broad market prospects in both the civilian and military bulletproof material markets.
6. Compressed glass carbon
Compressed glassy carbon is a new type of carbon material with the bonding characteristics of graphite and diamond. It is a hybrid material composed of sp2 and sp3, with peculiar properties, density, and conductivity similar to graphite.
Its compressive strength is significantly higher than that of metal and ceramic materials, and its specific strength is more than twice that of carbon fiber, polycrystalline diamond, silicon carbide, and boron carbide ceramics. Its hardness is equivalent to that of a gemstone, and it can scratch single crystals of silicon carbide. The elastic recovery rate of its local deformation under compression is over 70%, significantly higher than that of metal and ceramic materials, and even higher than that of shape memory alloys and organic rubber.
Compressed glass carbon combines lightweight, ultra strength, high hardness, high elasticity, and good conductivity, with excellent comprehensive performance and many potential applications, such as military armor and aerospace fields.
7. Artificial spider silk
Spider silk has good elasticity and flexibility, strong impact resistance, and good low-temperature resistance. It can still maintain its elasticity under -40 ℃ conditions, making it a project material for making bulletproof vests. Moreover, spider silk is composed of proteins, making it biodegradable and not polluting the environment.
Unfortunately, after a long exploration, it is still not possible to produce a large amount of artificial spider silk, and the strength of artificial spider silk can only reach one-third of natural spider silk, which cannot meet the requirements of bulletproof fibers. However, due to the advantages that spider silk, a protein fiber, does not possess in synthetic fibers, this material is still in the research and development stage.
8. Octopus eel mucus
The defensive mucus of the eight eyed eel mainly consists of two components, linear protein and mucin. The length of linear protein is 15 centimeters. When mixed with seawater, it expands and produces a large amount of transparent mucus, which contains a large number of very thin but highly resilient and stretchable fibers. Now, a team of scientists and engineers from the United States Navy has found a method to synthesize octopus eel mucus, aiming to provide a valuable new material for the military that could repel sharks or provide ballistic protection.
Overall, the development of bulletproof materials is rapidly moving towards comfort, lightweight, all-round protection, and biomimetic direction. The continuous emergence of new materials provides more and more possibilities for the development of bulletproof materials. Different new materials always have the most suitable application forms and places.