The early stage of armor
Ancient armor
Material: the earliest armor is made of animal skin, metal (such as iron, copper), horn, bone, leather and other materials. For example, the Mycenaeans in the sixteenth century B.C. and the Persians and Greeks in the fifth century B.C. used as many as fourteen layers of linen as “armor”, while in ancient China as early as around the eleventh century B.C., five to seven layers of cowhide armor.
Types: With the development of technology, there were various types of armor such as chain mail, scale armor, and Brigandine armor. Lockjaw armor consisted of chain links or wires made of iron, steel, or brass; scale armor was made of overlapping metal, horns, bone, leather, or scales of animals with appropriate scales; and Brigandine armor consisted of small, rectangular iron or steel plates riveted to strips of leather and overlapped.
Initial explorations of soft body armor
Silk bulletproof vest: In the late 19th century, the American priest Kasma Sagaran of Chicago invented a soft bulletproof undershirt woven with silk, which was the prototype of the early soft bulletproof vest. However, although this kind of bulletproof vest has a certain protective effect on low-velocity bullets, it is expensive and cannot be mass-produced.
The development of modern bulletproof vest
Body armor during World War II
Non-metallic body armor: at the end of World War II, the U.S. Army hosted the development of non-metallic body armor, including rigid plastic fiber plate vests and M12 nylon vests. M12 nylon vests weighing only 5.5 kilograms, but also can be inserted into the aluminum plate, and later became the standard equipment of the U.S. Army. 2.
Post-war breakthroughs in bulletproof technology
Fiberglass Platen: During the Korean War, the M51 body armor achieved a major breakthrough in material, using fiberglass platen as the insert.
Kevlar: In the late 1960s and early 1970s, DuPont developed Kevlar, a fiber whose impact strength is twice that of nylon fibers, making the protective performance of bulletproof vests significantly improved. The invention of Kevlar fiber is an important milestone in the history of the development of modern bulletproof vests.
The diversified development of modern bulletproof undershirts
Material innovation
High-performance fibers: In addition to Kevlar, there are also a variety of high-performance fiber materials such as Tevlon, Spectra fiber, etc.These materials have the advantages of light weight, high strength, good impact resistance, etc., are widely used in the production of modern bulletproof undershirts.Soft and hard composite bulletproof vest: In order to further enhance the protective ability, people have developed a soft and hard composite bulletproof vest, that is,on the basis of soft bulletproof materials to add ceramic pieces, metal alloys and other hard inserts, in order to resist the higher speed and power of the bullet attack.
Metal materials
Special steel, aluminum alloy, titanium alloy: these metal materials have high hardness and strength, and can effectively resist the impact of bullets.However, metal bulletproof undershirts are usually heavier and prone to secondary injuries, so their application in modern bulletproof vests is gradually decreasing, but they are still used for some specific occasions or as reinforcing materials.
Ceramic materials
Boron carbide, silicon carbide, alumina and other ceramic sheets: ceramic materials with high specific stiffness, high specific strength and good chemical inertia, is commonly used in bulletproof vests in the hard bulletproof material. When a bullet hits the ceramic layer, the ceramic sheet will shatter or crack to consume most of the bullet’s energy. Ceramic bulletproof undershirts are usually used in combination with soft materials to provide better protection.
High-performance fiber materials
Kevlar (Kevlar) fiber: Kevlar fiber is a high-performance synthetic fiber with extremely high strength and toughness. When a bullet hits the Kevlar bulletproof layer, the fiber will absorb and disperse the kinetic energy of the bullet, thus preventing the bullet from penetrating. Kevlar bulletproof undershirts are lightweight, comfortable and provide good protection, and are one of the most widely used materials in modern bulletproof vests.
Ultra-high molecular weight polyethylene fibers (UHMWPE): These fibers have very high specific strength and specific modulus, low density and good abrasion resistance. Similar to Kevlar fibers, UHMWPE fibers are effective in absorbing and dispersing the kinetic energy of bullets, providing excellent protection.
Nylon (PA): Nylon fibers are also one of the commonly used materials in body armor, offering good abrasion and impact resistance. However, compared with Kevlar fibers and ultra-high molecular weight polyethylene fibers, the protective performance of nylon is slightly inferior.
Composite materials
Soft and hard composite bulletproof vest: this kind of bulletproof vest combines the characteristics of soft and hard materials, usually based on the inner lining of soft materials (such as Kevlar or ultra-high molecular weight polyethylene fibers), and the outer layer covered with hard materials (such as ceramic sheet or metal alloy plate). When the bullet hits the bulletproof vest, the outer hard material first consumes most of the energy, and the inner lining of soft material further absorbs and disperses the remaining energy, thus providing a more comprehensive protective effect.
Other new materials
Liquid bulletproof material: this material is mainly composed of special “shear thickening liquid (STF)”, when subjected to impact can quickly harden and absorb energy. Although the application of liquid bulletproof materials in bulletproof vests is still in the research and development stage, but its unique performance for the future development of bulletproof vests provide new ideas.
Design innovation
Modular design: Modern bulletproof undershirts mostly adopt modular design, which can be flexibly matched with various accessories and inserts according to different needs, such as bullet pockets, grenade pockets, etc., improving the practicality and adaptability of the equipment.
Comfort Enhancement: With the development of science and technology, the comfort of bulletproof undershirts has also been significantly improved. Through the use of breathable materials, ergonomic design and other means, it enables the wearer to maintain a good degree of comfort even when wearing it for a long time.
Expansion of application fields
Military field: Bulletproof undershirt has become one of the standard equipment of national armies and plays an important role in protecting soldiers’ lives.
Law Enforcement: Law enforcement officers often wear bulletproof undershirts to ensure their own safety when carrying out high-risk tasks.
Civilian field: with the improvement of security awareness and technological progress, bulletproof undershirts have gradually entered the civilian market, providing more choices for those who need special protection.