Each generation living in this or that temporary era has its own rules and principles, requirements for mobility and quality of life. Accordingly, the acceleration of scientific and technological progress in all sectors is followed by an increase in the general pace, and the new time dictates its own rules. So a peculiar fashion for things with the inclusion of Kevlar threads touched not only specialized units, including the military, but also ordinary inhabitants, who value their safety and love comfort.
Kevlar: what is it?
Strong Kevlar fibers have long been woven into the structure of developments in the automotive, construction, and military industries, partially replacing less durable and practical steel. The material “woven” from organic threads has become simply indispensable due to its unique characteristics. So, now we will examine in detail the question of what Kevlar is and what it is, and we will find out the history of its appearance.
Briefly on the occurrence
In a sense, the new polymer became the “child” of His Majesty the Case, born in the laboratories of Dupont, which already at that time had the invention of such a material as nylon. Then, in 1964, the research team was looking for a solution on how to replace steel cord in car tires with significantly lighter polymer threads, for example polyaramide. Accordingly, the lesson was not easy, since polyaramides must first be dissolved (which is not an easy task in itself), and then the threads should be “spun” from the resulting mass. A positive result was achieved by Stephanie Kwolek. She managed to get fibers of exceptional strength, which after testing showed stunning results - the new thread was stronger than steel.
But this was only the beginning of the brilliant history of this material. Kevlar fabric appeared on the market in 1975, and since then there is no need to complain about the lack of demand. And he gives birth to production, so Dupont does not stop there. The company carries out significant financial investments aimed at modernizing the patented Kevlar material and endowing it with improved characteristics.
Status for today
Now let's move on to our time. Modern Kevlar - what is it? And this is surprisingly light and soft material, which does not burn in the fire and even almost does not smolder, absorbs moisture perfectly, allowing the skin to “breathe”, and at the same time surpasses steel by its strength, withstanding a tensile load of 2500 N Yes, and the processing of fabric is quite easy and does not require narrow-profile equipment.
How to produce
Fiber-forming polymers are produced at low temperature by polycondensation in solution. Reagents are added to the latter and mixed vigorously. From this solution, the polymer is released in the form of chips or gel. Then it is washed and dried. Then the polymer is dissolved in strong acids (for example, in sulfuric). Filaments and fibers are formed from the resulting solution by extrusion. They are washed and dried.
Kevlar fibers are a crystallizing polymer. Their structure is characterized by a high degree of rigidity. This is due to the presence of benzene rings. The structure of Kevlar refers to cross-linked polymers. It is produced in the form of technical threads having different linear density and structure. The number of fibers in the threads can be different: from 130 to 1000 in the production of Kevlar fabric and from 500 to 10 thousand in the manufacture of cord and ropes. This material is available in the form of roving, fabric and yarn. The fibers are opaque, their average diameter is 11 microns.
Fields of application
Kevlar finds its application in those industries where wear resistance and thermal stability, low structural rigidity and maximum lightness, as well as excellent strength with low weight are extremely important. Therefore, it is not surprising that this material came to the “court” in the manufacture of personal protective equipment, in particular body armor, helmets.
Kevlar: we defend with comfort
Today, various Kevlar clothes are made, designed not only for military personnel and various special forces, but also for those who choose an ultra-active lifestyle and are obsessed with the same hunting or airsoft. Of course, an airsoft player doesn't need Kevlar armor with a high level of protection and additional armor plates, but a T-shirt with special Kevlar inserts would be very appropriate. In addition, such elements are easy to hide under outerwear, and models suitable for design have been developed.
Perhaps the most popular products from Kevlar are armor helmets, tactical gloves and, of course, body armor. By the way, it is from this fabric that the passive protection means adopted by NATO are made.
Hand protection
Tactical gloves with Kevlar in the form of protective inserts on the palms and knuckles not only protect the hand from damage in a collision, for example, with the teeth of the enemy, but also significantly strengthen the blow, making it crushing. Such a peculiar modern analogue of brass knuckles. Given the strength, warmth and resistance to moisture and damage, such accessories have recently been popular not only among employees of specialized units, but also among extreme sportsmen, street fighters, and lovers of an active lifestyle. They are also in demand by those whose dark streets of their native village cause well-founded fears.
And the bullet and the bayonet ... will Kevlar stop?
Kevlar body armor is considered to be one of the most reliable means of individual passive protection. Due to its unique lightness, strength and relative durability, such "armor" is able to protect the owner from the sliding blows of cold weapons and mitigate the effects of bullets, preventing the penetration and spread of fragments.
When choosing a bulletproof vest based on this polymer, one should take into account some of the nuances with which it is endowed. Kevlar - what is it? Soft armor that will not save from a point-blank shot or penetrating blow with a knife or awl, therefore models with special hard panels have been developed to further absorb the shock.
Everyone has their minuses
The disadvantages of Kevlar include photosensitivity - with prolonged exposure to sunlight, the miracle material begins to break down, albeit very, very slowly. Sewing elements with Kevlar filaments into a denser fabric has become an optimal means of protection.
The price of products with paraamide yarns is quite high, and this is what prevents the general "Kevlarization". Only countries developed economically can afford to equip the army with tactical products from this material.
In conclusion
Today it is extremely difficult to imagine passive protection without Kevlar fibers, and body armor made of such fabric and helmets, helmets have saved many lives. Therefore, the creators have much to be proud of. And manufacturers need to expand the production of Kevlar and constantly improve its quality characteristics.