A new, finer type of fiber makes ballistic vests stab-proof as well. This is one of the innovative projects Teijin Aramid is working on to make the jobs of soldiers and police officers safer. Teijin Aramid, fiber maker and former subdivision of AKZO, is growing fast. The company, spinning all sorts of yarn in the Netherlands, is currently developing the next generation of bulletproof vests and helmets. With Twaron, a polyaramid fiber and the counterpart of the much better known Kevlar, they have become market leaders over the years. Now that the patent on their microfiber has expired it is time for something new; an ultra-microfiber, as they call it, which is even finer woven. For example, one square inch of bulletproof vest will contain up to 10 times more yarn. A demonstration in the monumental factory building where the ballistic research of Teijin takes place makes clear the usefulness of such an innovation. The finer fibers provide less weight with equal protection. For example, the Twaron cardigan can stop a 9mm bullet shot from a handgun. Another advantage of the finer fiber is that it is stab-proof; knives or ice picks do not get through. “We can make this kind of thing thanks to all the research that has allowed Teijin to find a special way of spinning the yarn,” says Jan Roos, head engineer at Teijin Aramid.
Making aramid involves a complicated process of thread making, which requires washing and spinning the yarn. This is a process that the Netherlands’ Arnhem Company (with factories in Delfzijl and Emmen) has mastered and keeps secret. “This spinning technology is the result of a lot of research that has enabled us to advance beyond of our competitors.”
Both law enforcement and the U.S. Army do business with Teijin, which is also being sold on the American market. This is remarkable because Kevlar comes from the great American DuPont. “We have become much better over the years,” says marketing director Martin Klang. He becomes fierce when the topic of Kevlar comes up in conversation. According to him it is purely through marketing that Kevlar became so famous. The two fibers were more or less discovered at the same time, but Kevlar came on the market earlier. AKZO was in financial trouble at that time, so the launch of Twaron was delayed for two years. The distance has now been largely overcome. “Law enforcement agencies and the U.S. military now use Twaron because we were the first to meet the Army’s new weight requirements.”
The development of bulletproof materials may not have happened quickly, but there has certainly been progress. Christian Schmidt, Teijin researcher and former soldier fought in 1993 with 23kg armor. “Currently, the same protection weighs only 10 kilos,” he says while inserting a protective plate. The protection of soldiers is certainly of a different order than police protection. A ceramic plate behind the aramid and polyethylene layer ensures that even the heaviest of bullets are stopped. All this becomes clear at a shooting range demonstration; Twaron stops a 9mm round, polyethylene the Kalashnikov round and with ceramic, an armor piercing-round from a sniper rifle is stopped. This does not mean that the wearer comes out unscathed; a clay plate behind protective clothing still means that a huge bruise and a broken bone or two are the least of the injuries a soldier will suffer.
Even in war there are new threats. For example, Teijin wants to reduce the damage caused by roadside bombs with their new ultra-fine fiber. The problem with this type of bomb, which has been so prolific in Afghanistan, is that the grit flying out is so fine that the injuries it causes are very difficult to protect against. By making the fibers of protective vests so fine that those gritty particles cannot penetrate the chances of being injured are reduced. Finally, the company is experimenting with helmets in Wuppertal. These are almost always made of a polyaramide, due to the balance it offers between weight and protection. The Twaron layers are pressed into a helmet shape using a hydraulic press. The result is a hard and stiff product unlike soft armor vest panels, which are flexible. The pressing process can also result in a slightly decreased ability to catch bullets and spread the bullets’ energy. This is why Teijin is now trying to make a stiffer helmet. A mix of polyaramid and polyethylene could offer a solution.
“This is still in the experimental stage,” says Dutchman Joran van der Eem, “but this is the direction we’re going in.” In theory, such a helmet would be capable of stopping AK-47 bullets. But the helmets would be heavier and therefore impractical. Moreover, polyethylene is considerably more expensive than aramid, and the protective capacity is not proportional to the increase in cost. On the other hand, aramid helmets have been on the market for 35 years, so it is time for something new. German Special Forces have already been testing the new generation of helmets in Afghanistan. The results are secret, but the fact that Teijin is still developing the new helmets suggests there is demand. “It is a remarkable world, that of ballistic protection,” according to marketing director Klang, “It is a very competitive market, but one never hears much of anything because of the secrecy surrounding military technology.” Now it appears that the industry is doing a lot of research in order to better protect people and to make wearing that protection more comfortable.
Original Source: De Ingenieur Magazine.