Inorganic-organic hybrid polymers improve the stab resistance of ballistic fabrics

摘要

Since the 1970's, p-aramid fibers have been used for the production of bullet proof vests due their enormous tensile strength which is about five times higher than that of steel. The high tensile strength of the fiber material guarantees that a projectile hitting a bundle of p-aramid fabrics is deformed and stopped after only a few layers of the fabrics. The strength of the fibers is sufficient to protect against most small arms. At the first sight, people wearing such kinds of vests seem to be protected on an optimal level. A more usual threat to the police or security people is seen in attacks with thrust weapons, as these weapons are more widely spread. The protection against knives is poor because the fibers show a low stability perpendicular to the fiber axis. For this reason, a blade will easily sever a fiber and penetrate through the bundle of ballistic fabric. Additionally, the physiology of clothing is unsatisfactory and the vests mostly restrict the freedom of movement, which is an especially big disadvantage in case of hand-to-hand fighting. A number of approaches to create stab resistant and bullet proof vests are on the market, these are, for example, combined with titanium or ceramic plates, which leads to a noticeable increase in weight and an additional restriction of the freedom of movement.