The use of personal protective equipment has actually taken shape as early as ancient times. At that time, soldiers were wearing thick metal or leather armor, but such armor was extremely restricted due to its weight. Daily activities. Now, after the "9.11" incident, the world has been preparing for a long-term war on terrorism, which has also caused personal protective equipment to become an important worldwide issue. How can personal safety be better protected? This requires a large number of personal protective armor materials such as bulletproof vests, helmets, cut-resistant gloves, stab-resistant cut-resistant cloth, etc. Some countries have strictly controlled the use of guns and ammunition. , The rest is how to protect the human body from bayonet, dagger and sharp weapon, which is an urgent problem that needs to be solved.
The damage caused by knives and daggers can be divided into two types, cut-proof and stab-proof. During the puncture process, the knife will come into contact with the stab and cut-resistant cloth and begin to cut the fabric. Therefore, the material requirements of the stab-resistant and cut-resistant cloth must be tightly organized to hold the tip of the knife. At the same time, multiple layers of fabric Overlap to resist the energy accompanying the tip of the knife. The task of puncture prevention is to defend the initial cutting and energy dissipation of the knife. The anti-cutting performance is the basis of the anti-cutting performance, but the anti-cutting performance does not guarantee good puncture resistance. A certain degree of tightness of the material is also required. Generally speaking, puncture prevention is more difficult than cut prevention. According to previous data, the anti-stab mechanism is mainly a friction self-locking mechanism. With the deepening of the thorns, the yarn will pull out and slip, and the expansion of the yarn will make the adjacent yarns pull out and slip and tighten. The force required for yarn extraction is the sum of the frictional force on the thread being drawn during the extraction process. During the process of piercing, when the pierced yarn reaches the point where it cannot continue to expand, the blade will stop deepening. The yarn friction force required for expansion is very large. As long as the loop thread can continue to slide, the blade will continue to deepen. If the strength of the yarn is large enough, when the loop thread reaches the level that it cannot slide, the fabric will deform. The state is called "locked" state. This state is achieved because the adjacent thread is tightened due to the sliding of the yarn during the penetration of the thorn, and the number of tightened yarns as the yarn slides.
It can be known that the main damage mechanism of the stab-resistant and cut-resistant cloth is the compression shear of the tool along the cross-section of the material and the tensile fracture of the yarn along the axial direction. Therefore, the yarn material in the stab-resistant material is required to have high shear resistance. Ability and high tensile strength. In addition, piercing knives generally have a sharper tip. Therefore, in order to prevent the tip of the knife from penetrating the fabric, it is necessary to have sufficient tightness of the stab-resistant fabric.