Which is better for stab-resistant/bulletproof vests, "Kevlar" fiber or "PE" fiber?

From silk to metal, bulletproof materials have evolved in China, and private enterprises are allowed to produce bulletproof vests. How is the quality of bulletproof vests produced by Chinese private companies? One of the most well-known instances is a video test conducted by a U.S. shooting evaluation blogger on Chinese-manufactured Level IV ceramic ballistic plates. He and another shooter successively used handguns, rifles, and assault rifles to fire various shots at a distance of around 10 meters. After 15 shots, the plate remained intact, and the blogger was astonished by the protective capabilities of this $100 Chinese ballistic plate.

The AK-47, firing 7.62mm caliber bullets, achieves a muzzle velocity of up to 725 meters per second. Upon impact with the human body, it creates a large cavity, causing damage to internal organs, with fragments embedding into the body. However, wearing a bulletproof vest provides almost complete protection, allowing one to withstand a gunshot with minimal harm.

Bulletproof vests save lives by deforming, fracturing, absorbing, and dissipating the kinetic energy of bullets or fragments, preventing them from penetrating. On the battlefield, bulletproof vests encounter not only bullets but also fragments from explosive devices such as grenades and shells.

According to China's police bulletproof vest standards, the highest level for soft bulletproof vests is Level 4, which can withstand most handgun and submachine gun shots at a distance of 5 meters. However, this may not be sufficient, and to withstand more powerful weapons like rifles and sniper rifles on the battlefield, a hard bulletproof vest is more reliable. The key feature of a hard bulletproof vest is the addition of bullet-resistant plates on the basis of soft bulletproof vests. These plates can mainly be made of three materials: metal, composite, and ceramic.

Composite ceramic plates currently offer the best ballistic performance. These plates are constructed by bonding high-strength structural ceramics such as aluminum oxide, silicon carbide, and boron carbide with materials like ultra-high molecular weight polyethylene. The thickness of these ceramic ballistic inserts is typically around 3cm, with a weight of 2-3KG. When subjected to gunfire, the ceramic plate undergoes intense friction with the rapidly rotating metal projectile, sharpening its tip and reducing its penetrative ability. Through localized fragmentation and the deformation of the fiber material backing, the ceramic ballistic insert ultimately absorbs the kinetic energy of the bullet. Ceramic inserts can achieve Level 6 or even higher ballistic standards. They are capable of stopping heavy sniper rifles like the Barrett M82, which uses 12.7mm caliber bullets.

Author: Amazing Chinese Manufacturing Link: //www.zhihu.com/question/264704052/answer/3266688241

Source: Zhihu