Bulletproof Vest Essay

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JS1 Bullet Proof Vest (Kevlar) The year 1965 proved to be a crucial in terms of current events: Martin Luther King Jr. leads more than 25,000 civil rights activists to Montgomery, Alabama which will later be a critical turning point to the civil rights movement; President Lyndon B. Johnson is elected and sworn into office; and the para-aramid synthetic fiber, Kevlar was developed in a small DuPont laboratory by Stephanie Kwolek. As the years went by, Kevlar proved to be one of the most important manmade organic fibers ever developed. And, one of the most popular uses for Kevlar is for the manufacturing of bullet/ballistics proof vests. One of the first uses for bullet proof vest date as far back as the medieval times in 1538 during the English civil war, when Filippo Negroli developed a full cuirass made up of forged steel and copper. For about the next 450 years different variances of the steel bullet proof vest would emerge (Williams). But it wasn’t until 1971 when the invention of Kevlar completely revolutionized any kind of ballistics protection armor. The official name of Kevlar is Poly-paraphenylene terephthalamide. It is produced by monomers “ 1,4-phenylene-diamine (para-phenylenediamine) and terephthaloyl chloride in a condensation reaction yielding hydrochloric acid as a byproduct. The result has liquid-crystalline behavior, and mechanical drawing orients the polymer chains in the fiber's direction. Hexamethylphosphoramide (HMPA) was the solvent initially used for the polymerization.”(Citation 2) This reaction ultimately yields the fiber Kevlar. Refer to Figure 1.1 [pic] Figure 1.1 To form the actual fiber it goes through a process called wet spinning. Wet spinning is the oldest of the four processes of dry, extrusion, and melt spinning. This process is used for polymers that need to be dissolved in a solvent to be spun through
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