Kevlar is made of long chain-like molecules known as polymers. It is a very strong material used in bulletproof vests.
A Kevlar fiber is an array of molecules oriented parallel to each other like spaghetti. This orderly, untangled arrangement of molecules is described as a crystalline structure. Crystallinity is obtained by a manufacturing process known as spinning, which involves extruding the molten polymer solution through small holes. The crystallinity of the Kevlar polymer strands contributes significantly to Kevlar's unique strength and rigidity. Hydrogen bonds form between adjacent polymers, holding them together.