hair dryers

A blowdryer or hairdryer is an electromechanical device designed to blow cool or hot air over wet or damp hair, in order to accelerate the evaporation of water particles and dry the hair. Blowdryers allow to better control the shape and style of hair, by accelerating and controlling the formation of temporary hydrogen bonds inside each strand. These hydrogen bonds are very powerful (allowing for stronger hair shaping than even the sulfur bonds formed by permanent waving products), but are temporary and extremely vulnerable to humidity. They disappear with a single washing of the hair. Hairstyles using blowdryers usually have volume and discipline, which can be further improved by the use of styling products and hairbrushes during drying to add tension, hold and lift. Blowdryers were invented around the end of the 19th century. The first model was created by Alexander Godefoy in his salon in France. The handheld, household hair-dryer first appeared in 1920.