Hair dryer

A hair dryer, hairdryer or blow dryer is an electro mechanical device designed to blow normal or hot air over damp hair to accelerate the evaporation of water particles and dry the hair. Blow dryers allow better control over the shape and style of hair, by accelerating and controlling the formation of temporary hydrogen bonds inside each strand. These hydrogen bonds are powerful  but are temporary and extremely vulnerable to humidity. They disappear with a single washing of the hair.