Hair dryer

Hair dryer or hair drier is an electromechanical device designed to blow normal or hot air over damp hair, in order to accelerate the evaporation of water particles and dry the hair. Hair dryers 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 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.

History

The first model was created by Alexander F. "Beau" Godefroy in his salon in France in 1890. The handheld, household hair dryer first appeared in 1920. Early hair dryers used an electric fan and heated coils; as the technology advanced, they were powered by a universal motor and produced more heat. In the 1970s, manufacturers started using a Nichrome wire wrapped around mica to produce heat.

Types

Hair dryers have been cited as an effective treatment for head lice. They are also used in beauty salons by professional stylists to create and maintain hairstyles.

There are two types of hair dryers:

• Ionic hair dryers - These hair dryers produce negative ions, which help break down water molecules on the hair shaft. The water molecules are divided into smaller particles that can penetrate the hair shaft and hydrate it. This process helps to reduce frizz and increase shine.

• Ceramic hair dryers - These hair dryers use ceramic heating units. These dryers generate infrared heat that penetrates the hair shaft and dries hair from the inside out. Ceramic dryers are less damaging to hair than other types of dryers and tend to be the most expensive.

Safety

Hair dryers have been associated with safety risks, as they may cause electrical shock if they come in contact with water. In the United States, consumer product safety rules require that hair dryers have a ground fault circuit interrupter that can prevent electrocution.

Environmental impact

Hair dryers use a significant amount of electricity. This, combined with the greenhouse gas emissions from generating electricity, means that the use of a hair dryer contributes to global warming. Template:Hairdressing-stub Template:Home appliance-stub