A hair dryer is an electrical device that blows hot or ambient air over our hair to help evaporate the water in it and allow us to shape it. Its basic operating system hasn’t changed much over the years, although some models add special technologies like ionic or ceramic or new materials like tourmaline to improve the drying efficiency.
The body of a hair dryer is typically made from injection-molded plastic, which involves injecting hot, molten plastic into a die that’s been heated to form it into the desired shape. After the plastic cools and hardens, it’s removed from the die. The bottom half of the hair dryer is molded with a series of holes and pins that line up with matching ones on the other half to make them lock into place during assembly. Screws and other fasteners are used to anchor the parts together.
During operation, the hair dryer’s small electric motor generates current that makes its attached fan spin. This airflow is directed down the heating element and over it, warming it by forced convection. The warm air then streams out the hair dryer’s barrel.
Some models feature a safety cut-off switch, which shuts off the motor when it reaches 140 degrees Fahrenheit (60 degrees Celsius) or higher, to prevent burning your head. This and other safety features are why it’s important to read a hair dryer’s instruction manual carefully and to be careful when using it. a hair dryer