Hair dryer

A hair dryer, also known as a blow dryer, is an electrical appliance used to dry and style hair. It uses an electric fan to blow air into the heating coil. As the air passes through the dryer, it heats up. When hot air reaches wet hair, it helps the water to evaporate. So the run is dry. Hair dryers can be used with different brushes and combs for different hairstyles.

The history of the hair dryer

The first hair dryer hit the market in 1925. It produced only 100 watts of heat and therefore was not powerful enough to dry hair quickly. Made of heavy steel and zinc, it weighed more than 1 kg. Over the next 20 years, engineers improved the design and tripled the heat output to 300 watts. By the 1960s, further improvements in electrical technology allowed the production of hair dryers with power up to 500 watts.

In the late 1970s, manufacturers began working to improve the safety of dryers. This was because early hair dryers were dangerous because they could short-circuit and electrocute if they accidentally came into contact with water. In those years, there were hundreds of electrocution deaths when a hair dryer accidentally fell into a bathtub or sink full of water while using it. In the late 1970s, the Consumer Product Safety Commission (CPSC) recommended that hair dryer manufacturers follow regulations that could create safer products.

The power of hair dryers was limited by the available electric motors. As smaller, more efficient engines were developed, greater airflow and greater heat output could be achieved. Until the 1990s, portable hair dryers could produce more than 1,500 watts of heat. The improvement of plastic technology and the discovery of new insulation materials made possible the production of a new generation of lightweight hair dryers. Nowadays, modern hair dryers can produce up to 2000 watts of heat and dry hair faster than before.

Design

One of the main factors to consider when designing portable hair dryers is the amount of heat power it can produce. Because warm air has a greater ability to absorb moisture than cold air, the temperature of the air stream is important. By calculating the specific heat of the air and the maximum temperature that can be used without burning the skin, engineers can calculate the power required for the heating element. This ensures that the device generates enough heat to dry the hair quickly. However, simply raising the temperature of the hair is not enough. Also, for moisture to leave the hair effectively, air must also pass through the hair quickly. Another key design criteria is device security. First, the hair dryer should not be hot enough to burn the hair or scalp during operation. The plastic housing must remain at normal temperature and not overheat, otherwise it may melt or catch fire. To solve this problem, engineers have developed thermal cut-off switches that prevent overheating of the heating battery. This switch also turns off the heater coil when the blower motor stops running. Secondly, the hair dryer should not cause an electric shock. To prevent accidental electrocution, modern hair dryers have a special surge protection device, a Ground Fault Circuit Interrupter (GFCI).

Other factors to consider include the hair dryer's weight and ease-of-use design. For convenience, blow dryers are designed to weigh only about 1 pound (500 grams) and are easy to handle during use.

The future of hair dryers

The quality of portable hair dryers has greatly improved over the past 70 years. The improvements made have increased the safety of hair dryers and increased their power by about 20 times. Very few changes have been made in the design. Future dryers are unlikely to be more powerful, as they already produce close to their maximum amount of heat.

Future design improvements are more likely. So it may be possible to use blow dryers more quietly and to make handling easier. Some manufacturers focus on improving the appearance of hair dryers.

Perhaps, thanks to technological advances, new types of hair dryers will appear. In 2000, a manufacturer introduced a new ionic hair dryer that uses ions to evaporate water faster, causing less damage to the hair. At the time of this launch, it was not yet known whether this new hair dryer would be successful.