The hairdresser uses the back of the hair dryer to blow hair because of the need for styling. The reason is that the front end of the hair dryer is hot air. After softening the hair, the cold air at the back end is used to quickly cool it before styling. The back of the hair dryer is completely a suction fan, which is used to blow the hair docilely. Of course, if you blow the hair completely inward, it will look fake. Blow it with the back, which will make it more natural.

The hot air blown in front of the hair dryer makes the molecular structure of the hair move. The molecular structure of the hair moves, and then you use a comb or your hands to style it. This way you can create a style. Since the hair cools very slowly, the cold air behind it cools it quickly. , the style will last.

A hair dryer is composed of a set of electric heating wires and a small fan. When energized, the electric heating wire will generate heat, and the wind blown by the fan passes through the electric heating wire and becomes hot air. If only the small fan is rotating but the heating wire is not hot, then the air blowing out will be just wind but no heat.

Extended information:

The working principle of the hair dryer:

The hair dryer directly relies on the motor to drive the rotor to drive the fan blades to rotate. When the fan blades rotate, the air flows from the air inlet Inhaled, the resulting centrifugal airflow is blown out from the front mouth of the hair dryer. When the air passes through, if the heating wire on the heating bracket installed in the air nozzle is energized and heated, hot air will be blown out; if the selector switch does not enable the heating wire to be energized and heated, cold air will be blown out. This is where the hair dryer is used for drying and shaping purposes.

The selector switch on the handle of the hair dryer is generally divided into three positions, namely, off position, cold air position, and hot air position, and is accompanied by white, blue, and red color indicators. Some hair dryers are also equipped with a motor speed control switch on the handle, which can be used to select the air volume and hot air temperature.

The back or side of the casing of various hair dryers is equipped with a rotatable circular air-adjusting hood. By rotating the hood to adjust the cross-sectional size of the air inlet, the delivered wind speed and the temperature of the hot air can be adjusted.

According to the way of use, there are hand-held and pedestal hair dryers. The pedestal hair dryer can be placed on the table or hung on the wall, allowing you to blow dry yourself.

According to the air supply mode, there are centrifugal hair dryers and axial flow hair dryers. The centrifugal type relies on a motor to drive the fan blades to rotate, so that the air entering the hair dryer obtains inertial centrifugal force and continuously exhausts the air outward. Its disadvantage is that not all the exhaust air flows through the motor, and the motor heats up higher; its advantage is that the noise is lower.

The axial flow motor drives the fan blades to rotate, pushing the air entering the hair dryer to flow axially, and continuously exhausting the air outward. Its advantage is that all the exhaust air flows through the motor, the motor has good cooling conditions, and the insulation is not prone to aging; its disadvantage is that it makes a lot of noise.

According to the material used in the shell, there are metal hair dryers and plastic hair dryers. Metal-type hair dryers are durable and can withstand higher temperatures. Plastic hair dryers are light in weight and have good insulation properties, but they are prone to aging and have poor high temperature resistance.

Reference: Baidu Encyclopedia-Hair dryer