The Blow/Hair Dryer

Introduction

A hair dryer, also known as a blow dryer, is an electrical device used to dry and style hair. It uses an electric fan to blow air across a heating coil; as the air passes through the dryer it heats up. When the warm air reaches wet hair it helps evaporate the water. Hair dryers may be used with a variety of brushes and combs to achieve different hair styles. Earlier to hair dryer men and ladies really utilized the vacuum cleaner in arrange to dry their hair with the hose.

The hair dryer was designed by Alexander Godefroy in France in 1890 and was accessible for a commercial deal in 1920. (Tooth man, Jessica 2016). To begin with hooded dryer was associated to a gas stove or chimney pipe which create the heat. The cap contained little openings which permitted wind stream. Hooded dryers are still prevalent in numerous salons to this day. Today’s best hair dryers have come with imaginative innovation counting tourmaline and ionic dryers with various warm and speed settings. Today’s dryers can indeed dry hair from the interior out and break down water particles for quicker drying times. The blow dryer has come a long way!

The hairdryer is an electromagnetic machine which means that it uses electricity as its power source. Turning a hairdryer on causes electricity to power on the motor that spins a fan located inside the hairdryer. The fan is what brings the room temperature air inside the hairdryer.

Body

Hairdryers are assembled from a series of components including the electrical motor, the fan blade, copper wiring, switching mechanisms, and various other electrical components. The plastics used to make the outside shell of the hair dryer must be durable, yet light-weight. (Figure 1).

Figure 1. Main Parts (Tooth man, Jessica, 2016).

2.1 Electric Motor

Hair dryers use the motor-driven fan and the heating element to transform electric energy into convective heat. The whole mechanism is really simple: When you plug in the hair dryer and turn the switch to “on,” current flows through the hair dryer. (Figure 2).

Figure 2. Electric Motor (Electrical Products, 1977-2017)

2.2 Fan Blades

The centrifugal movement of the fan blades draws air in through the small round air inlets in the side casing of the hair dryer. These holes are covered by a safety screen that prevents other objects (such as strands of your hair) from being sucked in as well. The air is then blown down the barrel of the hair dryer. (Figure 3).

Figure 3. Fan Blades (Geometric Consilio, 2020)

2.3 Wire Coils

The heating element in most hair dryers is a bare, coiled nichrome wire that’s wrapped around insulating mica boards. It’s a poor conductor of electricity compared to something like copper wire. This gives the alloy enough resistance to get hot from all of the current flowing into it. It doesn’t oxidize when heated. (Figure 4).

Figure 4. Wire Coils (Jessika Toothman & Ann Meeker-O’Connell, 2001)

2.4 Shell

The body of the hairdryer consists of a gun shaped plastic shell. This shell is divided into two sections to allow for easy assembly. The plastic parts are created by injection molding, a process that involves injecting hot, molten plastic (such as polypropylene) into a stainless steel die. (Dalton, John W, 1985). After the mold is filled with hot plastic, cold water is circulated around the die to cool the plastic and make it harden. When the die is opened, the plastic parts are removed. One side of the plastic shell has a series of holes molded into it while the matching half has a series of short pins. These help align the two halves during manufacture and keep them firmly attached.

The shell is molded with multiple compartments to hold the various electrical components. The handle of the gun contains the switch apparatus and the controls to operate the dryer. The electric motor and fan are found in the central part of the drier located just above the handle. The long barrel of the device contains the heating element. (Figure 5).

Figure 5. Shell (Decision of President of the European, 2007)

2.5 Cord

Replacement power cord suitable for 120V/60Hz appliances up to 13A. This cord and plug can be used to plug in a hand dryer or other appliance into a standard 120 volt power socket. Many of the hand dryers and other products that we sell are designed to be hard-wired. You can use these cords to enable them to plug-in. (Figure 6).

Figure 6. Cord (Restroom Direct, 2008)

2.6 Switch

Dryers contain a safety cut off switch that prevents the temperature of the drier from exceeding 140°F (60°C). (Dalton, John W, 1985). This switch is a bimetallic strip, which is made from a sheet composed of two metals. These metals expand at different rates when they are heated. As the temperature inside the drier increases, the strip will bend one way or another as the metal strips expand at different rates. When a certain temperature is reached the strip bends to appoint where it trips a safety switch that cuts off the power to the drier. (Figure 7).

Figure 7. Switch (Birth of Beauty Massachusetts, 2019)

2.7 Screws

Screws and other fasteners are used to anchor the plastic parts together and hold them in place. Early hair dryers used dozens of screws to lock the shell hands to place. Because of more efficient designs, modern models only require a few key screw components. This helps control cost and reduce assembly time. (Figure 8).

Figure 8. Screws (Co-authored by wikiHow Staff, 2021)

How hair dryers work

When you plug in the blow dryer and turn the switch to “on,” air current flows through the hair dryer.
The circuit first supplies power to the heating element. In most blow dryers, this is a bare, coiled wire.
The current then makes the small electric motor spin, which turns the fan.
The airflow generated by the fan is directed down the barrel of the blow dryer, over and through the heating element.
As the air flows over and through the heated element, the generated heat warms the air.
The hot air streams out the end of the barrel, through the nozzle.

Conclusion

To conclude hair dryers work due to the system of parts that make them up. The fan creates airflow and the shape of the blow dryer directs the airflow towards the nozzle of the blow dryer. Before the airflow reaches the nozzle, it has to pass through the heating elements, thus blowing out hot air. How hot the air coming out of the dryer can get depends on the power supplied to the heating element, and the time the air spends in the barrel of the dryer being heated by the nichrome wire. The higher the wattage, the more heat is generated by the heating element and transferred to the air. Most hair dryers limit this to approximately one-half second to prevent the air temperature from getting too high.

Self-Reflection

I was excited to do this job, as reading and reviewing various websites about hair dryers I realized that there are several types and different technologies each. As they were written, analyzed and investigated each one motivated me to know more about this invention. When it was created, by whom it was created, when it was launched, how was the first hair dryer? These were questions that came to me when doing this work, but with the help of the research I was able to know each of those questions. I really enjoyed doing research like this in the field of engineering, which as you know is a branch that never stops that always advances with the rhythm of modern technology, it encourages me to always be reading scientific journals where there is always news from those that one day I would like to participate in them, for and with society. I feel comfortable doing this work since I like to do research work, in this way I enrich my knowledge, expand my vocabulary and I am open to talk about more topics.

In short, I liked it very much and I felt very good to learn about this, it helps me as a professional to have a better recognition, so that I am not just another researcher, but a great researcher and professional.

In the future I hope to do more work like this to be able to enrich my knowledge and little by little understand the importance of research.

And I hope that other people understand and understand the importance of research in science, engineering or medicine, in any branch, as I learned with this work.

References

Tooth man, Jessica. “How Hair Dryers Work.” How Stuff Works. How Stuff Works, 15 Dec. 2000. Web. 02 Dec. 2016