A conductor is a material that allows electricity and heat to pass through it and offers no resistance to the charge flow, while an insulator is a substance that opposes the electricity and heat traveling inside the material.
Is a Wooden Chair a Conductor or Insulator? A wooden chair is an insulator because heat and electricity cannot pass through it because of the air packets, cellulose structure, and tightly packed atoms. However, it conducts free electrons if exposed to moisture, impurities, and high voltage current. Wooden materials cannot transfer heat, which makes them a thermally insulating substance.
Pure wood is an excellent insulator that restricts the electricity flowing through it because of the pores and air packets in the cellulose structure. Wood has 15 times better insulating properties than masonry, 400 times better than steel, and 17770 times more insulator than aluminum.
Why is a wood chair an insulator?
Wooden chairs are perfect insulators if you do not polish a conductive finisher on them. However, wet wood is not completely an insulator, but moisture will allow the charges to travel through the pores.
Wood can expand and contract with temperature, but this change is negligible unless a temperature is below 0 degrees, which causes frost cracks on the wood surface.
Wood has low thermal conductivity compared to metal, marble, iron, and glass, which means that the insulating capacity of wood is high.
For example, the heat transfer from the wooden material to the environment is low if you place it under the sunlight. Therefore, it can maintain its temperature unless a high temperature is applied, which causes the wood to get hot or burn.
Thermal conductivity allows the heat to transfer or conduct through it, and the thermal conductivity of a material increases as the density and moisture level increase.
Therefore, dry wood has better-insulating properties and resists the heat flow through the dense wooden structure. It prefers to hold the heat inside instead of transferring it to the surroundings and other items.
You can understand it by experimenting, such as the place a wooden spoon and a metal spoon in boiling water.
The metal spoon gets hot soon, and it becomes difficult to touch it from the outer edge of the spoon placed outside the container, while the wooden spoon is comfortable to touch. This shows that heat transfer more rapidly in metal bodies than in wood materials.
The wood chair is also an electrical insulator, such as the charges are not allowed to pass through the loose air packets and cellulose structure.
The presence of free electrons inside a material causes the flow of electricity through it, as the motion of free electrons produces current.
Wooden material is an electric insulator because the atoms are tightly packed. Therefore, the air packets do not let the electrons pass, making them reside in the air spaces.
The wooden chair consists of various molecules of lignin, cellulose, hemicelluloses, and their derivates, which do not have any free electrons in their outermost shell.
This causes the whole wooden structure to become an insulator of electricity. However, the metal handles or arms of the chair can conduct electricity because metal is an excellent conductor of electricity and has a large number of free electrons.
The temperature and length of wooden materials affect the electrical conductivity, as the larger the wooden piece, the lower the conductivity. High temperature causes an increase in electrical conductivity because it causes the ions to become more active.
Why does an iron chair feel colder than a wooden chair?
The iron chair feels colder compared to a wooden chair because iron is the conductor of heat and electricity, while wood is thermally and electrically an insulator.
The iron chair feels colder when placed outside because it has high thermal conductivity and can transfer heat to the surroundings and maintain its temperature as the surrounding.
On the other hand, wood has low thermal conductivity and does not transfer or obtain heat from the surroundings. Therefore, iron extracts heat from your hand, and you feel the iron surface colder, while wood cannot extract heat, and it feels normal to touch.
The body temperature is always less than the room or surrounding temperature. Therefore, the iron feels colder because it starts conducting heat from your body to the iron chair, and it feels colder.
Similarly, the iron chair feels warmer than a wooden chair if placed in sunlight because iron can transfer heat to your body more rapidly and strongly than wood.
Why do electricians stand on a wooden chairs?
Electricians stand on wooden chairs while doing electricity-related tasks or repairs because wood is an insulator, and current cannot pass through an insulator.
It prevents electrocution and electric shocks when doing electrical work. The current starts from your hand and travels to your feet, but the wooden chair will restrict the electrons passing through the insulating material and goes back to your hands and cancels the current. The whole process takes 10 nanoseconds which is not enough for an electric shock.
Current needs a path or a complete circuit to flow, but the wooden material under your feet acts as a boundary to the current flow and does not allow the circuit to complete.
An electric field travels at the speed of light from your body and hits the wood, which does not encourage the electrons to pass, as the electrons are too tightly bound to their outermost shells.
However, you can get an electric shock if the wooden chair has metal handles and arms and you touch these handles while doing work with the live wire.
Current can pass through the metal bodies, and the chances of electrocution increase if you come in contact with the metal and the live wire simultaneously.
Similarly, current cannot pass if you are standing on an iron chair with rubber boots with strong rubber soles. The free charges cannot find their way to complete the circuit, and rubber reflects them without any electrocution.
What makes the wood chair a conductor?
The wooden chair is an insulator, but different condition causes the material to allow the charges and heat to pass through it.
Moisture affects the overall thermal and electrical conductivity of a material.
Moisture causes the thermals and electrical conductivity to increase because water is a conductor of electricity. It causes the free electron to travel through the material and rise in the conduction of the wooden substance and other insulating materials.
The water inside the wood reacts with the wood compounds and produces salt ions, which causes wet wood to conduct electricity.
The impurities present inside the wood also cause it to conduct heat and electricity, such as the finishers and metal paints, which allow the electron to travel through it.
However, some paints and finishers are formulated to prevent electricity from traveling through the wooden chairs and tables.
The ability of electricity to pass through any material depends on the ease of free electrons traveling in this material.
It is difficult to move or separate electrons in dry wood because it contains hydrogen that binds the electrons strictly with the atoms and makes dry wood chair the perfect insulator.
High voltage also makes the wood conduct electricity because the high current flow will make its way through the tightly packed atoms. However, it cannot stop the high current or charge flow and causes the electricity to pass through the wood.
How to use electricity to make patterns on a wooden chair?
High voltage electricity is used to burn the wood and make patterns on the wooden chairs and other woo products. This process is known as fractal wood burning and is not safe for an unskilled and inexperienced person because it involves the use of high-volt electricity.
Fractal wood burning is a new technique to embellish and decorate the wood with lightning or tree-like designs and patterns.
Chemically-treated wood is subjected to high voltage current, which burns the wood to form patterns. Therefore, you need a device with a high-volt transformer to generate at least 2000-2200 volts to make designs on wood.
You should take certain precautions because the process needs very high electricity, which can be dangerous and provide harm. It is better to wear insulating shoes, protective gear, and a mask to keep yourself safe.