What are conductors and insulators? Classification and practical application

Electrical conductors and insulators are two important components that are indispensable in our daily lives. Let’s explore their definition, classification, and practical applications with RX Tradex to better understand the role of these materials in life.

1. Conductors and insulators

In the field of electronics and engineering, conductors and insulators play an important role in regulating and controlling electrical current. However, these two substances have opposite functions. The conductor allows the current to pass through easily, while the insulator prevents the current from passing through. This article will delve into the classification, what are the functions of electrical conductors and insulators, as well as their practical applications in industry and life.

1.1. Conductors

What is Conductor?

A conductor is an object or type of material that allows an electric current to pass easily in one or more directions. This allows the electrons to move easily inside them. Conductors with this property allow for the conversion of heat or light from one source to another.

Conductors are commonly used to make conductive devices and conductive parts in power tools. In nature, electrical conductors can exist as solids such as metals, liquids such as molten metals, electrolytes, or gases when at high electric fields.

Metals, humans, the earth, and animal bodies are examples of electrical conductors.

Metals, the human body, the earth, and the animal body are all examples of electrical conductors. Since the human body is a good conductor of electricity, it can create a path without resistance for current to pass through, leading to dangerous electric shock hazards.

How many types of conductive substances are there?

Conductors are generally classified into two main categories:

• Low resistivity conductors: Includes materials such as silver (Ag), copper (Cu), aluminum (Al), tin (Sn), lead (Pb), and some other alloys. Electrical conductors have a low resistivity, therefore, they are often used as conductive materials.
• High resistivity conductors: Includes alloys such as manganese, constantan, nickel-chromium, as well as carbon. Due to their high resistivity, these substances are often used to make electrical measuring instruments, resistors, resistors, sewing wires, and electrically heated devices.

Some of the best conductive metals today

Silver (Ag)

Properties: Silver is a soft, malleable metal.

Electrical Conductivity: Ranked first among the metals with the best electrical conductivity.

Uses: Although silver conducts electricity the best, its high cost makes it less used in the electrical industry. Instead, silver is often used in jewelry, minting, and mirroring.

Copper (Cu)

Properties: It is soft, malleable and easy to form.

Electrical Conductivity: Good

Uses: Copper is a popular choice in the fabrication of electrical conductors. In addition, copper is also widely used in the production of household appliances and handicrafts such as pans, statues, and welding rods. Some copper compounds are blue or green in color and are often used as dyes in fabric factories.

Gold (Au)

Properties: Good thermal and electrical conductivity, not easy to oxidize and highly aesthetic.

Electrical conductivity: Good.

Uses: Gold is mainly used as a unit of exchange for monetary value and jewelry. When working with electricity, it is necessary to avoid wearing gold jewelry to minimize the risk of electricity spreading quickly through the body, endangering life.

Aluminum (Al)

Properties: Aluminum is malleable, difficult to oxidize and has a high melting point.

Electrical conductivity: Good.

Uses: Aluminum is used in some cases to make electrical conductors. With high heat resistance, aluminum is also widely applied in construction, such as partitions, roof sheets, and house pillars.

Factors Affecting Electrical Conductivity

Electrical conductivity can be affected by the following factors:

Shape: Thick materials will have better electrical conductivity than thin materials of the same size and length.

Size: Where 2 pieces of material are of the same thickness, the shorter piece conducts electricity more efficiently than the long piece.

Temperature: Most metals conduct electricity better at normal temperatures and are less efficient when heated. Some materials can even become superconductors at extremely low temperatures.

Application of electrical conductors in practice

Electrical conductors are widely used in many practical fields such as:

• Conductive substances in the car’s radiator to transfer heat away from the engine.
• Iron plates are used to absorb heat quickly.
• Manufacture of iron vehicle engines for heat conduction.
• Using aluminum in the manufacture of cooking utensils and food storage to help transfer heat quickly.
• Use mercury in a thermometer to measure body temperature.
• Use copper, brass, steel, and aluminum in electrical circuits and systems as conductors.

1.2. Electrical insulators

What is an insulator?

Insulators are materials that have the ability to prevent and isolate electric current, not allowing current to pass through. Due to the very low conductivity, the insulators do not allow the electrons to move freely. Some common examples of insulators are rubber, plastic, ceramic, glass, gas (air). Insulators are often used to wrap wires, isolate electrical circuits, and in electronic components to prevent the transmission of electricity.

How many types of insulating materials are there?

Solid insulating materials have the common characteristic of very high dielectric constants, and surface discharge often occurs in these types of materials.

Solid Insulation Materials

Solid insulators are generally classified as follows:

Types of enamel and insulation paints

• Synthetic plastics: Including rubber, synthetic plastics.
• Inorganic substances: Such as cement, mica, fiberglass.
• Natural organic matter: Paper, fabric, silk.

Among solid materials, mica is one of the best, but high-cost, insulators, often used in high-voltage devices. However, materials such as paper, fabric, fiberglass are preferred due to their high mechanical strength, softness, and low cost.

Liquid Insulation Materials

Including petroleum oils, transformer oils, solid cable oils, thin cable oils, and silicone oils. The most common application is the use of transformer oil as an insulating material and cooling of transformers.

When selecting liquid insulators, important properties such as resistivity, dielectric permeability, dielectric loss, and dielectric strength should be taken into account.

Gaseous insulating materialsAir is commonly used to insulate overhead power transmission lines and equipment that works in the air.

Hydrogen gas, thanks to its light weight and good heat transfer, is used to cool thermoelectric generators and high-capacity synchronous compensators, helping to minimize losses due to friction and blowers.

Nitrogen gas is a colorless, odorless gas that makes up about 78% of the Earth’s atmosphere, commonly used in the manufacture of electronic components such as transistors, diodes, integrated circuits (ICs), and in the manufacture of stainless steel (stainless steel). In addition, inert gases such as argon, neon, and mercury vapor are also used in vacuum electrical appliances and light bulbs.

2. Conclusion

Conductors and insulators are two important contributors to the control and regulation of electrical current. Hopefully, the article will bring you useful information about the role and importance of electrical conductors and insulators in daily life and industries. In addition, if you want to explore advanced automation solutions or grasp the latest manufacturing trends in the electronics industry, don’t forget to attend  the NEPCON Vietnam international exhibition – the largest and only event of the year organized by RX Tradex. Register here.