There are two types of materials used in electricity: Conductors and Insulators. Conductors are known for their low opposition to electrical flow, whereas insulators have a high ability to stop current flow. Ideally, both materials have to work together to use electricity and wiring successfully. But…
Does plastic conduct electricity?
Because the electrons in plastic are tightly bound by their molecules, most plastics do not conduct electricity or do so only poorly. As a result, plastics are primarily used to insulate electrical system conductors.
Read on to learn more about the basics of plastics.
Is Plastic a Conductor or Insulator?
Plastic is an insulator because it doesn’t allow electricity to flow through it, making it a suitable material for electrical systems. Without plastic, you cannot run hot and neutral wires in the same wire. Instead, you will need to develop another means to convey electricity to different electrical gadgets safely. This can attract extra costs to do it safely.
But you might wonder, why plastic? Or why can’t one cover electrical wires with other materials known for their low opposition to electricity?
Plastic is used primarily for its elasticity and ability to enter junction boxes safely and bend around corners. Plastic also burns slowly, making it an excellent choice for electrical wire insulation.
Here are some of the distinct properties of plastic:
We all know that metals are good conductors of electricity, owing to the fact that electrons in metals move freely and are only loosely bound by their atoms. Because of this freedom, electrons will readily flow in the presence of an external electrical field to transport current.
Plastics are different in that their electrons are tightly bound by their molecules, making electrical current flow difficult.
For similar reasons, metals are good conductors of heat because the electrons move freely and can dissipate the thermal energy around. In plastics, the thermal energy must be transmitted by vibrating molecules colliding against each other. Therefore, it takes a lot more energy, slowing down the process of conducting heat.
You can use plastic as thermal insulators in vinyl sidings, such as in the styrofoam beverage cups used for holding hot coffee. Also, plastic’s properties make it helpful in wrapping wires. Electrical tape, for example, is made from a type of plastic called vinyl. However, some plastics have been purposefully formulated to act as electrical conductors in recent years, with polypyrrole and polyacetylene being the only examples.
Plastics are typically organic polymers, incorporating carbon, hydrogen, and other elements like oxygen. The long atom chains in plastic are packed together to create a flexible solid, meaning you can mold them into desired shapes.
Some plastics are thermosetting, so you can only shape them once, while others are thermoplastics that you can heat and mold multiple times.
Why Are Electrical Wires Covered in Plastics?
Though they are poor conductors of electricity, plastics can serve many purposes to fulfil different electrical needs. Learn more in this guide.
The most crucial reason for covering electrical wires in plastic is to protect you and the people sharing a similar workspace from electrical shock. Electricity is a hazardous form of energy that does not tolerate carelessness.
Covering your electrical wires in plastic ensures that the electrons streaming through wires won’t flow through your body when you touch the wire.
Tip: Besides covering electrical wires, plastics can serve a protective role in other parts of your home. For example, homeowners with outdated plumbing can consider PVC pipes a long-lasting replacement that can ease fears of rusty piping.
Electrons streaming through a conductor generate heat from their high-speed motion, creating a current flow. This heat and energy needed to move electrons can build up, and if enclosed by flammable materials like wood, it can ignite, causing fires. Plastic aids in dissipating the heat and prevents the wire from getting extremely hot and causing a fire.
Why is Plastic a Good Insulator of Electricity?
Plastic is a material with different uses, one of them being an excellent electrical insulator. But why is it such a good insulator? Plastics are great electrical insulators because they don’t have free-moving electrons. Loosely packed electrons create electrical currents.
However, the insulating properties of plastic are less desirable in products like plastic casings for mobile phones because they can overheat from the heat the device generates.
Note: Plastics come in many forms, and since they are durable and malleable, they’re widely used in various products, including electrical sockets, tubing, and coolers.
Types of Plastics that Conduct Electricity
Plastic boasts many commendable properties, but conductivity is not part of them. For this reason, metals remain the material of choice for most applications because of their conductive properties.
However, engineered plastics have quickly evolved to integrate materials lighter than metals and be designed to conduct electricity. To complement this tradition, product designers have developed conductive plastics filled with conductive additives to obtain a certain level of electricity.
Here is a list of conductive plastics:
Why Use Conductive Plastics?
Conductive plastics are handy for dissipating Electrostatic Discharge or transmitting an electrical charge. Static build-up can lead to severe electrical shocks or mechanical failure if not controlled well. To avoid risks, including conductive materials in your product design can boost its performance.
You can choose any conductive material depending on your design requirements to make plastic conductive. The good thing is that most plastics accept modified properties that won’t harm your product’s output.
When to use conductive plastics
You can use conductive plastic to fulfil different electrical needs. For instance, this semi-conductive material can play a conductive role in an electromechanical mechanism. It can also help to dissipate unwanted static from an engine. Other applications include food processing systems, medical devices, and industrial applications.
Types of Plastics That Are Good for Electrical Insulation
Insulation is an essential component for electrical wires since it protects them from the elements and other stresses. Plastic is among the best materials for insulating electrical wires, partly due to its excellent moisture resistance and flexibility.
Different kinds of plastics are used as insulating materials, and each one is designed to meet technical specs. Here are the types of plastics for insulation:
Thermoplastic insulation is the most typical plastic insulation material. It is highly flexible, making it easy to reshape. The plastic hardens at low temperatures (14 degrees Fahrenheit) and is available in the following formulations: THW, THHW, TW, and THHN.
PVC is a form of plastic made by combining resin, pigments, fillers, plasticizers, and lubricants. This plastic material makes excellent insulation for electrical wires and has flame-resistance properties. Besides electrical insulation, you can use PVC as insulation material for food-related and medical purposes. That’s because this material is odorless and non-toxic.
However, this insulation material exhibits high attenuation capacitance loss, increasing power loss when used with electrical systems.
Semi-Rigid PVC (SR-PVC)
Semi-rigid PVC is often used as primary insulation and is abrasion-resistant. It also withstands heat, water, acid, and alkali.
This lightweight insulating plastic component exhibits excellent abrasion resistance and tensile strength. It has a lower dielectric constant and gravity than other plastic materials. Other characteristics that make polypropylene suitable for cable insulation are excellent impact strength, moisture, and chemical resistance.
More importantly, this plastic material is ideal for high-frequency cables and upholds its basic properties under dynamic stresses. The two most common versions of polypropylene include isotactic polypropylene and atactic polypropylene.
Polyethylene makes for a tough all-purpose insulation cover that offers good moisture resistance and unmatched brittleness at low temperatures. You can use it for high-frequency electrical conductors because it can tolerate temperatures up to 900 degrees Celsius.
You can also cross-link polyethylene to create high resistance to soldering, cracking, cut-through, and solvents. This plastic material is also flammable, but manufacturers add additives to make it flame-retardant. However, this will forfeit the dielectric constant, increasing power loss.
Polyurethane is known for its extreme toughness, elasticity, and flex, even in cold weather. Again, it has excellent water, chemical, and abrasion resistance ratings. This material is well-suited for retractile cord applications and low-temperature military purposes.
Nylon acts as a tough jacket, courtesy of its strong abrasion and chemical resistance. Similarly, it’s very flexible, but one disadvantage is it absorbs moisture, degrading most of its electrical properties.
CPE has unmatched heat, oil, and weather tolerance. It is a low-cost alternative to value-minded materials like PVC. Its dependable performance when subjected to fire also makes this option a better pick over PVC insulation. It is typically found in control cables and industrial power applications.
Where to Use Plastics as Insulators?
Plastic insulation is used in many applications, from medical devices to food processing systems. They lower the utility bill whether you’re using it for electrical or thermal insulation. Here are the common applications for plastics as insulation:
Plastic insulation is a cost-effective way to seal off your windows. You’ll find plastic film insulation kits that use double-sided tape, which you can shrink with a hairdryer to develop an airtight seal.
Shock and fire-resistant plastics make rugged and durable handles for various tools, including paint-strippers, drills, vacuum cleaners, and hedge trimmers.
For similar reasons, plastic insulation is commonplace for most office equipment, including keypads for telephones, computers, laptops, and photocopying machines. Besides, plastic is also used to house goods like electric razors, food mixers, and hairdryers, preventing you from electric shock.
Electricity is vital to our living standards, but it’s also dangerous. Since plastics don’t convey current, they are used as electrical insulators in many applications requiring insulation properties. For instance, PVC is primarily used for insulating electric wiring, whereas thermosets are handy for light fittings, switches, and handles.
Why is Polyester Plastic Used to Insulate Electrical Wire?
Polyester plastic is used for electrical wire insulation because of its unique set of characteristics, such as:
- High Dielectric strength: Refers to the electrical power of individual insulating materials. In this context, polyester films: the thicker the film, the more robust the electric strength it has to withstand electrical currents at a higher level.
- Impressive Thermal Endurance: Polyester film retains longevity when used as electrical wire insulation because it has greater mechanical strength and is tear-resistant and flexible.
- Superior Electrical Barrier: Polyester is a fantastic electrical barrier. When used as insulation, polyester prevents electricity from arcing when the motor draws a large amount of current from the system.
As a result, polyester is frequently used in the wiring of digital printers and other motor-powered appliances.
Aside from the qualities mentioned above, polyester is also known for retaining chemical stability while remaining intact in temperature fluctuations.
Frequently Asked Questions (FAQs)
What is Conductive Plastic?
Conductive plastics are engineered elements loaded with conductive additives to achieve a predetermined electricity level. Carbon fillers such as graphite, carbon black, and other proprietary elements are used to achieve this.
What are Electrically Conductive Plastics Used For?
Conductive plastics serve as jacket coverings for high-power transmission cables, helping to reduce induced currents from close cables. You can also use electrically conductive plastics to protect sensitive electronic components.
How Do I Know Plastic Is a Poor Conductor of Heat?
Experimenting shows that plastics are poor heat conductors. To begin, heat two cups of water. Next, place your metal spoon in one and your plastic spoon in the other, then wait one minute. When you touch the spoons after the time has passed, you will notice that the metal spoon is hotter than the plastic spoon.
This experiment accurately testifies that plastic is a poor heat conductor while metal is a good conductor.
As previously stated, plastics are poor electrical conductors unless fortified with additives to make them so. To compensate for this disadvantage, plastics make excellent insulation materials and are preferred by manufacturers across a wide range of industries.
Thanks for sifting through this guide. I hope you now know the basics of plastic.