Does plastic conduct electricity?
Plastic doesn’t conduct electricity very well and that’s why it’s a great insulator. It’s used for insulating cables and shielding in electronics, blocking unintended electrical currents and protecting users from electric shock.
Why does plastic not conduct electricity?
Time for the science! A material’s ability to conduct electricity is determined by the movement of electrons within it. In conductors, like metals, there are lots of free electrons whizzing around, and this freedom of movement enables the flow of electric current. But, in insulators, like most plastics, the situation is quite different.
Way down at atomic level, plastics are made up of long chains of carbon atoms, bonded with hydrogen, oxygen, or other elements. The electrons in these bonds are tightly held and they can’t move about like they do in metals.
However, there are some specially formulated plastics, conductive plastics, that can conduct electricity. These plastics are infused with conductive materials, like carbon or metal particles, to give them conductive properties.
What are conductive plastics?
Conductive plastics are a unique subset of polymers that have been modified to conduct electricity. They take the best bits of plastic, such as flexibility, durability, and ease of processing, and combine them with the ability to conduct electricity.
How are plastics made conductive?
To turn your everyday plastic into something that can carry a charge, conductive fillers or additives are added into the polymer matrix. These fillers can include:
- Carbon-based materials: This includes carbon black, carbon fibres, and graphene. These materials provide good conductivity and are commonly used in many conductive plastic formulations.
- Metallic fillers: These can be metal flakes, powders, or fibres. Examples include silver, copper, and aluminium. These fillers offer high conductivity but can be more expensive.
- Intrinsically conductive polymers (ICPs): These are polymers that are inherently conductive without the need for fillers eg polyaniline, polythiophene, and polypyrrole.
- Electrical conductivity: This can range from being antistatic (preventing static charge build-up) to being as able to conduct electricity as some metals can, depending on the type and amount of filler used.
- Retained mechanical properties: While adding fillers can change the mechanical properties of the base plastic, plenty of conductive plastics can retain the characteristics of normal plastic.
- Chemical resistance: Like many plastics, conductive plastics can resist a wide range of chemicals, making them suited to a wide range of environments.
Where are conductive plastics used and what for?
- Electrostatic Discharge (ESD) protection: In electronics manufacturing, components can be sensitive to static electricity. Conductive plastics can be used to make containers, trays, or tools that prevent the build-up of static charge, protecting these components.
- Electromagnetic Interference (EMI) shielding: Devices like smartphones, computers, and other electronics can emit or be susceptible to electromagnetic interference. Conductive plastics can be used in casings or components to shield devices from EMI.
- Heating elements: Due to their ability to conduct electricity, these plastics can be used to create flexible heating elements in applications like car seats, mirrors, or even in some wearable tech.
- Sensors: Conductive plastics can be used to create flexible sensors for detecting pressure, strain, or other forces.
- Touch screens: Some touch screens use conductive polymers as part of their sensing mechanism.
- Fuel lines and tanks: In vehicles, conductive plastics can prevent the build-up of static electricity, which can obviously be a hazard in something that uses fuel to operate.
- Batteries and capacitors: Some advanced energy storage devices utilise conductive polymers in their design.
What are the advantages and disadvantages of conductive plastic?
- Lightweight: Compared to traditional metal conductors, conductive plastics can be much lighter.
- Corrosion resistance: Unlike metals, plastics don’t corrode.
- Design flexibility: Plastics can be moulded into complex shapes, allowing for more design options.
However, there are a couple of distinct disadvantages:
- Cost: The addition of conductive fillers, especially metals, can increase the cost of the material.
- Conductivity limits: While they can be made to conduct electricity, conductive plastics can’t usually match the conductivity levels of pure metals.
Wheatley Plastics has worked with many electronics manufacturers over the years, moulding plastic for products such as security cameras and measuring instruments. To find out how we can help you, please get in touch for an informal chat.