This may come as a shock to most people, but static electricity is the unseen curse of production.
For most people static electricity is nothing more than a mild shock when touching a car or a party trick with a balloon rubbed on the hair and stuck to the wall. However, for thousands of manufacturers the ability to make something free of static electricity is a crucial component.
But what exactly is static electricity, and where are anti-static products used?
While the first writings on static electricity date back to the 6th century B.C., it is only in the last few years that nanotechnology researchers have truly begun to understand why rubbing two surfaces together can create electricity.
This is because the root cause of static electricity is from the minuscule bumps and crevices that can be seen on objects at the nanoscale.
As Christopher Mizzi, a doctoral candidate in materials science and engineering at Northwestern University, explains, “If you look at Earth from far away, the planet looks very smooth, like a perfect sphere. We know, however, that in reality, Earth is far from smooth, but you have to look at it closely to see that. It's only when you zoom in far enough you notice that there are mountains and hills.”
For nanotechnology researchers, the tiny mountains and hills on everyday objects, such as the surface of a balloon, are called ‘asperities’.
Mizzi and his co-authors studied the way that asperities create electrical charge at the nanoscale and have now published their findings in the journal Physical Review Letters.
As the journal LiveScience explains, “Mizzi and his colleagues discovered that static electricity is produced when the asperities in insulators [such as rubber, wool, and hair] rub against each other and interfere with the electron clouds. Since the electrons in insulators can’t move around easily, that rubbing can bend the electron clouds out of shape.”
In insulating materials, the cloud of electrons around atoms is usually symmetrical, but if the electron cloud is squeezed, it deforms and becomes asymmetrical.
“When the two materials rub against each other,” the report explains, “the bumps on one surface drag along the asperities on the opposing surface, causing them to bend. When this bending happens, the electron clouds in the atoms that make up the asperities get squished into asymmetrical shapes, causing a very, very small difference in voltage.”
If the difference in voltage is enough, we can feel or even see static electricity when the insulator comes into contact with a conductive surface.
For the man in the street, this is no more than a slightly painful inconvenience, but for manufacturers and product designers it can destroy equipment. The importance of which should not be understated, in the wrong place, static electricity can even be lethal.
For this reason, a variety of anti-static products have been created. These include the following;
Anti-static coatings are needed for all kinds of tanks where the build-up of static electricity could either cause an explosion or damage the tank’s contents. As such they can often found in fuel tanks, barge tankers, chemical processing tanks, hopper cars, as well as road and rail tankers.
Anti-static coatings are often made of epoxy resins that possess excellent conductive/static-dissipating properties, superior bond strength and adhesion, as well as high resistance to both abrasion and impact. They are also often required to be water and chemical resistant, and as they are frequently used for transportation they must be flexible and be able to withstand vibration.
Anti-Static Protection for Electronic Devices
There is a wide range of anti-static raw materials that are used to protect electronic equipment. These include polyester gelcoatings that are used on small control and measuring instruments as well as other equipment in the oil and gas industry.
Anti-static PET film for screen protection in mobile phones.
Anti-static PET trays for the storage and packaging of electronic devices, such as laptop, printed circuit boards, memory modules, PCBA storage, hard drives and electronic telecommunication devices.
Anti-static PSA films for use in flexible components such as LCD displays, as well as packaging for electronic devices and dust containment coverings. These films are also used to make anti-static tapes and labels.
To find out more about how industry is solving the problems of unwanted static electricity, read: Anti-Static; Problems, Solutions, Products Part 2