Static electricity is an imbalance of electrical charges within or on the surface of a material. The charge remains until it is able to move away by means of an electric current or electrical discharge.
Nature likes things to be in balance, therefore static electricity will inevitably result in an electrical discharge unless otherwise redirected by means of a pathway or current.
So the question is… How does an imbalance of electrical charges occur?
The answer is with the Triboelectric Effect.
To understand it, we first need to review a few basics.
Where Electrical Charges Come From
At rest, objects are neither negatively nor positively charged. In this state, they are considered neutral with respect to electrical charge.
If you remember your high-school physics on the construction of the atom, you’ll recall that every atom has protons (which are positively charged) and neutrons (which are neither positively nor negatively charged) in the nucleus, which is surrounded by electrons (which are negatively charged).
The atom holds onto its nucleus very tightly—in fact the forces that hold the nucleus together are, quite literally, nuclear.
The electrons, on the other hand, have the ability to flow from one object to another by contact. Some objects are more willing to release electrons than others, while other objects are more able to attract electrons. Whether electrons are likely to come or go really depends upon the materials, the pairing of two objects and other environmental conditions, such as air quality.
Materials have been ranked by scientists in the order of their ability to hold or give up electrons upon contact. This ranking is called the Triboelectric Series.
The Triboelectric Effect
Under ideal conditions, if two materials are rubbed together, the one higher on the list should give up electrons and become positively charged.
With repeated contact, a bond is created between the objects as the two items exchange electrons. However, when separation occurs, each object does not necessarily carry off the same number of electrons that it brought to the party.
Therein lies the imbalance of electrical charges where one object will have a buildup of negative charges and the other a buildup of positive charges.
This process of building up an electrical charge through contact is known as the Triboelectric Effect.
How Does Electrostatic Discharge Occur?
You have heard that opposites attract. So it is with the negatively charged and positively charged objects.
Remember we said earlier that nature will seek out a balance? Therefore, when you move a more positively charged item close to an item that is neutral or more negatively charged, the electrons will be attracted to—and try to flow toward—the positive charge. The same is true in reverse.
This movement of the electrons seeking balance is the electrostatic discharge, which creates a shock or spark—sometimes too small to detect, and other times quite powerful and destructive!
It is very important to be aware and understand the movement of these electrons through a work space in order to limit the possibility of costly and damaging discharges of static electricity.