Static discharge is a term that refers to electricity at rest that produces excess cations (positively charged ions) or anions (negatively charged ions) when the molecular structure of an insulating material like plastic or paper becomes unbalanced. Most often, this imbalance is created through separation, changes in temperature and friction.
A disproportionate number of ions can create a number of problems, such as the risk of equipment damage, minor electrical shocks to workers, and fires. To combat these risks, manufacturers produce static eliminators. These, also known as antistatic devices, are any product that protects susceptible products from the effects of static electricity, by either dampening, reducing, or otherwise inhibiting its buildup or discharge.
Those seeking to combat the effects of static electricity may employ two main types of solutions: active and passive. Active static control systems are those that require power in order to function, whereas passive control systems are those that reduce the surface charge associated with static electricity by absorbing it. Read More…
Of the two types, active static control solutions are far more effective because rather than just reducing the static electricity, they eliminate it. The most common active solution is ionization, or the formation of ions, which neutralizes an unbalanced charge and nullifies any particle attraction that would have led to the creation of more static electricity.
Ionizers achieve ionization through a variety of means, including via chemical reactions, electrical discharge, radiation, high temperatures, or particle collision. Static eliminating ionizers can be divided by whether they use an alternating current (AC) or a direct current (DC). They both have strengths and weaknesses, but AC ionizers have a large advantage in their inherent opposite polarity. In DC ionizers, this quality must be acquired through the use of additional circuitry or power supplies.
Passive static control solutions include grounding and electro-static induction. Grounding reduces static electricity by setting up a direct electric connection to the earth through which excess electrical charges can be discharged. The most frequently used type of grounding static eliminator is the grounding strap, which is used in industrial manufacturing to ground equipment and machinery. Similarly, grounding wrist straps, or grounding bracelets, are worn by people working on or with very sensitive electronic equipment, as well as with those working around explosives.
They prevent electrostatic discharge (ESD) by grounding workers and preventing the buildup of static electricity on their bodies. Likewise, other grounding static eliminators include a variety of grounding garments or clothing. The other main method of passive static electricity control, electro-static induction, works by placing a material or object with the capacity to develop the opposite electrical charge of the unbalanced item, within close proximity of said item.
When they are close enough to each other, the static eliminator will develop a proportionate set of opposite ions and thus balance the unbalanced item. Examples of static eliminators that use induction include anti-static brushes, anti-static bags, and anti-static mats. Various other type of static eliminators include anti-static spray, anti-static gloves, and corona treaters.
Anti-static spray is an atypical mechanism of static elimination that works by coating surfaces with a thin, translucent layer of buildup-deterring spray. This spray is usually made from a soap-based material that has been diluted in a solvent like mild alcohol and, commonly, a flame retardant that works against the solvent’s flammable nature. They work well on surfaces with exceptionally high electric charges, in hard-to-reach places and blocked surfaces, and with products that move at high speeds.
Corona treatment is another uncommon form of static control. In fact, it is actually more of a surface treatment that provides static control as a byproduct. The goal of corona treatment is to condition a surface to be more receptive to bonding with adhesives, inks, and other materials. By exposing surface material to an electrical discharge, called a corona, corona treaters both increase the surface’s bonding capabilities and protect it against static electricity buildup.
Static electricity can impact products in a wide variety of industries, such as automotive, electronics, medicine, plastics processing, printing, power generation, semiconductor processes, and residential services. To determine if their products or processes have been compromised by static electricity and require the service of static eliminators, manufacturers should test them with a static meter, such as an electrostatic fieldmeter or an electrostatic voltmeter.