Static electricity is something that we talk about often here at EXAIR. When an atom gains or loses an electron from its outer shell, it becomes electrically imbalanced. A material’s propensity to either gain or lose an electron is “ranked” on a list known as the Triboelectric Series. Static Electricity is generated in a few different ways: contact static build up, detachment static buildup, and frictional static build up.
Detachment static build up occurs when a material is in contact with another and these two surfaces separate from one another. During the separation, not all of the electrons are able to get back to their original molecule. This results in an instantaneous static charge as the electrons are transferred from one object to another in accordance with the Triboelectric Series. Due to the large surface area in most detachment static buildup scenarios, the amount of static generated is typically far greater than contact static buildup.
One of the most common types of detachment static buildup occurs as material separates from a roll. This typically occurs at a high rate of speed and the large surface area across the width of the roll presents an ideal situation for static buildup. This charge can cause the material to stick to itself and not come off the roll properly, creating issues down the line. It can also result in painful shocks to operators, which not only presents a safety hazard but also negatively impacts productivity and morale.
I recently worked with a customer that needed a solution for removing this static from a roll as it was placed onto their work table. The customer manufactures a variety of clothing and equipment used by the military. One of the materials used in their combat clothing provides protection against heat transfer should the wearer be exposed to fire, explosions, etc. that are common on the battlefield. The material is lightweight, but a coating on the surface allows for a significant amount of static to generate as it is unrolled. This presents two separate issues for them. The machine must be stopped to fix the roll as it jams. When fixing the jam, the operator must grab a hold of the material and manually feed it back onto the roll. When doing so, they’re occasionally met with a very unpleasant jolt in addition to the time wasted stopping and restarting the process.
The solution was to install a 42” Gen4 Super Ion Air Knife blowing onto the roll as it unwinds. The positive and negative ions from the knife neutralized the charge on the surface of the material and stopped it from jamming. The customer estimated an increase in production of nearly 20% as they weren’t stopping to fix the jam. The shocks that resulted from having to fix the subsequent jams also stopped. If static is causing production problems in any of your processes EXAIR has the solution ready to ship from stock. Give us a call today and an Application Engineer will be happy to help prescribe the solution to all of your static woes.