Static is coming!!!! With the EXAIR Static Eliminators, we can eliminate any type of static to remove the “hiccups” in your operations. In the video, I will demonstrate the effectiveness of the Gen4 Super Ion Air Knife to remove static and debris on non-conductive surfaces.
One of the biggest issues in winter, besides being cold, is static. An outside sales representative was responsible for selling and servicing industrial inkjet printers. He started to receive more complaints about the quality of the print, especially from customers that used plastic bottles. This customer was printing a date code on the outside of a soda bottle prior to packaging. They noticed that the print on the back side was blurry and could be rejected by their distributor. We discussed how static can cause issues like this with printers.
We had a good discussion about how to solve their problem because EXAIR is the leader in Static Eliminators. The quality of the image is based on the dots per inch, or DPI. With very fine droplets, static charges can affect the “landing” area of the small droplets. For the application above, the plastic bottles were generating static charge by bumping and rubbing against each other. A static voltage is generated in either positive or negative charges. The stronger the charge, the stronger the force. To measure the static charges, EXAIR does offer a Static Meter to quantitatively measure the amount of voltage of the static surface.
With a decrease in the moisture that is present in the air, static charges are able to build easier and to a much higher level. Material is the other condition for static generation. The type of non-conductive material will determine how easily it will pass or except electrons. The soda bottles above are made from polyethylene terephthalate, or PET. This material has a moderate ability to generate static electricity. But the charge was enough to affect the print quality.
With the nature of static elimination, we want to target the affected area. In this instance, it was just before the inkjet printer. I recommended the model 8003 Gen4 Ionization Bar with the model 7960 Gen4 Power Supply. The EXAIR Static Eliminators are able to produce both positive and negative ions to neutralize any type of static. They were able to mount the Gen4 Ionizing Bar alongside the bottle near the print area. After they added the Ionization Bar, the static was removed and the date code printing was clear. They were so impressed that they contacted the manufacturer of the inkjet printer to have this as an option for similar applications. Static is a nuisance, and EXAIR has nine different types of Static Eliminators to handle industrial areas as well as labs and clean rooms. If you are experiencing static issues, you can contact EXAIR and speak to one of the Application Engineers. We will be happy to help you select the best solution for your static problems.
EXAIR published a white paper, Basics of Static Electricity, explaining what causes static electricity; how it is generated; and steps to eliminate it. You can download this paper HERE, and begin to remove the static issues in your plant or process.
In this blog, I would like to expand on the subject about how static can be generated. On a molecular scale, the outer electrons that are orbiting the nucleus can be “stripped” and redistributed from one atom to another. This will cause an electrical charge imbalance called static. An additional electron will create negatively charged static while atoms losing an electron will create a positively charged static. With non-conductive materials like plastic, paper, rubber, glass, etc., the electrons cannot move back to the original atom. There are three common methods of static generation that will cause this phenomenon to occur. I will explain each one in a brief detail below:
Contact – Whenever objects hit each other, electrons can be passed to or received from the surface of another object. The number of electrons being transferred is based on the type of triboelectric material. But, with plastic bottles or trays bumping into each other on conveyor belts, static can be generated relatively easy.
Detachment – when one material is being separated from another material by peeling, electrons may not able to return back to the original molecule. Adhesive tape and protective films are prevalent in generating static charges by detachment because of the larger surface areas. As an example; when the backing material is being removed from labels, the static will cause the labels to be misaligned or cause jams.
Frictional – This is one of the most common reasons for generating large static forces. It is caused by two non-conductive surfaces being rubbed together. The amount of force being applied to the material as it slides back and forth will create higher static charges. As an example, it is noticed when you rub a balloon on your hair. The more times that you rub the balloon against your hair, the stronger the static forces, allowing the balloon to “stick” to the wall. It is also noticed as sheets of material are stacked or running over rollers.
Static tends to propagate. The more contact, detachment, and friction that occurs; the higher the static charge. Even when the static is removed from the surface, static charges can still regenerate by the same mechanisms above. So, controlling the static can be determined by the type of treatment as well as the location for removal.
Another variable that affects static generation is humidity. Most process problems are noticed during the winter months as the ambient air is drier. With a lower relative humidity, static can develop easier and with greater strength. We always refer to winter as static season. You may even notice this when you walk across the carpet and get zapped by touching a door handle.
Production problems can occur like dirty surfaces, tearing, alignment, jamming and shock to staff with static. EXAIR has a number of Static Eliminators to remove these process snags that can cost your company money. You can contact an Application Engineer at EXAIR to discuss any static issues that are occurring.
International Application Engineer
In a recent blog post, I discussed the theory behind how static is generated (if you missed it, check it out here!!). One of the troublesome aspects about static electricity is that it’s hard to measure. The static charge on the surface of a part is not visible, that is unless the charge is high enough to result in a static discharge to nearby equipment or personnel. In most cases, issues related to static aren’t always 100% clear and are impossible to measure without the right equipment. So how do we measure static?
It’s actually simple: EXAIR’s Model 7905 Static Meter is designed to take the guesswork out of the equation when evaluating static charges. It allows for an easy one-hand measurement of the static charge on the surface. This allows you to measure in numerous places in the process to evaluate the true source of the static. In most cases, the highest voltage reading will indicate the source of your static problem.
The 7905 Static Meter is sensitive and responsive, indicating the surface voltage and polarity on objects up to +/- 20kV when measured at 1” from the surface! On the front face of the meter is a hold button, a battery indicator, and a “zero” button to zero out the instrument and ensure an accuracy of +/- 5% of the reading when 1” from the charged surface.
When looking for a method to identify the source of your static woes, EXAIR’s Static Meter is an ideal fit. Since the method used to neutralize this static is also invisible, using a Static Meter in conjunction with any EXAIR Static Eliminator allows you to confirm and quantify the result of the products working as intended. To do this, simply take a measurement of the surface before and after treatment with any EXAIR Static Eliminator. After being exposed to the static neutralizing ions, the residual static charge should be neutralized and able to be confirmed on the display of the Static Meter. For customers and applications that require it, EXAIR also offers an ISO 17025 Accredited Calibration service.
The Static Meter is the only device that will allow you to identify and quantify any static charge. Don’t continue to let static charges wreak havoc in your processes, we have them available to ship today from stock alongside all of our cataloged Static Eliminators!!!
Tyler Daniel, CCASS
Application Engineer/International Trade