Static electricity that we experience in our daily lives is generally harmless, but did you know that static electricity in industrial settings can be dangerous and expensive? With these 10 steps you can neutralize static electricity to minimize costly repairs, downtime, and even injuries caused by the shock, also known as re-balancing or static discharge.
Identify where the static problem is. This is usually the step that alerts that there is a static problem. Is plastic wrap or webbing clinging to itself or machinery? Do you have labels or tape not adhering to packaging properly? You might even have plastic bottles or other parts incorrectly moving across conveyors or mis-feeding. Identify and document all occurrences of a static problem.
Identify the materials involved. Certain materials are more likely to accumulate a static charge than others. Non-conductive materials, such as plastics, are the most common materials to be affected by static. Glass and fabric or fibers can also hold a charge, but may not be as easy to see. Some materials tend to hold more of a negative charge and others a positive charge. These are noted in the triboelectric table. Becoming familiar with where materials in your facility are positioned in the triboelectric series can help predict and prevent static issues.
What process is causing static-related problems? Packaging issues may be seen near the source of the static, while electronics and other things affected by the static may not show visible symptoms right away.
Describe the optimal outcome of treatment. Depending on the concerns of static in your facility, note the desired outcome from static control. Do you have materials that were not feeding correctly out of the hopper, and you want this corrected to reduce downtime and waste? Are you looking at static control to reduce cost and danger from static discharge/rebalancing in electronics and employees? Ionizers may be added/located near the source of the static for neutralization. Production speed can be adjusted to reduce friction. Remember, the source may not be just one location, and multiple areas may require treatment.
Identify the ideal treatment locations. Determine the areas that need static management, keeping in mind that neutralizing static does not necessarily need to be done at the source and that resolving the static at one location can affect other locations. For example, packaging picking up dust from a static charge does not really need to be resolved until right before labels or tape is adhered to them. Otherwise this neutralization might have to be done multiple times when it isn’t causing any harm. Identify all the locations that would make the most sense to apply the different treatment methods for your process and materials.
Measure the magnitude and polarity of charge Handheld meters can be used to test the presence, amount, and polarity of the charge. Measuring the static can let you know how much opposing charge is needed to level out the static imbalance.
Select the best ionizer for your needs. There are different types of ionizers for different purposes and area sizes. One type adds ions to a jet of compressed air. This method is manually operated and are typically used for cleaning small targets, such as packaging to be labeled. Another type of ionizer blows air past ion emitters. These can be used for a bit larger of an area and do not need air compressors. The downside to this type is that the ambient air may not be clean and could introduce contaminants to production. A third type of ionizer is used in areas where a long or wide target area needs to be treated. This type has bars that create a curtain of ionized air and can be positioned parallel or perpendicular to the objects path to better control the static reduction.
Install the ionizer and position according to target area. If an ionizer is needed to reduce static, proper placement and orientation is important to ensure that the ions are directed to the target area in the amount needed. Re-balancing will occur quicker if the ions are being generated as close as possible to the target, because the further away they are generated the more likely there will be interference or ions may go to other objects.
Adjust ionizer settings to meet needs. Having the ionizers on full power all the time could cause an issue in the opposite polarity from too many ions of that polarity being introduced. The speed of the fans in fan ionizers should be adjustable. Higher speeds provide ions faster, reducing the static faster, but also can upset light/loose items. Bar ionizers have controls on ion polarity, pulse frequency, and balance to give the greatest control. The compressed air ionizers have changeable nozzles and bars.
Observe, compare, and repeat if needed. Once the ionizer is in place and any other adjustments are made, observation and measuring is important to see if the changes are satisfactory. If there is still a static issue, ionizer settings may need to me adjusted, and the steps may need to be repeated. If the results do meet the optimal outcome, don’t forget to keep an eye on energy consumption and production costs.
To learn more or purchase ionizers, static sensors, or any other static control products, contact your local SMC branch.