Static Control Equipment
Controlling static does not have to be a hair-raising experience.
Talking about static – and the different places it comes from – might cause one to reminisce back to middle school science class. And some might even recall an inventive (or lazy) student rubbing a balloon on his head as his science project.Converting and packaging professionals are quite familiar with static electricity, and controlling it is part of day-to-day operations. H. Sean Fremon, of Cole Static Control, in the Encyclopedia of Packaging Technology, provides a concise but scientific definition, and discusses static’s relationship to packaging and converting: “Static is the excess or deficit of electrons on a material. A regular nonpolar atom has a nucleus with a positive charge and negatively charged electrons orbiting it. When one atom comes in close proximity to another, electrons from the orbit draw or tear away electrons, leaving one atom with an excess of electrons and the other with a deficit. This process, called ionization, leaves the atom with the excess carrying a negative charge, while the one with the deficit carries a positive charge. Static in packaging manufacturing is caused by friction, separation, heat change and improper grounding. Packaging and material handling equipment often incorporate a combination of these to accomplish its function."
Regardless of the cause, label converters are well aware of the negative effect static can have: machine jams, material waste, operator shocks, or decreases in product quality and productivity. In worse case scenarios, static electricity can injure employees, cause fires, and even explosions.
Though you cannot see, touch, taste or smell static charges, they become quite evident when they affect profitability and productivity. For the narrow web converter, there’s a wide range of products and machinery that prevents static from doing just that.
Simco, headquartered in Hatfield, PA, USA, offers several static control products, and has recently added to its offerings, having acquired Ion Industrial, a move that makes for a comprehensive product portfolio.
Simco’s PerforMAX IQ Remote Monitor gives operators real-time system feedback no matter where they are in the plant.
“One of our newest and most effective systems is the PerforMAX IQ. Ideal for various converting applications, this innovative system maximizes the controlled removal of static charge on films, paper and nonwovens. With static bars specifically engineered for high-speed webs, long-distance neutralizing, or hybrid installations, the PerforMAX IQ can be perfectly matched to the application. When combined with an IQ communication module, downstream static charge monitor, and optional remote control, operators have an extremely efficient system ideal for any narrow web slitting/rewinding operation,” says West.
Another product West says is popular among label converters is the PerforMAX Easy static neutralization system. “This rugged system is very compact, yet powerful. It consists of a high-efficiency static bar (available in various lengths) and an integrated high-voltage power supply. The bar’s reinforced profile makes it extremely durable and easy to clean without risk of bending and damaging the bar. PerforMAX Easy systems are also readily matched to high-speed as well as long-range applications for optimum static neutralization,” she says.
For converting applications that require a temporary static charge during production, the Chargemaster VCM is a good fit. “Depending on the application, the Chargemaster creates a powerful positive or negative charge to get one material to adhere to itself or another material,” says West. Common charging applications include pinning blown-in post cards during bindery, web-to-core leading edge pinning during continuous winding operations, pinning labels in molds prior to plastic injection, and pinning high-speed printed webs to chill rolls to eliminate unwanted condensate.
The programmable Chargemaster VCM can be paired with different charging applicators and bars to provide the best method of applying the electrostatic charge for the process, maximizing the efficiency of the application.
“Converters keep raising line speeds to yield higher productivity. As the web moves faster, however, more electrostatic charges get created. As lines run faster, more web material is put at risk should a process problem arise. Thus, controlling static charges becomes even more critical.”
The best solutions are the ones tailored to do the job effectively, West adds. “For example, Simco offers different systems engineered for neutralizing webs running speeds up to 3,000 fpm and distances up to 30" away. Closed loop systems monitor static charges on high-speed webs and automatically adjust neutralizing output. Portable communicators, like the PerforMAX IQ Remote Monitor, give operators real-time system feedback no matter where they are in the plant. Likewise, static control systems that easily integrate into process PCs or PLCs provide greater control over production quality.
“Regardless of line speeds, converters need the most efficient static neutralizing and static charging systems in order to meet today’s profitability goals, to keep workers safe, and to achieve optimum product quality without fail,” West says.
Exair, Cincinnati, OH, USA, offers multiple static control systems for the narrow web market. And according to Kirk Edwards, application engineer, choosing the best product for the application generally depends on two characteristics of the application. “First,” he says, “do you need compressed air assistance due to high speeds or distance from the target? Second, what size area do you need to cover with the static eliminating ions?”
Edwards notes that non-air assisted products like Exair’s Ion Bars and the Ion Point should be mounted within 2" of the target. “They are typically best for slower web speeds and are offered from 3" to 96" lengths. These products do well on narrow webs because they have a small footprint and can be mounted in the tight quarters of many narrow web applications.”
For applications that run at high speeds, or when products cannot be mounted within 2" of the target, some air assistance is necessary, Edwards says. “The Super Ion Air Knife, Ion Air Cannon and Ion Air Jet are air assisted and supply air flow to break the boundary layer of air created by the high speed web. They are also capable of covering larger areas than an Ion Point or Ion Bar. Choosing the product to cover the right sized area is the next simple step – A Super Ion Air Knife to cover the width of your web or an Ion Air Cannon mounted remotely to flood an area where operators are getting shocked,” he says, adding that Exair’s most popular items for narrow web applications are Ion Bars and Super Ion Air Knives.
Exair’s SuperIon Air Knife
As more a narrow webs and labels are coated or made from films and run at higher speeds, Edwards believes static will continue to be on the rise. He says, “And since static electricity will cause a variety of problems, including contamination, reduced ink quality and improper web feeding, static elimination will continue to be high on your priority list. If you want to keep up in this highly competitive market, the quality of your product may depend upon removing static from your process.”
Meech, with global headquarters in Witney, Oxfordshire, UK, has been around since 1907, and for the last 50 years has specialized in static control equipment.
David Rogers, business unit director, static control, points out that static control equipment has improved greatly over the past 10 years.He says, “Modern, resistively-coupled ionizing bars are several times more powerful than their predecessors and can control charges on the fastest of presses. In fact, they are regularly fitted to converting machinery capable of web speeds in excess of 800 m/min.
The Meech Model 915 is used on the web path
at points where charges need controlling.
Rogers says that for the label market, long range pulsed DC ionizingbars are particularly effective on unwinds and rewinds. “The Meech model 976 will control the charges that otherwise would cause dust attraction and operator shocks. Short range ionizing bars, like the Meech model 915, are used on the web path at points where charges need controlling.Both Meech bars are designed to operate effectively for long periods between cleaning operations. Despite being among the most powerful bars in their class, shockless emitter points make them safe for the operators to use,” Rogers says.
According to Rogers, RFID tags require particular expertise when it comes to static control. “The application and lamination of the tags is highly sensitive to static. Levels of static that would normally go unnoticed will damage the tags and lead to very low yield levels. Careful control of the charges on the web at each stage of the process is vital to raise productivity.This is an area where specialized help from experienced suppliers is required.”
Staticure, Marblehead, MA, a division of Alpha Innovation, focuses on static control products that are simple and easy to use.
Staticure’s StopStatic Rod
High static attracts dust to substrates, Larkin says, causing repeating defects on labels. The challenge is that the substrate needs to be kept static-free throughout the unwinding over several rollers before printing. “The Static String brand cord can be draped over the unwinding substrate and after each roller that generates static attraction. With attention to placement, attraction of dust can be eliminated. The ionRod has a magnetic mounting base so it is simple to position and move to where the static is generating. And when it comes to dealing with shocks to operators near statically charged materials, the ion360 rods can be placed near the substrate to eliminate the static,” he says.
Larkin emphasizes that unlike electric static bars and tinsel, Staticure customers enjoy how easy it is to move the products around to different locations. “It’s all about performance, ease of use and low cost,” he says. Consistency is another attribute. “The Stopstatic Cords and ion360rods are more consistent during use because they do not attract dust to points like the active electrical bars. They offer consistent performance because they do not need to be maintained or replaced,” Larkin adds.
“Simple is always better when it works,” says Larkin.“The Stopstatic products perform without high voltage transformers with little maintenance. Placement is very important, and this is our biggest advantage.”
NRD, Grand Island, NY, USA, manufactures a linear ionizer called the Nuclestat Bar. And what sets this device apart is that it’s self-powered. All the end user needs to do is properly place the bar and connect its ground strap.
“The Nuclestat Bar has no moving parts, nothing to fail, no points to clean as with traditional powered ionizers,” says Greg Gumkowski, director of sales and marketing. “It's like Ron Popeil’s favorite saying, ‘Just set it and forget it!’
The Nuclestat Bar will operate continuously for 12 months, he adds. “At the end of the 12 months, the end user can order a replacement and simply change-out the device.”
For high speed applications, the Nuclestat Bar can be ordered with “passive” stainless steel ionization brushes that are incorporated into the front protective grid.
“Another interesting facet of the Nuclestat Bar is that because it is self-powered, it is intrinsically safe for use around solvent based applications,” Gumkowski says.