EXAIR Eliminates Static – Public Enemy Number one in the Printing Industry

Static electricity is the enemy of the printing industry. Downtime and inefficiency caused by static means longer lead times and angry customers! EXAIR can remove static electricity in the many printing applications across wide and narrow webs.  With our rugged line of EXAIR Super Ion Air Knives and Ionizing Bars, EXAIR can improve your efficiency and printing quality.

Digital printing dries out the printed substrate, creating high static charge that can cause printing defects, ink overspray, and even print head clogging and print head shorting issues. If a press is printing on non-porous substrates like plastic, metallics and highly coated glossy papers, a device called a corona treater is used to increase the surface energy of the substrate to ensure the ink droplets adhere and do not spread too much on the substrate. A byproduct of the corona treatment is static charge, which must be removed. This can be achieved by installing an EXAIR Ion Bar after the corona treatment device across the web.

Static is also created anywhere in the printing or finishing operations where sheets are moved over each  other.   Sheetfed presses, for example, create friction in the stacking of individual sheets on top of each other.  This friction induced static creates misfeeds, print registration issues, multiple sheet pickups and equipment jams.

Folding operations cause static issues too. Like a sheetfed press, static is created by folded pieces being dragged across each other.

In both cases, installing an EXAIR Super Ion  Air Knife or Ion Air Cannon that can direct a stream of ions between the stack and the top sheet can eliminate the static that causes misfeeds and jams.

The typical easy fix printers employ is what’s called a tinsel bar. Also called garland, it looks just like what you drape on a Christmas tree, except that it’s made of highly conductive copper that needs to be grounded to the printing press.The problem with tinsel bars is that although they are cheap initially, they don’t last long. They’re not a set-it-and-forget-it solution. The sharp strands work on induction and interact with the static field on the substrate creating a neutralizing cloud that surrounds the area, reducing both positive and negative ions. Printing operations are usually dusty environments and when the tinsel becomes dusty, oxidized, or matted and crumpled, they don’t work as effectively.

Static is also created in unwinding and rewinding operations, when rolls are slit to needed widths of various presses. The removal of the web from the roll creates static charge that attracts dust to the substrate surface and can cause major problems in downstream printing operations. Installing an EXAIR Ion Bar on top of the web can elimnate this static.

EXAIR Super Ion Air Knives don’t need to be placed close to the surface like a tinsel bar. Static dissipation of 5 KV can occur in less than a half second up to 20 feet away and can be adjusted from a blast to a breeze, depending on static level.

If you are a printer, finisher or labeler, EXAIR has a static elimination product that can improve your operations. For more help you can contact one of our EXAIR application engineers to talk you through a solution.

Dann Woellert
Application Engineer
dannwoellert@EXAIR.com
@EXAIR_dw                    

EXAIR Gen4 Ionizing Bar Removes Static From Corona Treated Plastic

If you want to print on plastic, it’s challenging – most plastics are chemically inert and non-porous.  That means you can apply all the ink you want; it’s not going to stick.  In the 1950’s, a Danish engineer named Verner Eisby experimented with various techniques to overcome these challenges.  He found that exposing the surface to be printed on to gas flame or sparks modified the surface to improve adhesion with the ink.  It did so, though, in a crude & uneven manner, leaving imperfections & inconsistencies in the printed product.  He then tried applying a high frequency corona discharge in a linear array.  The plasma (gas in an ionized state) generated left a homogeneously treated surface on which to print, smoothly & evenly.

This has become the “industry standard” for many of the labels we see on commercial products, from shampoo & wine bottles on the grocery store shelf, to pennants & banners at public events.  It also leaves the surface even more prone to picking up a static charge from rolling or unrolling, stacking, sliding, etc.

One of our customers makes a great many labels for all kinds of these commercial products, and uses an EXAIR Gen4 Ionizing Bar immediately prior to the printing operation:

Model 8024 24″ Gen4 Ionizing Bar removes static from Corona treated plastic label film.

EXAIR Corporation has a variety of Static Eliminator Products to fit most any industrial or commercial application.  If you’d like to find out more, give me a call.

Russ Bowman
Application Engineer
EXAIR Corporation
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