Tag: printing

Video Blog: Eliminating Static in the Printing Industry

Published on by Tyler DanielLeave a comment

While we’re still dealing with the high humidity and heat of summer in much of the US, cooler temperatures and lower humidity is right around the corner. Your home energy bill will certainly thank you as the less humid conditions allow you to turn off your A/C. While that’s great for lowering your bills, it creates a favorable environment for the generation of static electricity.

When the relative humidity is high, there’s a higher concentration of water molecules present in the air. These water molecules “coat” the surface of the material, allowing electrons to move more freely and form a layer over the material. This layer of water molecules acts like a lubricant, reducing the forces that cause static to generate. There are many applications that static may only pose an issue once the climate changes.

Anyone who works in the printing industry is sure to be aware of the types of problems associated with static electricity. One common application for EXAIR’s Static Eliminators is the neutralization of static in sheet-feeding processes.

Check out this demonstration depicting how the Super Ion Air Knife can be used to “float” a stack of material and saturate it with static eliminating ions. The SIAK can be operated at very low pressures to prevent disturbing the process, while still maintaining the effectiveness required to neutralize any static present on the surface of your parts or material.

As we begin to approach fall and winter, make sure you’re prepared to handle any static by speaking with one of our Application Engineers. With a whole line of products designed for neutralizing static, we have a solution available to ship from stock to ensure you’re prepared this year!

Tyler Daniel
Application Engineer
E-mail: TylerDaniel@EXAIR.com
Twitter: @EXAIR_TD

Solving Static and Increasing Print Quality on Food Packaging

Published on by johnball2014Leave a comment

Gen4 Static Eliminators

A yogurt company printed bar codes on every cup that they produced. This was necessary for registering and tracing their product. After failing a bar code reader quality test, they started noticing some print issues during batch runs. They would have to stop their system, clean the inkjet printer head, and scrap product that would not register with the bar code reader.

This affects production rates, scrap rates, and overall cost. They stated that they threw away 30 to 40 cases per batch of yogurt due to this problem. They had an EXAIR catalog where they found a similar application within our Gen4 Static Eliminator product line. They contacted us to see if we could find a solution.

With non-conductive material like plastic, static is easily generated; especially during cooler weather. Static can be in a negative state or a positive state dependent on the material. For opposite charges, things are attracted to each other and will “stick” like magnets. For similar charges, they will repel each other. The higher the static charge, the stronger the force.

For the company above, the yogurt cups moved along a 7” (178mm) wide conveyor before they reached the bar code printer. This movement causes static to be generated on the surface of the cups. But, what about the inkjet printer? The function of the printer charges the ink droplets for direction and positioning. Since the ink droplets and the cup surfaces have the same charge, the droplets were being “pushed” back toward the printing head (reference photo below). Thus, the ink would dry on the surface and affect the quality of the bar code.

Bar Code Printer

When it comes to removing static, EXAIR is a leader in this market. We have a large product line of different types of Static Eliminators. Our design generates both positive and negative ions to remove any type of static charge. Since we only had to remove the static from the surface of the cup, I recommended a Gen4 Ionizing Bar. With a quick static decay rate, we can remove the static right before the bar code printer with only one Gen4 Ionizing Bar. For this application, I recommended the model 8003 3” Gen4 Ionizing Bar and a model 7960 Gen4 Power Supply. Together, it was very easy to mount and start using. EXAIR stocks lengths from 3” (76mm) up to 108” (2743mm), and we can ship a solution the same day. When you are losing 30 to 40 cases, time matters. And for this company, they received the items the next day to correct the misprints and short printing runs.

Gen4 Ionizing Bar w/ power supply

When problems occur, time can be of the essence. This is why EXAIR stocks our cataloged items for fast delivery.  For the company above, they had an EXAIR catalog which helped them to find a solution. If you would like to have an EXAIR catalog, you can click here to get one.   After they started using the Ionization Bar, the static was removed, the bar code was clean, and the operation ran smoothly. If static is causing issues for you, you can contact EXAIR and speak to one of our Application Engineers. We will be happy to assist you.

John Ball
Application Engineer

Email: johnball@exair.com
Twitter: @EXAIR_jb

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

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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.   Sheet-fed 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 sheet-fed 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 eliminate 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                    

 

 

 

Ionizing Bar

EXAIR Gen4 Ionizing Bar Removes Static From Corona Treated Plastic

Published on by Russ BowmanLeave a comment

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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