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:
A company that made credit cards was having issues in their print quality, and static was the culprit. They used PVC sheets as a base material to print on, and like with any non-conductive materials, static can be generated easily and create problems. For this company, static was attracting dirt to the surface of the material, causing blemishes in the print. They contacted EXAIR to find a solution.
When non-conductive materials slide, hit, peel, and rub; electrons from the surface can move from one atom to another; thus, creating static. The type of material and the amount of movement governs the amount of static forces. These strong static forces can attack debris and fibers, as well as generate shocks, misalignment, and machine jamming. Another feature of static is that it can regenerate if the materials continue to slide, hit, peel, and rub.
For the company above, they were printing on 30 cm by 48 cm (12” X 19”) PVC sheets. They used three different processes to print a complete credit card; silkscreen, digital, and offset. After each printing process, they would lose sections of the sheet due to poor image quality. At the end, they were losing between 20 to 30% in visual rejections.
For this application, we had to do two operations; remove the static and clean the surface from debris. The Gen4 Super Ion Air Knife can do both of these operations at the same time. With the laminar air stream that comes from the Super Air Knife, it can carry both positive and negative ions from the attached Gen4 Ionizing Bar. Together, they can remove any type of static charge as well as becoming a very effective tool as a non-contact wiper to remove debris. With this ability, the print quality would not be affected during cleaning. Since static is a surface phenomenon, I recommended to also remove the static from the other side of the sheets. We did not want to have any dirt or debris that could be remaining on the bottom surface to transfer from one surface to the next during stacking. This could scrape the finish during loading and unloading of the sheets.
I recommended two pieces of a model 112012 Gen4 Super Ion Air Knives that are manufactured to 12” (30 cm) in length. This customer can easily mount one above the sheet and one below the sheet prior to printing. To operate the attached Gen4 Ionizing Bar, EXAIR offers two types of power supplies, a two-output unit, model 7960, and a four-output unit, model 7961. They can save you money when needing multiple Static Eliminators to operate in your system. With a model 7960 Gen4 Power Supply, they now had a system to remove static and clean the sheets. Once they installed the Gen4 Super Ion Air Knives onto their system, the rejection rate dropped to near zero.
Rejected parts are costly, wasteful, and reduce production rates. If you have rejection from static problems in your system, EXAIR has a large line of Static Eliminators to help you. You can contact an Application Engineer to review your application. For the customer above, the Gen4 Super Ion Air Knives made it possible to generate more credit cards per sheet.
It’s “plug and play,” all the way. Connect the cable to the Power Supply, and hook it up to your compressed air system, and you’re ready to go.
It’s efficient and quiet. The high velocity jet entrains an enormous amount of air from the surrounding environment, where it’s ionized and ready to eliminate static charge quickly and effectively.
Instant static dissipation, at your fingertips (literally) – squeeze the trigger to blow ionized air, anywhere you want (well, within the reach of the 10 foot cable, anyway.)
Again, the Gen4 Ion Air Gun is just one of our Static Eliminator products. How do you know if it’s the right one? The selection of many EXAIR Intelligent Compressed Air Products comes down to the size & shape of the air flow that will solve the application. Static Eliminators are no different.
If you need to treat a large surface, you might be looking for a Gen4 Super Ion Air Knife. They come in lengths from 3 inches to 9 feet long, and blow a laminar, even curtain of ionized air that’s extremely effective and fast at static elimination, even at very low supply pressures.
If you’ve got large areas, multiple surfaces, or complex geometries to contend with, one (or an array) of these products might be the solution. For a simple, straightforward, hand held static elimination solution, though, it just doesn’t get any easier than the EXAIR Gen4 Ion Air Gun. Call me to find out how you can get one today.
***Order any qualifying EXAIR Static Eliminator by February 28, 2019, and we will include a FREE AC Sensor. Click here for details.***
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The Gen4 Super Ion Air Knife is a powerful static eliminator that prevents jamming, tearing, shocks and dust build up by neutralizing static and blowing away the debris.
The Gen4 Super Ion Air Knife combines the quiet and efficient Super Air Knife with the compact design of the rugged Gen4 Ionizing Bar resulting in a total solution to remove static electricity from plastics, webs, sheet stock and other product surfaces. Removing the static helps reduce or eliminate the process issues that the static electric causes, allowing for greater production speeds, improved product quality and a cleaner product.
The Gen4 Super Ion Air Knife floods an area or surface with static eliminating ions. With a uniform airflow across its length, misalignment to critical surfaces like webs is avoided. The force can be adjusted from a light breeze, to a full out blast of air. The Gen4 Super Ion Air Knife is electrically powered, is shockless and has no moving parts.
How It Works
In the diagram above, compressed air flows through an inlet (1) into the plenum chamber of the Gen4 Super Ion Air Knife. The flow is directed to a precise, slotted orifice. As the primary airflow exits, it creates a uniform sheet of air across the entire length, pulling in in surrounding air (2). An electrically powered Gen4 Ionizing Bar (3) fills the curtain of air with positive and negative charges. The air stream delivers the static eliminating ions to the product surface (4) where it instantly neutralizes static and cleans off dust and other particulates.
The Gen4 Super Ion Air Knives are powerful tools, and very quickly dissipates 5kV of static even at low compressed air supply pressures. At 5 PSIG, only 3.7 SCFM (0.3 BAR, only 105 SLPM) of compressed air per foot of length is required!! Sound levels are also very low, resulting in quiet operation.
Added Features –
Compressed Air Inlets are provided on each end and the bottom of the Super Air Knife
Thicker shims can be installed easily if a harder air flow is needed
Emitter points are sharp, durable stainless steel
The high voltage cable is armored to resist cuts and abrasion, and has integral grounding. Threaded bayonet connector is fully assembled and ready to use
Gen4 Ionizing Bars and Power Supplies are UL Component Recognized to U.S and Canadian safety standards and are CE and RoHS compliant
Power Supplies are 115/230 VAC selectable and come with 2 or 4 outlets
Standard lengths from 3″ to 108″ (76mm to 2743mm) are offered, and custom lengths are available to meet your process needs
Successful applications include web cleaning, pre-paint dust removal, shrink wrapper machinery, printing equipment, package cleaning,and bag opening/filling operations.
If you have questions about Gen4 Super Ion Air Knives, other types of Static Elimination products, or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.
The video below provides details on the simple conversion to the new Gen4 style Super Ion Air Knife from the previous style or the addition of a Gen4 Ionizing Bar to an existing Super Air Knife to add static elimination to an existing blow off.
If you have questions about the Gen4 Super Ion Air Knife or any of the 16 different EXAIR Intelligent Compressed Air® Product lines, feel free to contact EXAIR and myself or any of our Application Engineers can help you determine the best solution.
A manufacturer of high speed industrial machinery makes a sorting machine for seeds. There’s a clear plastic cover for operators to see the seeds as they pass through the machine. Many seeds are dense enough to move right on through, but some lower density seeds (canola, lettuce, and flax seed, specifically) bounce around a bit, and even the slight static charge that builds up as they move through causes them to cling to the inside of that viewing window.
This was a great fit for our Model 8406 6″ Gen4 Standard Ion Air Knife Kit…”fit” being the operative word. While the Super Ion Air Knives are more efficient and quieter, there simply wasn’t very much room at all for mounting inside, so the smaller profile of the Standard Ion Air Knife made all the difference in the world. Also, since they just need static dissipation of such a small area, and not much flow at all is required to blow off these lightweight seeds, the differences in compressed air consumption and sound level were not very much at all.
Recently, I worked with a production engineer at a Tier 1 supplier for the auto industry. An upcoming project was in the works to install a new line to produce headlight lenses. As a part of the process, there was to be a “De-static / Blow-off” station, where a shuttle system would bring a pair of the parts to a station where they would be blown off and any static removed prior to being transferred to a painting fixture and sent off for painting. For best results, the lenses were to be dust and lint free and have no static charge, ensuring a perfect paint result.
The customer was limited in compressed air supply volume in the area of the plant where this process was to occur. 50 SCFM of 80 PSIG was the expected air availability at peak use times, which posed a problem – the Super Ion Air Knives would need up to 105 SCFM if operated at 80 PSIG. A further review of the design parameters for the process revealed that the system needed to blow air for only 4 seconds and would be off for 25 seconds to meet the target throughput.
This scenario lends itself perfectly to the use of a Receiver Tank. Running all of the design numbers into the calculations, showed that the 60 Gallon Receiver Tank we offer, would allow for a 20 second run-time, and require 13.1 seconds to refill. These figures were well within the requires times, and would allow for the system to work as needed, without having to do anything to the compressed air supply system.
The moral of the story is – if you have a process that is intermittent, and the times for and between blow-off, drying, or cooling allows, a Receiver Tank can be used to allow you to get the most of your available compressed air system.
Note – Lee Evans wrote an easy to follow blog that details the principle and calculations of Receiver Tanks, and it is worth your time to read here.
If you would like to talk about any of the EXAIR Intelligent Compressed Air® Products, feel free to contact EXAIR and myself or one of our Application Engineers can help you determine the best solution.