Static Elimination Improves Credit Card Printing and Production

PVC Base Sheet for Credit Cards

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.

All EXAIR Gen4 Static Eliminators use one of two Power Supplies – your choice of the 2-port Model 7960, or the 4-port Model 7961.

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.

John Ball
Application Engineer
Email: johnball@exair.com
Twitter: @EXAIR_jb

Shocking Credit Cards Costs … In Manufacturing

Winter’s weather comes with a variety of problems. I hope that folks in the Northeast get a break from all this snow soon. In Cincinnati we have not had to deal with much precipitation this year, but it has been cold and gloomy for too long. Personally, I am ready for spring to come and to the see the flowers pop up. I’m also tired of the getting shocked every time I pet my dog. Also, his hair that generally falls everywhere is now stuck to the side of couch.

On a more serious note, the dry air of winter can have a significant impact on manufacturing processes. The same static that attracts dog hair to a couch will also attract dust on to a non-conductive substrate like plastic or glass. I was working with a customer this week who manufactures credit cards and gift cards with custom logos. They fell prey to the dry, statically charged air of winter which caused a quality issue during these winter months. To create the promotional cards, the company would first digitally print the logo on a PVC substrate. This substrate is then stacked to await lamination. As they pulled each sheet from the stack, a charge would build up on the surface which would attract any dust in the area. The dust needed to be removed before the last clear layer was applied or it showed up as ugly bumps on the card surface. This dust was nearly impossible to clean off and still maintain a good finish on the PVC substrate. They tried to wipe the material off with soft fabric, but the rubbing only increased the static while moving the dust around, not off the laminate.

1559 before
Laminating station two stacks of PVC substrate in the plastic bins
1559-photo
Laminating Station with the 110036″ Super Ion Air Knife installed

Using an EXAIR Static Meter, part number 7905, the customer measured 19.5 kV/inch on the PVC sheets before lamination. Because of this charge the customer installed a 36″ Super Ion Air Knife, part number 111036, above the lamination station. The operator would pull a sheet from the stack and pass it under the Super Ion Air Knife. After passing under the Super Ion Air Knife the charge on the sheet read 1.3 kV/Inch, and the dust was removed by the air blowing from the Super Air Knife. This dust removal drastically reduced their scrap levels. In the 3 months of winter, it was accepted that they would loss approximately 15% of all the cards they created do to blemishes on the cards. After installing the Air Knives, they only scrapped 3% of the cards they created. This scrap rate was even better than there summer production. The air knives will now be used year round.  The Super Ion Air Knife reduced scrap by 80%! Also, operators no longer tried to clean the dust with cloth, which allowed them to increase their production.

Dave Woerner
Application Engineer
@EXAIR_DW
DaveWoerner@EXAIR.com