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:
Just recently I worked with our Distributor in Argentina on an application for a manufacturer of bottled water. Once the bottles are filled, a protective security seal is placed along the top of the bottle. This serves two purposes, it prevents any form of tampering as well as keeps the cap of the bottle clean throughout the rest of the manufacturing process. Since most people drink directly from the bottle, this area needs to remain clean and not be exposed to contamination later on in the process.
Their problem was that static was building up on this plastic which caused an improper seal on the cap of the bottle. Further down the processing line, the bottles can be exposed to water that contaminates the bottles. They had to implement an inspection process as it was not acceptable to allow any contaminated bottles to leave the plant. Without a solution, they were losing time due to the necessary inspection as bottles were being rejected at a rate of almost 30%.
The recommended solution was to install a Model 8164 4″ Gen4 Super Ion Air Wipe just prior to the point in the process where the seal was applied. The plastic material passed through the center of the Super Ion Air Wipe which neutralized the static charge on the material. Without a charge, the seal was applied correctly and they were able to eliminate the need of a manual inspection. After installation, the reject rate dropped to 0%!!
The Gen4 Super Ion Air Wipe provides a uniform 360° ionized airstream and is available in both 2” and 4” ID sizes. Its clam-shell design makes it easy to clamp around a part for neutralizing static electricity and contaminants. The high volume, high velocity airflow attaches itself to the surface and wipes it down with static eliminating ions. The airflow stays attached to the surface and is effective up to 15’ away from where it’s mounted. It’s lightweight and easy to mount using the ¼-20 tapped holes on the back or can also be held into place with just rigid pipe.
As the temperatures begin to decline, so does the humidity in the air. Drier air results in an increase in static problems. Get ahead of it this year and check out EXAIR’s wide line of various Static Elimination products, all available to ship same-day from stock!
Quite simply the GEN4 Ion Air Cannon is based on the mechanics of the 2″ diameter Super Air Amplifier that has static reduction capabilities and as its name implies it amplifies the supply air up to 25 times!
This highly engineered product is very effective at cleaning product and reducing static at distances of up to 15′ away.
The GEN4 Ion Air Cannon comes in a handy stand/mounting unit for easy installation in a wide variety of applications. It can be mounted to machine frames, mounted out of the way from a process, or placed on a bench top.
The GEN4 Ion Air Cannon is used in many applications such as bottling, manufacturing of solar panels and preparing new automobile car bodies to be painted – to name a few. Wherever static reduction and/or cleaning is required the Ion Air Cannon can contribute.
EXAIR commonly works with plastic injection molding companies. They produce top quality plastic parts from both commodity and engineering-grade resins for many diverse industries. The customer reached out to us with a problem. A mold that they were running was having some issues. The parts were not releasing and ejecting properly, causing the need to use a mold release, which was slowing down the process by a manual operation to the process. Also, the parts were seeing push pin marks, causing cosmetic issues with the parts. The customer wanted to explore using compressed air to blow the parts free.
Based on the mold size and layout, a pair of 12″ Super Air Knives was installed. The knives are oriented to blow straight down along the face of the mold, one knife per part tree. The strong laminar flow of air hits the parts causing them to release and drop without the use of release agents. Also, the push pin marks are within normal standards, eliminating the the cosmetic concerns.
This is just one example of how intelligently using compressed air can help improve a process. By using air knives for wide areas or using a 1″ Flat Super Air Nozzle for very small parts, or anywhere in between, we can help to solve your part ejection issues and make your process run better, faster, and with higher quality.
If you would like to talk about Super Air Knives, Flat Nozzles or 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.