Our Greek distributor came to me the other day with a production issue for one of his clients. They manufacture foam in a variety of forms for many different end uses. In this particular case, the customer was working with a flat web of foam. As they are un-rolling and processing the foam, a decent amount of static charge builds up on the material which eventually causes discharges to the rollers in the machinery and to operators as well. The discharges are dangerous to personnel as they can be quite potent, causing a reflexive jerk back which can put the operators into a dangerous position with respect to machine components, not to mention that they are just flat out uncomfortable to receive. Another issue is that the discharges also cause blemishes on the surface of the white foam where they occur. Such blemishes are considered a defect and are therefore another reason that the customer wants to investigate active static elimination.
As you can see in the above photo, the customer has a couple of ground “probes” if you will, that ride on the surface of the foam web. They do this in hopes that the charges will “drain off” to Earth ground. While this kind of “passive” static elimination can be useful in certain circumstances, many times is just not sufficient to completely neutralize the material as needed for the process. We reviewed the line speed in the application and the web was moving at a reasonably slow 10 – 15 meters per minute. With this in mind, the EXAIR Ion Bar would be a perfect fit to provide the necessary ions to “actively” discharge the electrostatic field. By actively, I mean that the ion bar produces positive and negative ozone ions which are actively delivered and come into contact with the material. This causes the net charge to drop to a much lower level than simple grounding techniques just cannot get to.
We ended up recommending two pieces of model 7042 (42” Ion Bar) (one for each side of the web and model 7907 (2 outlet Power Supply, 230 VAC input) for the application. These bars have eliminated the blemishes on the foam web and removed the static shocks experienced by the operators.
With the very coldest of winter-time temperatures upon us now, it is what we term “static season” due to the low humidity in the air. Processes like this one can be rendered hopeless without the use of some form of active static elimination.
Are you in a converting business of some kind? Do you have static issues in your processes? If so, consider contacting us for some help with your application. Static electricity in a production environment does not have to be a problem.