A common question that we get about Static Eliminators is “Where is the best place to install them within our process?” While there is a definite strategy to mount the Static Eliminator at the last possible point before the application problem occurs, in some instances, you still may have to use more than one Static Eliminator in different locations.
A customer was working with plastic tubes for packaging that were roughly 1” (25mm) in diameter by 6” (152mm) long. At the beginning of the process, an operator would remove the plastic tubes from boxes and manually stack them in a hopper. They had a model 111012 Super Ion Air Knife mounted at the top of the hopper blowing down on the tubes. This helped to remove the “shock” hazard that previously existed in loading the hopper. To continue with the process from the hopper, the tubes are moved into an elevator and raised up to a feed chute in single file. They would roll down a feed chute before they would be dropped onto a conveyor belt. Just as the plastic tube would drop, static created from friction generated by the rolling action would cause one side of the plastic tube to “stick” to the prior tube, causing a jam in the system.
The customer was looking for a solution to stop the jamming. He had already mentioned that he was using the model 111012 Super Ion Air Knife at the hopper and wondered if it was working properly. A quick question quickly verified its operation. I asked if the operators were getting shocked from loading the plastic tubes into the hopper. He stated that they were not. So, the Super Ion Air Knife was removing the static charges as intended to keep the operators safe. The customer also sent pictures of the operation so I could better understand his process. From the photos, the plastic tubes were right up against each other lengthwise in the chute.
Static charges were re-generating through the movement of the parts going through the loading elevator, moving up to the feed chute, and sliding down to the conveyor; the plastic tubes were rubbing and rolling against each other. As with any non-conductive materials that are rubbed, slide against one another, or peeled, static electricity has a very good possibility to be generated or re-generated as in this case. Even though the static was being removed at the hopper, the friction between the plastic tubes caused the static to regenerate.
Since static was affecting the feed of plastic tubes onto the conveyor, we needed to re-focus our attention in this area. The problem area in this application has now become the feed chute. After talking things over with the customer, model 111006 Super Ion Air Knife was mounted above the end of the feed chute to provide an ionized airflow. It would be facing the length of the plastic tube and angled upward along the incline of the chute, setting up a good counter flow between the parts and the ionized air. Because static is a surface phenomenon, the ions have to hit the exposed surfaces to neutralize the charge. This arrangement would blanket the top surfaces of all the plastic tubes in the feed chute with ions as they roll by, neutralizing the charges before they became a problem at the end of the chute.
This is only one example of EXAIR Static Eliminators reducing a static charge in packaging applications. The product works well at eliminating the jamming, feeding, tearing, discharges to operators and other similar problems encountered within the packaging environment. Do you have a similar feeding application that you feel could use some help from static elimination? If so, we’d love to hear from you. Contact us with your application questions today!