I recently spoke with a customer who manufactures screw-top bottle caps made of plastic. The product was molded, ejected out the machine and onto a conveyor. The product traveled no more than 4 meters before being deposited into the final container in which it was shipped for end use. The customer had asked what static eliminators could do to help them with their problem. First, we needed to define the problem as the customer assumed we would already know what their problem was. In their case, the caps (closures) were picking up debris during their short conveyor ride to the shipping container. The problem could just as easily been that the product was discharging to an operator or perhaps blemishes forming due to static discharges among the finished product.
The “dirt” was described as small flakes of burned material that would drop out of the process. Other forms of “dirt” were small pieces of cardboard from containers used within the area. The customer had apparently done a little research into ionizers and asked whether we thought a static eliminator could help. After all, the caps were made of plastic and plastic is susceptible to generating static charge, right?
My first thought was yes, a static eliminator would be helpful in this application. However, the customer still needed to employ some reasonable level of housekeeping in his process to keep the occurrence of this contamination from being such a big problem in the first place. A quick look around the machine area where the parts were molded revealed a thick layer of all sorts of debris that could fall in with the product at any time. Obviously, cleaning up the processing area in this case yielded very good result and adding a static eliminating air knife to the application kept static fields low and kept the ‘dirt’ from sticking to the final product and the conveyor.
The point being that while the static eliminator equipment does do a good job at keeping static problems away, do not forget to employ simple but effective processes, such as improvement of housekeeping procedures to further aid in resolving the issue of ‘dirt” contamination in an application.