host posted on May 05, 2008 20:28
Ionizers in the form of static neutralizing bars have commonly been used to neutralize static charges on web and sheet materials since the 1930’s. The devices are mounted within the process machine in proximity to the moving material. As the material passes by the neutralizing bar, the surface charges are reduced or eliminated at that point in the process.
The static neutralizing bar produces both negative and positive charged gas molecules called air ions. These are free ions that are attracted to the charged surface. Positive fields attract the negative ions and negative fields attract the positive until the surface is in electrical equilibrium.
Periodic cleaning and evaluation of the static neutralizing bar is needed to ensure it is operational and performing at its optimum. Traditional systems require some degree of knowledge of how they operate so they can be properly evaluated. Additional instrumentation is also needed to perform the task. The new technology ionizers available today incorporate self-diagnosis circuitry with indicators that display system status and performance. Coupled with much higher performance, these features provide a considerable benefit to the web handling operation.
There are various forms of energy used to generate air ions. They include electrical AC and DC, radioactive and passive (induction). This paper focuses on electrically powered ionizers.
Read Full Article