The most common method of charge generation is triboelectric charging. Whenever materials are brought into close contact, a charge exchange may occur between the surfaces of the two materials. The magnitude of this charge exchange will depend on a number of factors, but the result is two oppositely charged objects when the materials are separated. The second common method of creating static charge is known as inductive charging. This occurs when a charge is “induced” on an isolated conductive object that is brought into the field created by the charge on another object.
Air ions are molecules of one or more of the gases that make up air (nitrogen, oxygen, carbon dioxide, etc.) that have gained or lost electrons. If they lose electrons the molecules have a net positive charge, and are “positive ions”. If they gain electrons, the molecules have a net negative charge, and are negative ions. Air ions are a normal constituent of outdoor air, but natural ion levels are too low to be used to neutralize static charge in indoor environments.
The moisture content in the air affects the conductivity of certain insulating materials and their ability to hold static charge. The higher the relative humidity (>50%), the higher the conductivity of these materials. Conversely, the lower the humidity (<30%), the more insulative these materials become and the more charge they hold. Logically, it would follow that high humidity would be an effective means of controlling static. However, even under high relative humidity, unacceptable levels of static charge can be generated and remain for long periods of time. Additionally, high humidity can contribute to other problems including oxidation and soldering difficulties. Using high humidity as a means to control static charge is slow, uncomfortable, expensive, and often ineffective.
The dust in the surrounding area is attracted by the static electricity and dust clings to surfaces that have a charge or static electricity. This may provoke that the process is disrupted. In order to remove the dust, ionisation is needed in the process to de-static the material and the dust in order to clean the surface with air or a blower or an anti-dust-cleaner. You can also prevent dust attraction by placing an anti static equipment at various strategic locations along the production process.
In production processes, static electricity can often be a severe disruption, as it means that materials get stuck to machine parts or to each other, the so called static-cling. Operators and other personnel that work with the machines do not like getting electric shocks. A direct spark can jump from the object to the person which is unpleasant and sometimes dangerous. Another possibility is that workers get shocks by standing close to the charged object. Simco-Ion has a special section about static shock!
In explosion or hazardous(ATEX) zones, static electricity can cause a spark, which in turn can cause a fire or even an explosion depending on the environment. Simco-Ion offers a large range of solutions for ionisation products and industrial static eliminators.
Besides that, static damages the material. Friction between idle rollers and film create a charge that can become several kilovolts. When a static charge exceeds a certain level, spontaneous discharges and sparks can occur causing damage to the material or electronic equipment in the vicinity. Also, due to static charges on the film you use in the production process, the layers will cling together causing problems when trying to separate the layers. This will cause customers to have problems with your materials.
No single method exists for controlling all static problems. The proper use of equipment and remedial procedures help cure most static problems.
Static on a conductor can be easily controlled if the object is grounded. Grounding provides a path so that charge can migrate to ground, effectively neutralising the charge. However, grounding an insulator does not work, because charges do not migrate on insulators.
Antistatic or static dissipative materials:
Insulative materials, usually plastics, that are made conductive with the addition of carbon or metal fillings. The conductive dispersion can be adjusted depending on the amount of fillings added to provide resistivity ranging from fully conductive to dissipative.
Air ionisers work by flooding the atmosphere with positive and negative ions. These ions are attracted to ions of the opposite polarity on a charged surface. As a result, the static electricity that has built up on products, equipment and surfaces is neutralised.
Training personnel and making them aware of electrostatic issues and the need for antistatic gloves, suits, smocks, and wrist/heel straps can make a large difference in the amount of problems that occur in a production facility.
There is no “best ioniser technology” for all applications. The application will determine the appropriate type to use.
This depends on the following factors:
position it too far “upstream” the charge could be regenerated by rollers or other static generative processes.
How far from the material? This depends on the type of static eliminator – there are short range, and long range static eliminators. Whichever type you use, the life of the ionised air produced is limited and generally good guidance says “the closer the better” subject to the minimum distance specified by the manufacturer.
The material should be in free air! This is a very important rule which is often ignored. When a material touches another object, such as a roller, the static charge couples with that object and is not available to be measured or neutralised. If you put an anti-static bar to neutralise film when it is travelling over a roller it will not be effective. This is probably the most common mistake in the installation of static control equipment.
Also static eliminators that control the static electricity and charge up to a desired level can be implemented. Solution can be provided by means of a broad range of ionization products, anti static, ionizing bars for these and more problems. Simco-Ion has an extended service department and many local dealers and distributors that are able to help you to solve the problems in your production or machine. We provide industrial static control equipment and a broad range of industrial static eliminators in different sizes and configurations like; Stand alone anti-static bars 24Vdc or ari-assisted applications like ionizing air blowers, air knife, air nozzles etc. all to help you to eliminate static electricity.
You can use 2 (old) Analogue devices on port 5 and 6 of the Manager IQ Easy. This can be the ThunderION IQ or Performax IQ Easy.
These devices will get the 24V from the manager and will indicate the HV OK signal from the bar to indicator if the bar is functioning OK. (Not OK means red Warning)
The bars can be set to run or standby or switched with remote on/off via the Manager IQ Easy.