Effect of static electricity
The unpleasant effects of static electricity are well known. People get shocks, materials cling together, a spark damages materials or even causes a fire. A electrostatic charge can also be very useful ! Materials can be charged deliberately to make them bond temporarily. Static charge can be an invisible helping hand in your production process. This method is already used in many processes in various industries.
Some examples are:
- Block a stack of paper or magazines to prevent shifting during transport or packaging.
- Fix an address label to a brochure before the brochure is packed in a wrapping film.
- Keep the last bag of a roll (ie.Garbage bags) fixed to the roll to make packaging in a carton easier
- Bond a small section of a film during winding on a roll to prevent the roll from telescoping.
Many products we use daily are produced with the help of an electrostatic charge without us knowing it.
Various terms are used for the same technique, electrostatic charging, static bonding, static charging, static clinging or electrostatic gluing.
A perfect example is packaging of food products and many plastic products for domestic use. Many products are produced with the aid of a static charge. Instead of printing directly or placing a sticky label onto the product, the print is achieved with a pre-printed plastic label. The pre-printed label is positioned into the injection mould and kept in place by a static charge. This way the label will be moulded together with the product shape and come out as a finished product.
A spectacular application of static bonding is keeping together large objects. Stacks of brochures or flooring laminate can be held together with a static charge to prevent them from shifting during transportation. This demonstrates the enormous force that can be generated by an electrostatic charge.
Extraordinary, but not obvious applications of using static charge appear regularly. Applying a homogeneous static charge to a surface has a very positive effect in processes where fluids need to be dispersed across the surface. A common application is the production of DVD discs. Each DVD disc consists of two thin plastic layers that are glued to form the finished disc. A electrostatic charge is induced on one surface which causes the glue the disperse much more evenly.
Do any ideas spring tomind on how to use a static charge in your production process?
Simco-Ion Europe has outstanding capabilities to develop ideas and implement solutions with static electricity that can simplify and optimise your process. A broad range of products are capable of performing tasks that go beyond your imagination.
A static charging system consist of a high voltage generator and an electrode. The high voltage generator supplies the high voltage needed to create a static charge. This can vary from 3 to 60 kVolts. The charging electrode comes in different shapes to enable an optimum result for each specific application.
Direct voltage opposite earth
The charging electrode is located opposite an earthed plate or roller. Because of the electrostatic field the material web will temporarily adhere to the reference earth.
Static charges can be used to pin labels tight against the inner mould surface during injection moulding. Finished product quality is greatly improved by this method. The label will not slip or change position in the mould. Simco-Ion’s patented IML charging method provides an easy way of constructing a charging electrode. It uses an anti-static foam material that provides a full contact with the label and even distribution of the electrostatic charge.
Direct voltage opposite an AC anti-staticbar (“virtual” earth)
There are also conditions without reference earth. Ions of different polarity attract each other, this causes an isolator (e.g. film) to adhere temporarily to a material with a different polarity, in this case an isolator as well.
Simplified IML charging
This simplified method of IML charging uses the anti-static foam material as a basis. Instead of applying the voltage directly to the foam electrode the label will be electro statically charged against the foam electrode. In the next step the label can be transferred into the mould.
Bipolar direct voltage
This is the most effective method. The negative ions of the upper electrode attract the positive ions of the lower electrode, thus creating maximum adhesion between the top/bottom layer and the intermediate carrier.