ABSTRACT
Since most polymers are nonconducting, the electrons gained or lost in contact with a metal, such as a roll to control the movement of a film, remains on the surface whereas the countercharge built on a metal dissipates quickly because of its electrical conductivity and grounding of a machine. The charge built on the polymer surface is cumulative if the contact with the same metal is repeated. If a folded film touches metal rolls repeatedly and the number of contact is different for one side of film and for another side, the energy levels shown in Figure 24.2 for one side and for another side become different. In such a case, two films of the same polymer folded create static charges and cling to each other. If such surfaces are two surfaces of a plastic bag, the bag cannot be opened until the static charges are dissipated.
