Static charges can be used to pin a decorative label tight against the inner mould surface during injection moulding without the use of vacuum. This procedure greatly improves finished product quality. Outside the mould a robot presents the label to a charging bar which applies an electrostatic charge to the label. The label is then placed into the mould cavity, where it sticks due to the electrostatic bond between the label and the metal mould wall. The label will not slip or change position in the mould.
A static charging system consists of a high voltage generator and an electrode or applicator and cabling. The high voltage generator supplies the high voltage needed to create a static charge. This can vary from 3 to 60 kVolt. The charging electrode or charging applicator comes in different shapes to enable an optimum result for each specific application. Size and shape differ to make optimum solutions for each situation.