Electret Treatment

There are three main methods: thermal polarization method, electron beam charging method and corona polarization method.

1.Thermal polarization method

In the thermal polarization method, when the temperature is increased from room temperature to the polarization temperature at a constant rate, the molecules start to move a lot of heat. It is easier to control the directional arrangement of the molecules by applying an electric field, and the temperature is quickly reduced to freeze the arranged dipole while maintaining the electric field electric field.

2. Corona polarization method

This method is one of the most widely used polarization methods. Its advantage is that during the corona charging process, the electret parameters such as grid voltage and temperature are controllable. Electret materials with surface charge or space charge distribution can be prepared by grid-controlled corona charging of the sample at normal temperature or high temperature.

3. Electron beam charging method

The principle of the electron beam charging method is that the cathode plate emits electrons, and the electrons rush to the anode plate at high speed under the action of the electric field force. The sample to be electret is placed at the anode plate position, and the electrons hit the sample surface at high speed. The main advantage of this method is that the sample after the electret has high charge storage stability.