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Plasma forming device

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Published on:

27 Aug,2020

Plasma forming device:

Generally, the energy of particles in low-temperature plasma is about several to dozens of electron volts, which is larger than the bonding energy of polymer materials (several to dozens of electron volts). It can break the chemical bonds of organic macromolecules and form new bonds. However, it is far lower than high-energy radiation, which only involves the surface of the material and does not affect the performance of the matrix.

The thermodynamic equilibrium conditions of low temperature plasma, electron has high energy, can fracture of material surface molecular bonds, improve particle chemical reactivity (more than hot plasma), and neutral particles temperature close to room temperature, these advantages for heat-sensitive polymer surface modification provides appropriate conditions.

Plasma with different properties and application characteristics can be obtained by selecting the appropriate discharge mode. Generally, hot plasma is generated by corona discharge of gas at atmospheric pressure, and cold plasma is formed by glow discharge of gas at low pressure.

The hot plasma device USES a charged body tip (such as a knife or needle tip and a slit electrode) to create an uneven electric field, which is called corona discharge. The application voltage and frequency, electrode spacing, treatment temperature and time all affect the corona treatment effect. If the voltage increases and the power supply frequency increases, the treatment intensity is large and the treatment effect is good.

However, too high power frequency or too wide electrode gap will cause too many ion collisions between the electrodes, resulting in unnecessary energy loss. However, if the electrode spacing is too small, there will be induction loss and energy loss. When the treatment temperature is high, the surface characteristics change rapidly and the treatment time is prolonged, and the polar groups increase. However, if the time is too long, decomposition products may be generated on the surface, forming a new weak interface layer.

Cold plasma device is set in an airtight container, two electrode form electric field with a vacuum pump to achieve a certain degree of vacuum, with gas more and more thin, the distance between molecules and the free movement of distance between molecules or ions is also becoming more and more long, the electric field, they collide and form plasma, then have a glow, so called the glow discharge treatment. The pressure of glow discharge has great influence on the effect of material treatment, and is related to discharge power, gas composition, flow velocity, material type and other factors.

Different discharge modes, working material states and the factors above affecting plasma generation can be combined to form various low-temperature plasma treatment equipment.

Plasma forming device

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