Atmospheric Polymeric SiOx Thin Films Used in Printing Plates (Part 2)

2 Experimental results and analysis

2.1 Relationship between Plasma Torch Length and Power

The two types of intake methods start arc discharge at a voltage of 60 V, a current of 0.4 A, and a power of 24 W. The relationship between discharge power and arc length at a gas flow rate of 15L/min is shown in Figure 3

Figure 3 shows that the lengths of the two plasma torches in the single-cell mode increase with the increase of the discharge power, and the increases are similar, with no significant difference. In the initial stage, the arc length increases rapidly with the increase of discharge power, but when the discharge power increases to 40 W, the increase of the discharge power plasma torch lengthens slowly.

2.2 Relationship between plasma torch length and intake air amount

When the power is 55W, take the amount of intake air as a variable, observe the change in the length of the plasma torch, see Figure 4.

For the way in which the monomer is directly input into the plasma reaction zone, the plasma torch grows with the increase of the intake air amount, and there is a maximum point, and the arc length decreases with the increase of the intake air amount. For the inlet mode in which the monomer is input into the downstream region of the plasma, when the gas flow is small, the length of the plasma torch reaches a maximum, and a filament discharge occurs. As the flow rate increases, the arc length becomes shorter, but the plasma torch changes. Crude. This shows that the discharge is transformed into a uniform arc discharge with a filamentous arc discharge.

The plasma torch discharges directly downstream, and the plasma torch reaches its maximum directly. This may be due to gas splitting. The gas flowing out from the hollow inner electrode dilutes the ions flowing out of the discharge zone, and thus starts to glow at low flow rates later.

2.3 Electrode voltage and current curve

The current and voltage curves of the two injection methods are shown in Figure 5. The discharge curve is approximated by the linear relationship of a typical dielectric discharge. Due to the existence of the medium, the monomer is not dissociated and will not be absorbed by the electric field. On the electrode, it cannot reach the surface of the substrate.

(to be continued)